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Two novel phosphoramide containing thiazole derivatives with the name of bis(5‐amino‐1,3,4‐thiadiazol‐2‐yl) phenylphosphonotrithioate (C1) and O, O‐diethyl (5‐((diethoxyphosphorothioyl) thio)‐1,3,4‐thiadiazol‐2yl) phosphoramidothioate (C2) as corrosion inhibition were synthesized and identified by 1H NMR, 13C NMR, 31P NMR, IR, and mass spectroscopies. The electrochemical behavior of mild steel (MS) in hydrochloric acid 1‐M (HCl) solution was perused in the absence and presence of C1 and C2. To determine corrosion inhibition of phosphoramide compounds, scanning electron microscopy (SEM), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) were used. The EIS results show that the charge transfer resistance increases with the addition of inhibitors to the hydrochloric acid solution. The most inhibitor efficiency was 89%, which demonstrated the appropriate anti‐corrosion property of C1. EIS results show better charge transfer resistance on the surface of MS at increased inhibitor concentrations. The PDP analysis showed that C1 and C2 are mixed‐type inhibitors. The PDP examination appeared that C1 and C2 are mixed‐type inhibitors. To way better get the comes about of corrosion inhibition and structure of target compounds, the highest occupied molecular orbital (HOMO) and least unoccupied molecular orbital (LUMO) energies, hardness, dipole moment, and electrophilicity index of synthesized compounds were explored computationally using the density functional theory (DFT) strategy. The hypothetical comes about in great understanding with the exploratory information. [ABSTRACT FROM AUTHOR]

In this study, two novel phosphoramides containing 2-Amino-1,4-naphthaquinone, O,O -diethyl (2-naphthaleneyl-1,4-dione)phosphoramidothioate (NPT) and N,N´- bis(2-naphthaleneyl-1,4-dione) phenylphosphonic diamide (NPA) as cytotoxic agents, were synthesized and characterized by using spectroscopic methods. The anticancer activities of the synthesized compounds were investigated against the human breast cancer cell line SK-BR-3 and normal cells PC12 using MTT assay. The resulting data showed that NPA with an IC 50 value of 6.384 μg/ml had a better inhibitory effect against cancer cells than NPT (IC 50 = 10.08 μg/ml). According to the annexin V‐FITC/PI results, after treating cancer cells with synthesized compounds for 24 h, the overall population of apoptotic cells increased from 14.96% in the control group to 97.45%, 75.58% in NPA and NPT -treated cells, respectively. Given these results, NPA and NPT have considerable toxicity and apoptosis-inducing ability against SK-BR-3. The cytotoxicity results were supported by a molecular docking study to compute the interactions between synthesized compounds and transcription factor DNA (PDB ID: 1bg1). In order to know the structure-activity relationship (SAR) of synthesized compounds, the values of the quantum-mechanical descriptors were investigated computationally by the DFT method, and the obtained results were then compared with Cyclophosphamide (CY) as a standard anticancer drug. These results were in good accordance with those of in vitro investigation and molecular docking study. Antibacterial study of phosphoramides against Gram-negative (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) was carried out MIC, MBC and DDA methods. Additionally, the molecular docking study was performed for the interaction between E. coli beta-lactamase (PDB: 4HBT) and S. aureus beta-lactamase (PDB: 1MWU) with target compounds, the obtained results showed that these compounds are appropriate ligands for antibacterial activity against Staphylococcus aureus and Escherichia coli bacteria. [Display omitted] • Two novel phosphoramides containing 2-amino-1,4-naphthaquinone were synthesized and characterized. • Cytotoxicity studies revealed a notable dose- dependent against human breast cancer cells. • Synthesized compounds had a significant apoptosis-inducing ability at different concentrations. • DFT calculations and molecular docking simulation were applied to support the cytotoxicity results. • The obtained results showed that these compounds are appropriate for antibacterial activity. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) nanocomposites have attracted much attention in biomedical and catalytic fields due to their outstanding water dispersibility, cell permeability, high mobility of charge carriers, etc. This article reports the successful synthesis of GO–Co3O4 and phytic acid (PA)-modified GO–Co3O4 (GO–Co3O4–PA) nanocomposites by a facile hydrothermal method and studies of their antiproliferative properties. Various analyses were performed to characterize the synthesized nanocomposites. XRD revealed the characteristic crystallinity of GO–Co3O4 and GO–Co3O4–PA. FT-IR spectroscopy identified the different functional groups of nanocomposites. FE-SEM, AFM, EDX, and DLS analyses of GO–Co3O4–PA demonstrated multigonal particles with an average size of 837 nm on the basal planes of GO with signatures of Co and P. The zeta potential was −49.9 mV for GO–Co3O4–PA, which showed the moderate stability of nanocomposites. The Raman spectra of GO–Co3O4 and GO–Co3O4–PA nanocomposites indicated an increase in the surface defect density of GO due to the adsorption of Co3O4 and PA on the surface of GO. The use of nanocomposites for targeted breast cancer therapy was evaluated via an MTT assay. GO–Co3O4–PA showed considerable cytotoxicity with an IC50 value of 12.94 μg mL−1 towards the breast cancer cell line (MCF-7), which was five times lower than that of GO–Co3O4 (64.36 μg mL−1). As an anticancer agent, PA enhances the interaction of MCF-7 cell lines with nanocomposites and leads to higher cytotoxicity. MTT cytotoxicity, Annexin V/PI double staining, and intracellular reactive oxygen species (ROS) assays were performed. The GO–Co3O4–PA nanocomposite is a promising candidate for breast cancer therapy. Quantum mechanical calculations based on the DFT-D correction and PA adsorption on GO and GO–Co3O4 (1 0 0) in the presence of water were done in the adsorption locator module. Free energy calculations showed that adsorption is a spontaneous and more favorable process. Molecular docking studies were conducted to investigate the interaction of compounds on human topoisomerase IIα bound to DNA (4fm9) and Bcl-2 protein. The results indicated that GO–Co3O4–PA could properly dock into more amino acids with high negative energy scores and confirmed the MTT data. Moreover, GO–Co3O4–PA nanocomposites exhibited excellent catalytic ability towards the Biginelli reaction and showed significant advantages including excellent yields, mild reaction conditions, and short reaction times. [ABSTRACT FROM AUTHOR]

In this work, two novel well‐defined Cu (I) complexes of a Schiff base ligand are described. For this purpose, N, N′‐bis (trans‐cinnamaldehyde) ethylenediimine [C20H20N2] (L) and Cu (I) complex of the type [CuC20H20N2)PPh3Cl] (C1) and [Cu(C20H20N2)PPh3Br] (C2) were synthesised. IR, NMR, XRD and TGA analyses were used to characterise these compounds and single‐crystal X‐ray crystallography confirmed the structure of the compounds. The catalytic activity of the synthesised complexes was studied in azide‐alkyne click reaction (AAC) and the best reaction condition was 15 mol% catalyst, 30 min and 45°C in water, which can be considered moderate catalytic activity for the complexes. Material Studio 2017 software was used to obtain the geometry, energy, HOMO and LUMO of all structures by the quantum calculations (module DMol3 and LDA/PWC). The computational results showed catalyst C2 has more reactivity than catalyst C1, and the C1‐catalysed products form faster than the C2‐catalysed products exceptions 4a and 4b. Product 4b (resulting catalyst C2) is formed faster than product (4a). [ABSTRACT FROM AUTHOR]

The present study aimed to synthesis a proper scaffold consisting of hydroxylated polyphosphazene and polycaprolactone (PCL), focusing on its potential use in tissue engineering applications. The first grafting of PCL to poly(propylene glycol)phosphazene (PPGP) was performed via ROP of ε-caprolactone, whereas PPGP act as a multisite macroinitiator. The prepared poly(propylene glycol phosphazene)-graft-polycaprolactone (PPGP-g-PCL) were evaluated by essential tests, including NMR, FTIR, FESEM-EDS, TGA, DSC and contact angle measurement. The quantum calculations were performed to investigate molecular geometry and its energy, and HOMO and LUMO of PPGP-g-PCL in Materials Studio2017. MD simulations were applied to describe the interaction of the polymer on phospholipid membrane (POPC128b) in Material Studio2017. The C2C12 and L929 cells were used to probe the cell–surface interactions on synthetic polymers surfaces. Cells adhesion and proliferation onto scaffolds were evaluated using FESEM and MTT assay. In vitro analysis indicated enhanced cell adhesion, high proliferation rate, and excellent viability on scaffolds for both cell types. The polymer was further tested via intraperitoneal implantation in mice that showed no evidence of adverse inflammation and necrosis at the site of the scaffold implantation; in return, osteogenesis, new-formed bone and in vivo degradation of the scaffold were observed. Herein, in vitro and in vivo assessments confirm PPGP-g-PCL, as an appropriate scaffold for tissue engineering applications. [ABSTRACT FROM AUTHOR]

Two new Ag(I) complexes of N-(n-pyridinyl)diphenylphosphinic amide (n = 2 and 3) (Lo and Lm) with formulae Ag(Lo)NO3 (Co) and Ag(Lm)NO3·H2O (Cm) were synthesized. Infrared, NMR, and elemental analyses were applied to fully characterize them. The crystal structure of Cm was also assessed using single-crystal X-ray diffraction and the monoclinic nature of the silver complex was illustrated. The organization of four coordinated dinuclear Ag(I) complexes and intermolecular interactions were also studied. The supramolecule was formed by the cooperation of various intermolecular interactions, hydrogen bonds, M⋯π, π⋯π contacts, and CH⋯π synthons. Antibacterial studies of Ag(I) complexes and the corresponding ligands against Gram-negative (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were carried out by MIC, MBC, and DDA methods and Cm showed more bactericidal activity than Co against both bacteria (E. coli; MIC = 9.7 μg mL−1 and S. aureus; MIC = 78 μg mL−1). The potential antitumor activity of Co and Cm was also evaluated for human colon cancer cell lines (SW480) through anticancer (MTT and apoptosis) experiments, and it was revealed that Cm has the most toxicity (IC50 = 39.6 μg mL−1) by an MTT assay. An initial evaluation of the mechanism of cell death induced by Co and Cm was performed. Cell death was mainly from the activation of apoptosis processes. The results were further examined by docking studies to confirm that Cm has the potency to be a good candidate for biological applications. [ABSTRACT FROM AUTHOR]

In the present study, a new water-soluble proton transfer cytotoxic compound (dpp)(dapt).H2O (Dx) (where dpp = diphenylphosphinate and dapt = 2,6-diamino-4-phenyl-1,3,5-triazin-1-ium) was synthesized and characterized by IR and NMR spectroscopy. Its crystal structure was determined, and the non-covalent interactions responsible for extending its supramolecular network were characterized. Density functional theory (DFT) and natural bond orbital (NBO) calculations were used to analyze the non-covalent interactions in Dx. The main non-covalent intermolecular interactions were also studied by Hirshfeld surface analysis and fingerprint plots. Finally, the anticancer and growth inhibitory activities of the synthesized proton transfer compound were investigated against human breast cancer cell line MDA-MB-231 after an incubation time of 24 and 48 hours using MTT assay. The in vitro result showed a time- and dose-dependent cytotoxic effect of Dx in cells. This result was supported by a molecular docking study where a binding energy value of −13.76 kcal mol−1 clearly indicated the high affinity of Dx for interaction with DNA. [ABSTRACT FROM AUTHOR]

A series of phosphonic acid and bisphosphoramidate derivatives were synthesized and characterized. The bioactivities against the fungal pathogen Macrophomina phaseolina and human acetylcholinesterase AChE enzyme were studied using QSAR based on multiple linear regression. L17, with (p-Cl–C6H4–NH) (p-Cl–C6H4)C(H)P(O)(OC2H5)2 skeleton, demonstrated a great mortality on the M. phaseolina mycelial growth by 83% inhibition at 150 mg/L; the other tested derivative showed moderate to weak antifungal activity against the fungus. QSAR model based on the GA-MLR method revealed the importance of 3D descriptors (De, Mor18e, H8m, and Mor30p) on the antifungal activity. It showed good capability in predicting the fungicidal activity of the studied molecules. Another derivative, L5, with (m-CH3–NC5H4–NH)(m-CH3–C6H4)C(H)P(O)(OCH3)2 skeleton displays the most potent anti-AChE activity. The electronic parameters, ΔEL-H, and ELUMO, have the highest contribution of human AChE. The authors suggest that these models could be usefully employed in designing more effective crop protection compounds without side effects on non-target organisms. [ABSTRACT FROM AUTHOR]

Two new one‐dimensional metal–organic polymers (MOPs) {[Cu(L)(PPh2Py)·I2]·CH3Cl}n (I) and {[Cu(L)(PPh2Py)·Br2]·CH3Cl}n (II) (L = (1E,2E)‐1,2‐bis(pyridine‐4‐ylmethylene)hydrazine) (4‐bpmh)) have been synthesized and elucidated by single crystal X‐ray diffraction. The results of X‐ray diffraction analysis unambiguously revealed that the two polymers are isostructural with the major intermolecular CH⋯π and π⋯π interactions. Microstructures of these polymers were also synthesized using a sonochemical method in different concentrations and reaction times. Field emission scanning electron microscopy, powder X‐ray diffraction, thermogravimetric analysis and IR spectroscopy were applied to fully characterize these compounds. The photoluminescent properties of microrod MOPs were also evaluated to add to our understanding of their potential ability for nitro compound sensing. These experiments showed that MOPs I and II are good luminescence sensors for detection of nitro explosives in aqueous media. The probes maintained their high sensitivity and selectivity for 4‐nitrophenol (4‐NP). The energy transfer process accompanied by electrostatic interactions of 4‐NP with these MOPs can be considered as an influential reason for the selectivity of 4‐NP. The competitive study of the quenching process has a6lso shown superior operation with microparticles compared with bulky polymers. These results indicate that this method may be useful to synthesize luminescent materials possessing good sensing properties. [ABSTRACT FROM AUTHOR]

New derivatives of phosphoramido acid with the formula(C6H11NCH3)(NHCOCF3)P(O)(O−)(CH3–+NH2–C6H11)(1) (amidophosphoricacid), (C6H5)2P(O)(O−)(+NH3–C6H4–NH2)(2) (phosphonicacid), (C6H5O)2P(O)(O−)(+NH3–C6H4–NH2) (3) (phosphoricacidester) were synthesized and characterized by X-ray crystallography. The asymmetric unit of compounds 1–3 consists of one molecule with the P atom in a tetrahedral environment. The X-ray structural analysis showed that the H-bond patterns depend on the kind of atoms linked to the P atom. In the crystal packing of compound 1, P(O)···H–N and C(O)···H–N hydrogen bonds in 3 and P(O)···H–N distances in compounds 2 and 3 led to a one-dimensional arrangement. The energy of P–O···H–N hydrogen bond (EHB) model and stabilizing energies (E2) were calculated. Hirshfeld surface analysis demonstrated that the C···H contact is attributed to CH···π contact in the 2 and 3 compounds and the F···H contact is referred to hydrogen bond in one O···H counterion interaction. Quantitative structure–activity relationship (QSAR) was used to comprehend the relationship between molecular structural features and the inhibitory of investigated compounds. The use of density functional theory along with the QSAR model for enzymes revealed the importance of QH parameter in describing the anti-AChE and anti-urease activities of monophosphoramidates including P(O)–NH2 moiety. [ABSTRACT FROM AUTHOR]

Hydrogels based on chitosan or alginate biopolymers are believed to be desirable for covering skin lesions. In this research, we explored the potential of a new composite hydrogels series of sodium alginate (Alg) filled with cross-linked chitosan to use as hydrogel wound dressings. Cross-linked chitosan (CSPN) was synthesized by Schiff-base reaction with aldehydated cyclophosphazene, and its Cu(II) complex was manufactured and identified. Then, their powder suspension and Alg were transformed into hydrogel via ion-crosslinking with Ca2+. The hydrogel constituents were investigated by using FTIR, XRD, rheological techniques, and thermal analysis including TGA (DTG) and DSC. Moreover, structure optimization calculations were performed with the Material Studio 2017 program based on DFT-D per Dmol3 module. Examination of Alg's interactions with CSPN and CSPN-Cu using this module demonstrated that Alg molecules can be well adsorbed to the particle's surface. By changing the dosage of CSPN and CSPN-Cu, the number and size of pores, swelling rate, degradation behavior, protein absorption rate, cytotoxicity and blood compatibility were changed significantly. Subsequently, we employed erythromycin as a model drug to assess the entrapment efficiency, loading capacity, and drug release rate. FITC staining was selected to verify the hydrogels' intracellular uptake. Assuring the cytocompatibility of Alg-based hydrogels was approved by assessing the survival rate of fibroblast cells using MTT assay. However, the presence of Cu(II) in the developed hydrogels caused a significant antibacterial effect, which was comparable to the antibiotic-containing hydrogels. Our findings predict these porous, biodegradable, and mechanically stable hydrogels potentially have a promising future in the wound healing as antibiotic-free antibacterial dressings. [ABSTRACT FROM AUTHOR]

Hydrogels based on chitosan or alginate biopolymers are believed to be desirable for covering skin lesions. In this research, we explored the potential of a new composite hydrogels series of sodium alginate (Alg) filled with cross-linked chitosan to use as hydrogel wound dressings. Cross-linked chitosan (CSPN) was synthesized by Schiff-base reaction with aldehydated cyclophosphazene, and its Cu(II) complex was manufactured and identified. Then, their powder suspension and Alg were transformed into hydrogel via ion-crosslinking with Ca2+. The hydrogel constituents were investigated by using FTIR, XRD, rheological techniques, and thermal analysis including TGA (DTG) and DSC. Moreover, structure optimization calculations were performed with the Material Studio 2017 program based on DFT-D per Dmol3 module. Examination of Alg's interactions with CSPN and CSPN-Cu using this module demonstrated that Alg molecules can be well adsorbed to the particle's surface. By changing the dosage of CSPN and CSPN-Cu, the number and size of pores, swelling rate, degradation behavior, protein absorption rate, cytotoxicity and blood compatibility were changed significantly. Subsequently, we employed erythromycin as a model drug to assess the entrapment efficiency, loading capacity, and drug release rate. FITC staining was selected to verify the hydrogels' intracellular uptake. Assuring the cytocompatibility of Alg-based hydrogels was approved by assessing the survival rate of fibroblast cells using MTT assay. However, the presence of Cu(II) in the developed hydrogels caused a significant antibacterial effect, which was comparable to the antibiotic-containing hydrogels. Our findings predict these porous, biodegradable, and mechanically stable hydrogels potentially have a promising future in the wound healing as antibiotic-free antibacterial dressings. [ABSTRACT FROM AUTHOR]

Novel phospho guanidine and phospho pyrazine derivatives were synthesized and characterized by 31P, 13C, 1HNMR and IR spectroscopy to obtain novel and human-safe insecticides. Compound 35 [(C 4 H 4 N 2 NH) 2 P(O)(C 6 H 6)] was investigated by X-ray crystallography. The inhibitory effects of synthesized compounds were evaluated on human and insect acetylcholinesterase (AChE) using in vitro Ellman method. A few of these compounds, which had low human toxicity, were selected for assessing the killing effects (in vivo) on the elm leaf beetle (X.luteola). The in vitro and in vivo results indicated that compounds bearing both phosphoryl groups and aromatic systems were found to possess a good selectivity for the inhibition of insect AChE over human AChE; up to 550-fold selectivity was achieved for compound 19. Docking studies were performed to explain reasons for the selective behavior of AChE inhibitors. Additionally, the quantitative structure–activity relationship (QSAR) and density functional theory (DFT) results of AChEs demonstrated that the size, shape, dipole moment, and ability to form hydrogen bond played the main role in both models. In addition, the aromatic π − π interactions and charge of the amide nitrogen had a major effect on insecticidal activity of the compounds. The present research can be helpful to gain a better understanding of the interactions between the insect AChE and its inhibitors and introduces compounds which are capable of becoming human-safe insecticides. Unlabelled Image • Novel phospho guanidine and phospho pyrazine derivatives were synthesized and characterized by spectroscopy techniques • The anticholinesterase activities of subject compounds were appraised using both experimental and computational methods • Docking, QSAR and DFT were carried out to find inhibition affecting factors of compounds on human and insect AChE activities • The size, shape, dipole moment and ability to form hydrogen have a major effect on the inhibitory behavior of compounds. • The Homo energy, aromatic π−π interactions and nitrogen amide charge were important for insecticidal potency. [ABSTRACT FROM AUTHOR]

Abstract A comprehensive study was performed on 1H/13C/31P NMR chemical shifts (CSs) of some phosphoryl benzamide derivatives (R 1 C 6 H 5 C(O)NHP(O)R 2 R 3), [R 1 = CH 3 , OCH 3 , NO 2 , F, Cl, Br and R 1 , R 2 = NHC(CH 3) 3 or NC 4 H 8 O] by the GIAO method to find the most correlated level of theory with experimental values. All the structures (C 1 C 12) were firstly optimized at B3LYP, BP86, PBE1PBE, M06-2X, MPWB1K and MP2 methods with 6–31 + G* basis set. Computed structural parameters demonstrate that BP86 has the best agreement to experimental values. The def2-TZVP and aug-cc-pVDZ basis sets were also employed to inspect the effect of different basis sets. The correlation between experimental and computational values prove that 6–31 + G* basis set is the optimum case regarding minimization of the costs and results. Chemical shifts were calculated at all mentioned combinations and compared with experimental data, which demonstrate that in accordance with structural parameters, BP86/6−31 + G* gives the best results. Calculating 2 J PH values of studied compounds, focusing on the comparison between experimental and theoretical results was another aim of this study. Computed values of 2 J PH at the optimum level of theory reveal an acceptable agreement with experimental data. Eventually, the dependency between 2 J PH values and the bonding structures was inspected. NBO analysis at BP86/6−311++G** explicates the relationship between the electronic properties of studied compounds and 2 J PH values. Highlights • A study was performed on 1H/13C/31P chemical shifts (CSs) of some phosphoryl benzamide derivatives by the GIAO method. • Calculated CSs were compared with experimental data which demonstrates that BP86/6−31+G* gives the best results. • 2 J PH values were computed at the optimum level of theory which reveals an acceptable agreement with experimental data. • The relationship between the electronic properties of studied compounds and 2 J PH values is described by the NBO analysis. [ABSTRACT FROM AUTHOR]

• Different derivatives of bisphosphoramide were synthesized as urease inhibitors. • The activity of target compounds was compared with monophosphoramide derivatives. • The compounds containing aromatic substitutes exhibited high inhibitory activity. • Kinetic and docking studies were conducted to explain the mechanism of interactions. • QSAR studies were applied to determine the most important affecting descriptors. In an attempt to achieve a new class of phosphoramide inhibitors with high potency and resistance to the hydrolysis process against urease enzyme, we synthesized a series of bisphosphoramide derivatives (01 – 43) and characterized them by various spectroscopic techniques. The crystal structures of compounds 22 and 26 were investigated using X-ray crystallography. The inhibitory activities of the compounds were evaluated against the jack bean urease and were compared to monophosphoramide derivatives and other known standard inhibitors. The compounds containing aromatic amines and their substituted derivatives exhibited very high inhibitory activity in the range of IC 50 = 3.4–1.91 × 10−10 nM compared with monophosphoramides, thiourea, and acetohydroxamic acid. It was also found that derivatives with P O functional groups have higher anti-urease activity than those with P S functional groups. Kinetics and docking studies were carried out to explore the binding mechanism that showed these compounds follow a mixed-type mechanism and, due to their extended structures, can cover the entire binding pocket of the enzyme, reducing the formation of the enzyme-substrate complex. The quantitative structure-activity relationship (QSAR) analysis also revealed that the interaction between the enzyme and inhibitor is significantly influenced by aromatic rings and P O functional groups. Collectively, the data obtained from experimental and theoretical studies indicated that these compounds can be developed as appropriate candidates for urease inhibitors in this field. [ABSTRACT FROM AUTHOR]

Herein, we report on the synthesis of new copper(i) complexes with sulfur-containing ligands. Structural analysis unequivocally shows that S…S chalcogen bonding (ChB), CH…S hydrogen bonding, and CH…π contacts are the major intermolecular interactions. The influence of sulfur interactions on the supramolecular assemblies has been investigated by geometrical analysis and theoretical calculations. Topological analysis has also been conducted, with respect to the electron density, Laplacian of electron density, and electron localization function (ELF), in order to inspect the physical characteristics of the ChB interactions. The non-covalent sulfur interactions in crystalline structures have been evaluated by wave function and DFT methods to acquire insight into the ChB interactions. So, the S…X (X = S, O, N, Cl) interactions in the crystal packing can be categorized as lump–hole interactions; a region of charge depletion (hole) of sulfur interacts with a region of charge concentration (lump) of another involved atom in the valence shell charge concentration (VSCC) which forms a chalcogen bond. The presence of electron deficiency on the sulfur atoms leading to the S…X chalcogen bonds has also been visualized on electrostatic potential maps. Indeed, the lump–hole concept has shown that the existence of the hole in the VSCC of the sulfur atom is responsible for the generation and geometry of chalcogen bonded complexes. [ABSTRACT FROM AUTHOR]

A comprehensive investigation was performed on 1H, 13C, and 31P nuclear magnetic resonance (NMR) chemical shifts (CSs) of phosphoryl benzamide derivatives (C6H5C(O)NHP(O)R1R2), (R1, R2 = aziridine [L1], azetidine [L2], pyrrolidine [L3], piperidine [L4], azepane [L5], 4‐methylpiperidine [L6], propane‐2‐amine [L7], and 2‐methylpropane‐2‐amine [L8]) by the gauge‐independent atomic orbital method (GIAO) to find the most accordant level of theory with the experimental values. To achieve this goal, all the structures were optimized using the B3LYP, BP86, PBE1PBE, M06‐2X, MPWB1K, and MP2 methods with 6–31+G* basis set. Computed structural parameters demonstrate that BP86 has the best agreement to the experimental values between the other methods. The def2‐TZVP and aug‐cc‐pVDZ basis sets were also employed to inspect the effect of different types of basis sets with higher polarization and diffuse functions. The correlation between the empirical and computational values attests that 6–31+G* basis set is the optimum case regarding minimization of the costs and results. The comparison between calculated and experimental CSs at all mentioned combinations illustrated that in accordance with structural results, the best level of theory in CSs is also BP86/6–31+G*. Besides, 2JPH values were computed with an acceptable agreement to experimental data at the optimum level of theory. The dependency between 2JPH and the bonding structure of studied ligands was also scrutinized by the Natural Bond Orbital (NBO) analysis that interprets the relationship between the electronic properties and 2JPH values. What are the effect of bonding structure and the electronic properties of different substituents on 2JPH? [ABSTRACT FROM AUTHOR]

Abstract Two new N , N -bis(diphenylphosphino)-amine ligands [where amine = N-Aminophthalimide (in L 1) and Hydrazine dihydrochloride (in L 2)] and their Pd(II) complexes, C 1 and C 2 have been synthesized and characterized by IR and NMR spectroscopies. Single crystal X-ray diffraction techniques have been used to determine the crystal structures of the complexes. Moreover, the catalytic activities of mentioned complexes in Heck coupling reactions have been assessed. The NBO analysis has been used to investigate the nature of the metal-ligand interactions. In the case of L 2 , preparation route could have produced two different products (Pro.1 and Pro.2), but only one structure has been gained which has been prepared in high purity. To address the reason for this manner, kinetics and thermodynamics of two different pathways that could have led to possible products have been investigated theoretically. Graphical abstract Image 1 Highlights • Synthesis of two Pd(II) complexes with N , N -bis(diphenylphosphino)-amine ligands. • Molecular structure and crystal packing of the complexes were investigated. • Studied complexes represent high catalytic activity in the Heck coupling reactions. • NBO analysis is used to investigate the nature of the metal-ligand interactions. [ABSTRACT FROM AUTHOR]

Abstract A series of new bisphosphoramidate and (thio)phosphoramidate derivatives with the general formula R 1 R 2 P(X)–Y–P(X)R 1 R 2 have been synthesized and characterized by IR and NMR spectroscopies (L 1 – L 12). The crystal structure of compound 1,4-[(C 2 H 5 O) 2 P(S)(CH 2) 3 NH] 2 C 4 H 8 N 2 (L 4) is also investigated by X-ray diffraction analysis. Two novel organotin(IV) complexes μ-{1,4-[(C 6 H 5) 2 P(O)(CH 2) 3 NH] 2 C 4 H 8 N 2 }[SnR 3 Cl] 2 , R 3 SnCl (R = phenyl/butyl), C 1 and C 2 , respectively, are prepared by the reaction of new diphosphoryl ligand L 1 and R 3 SnCl under different conditions. C 1 and C 2 are characterized by IR and NMR spectroscopies and X-ray crystallography diffraction analysis. X-ray analysis illustrates that both complexes have similar structures containing binuclear triorganotin(IV) skeletons and ligand coordinates in a bridging mode through two phosphoryl groups. Sn(IV) coordination geometries are distorted trigonal bipyramidal (TBP) for C 1, and C 2 structures contained binuclear arrangement with two SnPh 3 Cl/SnBu 3 Cl groups linked via the bridging diphosphoryl ligand. The organization of the crystal structures and the intermolecular interactions are discussed. Hirshfeld surfaces and two-dimensional fingerprint plots are used to study short intermolecular contacts in C 1 , C 2, and L 4. Finally, the influence of chain length and the effects of various substituents on P=O and P=S bond strength in synthesized ligands (L 1 – L 12) and optimized ligands (L 13 – L 17) are theoretically investigated by NBO analysis to survey the character of mentioned bonds in these ligands. The AIM analysis is also used to determine the nature of the P=O bond in L 1 and also P=O and O⋯Sn4+ bonds in C 1 and C 2. Results show ionic character for O⋯Sn4+ interaction in both complexes and mostly electrostatic character for P=O bond in the free ligand, but with a little shift to the covalent character after the complexation. Graphical abstract Image 1 Highlights • Some new bisphosphoramidate and (thio)phosphoramidate derivatives are synthesized and characterized by IR and NMR. • The crystal structure of one ligand and two obtained complexes are characterized by X-ray diffraction. • The effect of chain length and various substituents are inspected by NBO to survey the character of bonds in the ligands. • The AIM shows ionic character for O⋯Sn4+ in complexes and electrostatic character for P=O bond in the free ligand. [ABSTRACT FROM AUTHOR]

Abstract Methylenebis(N,N′-dibenzylphosphoramidate) (MBDPA) is synthesized by 1:8 mol ratio reaction of Methylenebis(phosphonic dichloride) and benzylamine. MBDPA characterized by FT-IR, 1H NMR, 13C NMR, 31PNMR spectroscopy. Also, The IC50 value for MBDPA is 5.23 nM that show very strong urease inhibitory activity. The geometry optimization is performed using the B3LYP and PBE1PBE density functional methods with two basis sets; 6–311 G (d, p) and 6-311 + G(d,p). 1H, 13C and 31PNMR chemical shifts have been calculated by using the gauge independent atomic orbital (GIAO) method. The infrared spectra of MBDPA are calculated and compared with the experimentally observed ones. The assignments are determined on the basis of the potential energy distribution of the all vibrational modes. Results of this study showed that there is a good correlation between the experimental data and computational results. The electronic structure is studied by analyzing the frontier molecular orbitals and molecular electrostatic potential for the prediction of stability and activity of the MBDPA. Graphical abstract Image 1 Highlights • A novel bisphosphoramidate was synthesized and characterized. • Computational studies via B3LYP and PBE1PBE method were used with two different basis sets. • For biological evaluation, Electrophilic and nucleophilic sites are identified. • The IC50 value is 5.23 nM that was shown strong urease inhibitory activity. [ABSTRACT FROM AUTHOR]

Abstract: The palladium‐catalyzed Heck reaction is the most effective method for vinylation of unsaturated halides. Here, new thermally stable palladium(II) complexes {(4OMe−Ph) RPS2}2Pd [R= C5H11NH (1); R= CH3CH2NHCH3 (2); R=OCH3 (3)] were readily synthesized in a high yield by the reaction of PdCl2 with dithiophosphorus ligands. The molecular structures of 1 and 2 were determined by means of X‐ray diffraction analysis. The catalytic activity of all complexes was evaluated in Heck reaction. The results revealed that the complexes are highly active catalysts in coupling of aryl bromides with styrene. The Hammett plot of the competition experiments of various aryl bromides with styrene, catalyzed by the complexes, displayed very good linear correlation with a positive slope (ρ) within a range of 3.99‐4.39 for 1–3. The absence of any decomposition signs together with negative Hg‐poisoning tests indicated that the liberation of Pd(0) species in the catalytic cycle is unlikely. So, it was supposed that the palladium(II)‐catalyzed Heck reaction might not proceed via classical Pd(0)/Pd(II) catalytic cycle. To find the most probable mechanism, density functional theory calculations were performed and the predicted data compared with the experimental results. Upon the obtained results, the Pd(II)/Pd(IV) catalytic cycle was proposed as the most plausible mechanism. The overall free energy profile showed that the first step of the mechanism (oxidative addition) with a free energy barrier of 33.8 kcal/mol involves the highest energy barrier and can be considered as the rate determining step of the mechanism. [ABSTRACT FROM AUTHOR]

Three Pd(II) complexes of some hemilabile ligands, aminothiazole-based phosphines, were synthesized to investigate the catalytic activity of them in Heck cross-coupling reactions. The crystal structures of complexes PdCl2[(Ph2P)HN(C3H2NS)] ( C 1) and PdCl2[(Ph2P)HN(C7H4NS)] ( C 3) were determined using X-ray crystallography, which reveals that the ligand coordinates in a chelating mode through P and N (endocyclic) atoms in square planar geometry. Experimental and theoretical studies (atoms in molecules and natural bond orbital analyses) show that the Pd(II) interacts more strongly with the P atom than the N atom in the chelated ligand, N^P. This trait can promote catalytic activity of the complexes in comparison with our previous work in which chelated ligands with two phosphorus atoms, P^P, were used. The influence of non-covalent intermolecular interactions on the assembly of the solid-state structures is also discussed in terms of geometrical analysis. The prepared complexes turn out to be useful pre-catalysts in Heck cross-coupling reactions owing to the coordinative flexibility of the hemilabile ligands. The protocol affords the corresponding products in greater yield than the same reactions with bis(phosphino)amine Pd(II) complexes, as the catalysts in our previous work. [ABSTRACT FROM AUTHOR]

In an effort to identify the factors that affect the reactivity of nitrogen mustards, we prepared two phosphoramide mustard derivatives in interaction with DNA. The activity of these drugs was compared to that of cyclophosphamide and phosphoramide mustard. The effect of drug interaction on DNA aggregation and condensation was investigated in aqueous solution under physiological conditions, using a constant DNA concentration (6.25 mM) and various ligand/polynucleotide (phosphate) ratios of 1/160, 1/80, 1/40, 1/20, 1/10, 1/5, 1/2, and 1/1. Fourier transform infrared, two-dimensional infrared (2D IR), and ultraviolet (UV)-visible spectroscopic methods were used to determine the ligand binding modes, the binding constants, and the stability of the drug–DNA complexes in aqueous solution. Density functional theory (DFT) calculations followed by a natural bond orbital (NBO) analysis, Fukui functions, electron localization functions (ELF), generalized valence bond (GVB) calculations, and quantum theory of atoms in molecules (QTAIM) were used to find the relationship between the structure and reactivity of phosphoramide mustard derivatives. Together with these methods, docking studies were applied to understand the features that dominate the molecular orbitals, charges, and other binding parameters. Theoretical results that coincided with the experimental values were obtained under similar conditions of pH and temperature. The results showed that the reactivity of these compounds is controlled by the frontier molecular orbitals, as well as the factors affecting them, such as negative hyperconjugation. [ABSTRACT FROM AUTHOR]

Abstract: In this study, Quantitative Structure‐Activity/property relationships (QSAR/QSPR) by means of multiple linear regressions (MLR) was performed to investigate the relationship between the 48 compounds of Temephos (Tem) drivatives and their bioactivities against acetylcholinesterase (AChE) of Tribolium castaneum. Two compounds Propylene‐N, N′‐bis (O, O′‐di Ethyl Phosphorothioat (12) and Ethylene N, ′N‐ di Methyl bis (O, O′‐ di Phenyl Phosphoramidate (24) had the most mortality on the T. castaneum. The compound 24 (IC50=34.54 ppm) is a good alternative to Tem. Also, QSAR calculations indicated that the electrostatic characteristics of the most effective insecticide are applied. In docking data, Tem derivatives with the backbone of P (O)‐NH−P(O), P(O)‐NH‐NH−P(O) and P(O)‐X−P(O) are located in the active site gorge of both AChE and butyrylcholinesterase (BChE) so as to maximize the favorable contacts. These compounds relate to enzymes by non‐covalent interactions such as hydrogen bonding, electrostatic and hydrophobic (as Trp82 and Trp286). Also, these cannot reach the end of the hole because of compounds are locked in the middle between the peripheral and acyl pocket site in AChE and BChE enzymes. The results of MLR and GA‐QSAR/QSPR model of human ChE showed that topological parameters affect the inhibitory potencies of the compounds on both of logK and p(IC50). logK and p(IC50) results have a good linear relationship. [ABSTRACT FROM AUTHOR]

Herein, we report on the synthesis of a novel bisphosphoramidate compound (LOPhAn), (C6H5O)(C6H5NH)P(O)NC4H8N(O)P(OC6H5)(NHC6H5), with two polymorphic (I and III) and one methanol solvated pseudo-polymorphic (II.MeOH) structures in the solid state obtained by crystal growth from different solvents. Single crystal X-ray analysis revealed that Form (I) has one extended conformer of LOPhAn in the solid state, while Form (II) demonstrated one twisted conformer as well as the coexistence of solvent molecules (methanol) in the lattice. Form (III) shows conformerism in the solid state, and two different molecular conformers are found in this structure: one extended and one slightly twisted that has a different conformation from the others. The crystal structures of these polymorphs were investigated using geometrical analysis, the non-covalent interaction (NCI) approach, hydrogen bonding topological graphs and Hirshfeld surface analysis. The geometrical orientations and intramolecular and intermolecular interactions of these three forms were compared with structurally related crystal structures within CSD. The stability of isolated conformers in the gas phase and the lattice energy of structures were studied theoretically. Furthermore, the thermodynamic relationships of the polymorphs are examined through calorimetric analysis. [ABSTRACT FROM AUTHOR]

A series of temephos (Tem) derivatives with the general structure of P(O)NH-X-NHP(O) ( 1-22) were synthesized and characterized by P, C, H NMR and FT-IR spectral techniques. The electron density ( ρ) value at the bond critical point (bcp) of P(1′)-O(1′)···(1)H-N(1) (0.040 e Å) P(1)-O(1)···(1′)H-N(1′) (0.031 e Å) as well as the stabilization energy of electronic delocalization of results of NBO analysis showed the hydrogen bonding energy in P(1′)-O(1′)···(1)H-N(1) model ( E = −72.15 kJ mol) and P(1)-O(1)···(1′)H-N(1′) ( E = −45.67 kJ mol) of the crystal cluster 7. The activities of Tem derivatives were evaluated using the modified Ellman's method on cholinesterase (ChE) enzymes. The insecticide activity of Tem analogous appraised for the elm leaf beetle in which the 18 had more effective than the other compounds in inhibition α-esterase of insect. Principal component analysis-quantitative structure activity relationship (PCA-QSAR) models indicated that it was deduced that the frontier molecular orbital energy parameters in PC are predominated from those related to electronic in PC and structural parameters in PC equation. Multiple linear regressions-QSAR models clarified that the molecular descriptors like an integrated net charge of nitrogen atom ( Q ), polarizability (PL) and lowest unoccupied molecular orbital ( E ) proved important in defining the activity of the candidates. [ABSTRACT FROM AUTHOR]

Carbacylamidophosphates are important compounds with unique physicochemical properties and many biological and chemical applications. Here, new derivatives of this class of compounds containing nicotinamide (nia), with the formula (nia)P(O)R 2 , R = NC 4 H 8 ( 1 ), NC 5 H 10 ( 2 ), NC 6 H 12 ( 3 ), 4-CH 3 -NC 5 H 9 ( 4 ), NC 4 H 8 O ( 5 ) and N(CH 3 )(C 6 H 11 ) ( 6 ), were synthesized from the reaction of N-nicotinyl phosphoramidic dichloride with various cyclic aliphatic amines. The characterization and spectroscopic study of the products were carried out by 1 H, 13 C, 31 P NMR and IR spectroscopy, and elemental analysis. For molecules 1 – 3 , with the increasing ring size of the amine groups, from five-to seven-membered, the δ ( 31 P) peaks shift downfield, 3 J (P, C) aliphatic decreases, the P O bond gets stronger and the C O bond gets weaker. The 1 H NMR spectra of compounds 2 and 6 demonstrated interesting long-range 5 J P,H or 7 J P,H coupling constants. Long-range coupling of pyridine ring protons with 4 J (H,H) = 1.6 Hz were also detected for molecule 5 . The crystal structures of compounds 2 – 4 and 6 were also determined by X-ray crystallography. The data revealed that the six-membered aliphatic rings in compounds 2 , 4 and 6 have a stable chair conformation. The phosphoryl and the carbonyl groups have anti configurations in all crystals, the phosphorus atoms in these structures have a distorted tetrahedral configuration and the environment of most nitrogen atoms is practically planar in all the structures. All the structures form dimers through strong intermolecular P O…H N hydrogen bonds. These dimers connect to each other via various electrostatic weak bonds to produce a 3-D network in each lattice. Moreover, the in vitro antibacterial activities of compounds 1 – 6 were measured for Staphylococcus aureus and Escherichia coli bacteria in nutrient agar culture medium by the disk method. The antibacterial effect of all the compounds against E. coli was very similar to that of chloramphenicol. Compound 4 showed the most activity toward both tested bacteria and its activity against E. coli was even greater than that of chloramphenicol. The growth inhibitory zone (GIZ) of the synthesized molecules for both bacteria was dependent on the substituent nature of the phosphorus atom in each compound. [ABSTRACT FROM AUTHOR]

• Three new phosphoramide derivatives were synthesized, and characterized using spectroscopy techniques. • The inhibition and adsorption performances of these compounds on mild steel corrosion were investigated. • PDP studies demonstrated that the titled compounds behaved as mixed-type inhibitors. • DFT computations and MD simulations were accomplished to confirm experimental results. • These compounds formed strong Cl-H•••N-P hydrogen bonds with the HCl. Three new phosphoramide derivatives with the general formula of (R) 2 P(O)[C 9 H 21 N 2 ] (R= Ph, A), (R= OPh, B) (R= OEt, C) were synthesized and characterized by using spectroscopy methods. The inhibition effectiveness of synthesized compounds was inspected using potentiodynamic polarization (PDP), impedance measurement spectroscopy (EIS) and scanning electron microscopy (SEM). The synthesized compounds demonstrated acceptable protection power for the erosion of mild steel in 1 M HCl at room temperature. The PDP studies illustrated that the new phosphoramide derivatives behaved as mixed-type inhibitors. Density functional theory and molecular dynamics (MD) simulations were employed to support experimental results. The molecular electrostatic potential plot, the highest occupied molecular orbital and the lowest unoccupied molecular orbital profiles, thermochemical parameters, and quantum chemical descriptors such as electronic electronegativity, chemical hardness of the ground state, and electrophilicity index were calculated and discussed from a corrosion inhibition view point. With the aim of identifying the most stable configuration of inhibitor-HCl, the HCl molecule was approached to all probable reactive sites of inhibitors determined by MEP plots. The molecule A with the most inhibition efficiency (87.25%) and negative inhibitor-HCl interaction energy (-2.56 kcal mol−1) was chosen to study its adsorption behavior on the Fe (1 1 0) using MD simulations at T = 298, 308, and 318 K and in the presence of n = 1-4 inhibitor molecules. The corrosion behavior was investigated with the help of binding energies, radial distribution function analysis, equilibrated configurations, and mean square displacement (MSD) analysis. The theoretical results were in good accordance with the experimental results. [ABSTRACT FROM AUTHOR]

2,4-Bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide ( Lawesson’s reagent ) was made to react with benzylamine to produce [(PhCH 2 NH)(p-C 6 H 4 OMe)PS 2 ] − [PhCH 2 NH 3 ] + in a very facile manner. From the abovementioned product, two new complexes {Pd[(PhCH 2 NH)(p-C 6 H 4 OMe)PS 2 ] 2 } (C1) and {Cu 2 (PPh 3 ) 2 [(PhCH 2 NH)(p-C 6 H 4 OMe)PS 2 ] 2 } (C2) were obtained in high yields whose molecular structures were ascertained by X-ray diffraction analysis, IR and NMR spectroscopy, and elemental analysis. The catalytic properties of both complexes were evaluated in the Heck reaction. High turnover numbers (TONs) and yields were observed for palladium catalyst and it was revealed that dicopper(I) complex by a distance of 2.84 Å between metal ions, bearing triphenylphosphine and dithiophosphorus ligands, can catalyze the Heck reaction. This is the first report of Cu(I) complex as catalyst in the Heck reaction. Natural bonding orbital (NBO) analysis for C1 indicated that natural charge on Pd atom is −0.07e and Pd atom has formed four sigma bonds with S atoms. Similarly, NBO analysis revealed no significant Cu⋯Cu interaction in dicopper complex C2. [ABSTRACT FROM AUTHOR]

Two new divalent metal(II) aminodiphosphonates with layered structure, namely, Cu(H 3 L 1 ) 2 ·2H 2 O ( 1 ), [H4L 1 =methyl-N(CH 2 PO 3 H 2 ) 2 ] and Cd 2 (H 2 L 2 ) 4 ( 2 ), [H 4 L 2 =n-propyl-N(CH 2 PO 3 H 2 ) 2 ] were synthesized and characterized. The Cu(II) ions in complex 1 are octahedrally coordinated by four oxygen atoms from two chelating ligands and two phosphonate oxygen atoms from two neighboring Cu(H 3 L 1 ) 2 units. The Cu(H 3 L 1 ) 2 units are interconnected by bridging phosphonate groups, forming a 2-D metal phosphonate layer. The structure of complex 2 contains two unique Cd(II) ions octahedrally-coordinated by six phosphonate oxygen atoms from four H 2 L 2 diphosphonate anions. Corrosion inhibition performances of 1 and 2 were also compared with each other in order to study the effect of combinations of externally added Cd/H 4 L 2 and Cu/H 4 L 1 (1:1 ratio) on corrosion rates of carbon steel. It was found that at pH 3.0, Cd/H 4 L 2 or Cu/H 4 L 1 combinations do not have noticeable corrosion inhibition efficiency for carbon steel. In contrast, at pH 7.0, higher corrosion inhibition efficiency was achieved for Cd/H 4 L 2 . Physical characterizations such as scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) were applied to study the corrosion specimens and film material. [ABSTRACT FROM AUTHOR]

Herein, we reported the synthesis of copper(i) thiocyanate complexes with ortho-pyridinyl carbohydrazones containing a thiophene (L1) or a furyl ring (L2) as a mixture of two different crystals for each compound, linkage isomers of C1N, [Cu(NCS)(L1)PPh3] and C1S, [Cu(SCN)(L1)PPh3], for L1, whereas monomeric and polymeric structures C2N, [Cu(NCS)(L2)PPh3], and C2P, [–(NCS)Cu(L2)–]n, for L2. Crystallographic information and theoretical calculations, mainly noncovalent interaction reduced density gradient (NCI-RDG) analyses, were pursued to generate a profound understanding of the structure-directing interactions in these complexes. The supramolecular assemblies are first driven by cooperative π…π interactions and hydrogen bonds followed by CH…π, S…S and S…π linkages. In the case of the linkage isomers, intermolecular interactions may have a significant role in the formation of the less stable S-bound isomer C1S. [ABSTRACT FROM AUTHOR]

The reaction of 2,4-bis (4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawesson’s reagent) with phenylethylamine produced [H3NCH2CH2C6H5]+[(C6H5CH2CH2NH)(p C6H4OMe)PS2]−(1). Furthermore, reaction of1with NiCl2in dry methanol led to the novel complex2. The compounds were characterized by1H and31P NMR, IR spectroscopy, and elemental analysis. A single crystal X-ray structure of complex2showed that the nickel complex is square planar. The complex formed a supramolecular structure via intermolecular S1…H7B and O1…H2N2 hydrogen bonds. The X-ray crystallography of complex showed [R22](18) and R44(18) motifs in the monomers were connected to each other via S1…H7B, O1…H2N2 hydrogen bonds with donor–acceptor distance of 2.89 and 2.51 Å, respectively. The new compounds were additionally tested in view of their antibacterial properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three new phospho-thiadiazol derivatives were synthesized, and characterized using spectroscopy techniques. • The DFT method investigated their conformational, geometrical, and reactivity aspects. • Their cytotoxic activities were evaluated against cancer in the human glioblastoma cell lines. • The induced apoptotic synthesised agents and ReoT3D were carried out via Annexin V‐FITC/PI assay. • Both in vitro and in silico results showed that A has promising inhibitory potential and binding energy. In this study, three new phospho thiadiazole compounds (A , F and W) were investigated as possible cytotoxic agents. The compounds were synthesised and characterised by using spectroscopy methods. The crystal structure of compound A was investigated using X-ray crystallography, since the title compounds can exist as different tautomeric forms, their conformational and geometrical aspects were investigated computationally by the DFT method. NBO analysis suggested that these compounds can function as appropriate ligands for the reaction with the nitrogen bases of DNA. All the synthesised compounds were evaluated in vitro for their cytotoxic activities against cancer in the human glioblastoma cell lines (U-251) using the MTT assay. According to the annexin V‐FITC/PI results, a combination of synthesised compounds with ReoT3D showed a synergistic effect to increase the percentage of apoptotic cells. Molecular docking study for A (the most toxic compound) showed how it interacts with DNA. Both in vitro and in silico results showed that A has promising inhibitory potential (IC 50 : 48.1 ± 0.3 μM) and binding energy (−6.67 kcal/mol). [ABSTRACT FROM AUTHOR]

Two new diorganotin complexes with formula {SnCl 2 (CH 3 ) 2 L1} 2 (C1), L1 = N-nicotinyl, N′,N″-bis(diethylamine) phosphoric triamide and {SnCl 2 (CH 3 ) 2 L2} n (C2), L2 = N-nicotinyl, N′,N″-bis(cyclopentylamine) phosphoric triamide were synthesized and characterized by IR and NMR spectroscopy, and elemental analysis. Single crystal X-ray diffraction structural analyses confirmed all-trans and cis–trans configurations for distorted octahedral geometry in C1 and C2, respectively. Also, it revealed that the coordination of L1 and L2 to Sn atom results to a binuclear arrangement in C1 and one-dimensional polymeric chain in C2. The relative stability of M1 (SnCl 2 (CH 3 ) 2 L1) and M2 (SnCl 2 (CH 3 ) 2 L2) units in binuclear and polymeric arrangements were compared using density functional theory (DFT) calculations. Based on theoretical findings, M1 and M2 prefer polymeric chain structure from energy point of view though the stability difference of M1, in two arrangements, was much lower compared to stability difference of M2. Furthermore, nature of bonds and Sn–ligand interactions was studied by NBO analyses. In vitro cytotoxic assay of complexes against breast cancer cell lines MCF-7, MDA-MB-468 and T47-Dhuman, were also reported. MDA-MB-468 cells are exquisitely sensitive to cell death induced by C1 and C2 complexes treatment. C1 complex exhibited higher anticancer activity, compared to C2, which can be attributed to larger Cl Sn Cl angle in C1. [ABSTRACT FROM AUTHOR]

Single crystals of C5H4NC(O)NHP(O)[N(i-C4H9)2]2 were prepared and investigated by X-ray crystallography. Interestingly, four symmetrically independent conformers were detected in the structure of this compound by X-ray crystallography. The greatest difference in these conformers was different torsion angles. In all conformers, the phosphoryl and carbonyl groups showed anti-configurations, and the two terminal CH3 groups of each alkyl chain in amine parts have different spatial orientations due to their connection to a prochiral carbon atom. The diastereotopic protons of every CH2 moiety in amine groups also have different spatial orientations. Every conformer forms a centrosymmetric dimer with its own symmetrically generated analog via a hydrogen bond. The first conformer connects to others (A, B, and C) via electrostatic interactions and forms a tetramer. All hydrogen bonds and electrostatic interactions result in the formation of a three-dimensional polymeric network in the crystalline lattice of compound. To find the most stable conformer, density functional theory (DFT) calculations were performed. The computationally optimized geometric parameters are in good agreement with the experimental results. According to DFT calculations, B is the most stable conformer with energy of −987714.07 kcal/mol. In all conformers the electron density of HOMO is localized on P=O and C=O oxygen atoms and some parts of amine groups, while LUMO is localized on the nicotinamide part of the molecule. [ABSTRACT FROM AUTHOR]

Two N , N -bis(diphenylphosphino)-amine ligands [amine = 4-aminomorpholine ( L 1 ) or 1-amino-4-methylpiperazine ( L 2 )] and their Pd(II) complexes were synthesised and characterised by IR and NMR spectroscopies. The structures of ligand L 1 and both complexes C 1 and C 2 were determined by X-ray crystallography. The catalytic activity of C 1 and C 2 in the Heck coupling reactions was assessed. The effect of parameters such as palladium source, solvent, base and reaction time on the conversion was investigated to obtain the optimum conditions for the reaction. [ABSTRACT FROM AUTHOR]

Novel organophosphorus compounds, containing Nicotinamide, with formula CHNC(O)NHP(O)R, R=Cl ( 1), OH ( 2), N(CH) ( 3), N(CH) ( 4), N( n-CH) ( 5), NHCH ( 6), NHCH ( 7), were synthesized and characterized by H, C, P, NMR, IR, spectroscopy and elemental analysis. Single crystal structures of 3 7 were determined by X-ray crystallography. HNMR spectra of compounds 2, 3, 6- 8 demonstrated interesting long-range coupling constant, J ( n = 5 7). Crystallographic data revealed that in both molecules 3 and 7, the phosphoryl and the carbonyl groups have anti-configurations and the phosphorus atoms in these structures have distorted tetrahedral configuration. All the hydrogen bonds and electrostatic interactions make a three dimensional polymeric network for both 3 and 7. Interestingly, two independent conformers were detected in the unit cell of compound 7. The two conformers of the title compound can be observed in a solid phase but only one compound defined in a solution. These two conformers are connected to each other by a short contact, N (amine)···H-C (pyridine) with 2.626 Å distance. The molecular geometry of 7 was calculated by DFT/B3LYP (6-31+ G**) quantum chemical calculations. The computational optimized geometric parameters and vibrational frequencies showed a good agreement with the experimental results, considering reasonable variations arising from the differences between solid and gaseous phases. Theoretical calculations revealed that the more stable conformer of the title compound is conformer 1 with the energy of −1335.723996 a.u., which is about 1.17 kcal/mol lower than the energy of conformer 2. [ABSTRACT FROM AUTHOR]

Pyridinyl carbohydrazone ligands with different positions between functional groups of –NNHC(O)– and Npy (ortho-, meta- and para-) have been applied for the synthesis of cuprous halide complexes. X-ray crystallography reveals that the ortho analogous ligand, Lo, functions in a chelating mode, adopting a mononuclear structure in complex Co, [CuClLoPPh3], while the meta and para analogs, Lm and Lp, act as ambidentate ligands, coordinating through the Npy atom in halogen-bridged binuclear complexes [Cu(μ-X)LPPh3]2 (X = Cl, Br, I and L = Lm, Lp). The influence of non-covalent intermolecular interactions on the assembly of the final structures has been discussed by geometrical and Hirshfeld analyses. Moreover, the photophysical properties of the complexes have been explored, both experimentally and theoretically. The influence of ligand structure and halide variations on the structural and photophysical aspects of the complexes has been considered in this study. [ABSTRACT FROM AUTHOR]

Organotin complexes of bisphosphoramidates were prepared by the reaction of SnR 1 R 2 R 3 Cl (where R = alkyl/aryl/Cl) and Ph 2 P(O)XP(O)Ph 2 ligands (where X = diamine). All the compounds were characterized by NMR and IR spectroscopy. X-Ray crystallography confirms that the bridging ligand produces binuclear complexes with SnPh 3 Cl acceptors in C a3 and C a4 and offers a polymeric structure toward SnMe 2 Cl 2 in C c5 . The synthesized compounds were screened for the antibacterial activity against B. cereus and E. coli . Based on the MIC test, the ligands are devoid of antibacterial activity. Notably, among the complexes, triphenyltin adducts exhibited a marked activity only against Gram-positive bacterium B. Cereus (IC 50 = 0.78 μg/mL for C a3 and C a5 ). DFT–QSAR models revealed that the descriptor of the electrophilicity ( ω ) parameter is correlated with the inhibition activity on B. cereus . The correlation matrix of QSAR models and docking analysis confirmed that the electrophilicity parameter controls the influence of the net charge ( Q Sn ) and polarizability of Sn atom of complexes on the inhibition of B. cereus . [ABSTRACT FROM AUTHOR]

A new diorganotin(IV) complex with the formula SnCl2(CH3)2L2 ( C1a), L = 4-NC5H4CONHPO(NCH3CH2C6H5)2, was synthesized and characterized using 1H NMR, 13C NMR, 31P NMR, 119Sn NMR and infrared spectroscopies. The molecular structure of C1a was determined using X-ray crystallography, revealing that C1a contains hexa-coordinated Sn(IV) centres with trans-configuration of donor atoms around them. Each Sn(IV) atom is positioned in the centre of of an octahedron. C1a forms one-dimensional chains via two equal PO...HN hydrogen bonds. These hydrogen bonds produce centrosymmetric rings as a supramolecular hydrogen-bonded pattern. In order to compare the relative stability of C1a (with N-ligated configuration) and its possible O-ligated isomer, C1b, density functional theory calculations were performed, the results showing a preference of C1a over C1b from an energy point of view. Also, natural bond orbital analysis was carried out to obtain detailed information on the electronic features of the optimized structures. The theoretical results show that hydrogen bonding in the crystal structure has a significant role in the stabilization of C1a, and Sn(IV) interacts more strongly with the Npy atom than the PO functional group. Furthermore, the free ligand and its complex were tested against three human cancer cell lines, i.e. human cervical carcinoma (HeLa), human prostate cancer (PC-3) and human breast adenocarcinoma cancer (MCF-7). C1a displays moderate to good cytotoxicity towards all three cancer cell lines. Moreover, antibacterial tests were carried out using the disc-diffusion method, in which C1a shows high activity against selected Gram-negative and Gram-positive bacteria. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

• A novel water-soluble and proton transfer containing triazine has been synthesized • The structure of this compound was characterized by X-ray crystallography • In vitro cytotoxicity was studied against human breast cancer cell line • In vitro antimicrobial activities of the compound were tested • Molecular docking study was used for supporting the experimental data In this work, a novel water-soluble and proton transfer compound ( damt ) ( dpp ).H 2 O ( PT ) ( damt = 2,6-diamino-4-methyl-1,3,5-triazin-1-ium and dpp = diphenylphosphinate) was prepared and determined by IR as well as NMR spectroscopy. Also, the related structure of the crystalline state was obtained, and the main intermolecular interactions were examined by Natural Bond Orbital (NBO), Density Functional Theory (DFT) and Hirshfeld surface analysis. The anti-cancer activity of the synthesized proton transfer compound on the breast cancer cell line (MCF-7) was investigated via applying the MTT assay method; the obtained results were then compared with Cisplatin as a standard anticancer drug. In vitro results showed that the compound PT could significantly inhibit the proliferation of cancer cells, leading to inducing the death of them in MCF-7. Additionally, this compound displayed higher antibacterial activity against both S. aureus and B. subtilis bacteria; its activity was even higher than that of chloramphenicol, which is known as a kind of reference drug. For a better understanding of the interactions between PT -DNA and PT- protein of S. aureus , molecular docking was used. The results of molecular docking revealed that PT had a high binding affinity on the DNA and protein of S. aureus. [Display omitted] [ABSTRACT FROM AUTHOR]

Phosphorus and nitrogen-containing compounds widely are used as flame retardant for cotton fabrics. In this paper, two new phosphoramides with the formula of (C 6 H 5) 2 P(O)[N–C 3 H 5 N 2 O] (DIO) and (C 6 H 5) 2 P(O)[N–C 3 H 5 N 2 S] (DIT) were synthesised and characterised using 1H NMR, 13C NMR, 31P NMR, IR, and MASS spectroscopy. Crystal structures of DIO were investigated using X-ray crystallography to confirm the proposed structure. Experimental analyses such as VFT, LOI, SEM-EDS, TGA-DTG and cone caloriometer, indicated these compounds are noteworthy because of their thermal and flame retardancy properties. According to the cone calorimetric results, DIT/ cotton owning THR (18.26) and HRR (183.37) is better flame retardant than DIO/ cotton. After treatment with DIO and DIT , the mechanical properties of cotton decreased and improved slightly, respectively. In order to understand the Structure-Flame retardancy Relationship (SFR) of synthesized compounds, the values of HOMO and LUMO energies, dipole moments, hardness, softness, and electrophilicity index were investigated computationally by density functional theory (DFT) method. These results were in good accordance with those of flame retardancy investigation. • Two new phosphoramides were synthesised and characterised using spectroscopy techniques. • The thermal stability of phosphoramides were evaluated on cotton. • Flame retardant properties of phosphoramides were studied on cotton using cone calorimeter test. • Physical properties of phosphoramide-treated cotton fabrics were investigated. [ABSTRACT FROM AUTHOR]

This paper consists of new mono, bis, and tetraphosphonate compounds that were selected against COVID-19 M pro. Computational studies based on molecular docking, the quantitative structure–activity relationship (QSAR), and the pharmacophore studies were conducted to detailed study the inhibitory potency of compounds against COVID-19 M pro and the factors influencing inhibitory potency. [Display omitted] The global coronavirus (COVID-19) outbreak has prompted scientists to discover a cure for the disease. So far, phosphorus-based drugs have been proposed. These drugs have good inhibitory activity against the main protease (Mpro). Hence, in order to introduce a group of inhibitors the coronavirus, 51 compounds containing different mono, bis, and tetra phosphonates as Remdesivir derivatives, 32 of which are new, were synthesized and characterized by 31P, 13C, and 1H NMR and IR spectroscopy. Their biological activities were also investigated by Molecular Docking, QSAR, and Pharmacophore. Van der Waals, hydrogen bonding, and hydrophobic interactions were studied for all compounds as well as binding energy (△G, Kcal/mole) and the inhibitory constant Ki (μM) obtained by Molecular Docking. The results showed that the topology of the ligands and the change of the different groups attached to them can be effective in the placement position in the active site of the enzyme (Glu 166 and Gln 189). And bisphosphonates have a high interaction tendency with Mpro COVID-19. Compound L24 was identified as the best inhibitor with the −6.38 kcal/mol binding energy. The quantitative structure–activity relationship (QSAR) findings demonstrated that the polarity and topology of molecules in all phosphonate derivatives were important parameters affecting the effecting on the binding energy and inhibitory ability of compounds. The DFT and pharmacophore results are in good accordance with those of QSAR and molecular docking. This study can be helpful to gain a better understanding of the interactions between the Mpro of virus and its inhibitors in order to attain drugs with more effect on coronavirus (COVID-19). [ABSTRACT FROM AUTHOR]

A novel Zn(II) coordination polymer of N -nicotinyl phosphoric triamide ligand, {[Zn(L) 2 (H 2 O) 2 ]⋅(NO 3 ) 2 } n C1 (L = 3-NC 5 H 4 C(O)NHP(O)(NC 6 H 12 ) 2 ), has been synthesized and characterized by IR and 1 H, 13 C, 31 P NMR spectroscopy. Crystal structure analysis of C1 demonstrates a distorted octahedral geometry for Zn(II) ions. The oxygen atom of phosphoryl group (O phosphoryl ) and the nitrogen atom of pyridine ring (N pyridine ) of ligand take part in coordination to Zn(II) centers in a bidentate bridging mode. This coordination pattern results in infinite 1D polymeric chains along c axis, which are composed of metal shared 16-membered puckered rings. Structural data show that despite binding through O phosphoryl , the P O bond distance unexpectedly shortens in C1 when compared to that of the ligand, conceivably due to the steric factors in the solid state. This is confirmed by comparing the structural and electronic properties of C1 and L in the gas phase by using density functional theory (DFT) calculations. Natural bond orbital (NBO) analysis reveals the metal–ligand interaction for C1 as donor–acceptor type delocalizations (charge transfer). Besides, on the basis of the quantum theory of atoms in molecules (QTAIM) analysis, the nature of Zn O and Zn N bondings is found to be mainly electrostatic with a small amount of covalent character. [ABSTRACT FROM AUTHOR]

A new N -isonicotinyl phosphoric triamide ligand with the formula 4-NC 5 H 4 C(O)NHP(O)(NC 4 H 8 ) 2 ( L ) was synthesized and characterized by 1 H, 13 C, 31 P NMR and IR spectroscopies. The reaction of MnCl 2 ·4H 2 O with L led to the formation of a new 3D system {Mn L 2 Cl 2 } n ·34CH 3 OH ( C 1 ). X-ray crystallographic data revealed that the ligand binds to the neighboring manganese ions through the nitrogen atom of pyridine (N py ) and the oxygen atom of phosphoryl (O P ) in a bidentate manner. The Mn(II) centers showed a distorted cis (N py , N py ) cis (O P , O P ) cis (Cl, Cl) octahedral configuration. In order to compare the relative stability of C 1 (with all-cis configuration) and its possible all-trans isomer, C′ 1 , density functional theory (DFT) calculations were performed and the results showed the preference of C 1 over C′ 1 from energy point of view. Quantum theory of atoms in molecules (QTAIM) analysis was applied to elucidate the nature of interactions, and the results suggested an ionic character (closed-shell interaction) for Mn–O P bond, and a partial covalent contribution for Mn–N py interaction. Natural bond orbital (NBO) analysis was also used to calculate the charge distribution on atoms in the complex. The complex C 1 showed efficient catalytic activity in the oxidation reaction of some alkenes to their corresponding epoxides. In addition, the effect of temperature and reaction time on the conversion and selectivity of cyclohexene epoxidation reaction in the presence of C 1 as catalyst was investigated. [ABSTRACT FROM AUTHOR]

New phosphorus(v) hydrazide compounds containing the [–P(O)NHNHC(O)OR] fragment have been prepared by the reaction of mono- and di-chloro phosphoryl intermediates with methyl (R = CH3, 1–5) and tert-butyl (R = C(CH3)3, 6–9) carbazates, and characterized by IR and multinuclear NMR spectroscopy. Molecular structures of 1, 2, and 5 have been established by X-ray diffraction analysis to investigate the relative orientation of the present moieties, resulting hydrogen bonding motifs and stabilizing intermolecular interactions. The impact of the intermolecular contacts on crystal packing has been further studied by Hirshfeld surface analysis. The dependence of experimental δ31P and 2JPNH values on phosphorus substituents has been explored using natural bond orbital (NBO) analysis. Likewise, the reasons for maintaining the tetrahedral geometry around the phosphorus atom in the synthesized compounds and not rearranging to a trigonal bipyramidal one (in comparison with spirophosphoranes) have been investigated theoretically. Overall, the NBO results reveal the influential role of electronic delocalization and s-content in hybridization for the above-mentioned experimental evidence. [ABSTRACT FROM AUTHOR]

A novel zwitterionic bisphosphoramide compound with formula [4-NH-C5H4C(O)NHP(O)O-]2O•(H3O+)2 (H2O)2 was synthesized and characterized by NMR and FT-IR spectroscopy. The 31P{¹H} NMR spectrum illustrates a singlet peak at -16.51 ppm that is indicative of the structural symmetry. Also, the crystal structure of the title compound was determined by X-ray crystallography. In this structure there is one bisphosphoramide dianion BS two H3O+ cations that are co-crystallized with two H2O molecules. In the bisphosphoramide dianion, the two phosphorus atoms are connected to each other through an oxygen atom with P1-O3-P2 angle of 133.40(13)°. Intermolecular P-O. . . H-N, C=O. . . H-N and H-O. . . H-O hydrogen bonds led to a three dimensional network in the crystalline lattice. DFT computations were performed on the X-ray crystal structure and also on assumed cis and trans conformations of the two P-NR groups using Gaussian 98 software at B3LYP/6-31G* level of theory. The optimizations yielded identical pseudo-trans conformation for the both optimized cis and trans forms. [ABSTRACT FROM AUTHOR]

In this study, the synthesis and spectroscopic characterization of new phosphoramides based on 3-amino-5-methylisoxazole with the formula R2P(O)[NH-C4H4NO], R = C6H5O (1), C6H5 (2), RP(O)[NH-C4H4NO]2, R = C6H5O (3), CH3-C6H4O (4), C6H5NH (5), (C6H5)ClP(O)[NH-C4H4NO] (6) and two lanthanide complexes [Ln(2)2(NO3)3(EtOH)]·EtOH, LnIII = Ce (7) and Eu (8), have been reported. The structural study of (3) shows the presence of two conformers (crystallographically independent molecules) in the crystalline lattice, caused by different orientations of the phenyl and isoxazole rings. For (3), the intermolecular interactions have been studied by Hirshfeld surface analysis and fingerprint plots. Furthermore, the electronic and energy aspects of hydrogen bonds between molecules of (3) have been explored by density functional theory (DFT) calculations. X-ray crystallography of complexes (7) and (8) reveals that two phosphoramide ligands take part in coordination to the metal, one as monodentate from Ophosphoryl, and the other one as chelate through Ophosphoryl and Nring. The complexes are also composed of two conformers in the solid-state structure. Quantum theory of atoms in molecules (QTAIM) analysis discloses the electrostatic nature of the Ln-ligand interaction. [ABSTRACT FROM AUTHOR]

New Ag(I) complexes of N-nicotinyl, N′,N″-bis(cyclohexyl) phosphoric triamide, 3-NC 5 H 4 C(O)NHP(O)[NH(C 6 H 11 )] 2 ( L 1 ), and N-nicotinyl, N′,N″-bis(tert-butyl) phosphoric triamide, 3-NC 5 H 4 C(O)NHP(O)[NHC(CH 3 ) 3 ] 2 ( L 2 ), with formula Ag( L 1 ) 2 NO 3 ( C 1 ) and Ag( L 2 ) 2 NO 3 ( C 2 ) were synthesized and characterized by NMR, IR, UV–Vis spectroscopy and elemental analysis. Molecular structures of C 1 and C 2 were determined by X-ray crystallography and revealed that coordination of ligands to Ag(I) has been occurred from the nitrogen atom of the pyridine ring. Also, compound C 1 exists as two conformers in crystalline structure which are weakly connected to each other through intermolecular Ag…O C electrostatic interaction. Ag(I) complexes and the corresponding ligands were screened for their antibacterial activity against selected Gram-positive and Gram-negative bacteria, showing bactericidal activity for complexes. In vitro cytotoxicity of compounds was studied against human carcinoma cell lines, HeLa (cervical cancer), MCF-7 (breast cancer) and MG-63 (osteosarcoma). Results indicated that C 1 and C 2 possess strong cytotoxic activity against cancer cells with IC 50 values ranging from 3.3 to 15.3 μM for two exposure time (24 and 48 h). The cytotoxicity of complexes against non-tumorigenic breast cell, MCF-10A was further evaluated. Structure–activity relationships have been also discussed. [ABSTRACT FROM AUTHOR]

Novel (thio)phosphoramidate derivatives based on piperidincarboxamide with the general formula of (NH2-C(O)-C5H9N)-P(X = O,S)R1R2 (1-5) and (NH2-C(O)-C5H9N)2-P(O)R (6-9) were synthesized and characterized by 31P, 13C, ¹H NMR, IR spectroscopy. Furthermore, the crystal structure of compound (NH2-C(O)-C5H9N)2-P(O)(OC6H5) (6) was investigated. The activities of derivatives on cholinesterases (ChE) were determined using a modified Ellman's method. Also the mixed-type mechanisms of these compounds were evaluated by Lineweaver-Burk plots. Molecular docking and quantitative structure-activity relationship (QSAR) were used to understand the relationship between molecular structural features and anti-ChE activity, and to predict the binding affinity of phosphoramido-piperidinecarboxamides (PAPCAs) to ChE receptors. From molecular docking analysis, noncovalent interactions especially hydrogen bonding as well as hydrophobic was found between PAPCAs and ChE. Based on the docking results, appropriate molecular structural parameters were adopted to develop a QSAR model. DFT-QSAR models for ChE enzymes demonstrated the importance of electrophilicity parameter in describing the anti-AChE and anti-BChE activities of the synthesized compounds. The correlation matrix of QSAR models and docking analysis confirmed that electrophilicity descriptor can control the influence of the hydrophobic properties of P = (O, S) and CO functional groups of PAPCA derivatives in the inhibition of human ChE enzymes. [ABSTRACT FROM AUTHOR]