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Recent years have seen increasing interest in uranyl(VI) photocatalysis. In this study, uranyl complexes were successfully synthesized from ligands L1–L6 and UO2(NO3)2·6H2O under reflux conditions, yielding products 1–6 with yields ranging from 30% to 50%. The complexes were thoroughly characterized using NMR spectroscopy, single-crystal X-ray diffraction, and elemental analysis. The results indicate that complexes 1–5 possess a pentagonal bipyramidal geometry, whereas complex 6 exhibits an octahedral structure. The photocatalytic properties of these novel complexes for sp3 C-H bond functionalization were explored. The results demonstrate that complex 4 functions as an efficient photocatalyst for converting C-H bonds to C-C bonds via hydrogen atom transfer under blue light irradiation. [ABSTRACT FROM AUTHOR]

The article divulges the crystal growth, synthesis, and X-ray structure characterization of one centrosymmetric cadmium complex, [Cd{CdL(μ2-1,3-acetate)}2] using Salen ligand (SL). The complex is further characterized using spectroscopic and analytical techniques, including DRS, SEM-EDX, PXRD, and ICP-MS. The crystallographic study showed that the complex has a monoclinic space P21/c. Addison parameters (Ʈ) show the hexagonal geometry of the central Cd(II) metal ion. Hirshfeld surface and 2-D fingerprint confirm supramolecular contacts despite weak C–H⋯O and C–H···π interactions. Energy frameworks, FMOs, global reactivity parameters, MEP, and energy bandgap explain the complex reactivity outlook. The complex inter- and intramolecular bonding interactions were explored through natural bond orbital (NBO), QTAIM, NCI-RDG, Electron Location Function (ELF), and Localized Orbital Locator (LOL) quantization methods. In addition, the complex and its synthetic components in vitro antibacterial efficacy were investigated using Gram-positive and Gram-negative microbial strains. SAR (structure-activity relationship) correlates with biological potency. Molecular docking assessed antimicrobial potency with proteins S. aureus (PDB ID: 1JIJ), C. albicans (PDB ID: 1M7A), E. coli (PDB ID: 1T9U), P. aeruginosa (PDB ID: 2UV0), and A. Niger (PDB ID: 3K4P). The findings are backed by the Protein-Ligand Interaction Profiler (PLIP). The antifungal potency and cell viability test of C. albicans were conducted using photodynamic therapy (APDT).

Recent years have seen increasing interest in uranyl(VI) photocatalysis. In this study, uranyl complexes were successfully synthesized from ligands L1–L6 and UO2(NO3)2·6H2O under reflux conditions, yielding products 1–6 with yields ranging from 30% to 50%. The complexes were thoroughly characterized using NMR spectroscopy, single-crystal X-ray diffraction, and elemental analysis. The results indicate that complexes 1–5 possess a pentagonal bipyramidal geometry, whereas complex 6 exhibits an octahedral structure. The photocatalytic properties of these novel complexes for sp3 C-H bond functionalization were explored. The results demonstrate that complex 4 functions as an efficient photocatalyst for converting C-H bonds to C-C bonds via hydrogen atom transfer under blue light irradiation.

A new complexes of Ni(II), Pd(II), and Pt(II) have been synthesized from the reaction of Azo-Schiff base ligand (L1) that was prepared by the condensation firstly of salicylaldehyde with ethylene diamine in a 1:2 molar ratio and the prepared imine compound (S1) reacted with 2,5-dichloro aniline, and were employed in the preparation of complexes containing the metal ions Ni(II), Pd(II), and Pt(II). The structural characteristics of the synthesized compounds were investigated using UV-Vis, IR and NMR, molar conductance, elemental analysis, and mass spectroscopy. The results of the elemental analysis point to a 1:1 [M:L] stoichiometry. According to molar conductance studies, none of the prepared end products are electrolytic in nature. The complexes of Ni(II), Pd(II), and Pt(II) may have square planer geometry, according to spectral investigations. Then Pd(II), Ni(II), and Pt(II) complexes were evaluated for antimicrobial activity against different types strains of Gram-negative [Escherichia coli (ATCC 25922)] and positive bacteria [Staphylococcus aureus (ATCC 25923)] and showed good significant against these bacteria. The cytotoxic effect of the palladium complex on the prostatic malignant cell was examined via the PC3 cell line studied against normal cell WRL-68. The molecular docking of target microorganisms of these complexes will be studied by using MOE software. [ABSTRACT FROM AUTHOR]

A crystal structure and thermal characterization of a multisite Schiff base containing N2O2-inner and O4-outer coordination sites are reported. The title compound was characterized by X-ray structure analysis, 1H-NMR, 13C-NMR and ATR-FTIR spectroscopy, TG/DSC and TG-FTIR techniques. The compound crystallizes as a methanol solvate in the triclinic system, space group P 1 ¯ . The stable at room temperature compound, during heating in the air, first loses a methanol molecule. At higher temperature, the sample decomposition is associated with a strong exothermic effect and the emission of large amounts of carbon dioxide, carbon monoxide and ammonia. [ABSTRACT FROM AUTHOR]

Catalytic reactions of 3-membered heterocycles, such as epoxides and aziridines, with CO2 in the presence of metal–salen complexes are considered in this review (salens is a class of ligands, derived from diamines and salicylaldehyde or its substituted analogs). These reactions lead to copolymers or cyclic carbonates/oxazolidinones, which are important products of modern fine and industrial organic synthesis. The influence of metal ion, substituents in salen and the nature of cocatalyst on the catalytic performance of the systems based on metal–salen complexes, reported during two recent decades, is analyzed. It was shown that formation of bi- or polynuclear complexes, as well as incorporation of the organic cocatalyst (such as tetraalkylammonium cation) in the molecule of the metal-containing catalyst improved the catalytic performance of metal–salen species due to cooperative effect on several active sites in activation of epoxide and its reaction with CO2. The ways for creation of heterogeneous metal–salen catalysts for reactions of 3-membered heterocycles with CO2 are also summarized. [ABSTRACT FROM AUTHOR]

The degradation of the antibiotics discharged into water, and wastewater has become a challenge in environmental engineering. A new Z-scheme nanocomposite was designed, synthesized, and characterized for photooxidative degradation of the binary antibiotics (doxycycline and tetracycline) in an aqueous solution simultaneously. Firstly, the proposed nanocomposite was created from dendric fibrous nano-silica (KCC-1), as support, improved with Ti(VI)-salen, as an organometallic complex, and its structural and morphological properties were investigated. The band-gap energy achieved from the Tauc equation was in good accordance with the calculated one by the Gaussian software. Analysis of the band structure was used to deduce the probable Z-scheme heterojunction mechanism for the proposed photocatalyst. The photodegradation procedure was studied in terms of pH (2.0–6.0), catalyst amount (1.5–7.5 mg mL−1), the concentration of H2O2 (0–0.08% w/v), and irradiation time (5–25 min) under UV light. In optimal conditions, employing the simplex non-linear optimization algorithm, the photodegradation of doxycycline and tetracycline showed efficiencies higher than 95%. Optimal circumstances leading to the maximum simultaneous removal of doxycycline and tetracycline were discovered as pH of 3.6, catalyst dose of 6 mg mL−1, H2O2 amount of 0.06%w/v, and irradiation time of 16 min. Under the optimal circumstances, the kinetics data for investigated antibiotics were fitted employing a pseudo-first-order model. The nanocomposite could successfully remove doxycycline and tetracycline contaminations. Regarding the high degradation efficiency as well as fast kinetics, the observations suggest that the proposed photocatalyst has a significant capability of reducing antibiotic pollutants. [ABSTRACT FROM AUTHOR]

A crystal structure and thermal characterization of a multisite Schiff base containing N2O2-inner and O4-outer coordination sites are reported. The title compound was characterized by X-ray structure analysis, 1H-NMR, 13C-NMR and ATR-FTIR spectroscopy, TG/DSC and TG-FTIR techniques. The compound crystallizes as a methanol solvate in the triclinic system, space group P1¯. The stable at room temperature compound, during heating in the air, first loses a methanol molecule. At higher temperature, the sample decomposition is associated with a strong exothermic effect and the emission of large amounts of carbon dioxide, carbon monoxide and ammonia.

In this article, we have synthesized two contemporary ortho-vanillin-based Salen-type ligands (H2L1/H2L2) characterized by modern spectroscopic tools. EDX analysis supports the elemental composition (C, N, O, and Br). SEM examined the morphology of the synthesized compounds. The molecular geometry was optimized in the gas phase using B3LYP-D3/6-311G (d, p) level. The global reactivity parameters, HOMO-LUMO energy gap (Δ), atomic properties, MESP, and ADME/T, vividly explore the chemical reactivity and toxicity of two Salen-type ligands. The DFT simulated IR/NMR characterized essential structural assignments, and UV-Visible spectra were employed to predict the optical properties. The article demonstrated in silico molecular docking against the Gm + ve Bacillus subtilis (6UF6), and Gm -ve Proteus Vulgaris establishes the ligand binding ability with essential amino acids through conventional H-bonding or other significant interactions. The docking simulation is compared for two compounds better than the control drugs and confirms the antimicrobial activity. The theoretical drug-like properties have been explored in-depth by ADME/T using the SWISSADME database. The analysis estimated the molecule's lipophilicity, the consensus P0/W, and water solubility. Thus, using various pharmaco-logical parameters, toxicity explains where the electron-withdrawing Br group plays a more toxic effect in H2L2 than in H2L1.

Spontaneous self-assembly in the supramolecular entity is one of the enthralling synthetic routes. It produces disparate structure crystal complexes after selecting suitable M-L combinations in the pseudohalide sense. In this attempt, a novel cocrystal is synthesized from two independent components (0D + 1D), [PbCd(L1)(SCN)2]·[PbCd(L1)(SCN)2]n(1) using a Salen (H2L1) and NaSCN, which was characterized by spectroscopic, EDX, SEM, PXRD, and X-ray crystallography. The title complex crystallizes in the triclinic space group P1 with unit cell parameters: a = 8.5733(2), b = 11.3798(2), c = 27.105(5) Å, V = 2583.95(9) Å3, and Z = 4. X-ray structure divulges the de-protonated form of [L−2], comprising Cd(II)/Pb(II) ions placed in the inner N2O2 and outer O4 compartments. The Cd(II)/Pb(II) metal ions satisfy trigonal-prismatic and square pyramidal geometries. Crystal engineering and Hirshfeld surface approaches delineate the dominant interactions, e.g., H-bonding (36.4%), C⋯H (20.8%), and S⋯H (21.1%). The unique chalcogen (ChB)/tetrel bonds observed in its solid-state architecture were authenticated by DFT using the PBo-D3/def2-TZVP level of theory. The QTAIM/NCI plot reveals the nature of these contacts. The S···S distance is 2.499(4) Å, and the C–S···S angle is close to linearity (168.8°), confirming the typical ChB. The MEP surface explores the most nucleophilic part at the N-atom belonging to the bonding of Cd-NCS (– 42 kcal/mol). HOMO–LUMO energy gap and NLO parameters provide chemical reactivity and sensitive optical information about the molecules. Meanwhile, Molecular docking was conceded based on total energy with three bacterial proteins like Staphylococcus aureus (PDB ID: 1JIJ) and pseudomonas aeruginosa (PDB ID: 3JPU), and Escherichia coli (PDB ID: 5MMN). Docking and PLIP confirmed the bioactivity of the complex. The compound was screened in vitro against two-gram + ve and two-gram -ve bacteria. The complex had lower MIC (µg/mL) values (10.1) compared to the parent ligand (32.7), implying greater antimicrobial efficiencies. The time-kill kinetics led to the bactericidal activities of the complex. [ABSTRACT FROM AUTHOR]

A highly symmetrical substituted macrocycle was designed, synthesized and characterized as a novel supramolecular scaffold, whose structure was unequivocally characterized by 1H, 13C, COSY, HMBC, HMQC and DOSY NMR, UV‐Vis, FTIR spectroscopy and mass spectrometry. With its defined and electron‐rich aromatic cavity, this macrocycle could be a potential host for inorganic and organic cations. Preliminary investigations on the coordinating abilities of the studied macrocycle show a noticeable interaction between the obtained product and Pb2+ ions. These interactions have been highlighted by mass spectrometry, UV‐Vis spectroscopy, and supported by DFT and TD‐DFT modelling, making this new macrocycle an interesting candidate for possible heavy metal ions removal or for the design of artificial molecular machines. Good reaction yields, accessibility of reagents and absence of catalysts make this synthetic approach useful for systematic screening and up‐scaling of a large number of compounds. [ABSTRACT FROM AUTHOR]

The synthesis of a tetradentate Schiff-base ligand bis(salicylidene)ethylenediamine from salicylaldehyde and ethylenediamine , are important class of ligands . The results of the C.H.N study revealed the formation of a 1:1 [M:L] ratio. .[Er(Salen)(NO3)2]-, square antiprismatic geometry, is the proposed structure of lanthanide metal complex. 1H-NMR, FT-IR, UV-Visible spectral mesurements, and molar conductance were used to estimate the synthesized Schiff-base ligand and its complex. The stoichiometry of the complex has been found to be 1:1 (Er:Salen) matching with C.H.N. analysis. After deprotonation, spectral studies revealed that the ligand was tetradentately coordinated to the metal ion (N2O2) through azomethine nitrogen and phenolic oxygen. The biological activities of the Schiff base (Salen , H2L) and Er(III) complex against E.coli and Staphylococcus bacteria were examined, Schiff base ligand being less active than Erbium (III) complex.

We serendipitously designed one novel 1D hetero-binuclear Zn(II)-Pb(II) coordination polymer, namely [(Zn)(Pb)(L)(η1–NCS)(η1–SCN)]n (1) from Salen ligand (H3L) in the presence of NaSCN. The complex was structurally characterized by elemental, IR, Raman, NMR spectroscopy, Scanning electron microscope, Powder X-ray diffraction, and Single-crystal X-ray diffraction (SCXRD). The heteronuclear complex crystallizes in the monoclinic space group P21/c with Z = 4. The asymmetric unit contains one deprotonated ligand (L2−). SCXRD comprises metal ions of Zn(II) and Pb(II), fulfilled perfect square bipyramidal and Hemi-directed coordination spheres. We accomplished DFT by three different level basis set B3LYP, HF, and M062X with Lanl2dz to delineate Frontier molecular orbital, the Global chemical parameters, and the molecular electrostatic potential. Hirshfeld surface carried out non-covalent interactions like hydrogen bonding. This bonding considered the possible supramolecular topographies due to the flexible aliphatic –OH group. Besides H/H, C/H/H/C and N/H/H/N also dominated the supramolecular network. Van der Waals interactions appear to be more prevalent in the molecular packaging of the complex. Molecular docking finds the plausible binding process by implanting the complex into the active site of the crystal structures of estrogen receptor protein, the VEGFR kinase (liver cancer) protein, and the allosteric Eya2 phosphatase inhibitor (lung cancer) protein. The essential binding process is the polar and hydrophobic exchanges, π–π interaction, hydrogen bonds, and halogen. Advanced Protein–Ligand Interaction Profiler crucially examined the interplay of the protein with complex. Finally, NLO parameters polarizability (α) and hyperpolarizability (β) calculated the importance of nonlinear optical effects. [ABSTRACT FROM AUTHOR]

This article has serendipitously synthesized three trendy Salen ligands (H2L1/H2L2/H2L3) prepared from Salicylaldehyde/ortho-vanillin and the corresponding diamines backbone. The synthesized compounds were characterized vividly by different spectroscopic techniques. Further, the SEM examined the morphology of the ligands. B3LYP, HF, and M062X methods with 6–31++g (d, p) basis sets optimized the molecular geometry. The divergent DFT-based analysis considered the chemical and biological activities of the studied molecules. The global chemical reactivity parameters, HOMO-LUMO energy gap, and ESP ensure the same. However, it is seen that the activity of the H2L3 molecule is higher than the other molecules to the ΔE energy gap value. The cardinal information about the NLO properties of the molecules has been studied where the nonlinear hyperpolarizability (β) of the three studied molecules was fortunately compared. The numerical values of H2L1 and H2L2 were very close, but the value of H2L3 was 1.5 times. Beyond the bounds, the first two molecules had lower dipole moments than H2L3. Theoretical IR/NMR calculations explore important assignments. Molecular docking (MD) examines the activities of molecules against biological materials that are breast cancer protein (PDB ID: 1A52), liver cancer protein (PDB ID: 2JW2), and prostate cancer protein (PDB ID: 3A99). The theoretical drug properties have been investigated in-depth so they can be used as drugs by ADME/T analysis. The prepared compounds were screened in vitro against two grams + ve and two-gram −ve bacterial strains using the agar well diffusion method. MIC determines the good antibacterial activity of the compounds. The MIC values ​​for H2L1 range from 15.62 to 125 g/mL, while for H2L2, 31.25–500 g/mL, and for H2L3, 31.25–500 g/mL. Based on the MIC values, the tested compounds' potency order was H2L1 > H2L3 > H2L2. Eventually, the time-kill kinetics study led to promising bactericidal activities.

We clicked a salen ligand onto a thiol‐ethane bridged periodic mesoporous organosilica (Salen‐PMO) using a photo‐initiated thiol‐ene click reaction. This process resulted in a covalently bonded salen ligand on the PMO material. The final BET surface area amounts 511 m2/g and the pore size diameter is approximately 7 nm. The functionalized PMO material showed an excellent carbon dioxide uptake capacity of 1.29 mmol/g at 273 K and 1 bar. More importantly, by coordinating a MoO22+ complex onto the Salen‐PMO material, we obtained a heterogeneous catalyst with a good catalytic performance for the epoxidation of cyclohexene. The catalyst was highly reusable, as no decrease in its activity was observed for at least four runs (99% conversion). Finally, the metal‐free Salen‐PMO showed an exceptional catalytic performance in the cycloaddition of CO2 to epoxides. The obtained results clearly demonstrate the versatility of the Salen‐PMO material not only as metal‐free catalyst but also as a support material to anchor metal complexes for specific catalytic applications. With the same catalytic platform, we were able to firstly create epoxides out of alkenes, and subsequently turn these epoxides into cyclic carbonates, consuming CO2. [ABSTRACT FROM AUTHOR]

[Display omitted] • An X-ray characterized heteronuclear complex [Ni 2 (L)Pb(μ-1,3-SCN) 2 (H 2 O)] 2 was synthesized. • Compound molecular geometry was optimized employing the B3LYP/-31+G (d, p) level of theory. • Crystal structure explored supramolecular contacts substantiated by HS/2-D fingerprint plots. • As-synthesized complex fabricated a device like photosensitive Schottky barrier diode (PSBD). • An experimental and DFT/DOS/PDOS/OPDOS plots rationalizes the SBD function. This research article explores the synthesizing, structural characterizing, and photosensitive Schottky diode behaviour (PSBD) of one new hetero-nuclear Ni(II)/Pb(II)-Salen complex, [Ni 2 (L)Pb(μ-1,3 - SCN) 2 (H 2 O)] 2. The complex utilizes various analytical methods for characterization purposes, including single-crystal X-ray diffraction (SCXRD). Crystals have formed in the monoclinic space group P 2 1 / n within the compound. The complex asymmetric unit contains a deprotonated ligand (L2−), two Ni(II), one Pb(II), two SCN− ions, and Ni(II) metal coordination by H 2 O molecule. The crystallographic structure has octahedral and see-saw geometries around the Ni(II) and Pb(II) metal ions. The crystal structure reveals remarkable supramolecular interactions, with significant S⋯H contacts (13 %) evident from the Hirshfeld surface (HS) and 2-D fingerprint plots. The calculated optical band gap (3.14 eV) and UV–Visible measurement support the semiconductor behaviour. In addition, the compound shows electrical conductivity and photosensitivity (dark & light), suggesting potential applications in optoelectronic devices. The complex transports charge through space via a hopping process. The extensive experimental investigations indicate that exposure to visible light increases electrical conductivity compared to dark conditions, popularly known as PSBD behaviour. The complex conductivity function substantiates the DFT-based DOS, PDOS, and OPDOS plot analysis. Therefore, the heteronuclear complex has been successfully used in thin-film active devices despite technological challenges. [ABSTRACT FROM AUTHOR]

[Display omitted] • 6-Bromo-2-hydroxy-3-methoxybenzaldehyde involving Cu(II)-Hg(II) complex, was synthesized. • HSA, ESP, Fukui function, NLO, and Global parameters were successfully analysed. • The electron/electron cloud of the Br atoms determines dispersion energy in the complex. • The MD/PLIP methods were employed to explore the effectiveness of antimicrobial efficacy. This article vividly describes the synthesis and structural characterization of one 6-Bromo-2-hydroxy-3-methoxybenzaldehyde ligand involving heteronuclear complex, [Cu(L)Hg(Cl) 2 ]. X-ray single-crystal determined the complex crystal structure and characterized it by various physical methods, including elemental, FT-IR, Raman, PXRD, UV–vis, NMR, and SEM-EDX techniques. X-ray diffraction analysis reveals that the compound adopts a monoclinic space group C c during crystallization. The crystal structure exhibits unique supramolecular interactions, like intermolecular C-H∙∙∙π H-bonding and X-bonding (X = Halogen) between Br(1) and Br(2) atoms. Hirshfeld surfaces (HS) and 2-D fingerprint plots confirm significant H...Cl (21.9 %) contacts. Further, dispersion energy dominates due to Br atoms' higher electron/electron cloud. The complex underwent DFT calculations based on the Gaussian software package at B3LYP, HF, and M062x levels, utilizing the lanl2dz, sdd, and def2tzvp basis sets. The HOMO-LUMO, ESP, Global reactivity, Interaction energy and energy frameworks, and Fukui function investigated the complex properties in a multidimensional spectrum. The complex showed promising NLO activity, which has broad technological applications. Fukui function calculation identifies regions prone to nucleophilic (Nu-) and electrophilic (E+) attacks. The complex and synthetic components were examined for antimicrobial function against Gram+ve and Gram-ve bacterial and fungal strains. Molecular docking (MD) and Protein-Ligand Interaction Profilers (PLIP) further support the antimicrobial findings. [ABSTRACT FROM AUTHOR]

The crystal structure of the title complex (systematic name: trans-aquachlorido{2,2′[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolato-κ4O,N,N′,O′}manganese(III) monohydrate), [Mn(C16H14N2O2)Cl(H2O)]·H2O has been reported previously in the space group P21/n [Panja et al. (2003). Polyhedron, 22, 1191–1198]. We obtained the same hydrated complex through an alternative synthesis, and crystallized a new polymorph, in the space group P21. The molecular conformation of the complex is virtually unmodified, but the absence of the glide plane in the new polymorph halves the unit-cell parameter c, affording a non-centrosymmetric crystal structure with Z = 2, while the previously reported crystal is centrosymmetric with Z = 4. Both phases represent a case of packing polymorphism, similar to other dimorphic crystal structures retrieved from the Cambridge Structural Database.

The article divulges the crystal growth, synthesis, and X-ray structure characterization of one centrosymmetric cadmium complex, [Cd{CdL(μ 2 -1,3-acetate)} 2 ] using Salen ligand (SL). The complex is further characterized using spectroscopic and analytical techniques, including DRS, SEM-EDX, PXRD, and ICP-MS. The crystallographic study showed that the complex has a monoclinic space P 2 1 / c . Addison parameters (Ʈ) show the hexagonal geometry of the central Cd(II) metal ion. Hirshfeld surface and 2-D fingerprint confirm supramolecular contacts despite weak C-H⋯O and C-H···π interactions. Energy frameworks, FMOs, global reactivity parameters, MEP, and energy bandgap explain the complex reactivity outlook. The complex inter- and intramolecular bonding interactions were explored through natural bond orbital (NBO), QTAIM, NCI-RDG, Electron Location Function (ELF), and Localized Orbital Locator (LOL) quantization methods. In addition, the complex and its synthetic components in vitro antibacterial efficacy were investigated using Gram-positive and Gram-negative microbial strains. SAR ( structure-activity relationship ) correlates with biological potency. Molecular docking assessed antimicrobial potency with proteins S. aureus (PDB ID: 1JIJ), C. albicans (PDB ID: 1M7A), E. coli (PDB ID: 1T9U), P. aeruginosa (PDB ID: 2UV0), and A. Niger (PDB ID: 3K4P). The findings are backed by the Protein-Ligand Interaction Profiler (PLIP). The antifungal potency and cell viability test of C. albicans were conducted using photodynamic therapy (APDT)., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Dr Dhrubajyoti Majumdar reports administrative support, equipment, drugs, or supplies, and statistical analysis were provided by Tamralipta Mahavidyalaya Department of Chemistry. Dr Dhrubajyoti Majumdar reports a relationship with Tamralipta Mahavidyalaya that includes: board membership, employment, and non-financial support. None has patent Not applicable pending to Not applicable. All the authors declared no conflicts of interest or personal relationships that could have influenced the current research work. Further, no author serve as an editorial capacity for the journal like Dr Dhrubajyoti Majumdar and Dr Sourav Roy. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Published by Elsevier Ltd.)

The tetradentate salen ligand derived from (±)-trans-1,2-diaminocyclohexane and 2-hydroxy-4-dimethylaminobenzaldehyde is prepared and its complexes with Co(II), Cu(II), Ni(II), and Pd(II) are synthesized. The ligand is fully characterized by FTIR, 1H and 13C NMR and mass spectrometry. Structures of the metal complexes are determined by single crystal X-ray diffraction. With the exception of the Co complex that crystallizes in the monoclinic system (space group P21/c), all the other complexes crystallize in the triclinic system with the space group P-1. All the complexes have slightly distorted square planar geometries. The ligand and the metal complexes are screened for their in vitro anticancer activity against the human breast cancer cell lines MCF-7 and T47D. In comparison with the uncomplexed ligand, the cobalt complex shows a marked antiproliferative effect. [ABSTRACT FROM AUTHOR]

This work synthesizes a four‐coordinate Cu(II) complex {[CuII(LNH2)]; 1} of the tetradentate H2LNH2 ligand. The synthesized complex acted as an electrocatalyst for the CO2 conversion towards C1 and C2 products by activating the stable C−O bond. The catalyst ink (complex 1+DMF+Nafion; catalyst concentration ∼2 mg cm−2) was surface‐coated over the graphite plate to carry out the reduction reaction in a three‐electrode electrochemical system. An H‐type electrolyzer was employed in 0.5 M KHCO3 electrolyte solution at neutral pH in the carbonated system. A maximum amount of 36 % FE was achieved at −1.80 V vs. Ag/AgCl for 60 min of reaction. The total TON and TOF of the catalyst were calculated to be 9230 and 2.6 s−1, respectively. The CO2‐reduced products were obtained as HCOOH>CH3COOH>CH3OH>C2H5OH, which were formed through multiple–electrons transfer (2 e− to 12 e−) proton‐insertion reactions. The catalytic activity of the Cu(II) complex was enhanced by the presence of the terminal ‐NH2 anchoring‐group in the ligand backbone. The fact was confirmed by electrocatalytic CO2 conversion experiments in the presence of complex 2 {[CuII(L)]; 2} as the electrocatalyst, which did not contain the anchoring group in the salen ligand structure. [ABSTRACT FROM AUTHOR]

The title compounds, C23H21ClN2O2, differ from each other only by the position of the Cl atom on the corresponding benzene ring: meta relative to the central sp3 C atom for (I) and para for (II). In (I), the hydroxyphenyl rings are almost parallel, the dihedral angle between the mean planes being 9.2 (2)°, but in (II), the relative position of the ring is different, characterized by a dihedral angle of 48.5 (1)°. Compound (I) features intramolecular O—H...N and intermolecular C—H...O hydrogen bonds, while in (II), intramolecular O—H...N, C—H...N hydrogen bonds and weak intermolecular C—H...π interactions are observed. Compound (I) was refined as an inversion twin.

The crystal structure of the title complex (systematic name: trans-aqua­chlorido­{2,2′[ethane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolato-κ4O,N,N′,O′}manganese(III) monohydrate), [Mn(C16H14N2O2)Cl(H2O)]·H2O has been reported previously in the space group P21/n [Panja et al. (2003). Polyhedron, 22, 1191–1198]. We obtained the same hydrated complex through an alternative synthesis, and crystallized a new polymorph, in the space group P21. The mol­ecular conformation of the complex is virtually unmodified, but the absence of the glide plane in the new polymorph halves the unit-cell parameter c, affording a non-centrosymmetric crystal structure with Z = 2, while the previously reported crystal is centrosymmetric with Z = 4. Both phases represent a case of packing polymorphism, similar to other dimorphic crystal structures retrieved from the Cambridge Structural Database. [ABSTRACT FROM AUTHOR]

Abstract Two three-dimensional metal-organic frameworks {CdNa 2 (H 2 O) 2 (DMF)[(ML) 2 Na(H 2 O) 2 ]}·6H 2 O (L = C 22 H 18 N 2 O 6 ; M = Ni 1 , Cu 2) based on carboxylate-functionalized salen ligands were successfully synthesized by one-step synthesis of reacting 1,2-cyclohexanediamine- N , N ′-bis-(3-carboxylsalicylide) (H 4 L) with metal acetate. Both of them were characterized by single-crystal X-ray diffraction, powder X-ray diffraction (XPRD), elemental analysis, TG analysis, IR and UV–visible spectroscopy. X-ray Single-crystal structural analysis reveals that compounds 1 and 2 are isostructural, which display a 3D porous framework constructed by infinite [CdNa 2 (H 2 O) 2 (DMF)(COO) 4 ] n chains as nodes and [(ML) 2 Na(H 2 O) 2 ] (M = Ni 1 , Cu 2) units as linkers. They present the first examples of metal-salen-based MOFs constructed by heterometallic inorganic node. In addition, magnetic studies indicate that ferromagnetic interactions exist in compound 1. Graphical abstract Two metal-organic frameworks 1 and 2 based on carboxylate-functionalized salen ligands were successfully obtained by one-step synthesis. 1 and 2 are isostructural, which display a porous framework constructed by infinite [CdNa 2 (H 2 O) 2 (DMF)(COO) 4 ] n chains as nodes and [(ML) 2 Na(H 2 O) 2 ] (M = Ni 1 , Cu 2) units as linkers. Unlabelled Image Highlights • Compounds 1 and 2 present the first examples of metal-salen-based MOFs constructed by heterometallic inorganic node. • Compounds 1 and 2 were obtained by one-step synthesis without the preparation of “metalloligand” in advance. • Magnetic studies indicate that ferromagnetic interactions exist in compound 1. [ABSTRACT FROM AUTHOR]

The title compounds, C23H21ClN2O2, differ from each other only by the position of the Cl atom on the corresponding benzene ring: meta relative to the central sp3 C atom for (I) and para for (II). In (I), the hy­droxy­phenyl rings are almost parallel, the dihedral angle between the mean planes being 9.2 (2)°, but in (II), the relative position of the ring is different, characterized by a dihedral angle of 48.5 (1)°. Compound (I) features intra­molecular O—H···N and inter­molecular C—H···O hydrogen bonds, while in (II), intra­molecular O—H···N, C—H···N hydrogen bonds and weak inter­molecular C—H···π inter­actions are observed. Compound (I) was refined as an inversion twin. [ABSTRACT FROM AUTHOR]

The silicon (IV) compounds possessing SiNO ( 6), SiNOC ( 7, 8), SiNOCCl ( 9) and SiNO ( 10) coordinating frameworks have been synthesized in high yield by the reaction of the O,N,N,O- donor salen-type ligand N,N'-bis(salicylidene)ethylenediimine L with different silanes i.e. diethoxydiisocyanatosilane-(CHO)Si(NCO) 1, dichlorodiphenylsilane-PhSiCl 2, dichloromethyl- phenylsilane-MePhSiCl 3, trichlorophenylsilane-PhSiCl 4 and silicon tetrachloride-SiCl 5. The compounds 6- 10 have been characterized by elemental analysis, IR, H, C and Si NMR and mass spectrometry. The decomposition reactivity of these compounds has been studied using a Thermal Gravimetric Analyzer (TGA) at a heating rate of 10°C/minute in an inert atmosphere. [ABSTRACT FROM AUTHOR]

The syntheses, structures and photoluminescence properties are reported for two new binuclear cyclometalated iridium(III) complexes, [Ir 2 (ppy) 4 (L)] ( 1 ) and [Ir 2 (F 2 -ppy) 4 (L)] ( 2 ) (ppy=2-phenylpyridine, F 2 -ppy = 2-(2,4-difluorophenyl)pyridine, H 2 L=N,N′-bis(2-hydroxynaphthyl methylidene)-2-hydroxy-1,3-propanediamine. X-ray crystal diffraction shows that L ligands adopt a tetradentate mode to bridge ir(III) ions to form binuclear structures. There are π-π stacking interactions between the binuclear structures, which results in the formation of 3D supramolecular networks. UV–vis absorption spectra and photoluminescence spectra show that the introduction of F − groups in the benzene rings of ppy ligands causes blue shift. [ABSTRACT FROM AUTHOR]

• A unique complex [(SCN)Cd(L1)Pb(NCS)] n was synthesized using N 2 O 4 ligand and characterized. • Crystal engineering discloses tetrel bonding, and QTAIM/NCI plot reveals it. • The complex detects TNP with high selectivity and sensitivity in a dispersed aqueous medium. • The Fluorescence mechanism, LOD, and K SV were determined using the Stern-Volmer equation. • The quenching mechanism was rationalized by (a) AIM/RDG, (b) PET/FRET, and (c) 1H NMR titration. A new 1D coordination polymer (CP), [(SCN)Cd(L1)Pb(NCS)] n (1) was synthesized using N 2 O 4 -based Scaffold (H 2 L1 = N, N'-bis(3-methoxysalicylidenimino)-1,3-diaminopropane) and structurally characterized using various analytical instruments. X-ray structure disclosed complex (1) crystallize in the Orthorhombic space group P2 1 2 1 2 1 with Z=4. The crystal structure contains heteronuclear units of [(SCN)Cd(L1)Pb(NCS)] n , linked by a μ 1,1,3 thiocyanate (SCN−) bridging. Here weak S···S chalcogen, Pb···S tetrel bonding with two C-H···π(SCN) and one C-H···π(arene) like interactions are vividly observed. The QTAIM/NCI diagram successfully explains the nature of these contacts. Hirshfeld surface (HS) and 2D fingerprint plots analysis has described the non-covalent supramolecular features. The H...H interactions dominate the solid-state crystal structure. The complex fluorescence behaviour is eventually quenched in the presence of explosive nitroaromatic compounds. Complex (1) retained high fluorescence sensitivity and selectivity only for organo-toxin trinitrophenol (TNP). The Stern-Volmer equation evaluated the enhancement of the fluorescence mechanism, the limit of detection (LOD), and the quenching constant (K SV), which for TNP is 6.92 × 104 M−1. The turn-off fluorescence sensing mechanism is explained by (a) AIM/RDG surface interactions energy, (b) Charge-transfer complex, (b) Photo-induced electron transfer (PET) through the HOMO-LUMO approach, (c) Fluorescence resonance energy transfer (FRET), and (d) 1H NMR titration. Notably, the active dynamic sensing is due to a decrease in fluorescence lifetime after the successive addition of TNP with the polymer. Finally, the title complex (1) is employed as a quenched fluorescence response sensor for detecting TNP in a dispersed aqueous medium. [Display omitted] [ABSTRACT FROM AUTHOR]

In this article, we have synthesized two contemporary ortho-vanillin-based Salen-type ligands (H 2 L 1 /H 2 L 2 ) characterized by modern spectroscopic tools. EDX analysis supports the elemental composition (C, N, O, and Br). SEM examined the morphology of the synthesized compounds. The molecular geometry was optimized in the gas phase using B3LYP-D3/6-311G (d, p) level. The global reactivity parameters, HOMO-LUMO energy gap (Δ), atomic properties, MESP, and ADME/T, vividly explore the chemical reactivity and toxicity of two Salen-type ligands. The DFT simulated IR/NMR characterized essential structural assignments, and UV-Visible spectra were employed to predict the optical properties. The article demonstrated in silico molecular docking against the Gm + ve Bacillus subtilis (6UF6), and Gm -ve Proteus Vulgaris establishes the ligand binding ability with essential amino acids through conventional H-bonding or other significant interactions. The docking simulation is compared for two compounds better than the control drugs and confirms the antimicrobial activity. The theoretical drug-like properties have been explored in-depth by ADME/T using the SWISSADME database. The analysis estimated the molecule's lipophilicity, the consensus P0/W, and water solubility. Thus, using various pharmaco-logical parameters, toxicity explains where the electron-withdrawing Br group plays a more toxic effect in H 2 L 2 than in H 2 L 1 ., Competing Interests: The authors declare no competing interests or personal relationships that could have appeared to impact the work reported in this paper., (© 2023 The Author(s).)

Much attention has recently focused on helical structures that can change their helicity in response to external stimuli. The requirements for the invertible helical structures are a dynamic feature and well-defined structures. In this context, helical metal complexes with a labile coordination sphere have a great advantage. There are several types of dynamic helicity controls, including the responsive helicity inversion. In this review article, dynamic helical structures based on oligo(salamo) metal complexes are described as one of the possible designs. The introduction of chiral carboxylate ions into Zn3La tetranuclear structures as an additive is effective to control the P/M ratio of the helix. The dynamic helicity inversion can be achieved by chemical modification, such as protonation/deprotonation or desilylation with fluoride ion. When (S)-2-hydroxypropyl groups are introduced into the oligo(salamo) ligand, the helicity of the resultant complexes is sensitively influenced by the metal ions. The replacement of the metal ions based on the affinity trend resulted in a sequential multistep helicity inversion. Chiral salen derivatives are also effective to bias the helicity; by incorporating the gauche/anti transformation of a 1,2-disubstituted ethylene unit, a fully predictable helicity inversion system was achieved, in which the helicity can be controlled by the molecular lengths of the diammonium guests.

In this work, we revisited the disassembly approach (also known as the Zelder's approach) recently proposed for sensing pyrophosphate (PPi) in water and based on the decomposition of metal-salen complexes. A systematic study devoted to the structural optimization of this novel class of PPi-responsive fluorogenic probes was conducted. Screening of eight different vicinal diamines (i.e. , bridge of the salen ligand) combined with the use of 8-formyl-7-hydroxycoumarin (i.e. , salicylaldehyde derivative) as the fluorescent reporter, has led to a set of novel and fully characterized coumarin-salen Fe(III) complexes. A series of analytical validations helped us to identify that coumarin-salen Fe(III) complexes derived from ethylenediamine and racemic 1,2-propylenediamine backbones exhibit the best and selective PPi-sensing performances (the limits of detection were estimated as 3.15 × 10−6 M and 2.81 × 10−6 M respectively). The implementation of both fluorescence time-course measurements and RP-HPLC-fluorescence analyses has enabled us to gain further insights into the activation mechanism of the disassembly-based probes. This study therefore demonstrates that the disassembly approach is a valuable strategy to achieve fluorogenic activity-based sensing of anions. [Display omitted] • A series of coumarin-salen Fe(III) complexes with various diamine bridges were synthesized. • Coumarin-salen Fe(III) complexes were used to detect pyrophosphate (PPi) through a fluorogenic disassembly approach. • Fe(III) complexes with ethylene- and 1,2-propylenediamine bridges offered the best performances. • Fe(III) complex with 1,2-propylenediamine bridge showed good selectivity and a limit of detection of 2.81 × 10-6 M. • Disassembly mechanism was deciphered by NMR and RP-HPLC-fluorescence analyses. [ABSTRACT FROM AUTHOR]

A novel binuclear phenoxo-bridged zinc complex obtained from the interaction of ligand, 2,2-(1E,1E)-(2,2-dimethylpropane-1,3-diyl)bis(azanylylidene) bis(methanylylidene)diphenol with zinc chloride is reported. The synthesized and isolated zinc complex has been characterized by FT-IR, 1 H- and 13 C- NMR, ESI-MS, TGA/DTA and single crystal X-ray diffraction studies. The phenoxo-bridge in this binuclear Zn(II) complex is due to the phenolic oxygen of the salen liagnd. The complex crystallizes in monoclinic P-1 space group, and different geometry has been assigned for both zinc ions in the complex. [ABSTRACT FROM AUTHOR]

A pair of chiral Eu(III) complexes prepared from enantiopure bis(1 H -pyridin-2-one)salen ligands show strong sensitized luminescence and high circular dichroism activity in the region of π–π ∗ transitions. [ABSTRACT FROM AUTHOR]

Two 1-D homometallic coordination polymers1and2have been prepared by one-step hydrothermal reactions of carboxylate-functionalized salen ligands with Co(II) and Mn(II), respectively. Single-crystal X-ray diffraction analyses reveal that both the 1-D chains give 3-D supramolecular structures through intermolecular hydrogen bonds and??packing interactions. Magnetic investigation of2indicates the presence of antiferromagnetic interactions in 1-D chains. [ABSTRACT FROM AUTHOR]

Two new structure-related pyrazolone-type Salen ligands, N,N′-ethylamine bis[1-(4-methoxy-phenyl)-3-methyl-4-benzoylimino-2-pyrazoline-5-ol](H 2 L I ) and N,N′-ethylamine bis[1-(4-methoxy-phenyl)-3-methyl-4-acetylimino-2-pyrazoline-5-ol](H 2 L II ) have been designed and synthesized with the ultimate aim of self-assembling novel Zn(II) compounds with interesting fluorescence properties. Reactions of Zn(OAc) 2 with the two ligands led to the formation of two new Zn(II) complexes with the formulae of [ZnL I (CH 3 OH)] ( 1 ) and [Zn 2 L II 2 ] ( 2 ), which have been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR spectroscopy and thermal gravimetric analysis. Mononuclear complex 1 with the pentacoordinated zinc(II) ion hosted into the N2O3 compartment crystallized in the monoclinic space group P 2 1 / c , while the hydroxyl-bridged dinuclear [Zn 2 L II 2 ] complex ( 2 ) with the pentacoordinated zinc(II) ion hosted into the N2O2 compartment crystallized in the monoclinic space group C 2/ c and had a Zn–O–Zn–O four-membered ring. The structure determinations show that substituted group at the 4,4′-position of the this kind of Salen ligands are important factors influencing the crystalline array. The fluorescent properties of the two compounds at ambient temperature both in solid state and solution were also investigated. The results provided interesting insights into ligand effects on the structures and fluorescent properties of zinc(II) coordination complexes. [ABSTRACT FROM AUTHOR]

A highly selective fluorescent chemosensor for aluminum(III) ions, N,N′-bis(2-hydroxy-1-naphthaldehyde)-l,2-phenylenediamine (H 2 L) was synthesized and characterized. When aluminum(III) ions are added to H 2 L solution in DMF, the solution exhibits two remarkably enhanced emissions at 517 and 540 nm, which could not be observed with other metal ions. The results of 1 H NMR titration, MALDI-TOF-MS and DFT studies indicate that H 2 L and aluminum(III) ions form a 1:1 complex. The association constant K a was determined to be 2.67 × 10 6 and the limit of detection (LOD) was calculated to be 10 −6 M. The sensing mechanism can be explained by the photoinduced electron transfer (PET). [ABSTRACT FROM AUTHOR]

Complexation of N,N′-ethylene- and N,N′-butylene-bis(salicylideneiminato)cobalt(II) (Co(salen)) with nitrogen-containing heterocyclic ligands (pyridine, imidazole) and investigation into the mechanism responsible for the spin crossover behavior of these complexes have been computationally studied using the DFT B3LYP*/6-311++G(d,p) method. The results of calculations of geometric characteristics and energy parameters are in good agreement with an available experimental data. An addition of a base molecule to Co(salen) has been shown to be accompanied by the narrowing of the energy gap between the high-spin and the low-spin electronic states up to the values typical for spin crossover cobalt complexes. According to the calculations, the energy barrier of spin-forbidden rearrangement of a monoadduct of N,N′-butylene-bis(salicylideneiminato) Co(II) with pyridine does not exceed of 6 kcal/mol. This finding allows one to consider the adducts of Co(salen) with nitrogen-centered ligands as the prospective spin crossover systems. The computational investigation into the spatial and electronic structure of N,N′-butylene-bis(salicylideneiminato) Co(II) dimer predicts the simultaneous existence in a crystal cell of two types of molecules with different metal spin states. [ABSTRACT FROM AUTHOR]

Abstract: The one-pot reaction of (1S,2S)-(+)-1,2-diaminocyclohexane, 3-tert-butyl-2-hydroxybenzaldehyde and Zn(OAc)2·1.5H2O in methanol under reflux gives the diastereoselective formation of the first zinc(II)-salen double helicate, P-(S, S)-1, which adopts a right-handed helicity. The stereochemistry of the helicates can be readily tuned through varying the chiral diamine backbone. [Copyright &y& Elsevier]

Polymerizations of 1-octene were carried out in the presence of vanadium and titanium complexes bearing salen-type or phenoxyimine ligands activated with various co-catalysts. Vanadium complexes turned out active only in conjunction with MAO, whereas the titanium ones were active in combination with Al( i-Bu)/PhCB(CF). The activity of all catalysts was moderate or low and it was dependent on the ligand type: bis(phenoxyimine) complexes were more active than the salen ones. Both vanadium and titanium catalytic systems produced poly(1-octene)s possessing atactic structures with [ mmmm] sequences in the range from 12 to 56 % at room temperature. A temperature decrease to 0.5 °C for the reaction catalyzed by the vanadium catalyst led to poly(1-octene) of [ mmmm] = 70 %. The H NMR analysis showed that unsaturated end groups were present in poly(1-octenes) which were introduced to the polymer chains as a results of various chain transfer reactions. In case of vanadium catalysts, vinylidene and vinylene end groups were present in polymer products. For titanium catalyst, vinyl and tri-substituted unsaturated groups were present in poly(1-octenes) in addition to the end groups as mentioned before. [ABSTRACT FROM AUTHOR]

The chiral ligand synthesized from L-diphenylvalinol and salicylaldehyde is found to catalyse the asymmetric Henry reaction with copper(II)acetate monohydrate. Various nitroaldols were formed with 77-95% ee and good yield. The mechanism for the formation of a particular enantiomer is also discussed. The enantioselection in the formation of the chiral nitroaldol is discussed in terms of steric bulkiness of the catalytic system. [ABSTRACT FROM AUTHOR]

Abstract: Two dimeric chiral (pyrrolidine salen)Mn(III) complexes 3 and 4 were prepared, in which the two (pyrrolidine salen)Mn(III) units are linked either by a p-xylylene or by a p-phthalyl bridge. High yields were attained for asymmetric epoxidation of styrene and substituted chromenes at 0.5–4.0mol% catalyst loading of 3 and 4 using NaClO/PPNO and m-CPBA/NMO as oxidant systems, with 37–39% ee for styrene and 86–95% ee for substituted chromenes. Dimeric complexes 3 and 4 displayed higher activities than their parent monomeric complexes 1 and 2 of double equiv for epoxidation of substituted chromenes. Complex 3 bearing two tertiary amine units displayed considerably higher activity than analogous dimeric complex 4 containing two carboxamide units in the aforementioned reaction. The effect of excess CH3I on the epoxidation of 6-nitro-2,2-dimethylchromene catalysed by 3 in the aqueous/organic biphasic medium was explored. The recovery and recycling possibilities of the dimeric complexes 3 and 4 were studied. [Copyright &y& Elsevier]

We report the synthesis of a covalently linked complex that mimics the salen ligand within the main chain of the polyimide network. The thermally-stable solid polyimides offer suitable sites for metal coordination, which is a crucially important step in establishing steroselectivity. The ligand synthesized by the sequential treatment of a chiral trans-1,2-diaminocyclohexane and p-dimethylaminobenzaldehyde was used to prepare polyimides by a one-step polymerization in the dipolar media. A series of stable polyimides was synthesized from (1S,2S)- and (1R,2R)-bis(p-dimethylaminobenzylideneamino)-1,2-cyclohexyl and various aromatic dianhydrides had inherent viscosities ranging from 1.45 to 2.21 dl/g and were soluble in polar solvents. The glass transition temperatures were 264–319°C, and the 10% weight loss temperatures were above 406–487°C. [ABSTRACT FROM AUTHOR]