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The Mannich base ligand was synthesized in an ethanol medium through a condensation reaction of 2-mercaptobenzimidazole and ciprofloxacin at room temperature. Subsequently, several metal complexes of this ligand were prepared. To characterize both the base ligand and the metal complexes, various techniques were employed, including elemental analysis, FT-IR spectroscopy, UV-Vis spectroscopy, molar conductivity measurements, magnetic moment determination, and melting point analysis. The results were shown that the metal complexes formed have the formula [Cr(L)2Cl2] Cl.H2O and [Rh(L)2(H2O)2] Cl3.H2O, where L= mannich base ligand. Based on spectroscopic analytical, coordination with metal ions involves the 'N' donor atom of mannich base and 'N' atom of piprizaing ring, and two complexes are A six-coordinated octahedral structure is suggested. Molar conductivity of these complexes showed that they were electrolytic in nature. In this study, the anticancer and antioxidant potential of the Mannich base ligand and its metal complexes were investigated against MDA-MB-231 cell lines and using the DPPH free radical scavenging assay. Moreover, the in vitro efficacy of the ligand and its complexes against Gram-negative bacteria (E. coli) and Gram-positive bacteria (Staphylococcus aureus), as well as the fungal strain Candida albicans, was evaluated using the disc diffusion method. The results indicated that Cr (III) and Rh(III) complexes demonstrated the highest levels of cytotoxicity against MDAMB-231 cell lines, enhances antioxidant and antimicrobial activity more than the free ligand. These findings suggest that these metal complexes may have promising applications in the development of novel anticancer, antioxidant and antimicrobial agents. [ABSTRACT FROM AUTHOR]

Schiff base labeled as H2L1 was synthesized, which was derived from pyridine-2,6-diamine and 2-hydroxynaphthaldehyde. Types of complexes [ML]Cl2 and [ML(py)2]Cl2, were formed with Co2+, Ni2+, Cu2+, and Zn2+. Additionally, adduct complexes [ML(py)2] were prepared in a ratio of 2:1. Diverse analytical techniques, elemental analyses, (FT-IR, UV-Vis, 1H NMR), conductance measurements, and magnetic susceptibility, were employed to characterize these complexes and adducts. The data acquired validated that the ligands donor atoms act as (ONNO) tetra-dentate bibasic chelating ligands with metal ions. Depending on spectral and magnetic measurements, the suggested shapes of these complexes were reported to be either tetrahedral/octahedral in geometry. Density functional theory (DFT) was used to get some theoretical data about the generated complexes. The data obtained includes the energy of the highest and lowest occupied molecular orbitals (HOMO and LUMO), electron density, ionization potential (IP), electron affinity (EA), electronegativity (En), electrophilicity (), chemical hardness (, and dipole moment (µ). Different characteristics of the complexes have been investigated and explained based on these studied parameters. The molecular docking of target microorganisms of these complexes will be studied. The interaction of DNA gyrase 4ckk with the compounds visualized by LigPlot software. [ABSTRACT FROM AUTHOR]

Ni(II) metal complex of Schiff base (SB) ligand 2-methoxy-4-[(4-nitrophenyl) iminomethyl]phenol (MNIMP); derived from vanillin and 4-nitroanilline was synthesized in 1:2 M:L by refluxing solution containing metal salt (NiCl2.6H2O, 97.0%) and SB in ethanol and characterized based on powder (XRD), NMR, FT-IR, UVVis spectrophotometer, and physicochemical measurements. The FT-IR spectra revealed that the complex is coordinated through azomethine nitrogen and phenolic oxygen of the bi-dentate ligands. The chemical shift d = 9.8 ppm in 1H-NMR of SB; corresponds to the azomethine proton of the ligand suggesting the presence of -C=N- linkage and 13C-NMR confirms the presence of 14C in the ligand and the complex. The shift to a lower wavelength of UVVis spectra of the complex compared to the ligand signifying complex formation. The powder (XRD) pattern put forward the crystalline phase of the complex through nickel(II) occupying the center of octahedron geometry. The higher molar conductance value of the complex confirms its electrolytic nature. In-vitro antibacterial activities for synthesized compounds have been evaluated towards human pathogenic microbes Staphylococcus aureus and Escherichia coli and compared with standard, gentamicin. The result demonstrated that Ni(II) complex; [Ni (MNIMP)2(H2O)2]Cl2 has greater zone of inhibition against the tested organism than free MNIMP ligand as antibacterial agent. [ABSTRACT FROM AUTHOR]

A series of rare earth alkoxides bearing amine‐bridged bis(phenolato) ligands were synthesized through sequential reactions of RE(C5H5)3(THF) (RE = Y, Lu) or Nd[N(SiMe3)2]3 with bis(phenols) LH2 and CF3CH2OH. Complexes REL(OCH2CF3)(THF)n (1–6) bearing different aryl‐substituents were obtained in good yields of 59–70 %. They were applied in the ring‐opening polymerization (ROP) of rac‐β‐butyrolactone (rac‐BBL), which showed good activity (TOF up to 27,300 h−1), resulting in syndiotactically enriched poly(3‐hydroxybutyrate) (PHB) (Pr up to 0.86) with narrow polydispersities (PDI ≤ 1.27). The yttrium complex 3 bearing bulky o‐1,1‐diphenylethyl substituents outperformed other complexes, suggesting that the smaller ionic radii of metal centers and bulky ortho substituents of ancillary ligands play crucial roles in controlling the activity and stereoselectivity in ROP of rac‐BBL. Kinetics of the polymerization of rac‐BBL initiated by complex 3 was investigated, which revealed first order dependences on the monomer and initiator concentrations, respectively. [ABSTRACT FROM AUTHOR]

Nowadays, the dilemma of drug resistance to antibacterial strains is of huge concern. Among the bacteria, Escherchia coli (E. coli) is the major pathogen, which is found in human and other animals. It is responsible for variety of severe diseases. A variety of commonly used antibiotics such as amoxicillin, gentamycin, etc and fluid replacement method are the suggested treatments for the infections caused by E. coli. In a study, it was established that the metal-based heterocyclic drugs demonstrated a different mode of action compared to the commonly used heterocyclic antibacterial drugs. Coumarin, an oxaheterocycle, is a privileged scaffold in medicinal chemistry. Metal complexes of coumarin-derived Schiff's bases exhibit a broad range of pharmacological activities. Therefore, in the present review article, we have focused on the synthesis of metal complexes of coumarin derived Schiff's bases as well as their respective Schiff's base ligands and their antibacterial activities against the gram-negative bacterium E. coli. [ABSTRACT FROM AUTHOR]

[Display omitted] Chromatography–mass spectrometry of samples representing the interaction products of ferrocene, radical initiator and monomer taken in the molar ratio of 1:2:10 in toluene solution was used for experimental detection of products indicating the structure and mechanism of formation of metal complex active centers of radical-coordination polymerization. Structures similar to those proposed by the quantum-chemical modeling were demonstrated to be formed with the participation of secondary radicals. [ABSTRACT FROM AUTHOR]

Metal complexes have a significant impact on the treatment of human cancer. However, the scarcity of these compounds, resulting from their limited synthesis, hinders the comprehensive investigation of their anticancer mechanisms. Organic palladium compounds, known for their distinctive stability and properties, are thus an essential area of research in the development of anti‐tumor therapy. In our study, we synthesized two novel ferrocene cyclopalladated compounds (C2 and C4). Its configuration was thoroughly characterized by employing 1H, 13C NMR, ESI‐MS, and elemental analysis techniques. The molecular structures were determined by X‐ray single‐crystal diffraction. In an in vitro anticancer study, it was observed that both C2 and C4 exhibited excellent suppression of viability in various tumor cell lines. These compounds showed better potency than cisplatin and demonstrated lower toxicity in normal cells. Particularly, C4 displayed approximately 22 times greater potency than cisplatin in suppressing melanoma cells (B16F10). Our study suggests that ferrocene cyclopalladated compounds have the potential to be promising candidates for the development of innovative anticancer drugs. [ABSTRACT FROM AUTHOR]

The reaction of N‐(4‐methyl‐2‐pyridinyl)‐P,P‐diphenylphosphinous amide ligand 4‐Me‐C5H3N‐2‐NH(PPh2) (1) with M(CO)6 (M=Cr, Mo, W) in refluxing toluene afforded a mononuclear group VIB metal tetracarbonyls [M(CO)4{1‐κ2P,N}] (M=Cr(2), Mo(3), W(4)). Complexes 2–4 were characterized by multinuclear NMR (1H, 13C and 31P NMR) and IR spectroscopy, and their structures were also determined by single crystal X‐ray diffraction. 2 and 4 represent the first examples of structurally characterized complexes of such ligands with group 6B metal carbonyls. [ABSTRACT FROM AUTHOR]

AAZTA (6-amino-6-methylperhydro-1,4-diazepinetetraacetic acid) is a mesocyclic chelating agent forming stable complexes with several metal ions. Over the past 20 years since its inception, AAZTA and its bifunctional derivatives have gained a growing role in several applications ranging from MRI contrast agents to diagnostics and nuclear medicine. The recent market restrictions applied to nitroethane preclude the easy preparation of AAZTA, prompting the search for a suitable alternative. In this work, we report the synthesis of two structural analogs (AAZTA-Bn and AAZTA-Et) from commercially available chemicals and the thermodynamic and kinetic study of their complexing ability towards selected metal ions. A comparison of the complexing properties of AAZTA-Bn and AAZTA-Et with the former AAZTA allows us to identify the possible heir of this efficient chelating agent. [ABSTRACT FROM AUTHOR]

The capability of bis(dioxolene) ligands to access multiple redox states makes them ideal candidates to tune the electronic properties of metal complexes, for example to achieve valence tautomerism (VT). In this study, a family of dinuclear cobalt complexes have been isolated with the bridging bis(dioxolene) thean− ligand in the cat2−‐cat2−, cat2−‐SQ⋅− and SQ⋅−‐SQ⋅− states (cat2−=catecholate, SQ⋅−=semiquinonate): [{CoIII(tpa)}2(theacat−cat)](PF6)2 (1), [{CoIII(tpa)}2(theacat−SQ)](PF6)3 (2), and [{CoIII(tpa)}2(theaSQ−SQ)](PF6)4 (3) (theaH4=2,3,6,7‐tetrahydroxy‐9,10‐dimethyl‐9,10‐dihydro‐9,10‐ethanoanthracene, tpa=tris(2‐pyridylmethyl)amine). Multi‐technique analysis confirms that 1, 2 and 3 adopt low spin‐CoIII containing {CoIII‐cat‐cat‐CoIII}, {CoIII‐cat‐SQ‐CoIII} and {CoIII‐SQ‐SQ‐CoIII} states, respectively. Compound 1 undergoes thermally‐induced {CoIII‐cat‐cat‐CoIII} ⇌ {CoIII‐cat‐SQ‐CoII} VT in the solid‐ and solution‐states above 300 K, involving high spin‐CoII. This interconversion is contrary to expectations, as tpa typically stabilizes low spin‐CoIII‐catecholate. Compound 2 is mixed‐valence class II/II–III, indicating a localized electronic structure, with electron transfer faster than the EPR and solvent rearrangement timescales, but slower than the infrared timescale. Compound 3 exhibits strong antiferromagnetic exchange. The overlap between the dioxolene π‐orbitals in thean− increases the accessibility of the cat2−‐SQ⋅− state, resulting in VT for 1. This study demonstrates that thean− can be isolated in multiple oxidation states in metal complexes, which is promising for applications in magnetic materials. [ABSTRACT FROM AUTHOR]

This paper presents the results of obtaining new cobalt and zinc complexes based on dicyanophenoxy-substituted carboxypthalocyanine. The original method of synthesis and isolation of the compound is shown; its spectroscopic and photophysical characteristics are studied. Studies show the absence of aggregation processes in organic media for solutions of complexes in working concentration ranges. This shows the possibility of the practical application of structures as catalysts. The high catalytic activity of cobalt complexes with dicyanophenoxy-substituted carboxyphthalocyanine ligand in the conversion reaction of sodium diethyldithiocarbamate to disulfiram, which is an active component of drugs for the treatment of alcohol dependence, is determined. [ABSTRACT FROM AUTHOR]

A novel and efficient protocol for the microwave‐assisted synthesis of diversely substituted 2,2′‐bisbenzimidazol‐5,6′‐dicarboxylic acid (BIMCA) from the reaction of 3,4‐diaminobenzoic acid with oxalic acid has been developed, which proceeds through sequential nucleophilic addition and electrophilic substitution in accordance with the Philips method. The synthetic utility of this strategy was demonstrated by the concise, one‐pot synthesis of (BIMCA) and metal complexes. (BIMCA) with a [{Fe(salen)}2O] Schiff base ligand complex and new benzimidazole coordination compounds with double oxygen [(BIMCA){Fe(salen)}2] ligand complexes were obtained. The resulting [(BIMCA){Fe(salen)}2] ligand complex was then synthesized from Co(CH3COO)2.4H2O, Ni(CH3COO)2.4H2O and Cu(CH3COO)2.H2O heteronuclear complexes. The condensations proceed with good yield to give products that, in certain instances, are not readily attainable by conventional condensation techniques. The structures of the compounds were identified by Fourier‐transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), elemental analysis and magnetic susceptibility. The mutagenic potential of the synthesized chemicals was evaluated by the Ames test towards mutant Salmonella typhimurium strains TA98 and TA100. It was recorded that these chemicals had no mutagenic action. Also, antimicrobial activities were screened by broth microdilution test. It was seen that the minimum inhibitory concentration (MIC) against Klebsiella pneumoniae, Staphylococcus aureus and Staphylococcus epidermidis was 0.195 mg/mL, followed by a MIC value of 0.390 mg/mL against Escherichia coli and Salmonella typhimurium. [(BIMCA){Fe(salen)}2Co(II)] demonstrated significant antimicrobial activity against Proteus mirabilis and Staphylococcus aureus, with an MIC of 0.195 mg/mL, followed by an MIC of 0.390 mg/mL against Pseudomonas aeruginosa, K. pneumonia and Salmonella typhimurium. The antioxidant properties were examined using various chemical assays, and [(BIMCA){Fe(salen)}2O] and (BIMCA) exhibited greater 2,2'‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging ability, when compared with other compounds. Enzyme inhibitory effects were tested against acetylcholinesterase (AChE), amylase, butyrylcholinesterase (BChE) and tyrosinase. [(BIMCA){Fe(salen)}2Cu(II)] displayed the best AChE (IC50 0.51 mg/mL), BChE (IC50 0.51 mg/mL) and tyrosinase (IC50 1.52 mg/mL) inhibitory effects. Furthermore, molecular docking calculations were performed to gain insights into the interaction between [(BIMCA){Fe(salen)}2] and AChE, and between [(BIMCA){Fe(salen)}2Cu(II)] and amylase. Both compounds showed the potential inhibition of the protein targets. [ABSTRACT FROM AUTHOR]

Metal piano-stool complexes based on pyridinecarbothioamide (PCA) have shown promising antiproliferative and in vivo anticancer activity, in particular [Ru(cym)(p -F-PCA)Cl]PF6 (cym is η 6- p -cymene; plecstatin-1). The impact of modifications of the PCA and π-bound ligands on biological properties has been extensively investigated. Herein, we explored the influence of exchanging the chlorido ligand with the N -heterocycles 1-methylimidazole, 1-methylbenzimidazole and pyridine. In solution, an equilibrium between the protonated and deprotonated forms of the thioamide bond was observed, which was found dictated by the solvent system with both species detected in polar solvents. [Ru(cym)(PCA)Cl]+ complexes exhibit unique behaviour in an aqueous environment where they rapidly form dimeric species after substitution of the chlorido ligand for the sulfur donor of the PCA ligand of a second complex molecule. This was also observed for the synthesised complexes with the N -heterocyclic ligands being cleaved from the Ru centre allowing for dimerisation, which may be reversed by acidification of the solution resulting in the formation of equivalent mononuclear compounds. This behaviour explains the similar biological properties of the complexes with respect to that of plecstatin-1. Replacing the chlorido ligand in [Ru(η 6- p -cymene)(p -fluoropyridinecarbothioamide)Cl]PF6 with the N -heterocycles 1-methylimidazole, 1-methylbenzimidazole and pyridine gave complexes with similar antiproliferative activities in human cancer cells at low micromolar concentrations. This can be explained by dimerisation in aqueous solution and formation of the same di-Ru complexes after cleaving of the chlorido or N -heterocycle ligands. (Image credit: Saawan Kumar.) This article belongs to the 10th Anniversary Collection of RACI and AAS Award papers. [ABSTRACT FROM AUTHOR]

Several novel copper (II) complexes of reduced Schiff bases containing fluoride substituents were prepared and structurally characterized by single-crystal X-ray diffraction. The complexes exhibited diverse structures, with the central atom in distorted tetrahedral geometry. The biological effects of the products were evaluated, specifically their cytotoxicity, antimicrobial, and antiurease activities, as well as affinity for albumin (BSA) and DNA (ct-DNA). The complexes showed marked cytotoxic activities in the HepG2 hepatocellular carcinoma cell line, considerably higher than the standard cisplatin. The cytotoxicity depended significantly on the substitution pattern. The best activity was observed in the complex with a trifluoromethyl group in position 4 of the benzene ring—the dichloro[(±)-trans-N,N′-bis-(4-trifluoromethylbenzyl)-cyclohexane-1,2-diamine]copper (II) complex, whose activity (IC50 28.7 μM) was higher than that of the free ligand and markedly better than the activity of the standard cisplatin (IC50 336.8 μM). The same complex also showed the highest antimicrobial effect in vitro. The affinity of the complexes towards bovine serum albumin (BSA) and calf thymus DNA (ct-DNA) was established as well, indicating only marginal differences between the complexes. In addition, all complexes were shown to be excellent inhibitors of the enzyme urease, with the IC50 values in the lower micromolar region. [ABSTRACT FROM AUTHOR]

The medicinal properties of transition metal complexes are greatly influenced by the nature and physico-chemical features of the ligand present in the complex structure. Due to the unique biological properties of the organoselenium compounds reflected in the variety of pharmacological activities (such as antioxidative, antiviral, antimicrobial and anticancer), the last years have brought increased interest for their use as a ligands compounds in the design and syntheses of range of transition metal-based coordination compounds that have been explored as antitumor and antimicrobial agents. Our aim in this review is to provide the overview of an recent development of the transition metal complexes bearing organoselenium ligands in the structure that could be promising choice for the treatment of various diseases, particularly cancer and infective diseases. For this purpose, the complexes of Co, Ni, Cu, Zn, Ru, Pd, Pt, Au and Sn as the most explored examples will be included and discussed. [ABSTRACT FROM AUTHOR]

Cisplatin coined a term Metallodrug and later a tradition of Metallodrugs was established. Later, severe renal and metabolic toxicities of the platinum based drugs prompted the medicinal chemists to develop new and novel metallotherapeutics with different metal cores. Henceforth, chemists designed the metal complexes based on copper, cobalt, vanadium iron and zinc. These complexes were reported for their antibacterial, anticancer, antidiabetic and enzyme inhibitors. Later, chemists also focused on lanthanide metal ions and resulted in the design of metal complexes for the application of bio imaging cellular studies as well as chemotherapeutic agents. This review throws a light on the recent advances in the development of the samarium complexes as efficient and versatile biological agents. Samarium complexes based on various ligand systems and ancillary ligands have been mentioned in this review stating their biological efficacy and potency against variable cancer cell lines, their DNA interactive behaviour. [ABSTRACT FROM AUTHOR]

Levofloxacin and 4‐aminoantipyrine undergo a condensation process to synthesize a novel Schiff base ligand (L). Metal complexes containing Co(II), Cu(II), Cd(II), Mn(II), Zn(II), Cr(III), Ni(II), and Fe(III) metal ions are prepared using this Schiff base ligand. The new ligand and its complexes are characterized by elemental analyses, Fourier transform infrared, mass spectrometry, ultraviolet–visible, magnetic moment, 1H‐NMR, molar conductivity, and powder X‐ray diffraction, and further thermogravimetric analysis (TG, DTA) verifies their thermal stability. The metal to ligand ratio is 1:1, according to the analytical results. Spectroscopic methods reveal that metal complexes are expected to have an octahedral geometry and demonstrate a neutral tridentate ligand behavior. It also becomes apparent from the molar conductivity values that all metal complexes are electrolytic in nature except zinc(II) and cadmium(II) complexes which are non‐electrolytes. Moreover, the bioactivity of the compounds are investigated. The antibacterial activity is investigated in relation to various Gram‐positive and Gram‐negative bacteria. The results give good indication for higher activity of the prepared compounds than the standard antibiotic drug. Also, the antioxidant activity of the newly prepared ligand and its complexes has been investigated via 2,2‐diphenyl‐1‐picrylhydrazyle (DPPH) free radical scavenging assay. The findings show that Schiff base complexes exhibit good antioxidant activity. Finally, theoretical density functional theory using density functional theory/B3LYP method and molecular docking studies with two receptors of 3T88 and 3Q8U are calculated for the investigated compounds. [ABSTRACT FROM AUTHOR]

Malaria caused by Plasmodium protozoa, transmitted by the Anopheles mosquitoes' is one ofthe most important diseases. Current antimalarial drugs target vital parasite progressions ormetabolic pathways essential for parasitic development, thus aiding the host in overcomingthe infection by inhibiting protozoa growth. However, at the same time, it also produces adisruptive consequence on the host cells. These cause severe adverse effects on the host andlead to drug resistance. The urgent need for novel, non‐toxic anti‐protozoal compounds isevident due to the resistance developed against drugs like chloroquine andhydroxychloroquine. Metal complexes of various elements like iron, gold, ruthenium, and othershave shown their anti‐malarial potential. We have reviewed the research ongoing globally on the developments of new molecules of chloroquine coupled with different transition elements and describe the structure–activity relationship of chloroquine, which also provides insights into the chemistry of these compounds. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CIPH) was classified as one of the most effective quinolone antibiotics, which is commonly used to cure a wide range of infections resulting from Gram-negative and Gram-positive microorganisms. The complexes which formed due to the interaction of Ni(II), Zn(II), Cu(II), Gd(III) and Sm(III) with ciprofloxacin were characterized by CHN% analysis, conductivity, FTIR, electronic spectra, fluorescence measurements, and magnetic susceptibility, besides studying the complex–DNA interaction. Meanwhile, the molar conductance values (0.001 mol·L−1 in DMSO) revealed the electrolytic behavior of the complexes and could be designated with the A−B+ formula. In addition, the geometry of the compounds was confirmed from the electronic transitions as well as the μeff values as octahedral for all complexes. The postulated formula could be generally assigned as [M(CIP)a(CIPH)b(H2O)c](NO3)(H2O)n(C2H5OH)m. Moreover, the interaction between metal complexes and DNA revealed that the Cu complex had the highest binding constant. Nanotechnology was applied to synthesized compounds using silica nanoparticles (SiNPs), which were prepared using a sol–gel process. The silica nanoparticles were chemically functionalized for binding the ligand and its metal complexes; this enables the as-prepared compounds to enhance their features as a drug delivery platform. Meanwhile, the antimicrobial activity was tested for the free complexes and SiNPs composites. Collectively, Sm complex gave the largest zone of inhibition, while the Cu(II)–SiNPs composite showed the strongest potential to reduce the bacterial activity. Furthermore, the fluorescence data of CIPH, ligand–metal mixture and the effect of silica nanoparticles on them were studied. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Curcuminoids are widely studied due to their well-recognized therapeutic properties. These molecules are often derivatized with metals, producing their corresponding homoleptic metal complexes. Numerous crystal structures of homoleptic symmetric curcuminoids with physiologically essential metals are known, although the literature lacks reports of homoleptic metal complexes of unsymmetric curcuminoids (or hemi-curcuminoids) as ligands. Three unknowns must be solved when an unsymmetric curcuminoid ligand is reacted with a metal ion: (a) the degree of coordination (MLn); (b) the spatial geometry; and (c) the conformational nature (syn or anti) of the complex. Herein, we report the structure of the anti-isomer of the Zn complex of the hemi-curcuminoid 5-hydroxy-1-(4-methoxyphenyl)hexa-1,4-dien-3-one. While the NMR shows only one set of signals for this homoleptic complex, the unambiguous stereochemistry was established through single-crystal X-ray diffractometry, revealing an anti-hexacoordinated octahedral ML2 structure. [ABSTRACT FROM AUTHOR]

Curcumin, as the main active component of turmeric (Curcuma longa), has been demonstrated with various bioactivities. However, its potential therapeutic applications are hindered by challenges such as poor solubility and bioavailability, rapid metabolism, and pan-assay interference properties. Recent advancements have aimed to overcome these limitations by developing novel curcumin analogues and modifications. This brief review critically assesses recent studies on synthesising different curcumin analogues, including metal complexes, nano particulates, and other curcumin derivatives, focused on the antioxidant, anti-inflammatory, and anticancer effects of curcumin and its modified analogues. Exploring innovative curcumin derivatives offers promising strategies to address the challenges associated with its bioavailability and efficacy and valuable insights for future research directions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Faculty of Pharmacy of Ankara University / Ankara Üniversitesi Eczacilik Fakültesi Dergisi is the property of Ankara University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work reported “trinitarian” porphyrin nanobelts, contained hetero‐trimetal ions. The high‐resolution mass spectrometry and X‐ray crystallography proved PNBNiCuPd consisting of three different bent porphyrin(2.1.2.1) metal complex moieties. The redox properties indicate porphyrin nanobelts demonstrate the multielectron donating and accepting properties, more than nine redox processes. [ABSTRACT FROM AUTHOR]

The document is a contents list of the journal "Dalton Transactions: An International Journal of Inorganic Chemistry," which covers various topics related to inorganic chemistry. It includes articles on metal complexes, electrocatalysts, nanocrystals, and organic synthesis. The journal aims to provide original research and perspectives to contribute to scientific progress in the field of chemistry. One article discussed in the document is about the synthesis and characterization of copper complexes that can be used in the degradation of organic dyes using visible light. Another article focuses on the synthesis and characterization of palladium complexes for use in focused electron beam induced deposition. [Extracted from the article]

This perspective summarizes our group's extensive research in the realm of organometallic lanthanide complexes, while also placing the catalytic reactions supported by these species within the context of known lanthanide catalysis worldwide, with a specific focus on phosphorus-based catalytic reactions such as intermolecular hydrophosphination and hydrophosphinylation. α-Metalated N,N-dimethylbenzylamine ligands have been utilized to generate homoleptic lanthanide complexes, which have subsequently proven to be highly active lanthanum-based catalysts. The main goal of our research program has been to enhance the catalytic efficiency of lanthanum-based complexes, which began with initial successes in the stoichiometric synthesis of organometallic lanthanide complexes and utilization of these species in catalytic hydrophosphination reactions. Not only have these species supported traditional lanthanide catalysis, such as the hydrophosphination of heterocumulenes like carbodiimides, isocyanates, and isothiocyanates, but they have also been effective for a plethora of catalytic reactions tested thus far, including the hydrophosphinylation and hydrophosphorylation of nitriles, hydrophosphination and hydrophosphinylation of alkynes and alkenes, and the heterodehydrocoupling of silanes and amines. Each of these catalytic transformations is meritorious in its own right, offering new synthetic routes to generate organic scaffolds with enhanced functionality while concurrently minimizing both waste generation and energy consumption. Objectives: We aim for the research summary presented herein to inspire and encourage other researchers to investigate f-element based stoichiometric and catalytic reactions. Our efforts in this field began with the recognition that potassium salts of benzyldimethylamine preferred deprotonation at the α-position, rather than the ortho-position, and we wondered if this regiochemistry would be retained in the formation of lanthanide complexes. The pursuit of this simple idea led first to a series of structurally fascinating homoleptic organometallic lanthanide complexes with surprisingly good stability. Fundamental studies of the protonolysis chemistry of these complexes ultimately revealed highly versatile lanthanide-based precatalysts that have propelled a catalytic investigation spanning more than a decade. We anticipate that this summative perspective will animate the synthetic as well as biological communities to consider La(DMBA)3-based catalytic methods in the synthesis of functionalized organic scaffolds as an atom-economic, convenient, and efficient methodology. Ultimately, we envision our work making a positive impact on the advancement of novel chemical transformations and contributing to progress in various fields of science and technology. [ABSTRACT FROM AUTHOR]

Coordination compounds are molecules that contain one or more metal centers bound to ligands. Ligands can be atoms, ions, or molecules that transfer electrons to the metal. These compounds can be charged or neutral. When charged, neighboring counter-ions help stabilize the complex. The metal ion is located at the center of a complex ion, surrounded by other molecules or ions known as ligands. Ligands can be thought of as covalently bonded to the core ion through coordination. Understanding coordination theory in chemistry provides insight into the geometric shape of complexes and the structure of coordination compounds, which consist of a central atom or molecule connected to surrounding atoms or compounds. Inorganic coordination compounds exhibit different properties and are used in synthesizing organic molecules. The coordination of chemicals is vital for the survival of living organisms. Metal complexes are also essential for various biological processes, with many enzymes, known as metalloenzymes, being composed of metal complexes. These metal complexes occur naturally. [ABSTRACT FROM AUTHOR]

Sterically loaded, anionic pyridine has been synthesized and utilized successfully in the stabilization of a isoleptic series of coinage metal complexes. The treatment of [4‐(Ph3B)‐2,6‐Trip2Py]K (Trip=2,4,6‐iPr3C6H2) with CuBr(PPh3), AgCl(PPh3) or AuCl(PPh3) (Py=pyridine) afforded the corresponding [4‐(Ph3B)‐2,6‐Trip2Py]M(PPh3) (M=Au, Ag, Cu) complexes, via salt metathesis, as isolable, crystalline solids. Notably, these reactions avoid the facile single electron transfer chemistry reported with the less bulky ligand systems. The X‐ray structures revealed that they are two‐coordinate metal adducts. The M−N and M−P bond distances are longest in the silver and shortest in the copper adduct among the three group 11 family members. Computational analysis revealed an interesting stability dependence on steric bulk of the anionic pyridine (i. e., pyridyl borate) ligand. A comparison of structures and bonding of [4‐(Ph3B)‐2,6‐Trip2Py]Au(PPh3) to pyridine and m‐terphenyl complexes, {[2,6‐Trip2Py]Au(PPh3)}[SbF6] and [2,6‐Trip2Ph]Au(PPh3) are also provided. The Au(I) isocyanide complex, [4‐(Ph3B)‐2,6‐Trip2Py]Au(CNBut) has been stabilized using the same anionic pyridylborate illustrating that it can support other gold‐ligand moieties as well. [ABSTRACT FROM AUTHOR]

Reaction of a nucleophilic germylene Ge[CH(SiMe3)2]2 with the phosphanyl phosphaketene [{(H2C)(NDipp)}2P]PCO induces decarbonylation to form a phosphanyl phosphagermene [{(H2C)(NDipp)}2P]P=Ge[CH(SiMe3)2]2 (1; Dipp=2,6‐diisopropyl‐phenyl). Addition of CO2 or MeCN to 1 results in [3+2]‐cycloaddition reactions to afford five‐membered heterocycles. This mode of reactivity is reminiscent of that observed for frustrated Lewis pairs, with the pendant phosphanyl group acting as a base and the germanium center as a Lewis acid. Contrastingly, 1,2‐addition across the P=Ge bond was observed when using ammonia, small primary amines (NH2nP), or metal complexes (e. g. Au(PPh3)Cl and ZnEt2). These latter reactions allow for the one‐step synthesis of metal phosphide complexes. [ABSTRACT FROM AUTHOR]

The synthesis of sulfoxide‐functionalized NHC ligand precursors were carried out by direct and mild oxidation from corresponding thioether precursors with high selectivity. Using these salts, a series of cationic [Ru(II)(η6‐p‐cymene)(NHC‐SO)Cl]+ complexes were obtained in excellent yields by the classical Ag2O transmetallation route. NMR analyses suggested a chelate structure for the metal complexes, and X‐ray diffractometry studies of complexes 4 b, 4 c, 4dBArF and 4 e unambiguously confirmed the preference for the bidentate (κ2‐C,S) coordination mode of the NHC‐SO ligands. Interestingly, only one diastereomer, in the form of an enantiomeric pair, was observed both in 1H NMR and in the solid state for the complexes. DFT calculations showed a possible intrinsic energy difference between the two pairs of diastereomer. The calculated energy barriers suggested that inversion of the sulfoxide is only plausible from the higher energy diastereomer together with bulky substituents. Inverting the configuration at the Ru center instead shows a lower and accessible activation barrier to provide the most stable diastereomer through thermodynamic control, consistent with the observation of a single species by 1H NMR as a pair of enantiomers. All these complexes catalyse the β‐alkylation of secondary alcohols. Complex 4dPF6 bearing an NHC‐functionalised S‐Ad group has been further studied with different primary and secondary alcohols as substrates, showing high reactivity and high to moderate β‐ol‐selectivities. [ABSTRACT FROM AUTHOR]

This review focuses on functional materials that contain terpyridine (terpy) units, which can be synthesized from biomass-derived platform chemicals. The latter are obtained by the chemical conversion of raw biopolymers such as cellulose (e.g., 2-furaldehyde) or lignin (e.g., syringaldehyde). These biomass-derived platform chemicals serve as starting reagents for the preparation of many different terpyridine derivatives using various synthetic strategies (e.g., Kröhnke reaction, cross-coupling reactions). Chemical transformations of these terpyridines provide a broad range of different ligands with various functionalities to be used for the modification or construction of various materials. Either inorganic materials (such as oxides) or organic ones (such as polymers) can be combined with terpyridines to provide functional materials. Different strategies are presented for grafting terpy to materials, such as covalent grafting through a carboxylic acid or silanization. Furthermore, terpy can be used directly for the elaboration of functional materials via complexation with metals. The so-obtained functional materials find various applications, such as photovoltaic devices, heterogeneous catalysts, metal–organic frameworks (MOF), and metallopolymers. Finally, some possible developments are presented. [ABSTRACT FROM AUTHOR]

In this article, we have reported the synthesis and structural characterization of complexes containing Co(III), Cu(II), Zn(II), and Hg(II) metal cations. The ligand potassium azepane-1-carbodithioate (acdt) behaves as a monodentate and bidentate and forms complexes with the metals mentioned above. We investigated the electronic and emission spectra of the ligand potassium azepane-1-carbodithioate (acdt) and its metal complexes [Co(acdt)3]·CHCl3 (1), [Cu(acdt)2] (2), [Zn2(μ2-acdt)2(acdt)2] (3), and [PhHg(acdt)] (4). A photoluminescence study was also carried out and the results revealed that all compounds are fluorescent. Furthermore, this synthesized ligand and its complexes are passed through to examine their cytotoxic activity against human breast cancer cell line MDA-MB-231 and results suggested that complex [Co(acdt)3]·CHCl3 has sufficiently better activity than others. Furthermore, we have explored the impact of the synthesized ligand and its transition metal complexes on glucose metabolism within the human breast cancer cell line MDA-MB-231. Inhibiting glucose uptake can induce starvation in cancer cells, potentially resulting in cell death due to energy deprivation. Our results indicate that the Co(III) complex-treated group exhibited a greater inhibition of glucose uptake compared to groups treated with ligands and other metal complexes such as Cu, Zn, and Hg. Furthermore, we also measured the extracellular NO level in the ligand and its metal complexes of Co(III), Cu(II), Zn(II), and Hg(II) treated MDA-MB-231 cells and results indicated that the free ligand and its metal complexes induced the production of nitric oxide in MDA-MB-231 cells. Among the four metal complexes, Co-complex 1 elevated the nitric oxide level in MDA-MB-231 cells to 75.91 μM. In contrast, the groups treated with the complexes of Cu(II) (2), Zn(III) (3), and Hg(II) (4) induced NO levels of 62.91, 49.24, and 33.10 μM, respectively. This suggests that complex 1 induces nitric oxide production and enhances oxidative stress in MDA-MB-231 cells more significantly compared to the groups treated with the free ligand as well as with metal complexes 2–4. Overall, the data strongly suggest that complex 1 exhibits significant anticancer activity against the human breast cancer cell line MDA-MB-231, making it a promising candidate for combating breast cancer progression. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "A robust and porous titanium metal-organic framework for gas adsorption, CO2 capture and conversion" published in the journal Dalton Transactions. The correction notice, numbered 12797, acknowledges an error in the original article but does not provide any specific details about the nature of the error or the correction made. The article itself explores the topic of a titanium metal-organic framework and its potential applications in gas adsorption, CO2 capture, and conversion. The journal, published by The Royal Society of Chemistry, covers a wide range of topics in inorganic chemistry and is a respected resource in the field. [Extracted from the article]

A new type of diborate clathrochelate (cage) ligand featuring nine inwardly pointing nitrogen donors that form a large, rigid cavity, termed a mausolate, is presented. The cavity size and high denticity make this an attractive delivery vehicle for large radionuclides in nuclear medicine. Metal mausolate complexes are stable to air and water (neutral pH) and display extremely high thermal stability (>400 °C). Lanthanide uptake by the mausolate ligand occurs rapidly in solution at room temperature and once complexed, the lanthanide ions are not displaced by a 250‐fold excess of a competitive lanthanide salt over more than one week. [ABSTRACT FROM AUTHOR]

Mixed ligand complexes of manganese(II), cobalt(II), copper(II), and cadmium(II)with an innovative Schiff base ligand denoted as (L1), 4-(2-((1E,2E)-1-(2-(p-tolyl)hydrazineylidene)propan-2-ylidene)hydrazineyl), served as the principal ligand, while glycine (L2) was employed as secondary ligand were successfully effectively characterized through a comprehensive set of analyses, including Elemental analysis, UV–Visible, FT-IR, Mass spectra, and conductometric measurements. Density functional theory (DFT) computations were executed to discern the enduring electronic arrangement, the energy gap, dipole moment and chemical hardness of the hybrid ligand assemblies. The proposed geometry for the complexes is a distorted octahedral structure. The antimicrobial efficacy of these compounds was assessed against a range of bacterial and fungal strains. Notably, these complexes exhibited promising antimicrobial activities, with the cadmium (II) complex demonstrating superior efficacy towards all tested organisms. These compounds were also examined for their antibiotic properties against H. pylori to explore their broader medical potential. The Schiff base ligand and its corresponding metal complexes displayed substantial potential as an antibiotic against H. pylori. Additionally, the antitumor potential of the synthesized complexes was assessed against MCF-7 (Breast carcinoma) cells—the Cu (II) complex demonstrated superior activity with the lowest IC50 value compared to cisplatin. Moreover, it exhibited reduced cytotoxicity towards normal cells (VERO cells) compared to cisplatin, establishing it as the most potent compound in the study. Furthermore, molecular docking was explored of the Schiff base ligand and its corresponding cadmium(II) complex. The analysis of the docking study yielded valuable structural insights that can be effectively utilized in conducting inhibition studies for example against COVID-19. This comprehensive study highlights these synthesized compounds' multifaceted applications and promising bioactive properties. [ABSTRACT FROM AUTHOR]

Quite recently we discovered that copper(II) complexes with isomeric morpholine-thiosemicarbazone hybrid ligands show good cytotoxicity in cancer cells and that the molecular target responsible for this activity might be tubulin. In order to obtain better lead drug candidates, we opted to exploit the power of coordination chemistry to (i) assemble structures with globular shape to better fit the colchicine pocket and (ii) vary the metal ion. We report the synthesis and full characterization of bis-ligand cobalt(III) and iron(III) complexes with 6-morpholinomethyl-2-formylpyridine 4N-(4-hydroxy-3,5-dimethylphenyl)-3-thiosemicarbazone (HL1), 6-morpholinomethyl-2-acetylpyridine 4N-(4-hydroxy-3,5-dimethylphenyl)-3-thiosemicarbazone (HL2), and 6-morpholinomethyl-2-formylpyridine 4N-phenyl-3-thiosemicarbazone (HL3), and mono-ligand nickel(II), zinc(II) and palladium(II) complexes with HL1, namely [CoIII(HL1)(L1)](NO3)2 (1), [CoIII(HL2)(L2)](NO3)2 (2), [CoIII(HL3)(L3)](NO3)2 (3), [FeIII(L2)2]NO3 (4), [FeIII(HL3)(L3)](NO3)2 (5), [NiII(L1)]Cl (6), [Zn(L1)Cl] (7) and [PdII(HL1)Cl]Cl (8). We discuss the effect of the metal identity and metal complex stoichiometry on in vitro cytotoxicity and antitubulin activity. The high antiproliferative activity of complex 4 correlated well with inhibition of tubulin polymerization. Insights into the mechanism of antiproliferative activity were supported by experimental results and molecular docking calculations. [ABSTRACT FROM AUTHOR]

A Schiff base (imine) ligand, (E)-4-((2-hydroxy-3,5-diiodobenzylidene)amino)-N-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide (HL), was synthesized by condensation of 3,5-diiodosalicylaldehyde with sulfamethazine. The ligand was then complexed with Zn(II), Cu(II), Ni(II), Co(II) and Fe(II) employing a metal to ligand ratio of 1:2 to form chelates (1-5), [M(L)2(H2O)2]. Characterization was done by UV-visible, FTIR, 1H and 13C NMR spectroscopy, elemental analysis, magnetic moments, thermogravimetric analyses (TGA) and conductance studies. The Schiff base behaved as a bidentate ligand and metal chelates assumed octahedral geometry. MOE-docking was employed to assess binding of the Schiff base (HL) and its chelates (1-5) with 1T2P, 1VVQ, 2W61, 3U2D, 4H8E and 5K18 proteins. Results indicated that Zn(II) chelate (1) and Fe(II) chelate (5) are the most potent compounds. Antibacterial and antibiofilm activities were executed against Enterococcus faecalis, Staphylococcus aureus, Proteus mirabilis and Klebsiella pneumoniae. Antifungal activities were performed against Candida albicans and Aspergillus niger. The Schiff base exhibited moderate antibacterial/antifungal activities that were enhanced on chelation with metal ions. Zinc(II) chelate (1) and Fe(II) chelate (5) show excellent antibacterial/antifungal activities. Complex 2 exhibited good antibiofilm activity. [ABSTRACT FROM AUTHOR]

A set of seventeen metal complexes with 1-(5-acetyl-2,4-dihydroxyphenyl)ethylidene) hydrazono)ethyl)-2,4-dihydroxyphenyl)ethylidene)hydrazono)-3-(hydroxyimino)pentan-2-one have been elaborated. The characterization of the synthesized hydrazonic chelator and its complexes have been carried out by physical, analytical and spectral techniques such as 1H-,13C-NMR, FT-IR, UV–Vis mass and ESR spectra, in addition to elemental, thermal, conductivity and magnetic moments measurements. It was found that the hydrazonic chelator attached with the central ions via ON donors as a mononegative or neutral bidentate fashion in complexes (2-17) bonded with the central ions through the nitrogen of protonated/deprotonated oximato and azomethine groups. All metal complexes are nonelectrolytic in nature and have various geometries. The ESR showed that the complexes of copper(II) have a d9 configuration with an axial symmetry type of a d(x2-y2) ground state with significant covalency features. The TG study verified that the complexes had been disintegrated in two, three or four phases beginning with the libration of crystallized, coordinated water molecules or anions exclusion and was finished with the full decomposition of the complexes, leaving the oxide of the metal. The microbicide screening data showed that the prepared compounds have a greater fungicide activity against A. flavus than S. cerevisiae, while all compounds have low activity against bacteria E. coli, and B. subitilis. [ABSTRACT FROM AUTHOR]

C–H bond activation is a crucial synthetic strategy widely utilized in both academic and industrial settings. Due to the strong and kinetically inert nature of the C–H bond, its functionalization typically requires metal-based catalysts. This review highlights the most significant advancements in homogeneously catalyzed reactions using pincer complexes with metals from groups 8–10, capable of promoting challenging C–H activation, published since 2010. In particular, it focuses on C–H bond activation for borylation, isomerization, and dehydrogenation, among other processes, discussing their scope and mechanistic insights. [ABSTRACT FROM AUTHOR]

Metal complexes of benzotriazole-type ligands continue to attract the intense interest of many inorganic chemistry groups around the world for a variety of reasons, including their aesthetically beautiful structures, physical properties and applications. 1-methylbenzotriazole (Mebta) is the N-substituted archetype of the parent 1H-benzotriazole. The first attempt to build a "periodic table" of Mebta, which includes its complexes with several metal ions, is described in this work. This, at first glance, trivial ligand has led to interesting results in terms of the chemistry, structures and properties of its metal complexes. This work reviews the to-date published coordination chemistry of Mebta with Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(I), Cu(II), Zn(II), Pd(II), Au(I) and {UVIO2}2+, with emphasis on their preparations, reactivity, structures and properties. Unpublished results from our group comprising other Co(II), Ni(II), Cu(II) and Zn(II) complexes, as well as Cd(II), Hg(II), Ag(I), In(III) and Sn(IV) ones are briefly reported. Mebta can also provide access to 1D and 3D heterometallic thiocyanato-bridged Co(II)/Hg(II) and Ni(II)/Hg(II) compounds. In almost all cases, Mebta behaves as a monodentate ligand with the nitrogen of position 3 of the azole ring as the donor atom. However, there are two copper complexes in which this molecule adopts a bidentate bridging coordination behavior. Our efforts to complete the "periodic table" of Mebta are continued. [ABSTRACT FROM AUTHOR]

Herin, the high yielding synthesis of the chiral carbodiphosphorane (3) prepared in a two‐step procedure from commercially available (R)‐BINAP (([1,1′‐binaphthalene]‐2,2′‐diyl)bis(diphenylphosphane), BINAP) and dibromomethane is presented. In the first reaction step, the bis phosphonium salt 1[Br]2 is obtained, which is subsequently deprotonated either with potassium hydroxide to yield the mono phosphonium salt 2[Br], or with potassium hexamethyldisilazide to produce 3. Moreover, coinage metal complexes of 3 were prepared via reaction with CuCl (4Cu, 5Cu, 6Cu), Cu(OTf)⋅toluene0.5 (7Cu) or AuCl ⋅ (tht) (5Au, 6Au). The prepared compounds were characterised by NMR‐ and IR‐spectroscopy, mass spectrometry, elemental analysis, single crystal X‐ray diffraction and UV/Vis spectroscopy. Photoluminescence emission spectra were obtained for most of the complexes (3, 4Cu, 5Cu, 6Cu and 6Au). [ABSTRACT FROM AUTHOR]

Antifungal activity of newly synthesized submicrometer particles of the CsTeMoO6 complex metal oxide was studied. They were found to inhibit spore germination of active micromycete degraders of industrial materials both in the dark and under illumination. Illumination increased the fungicidal activity of the studied compounds due to their photocatalytic activity. This is the first report on production of micromycete-resistant composites of a number of polymers containing the complex metal oxides CsTeMoO6 and RbTe1.5W0.5O6. Upon addition of the studied complex oxides into the composition of the previously micromycete-sensitive materials, the latter were found to exhibit micromycete resistance both in the dark and under illumination. Treatment with light resulted in a more pronounced antifungal effect. [ABSTRACT FROM AUTHOR]

Polarization and charge-transfer interactions play an important role in ligand–receptor complexes containing metals, and only quantum mechanics methods can adequately describe their contribution to the binding energy. In this work, we selected a set of benzenesulfonamide ligands of human Carbonic Anhydrase II (hCA II)—an important druggable target containing a Zn2+ ion in the active site—as a case study to predict the binding free energy in metalloprotein–ligand complexes and designed specialized computational methods that combine the ab initio fragment molecular orbital (FMO) method and GRID approach. To reproduce the experimental binding free energy in these systems, we adopted a machine-learning approach, here named formula generator (FG), considering different FMO energy terms, the hydrophobic interaction energy (computed by GRID) and logP. The main advantage of the FG approach is that it can find nonlinear relations between the energy terms used to predict the binding free energy, explicitly showing their mathematical relation. This work showed the effectiveness of the FG approach, and therefore, it might represent an important tool for the development of new scoring functions. Indeed, our scoring function showed a high correlation with the experimental binding free energy (R2 = 0.76–0.95, RMSE = 0.34–0.18), revealing a nonlinear relation between energy terms and highlighting the relevant role played by hydrophobic contacts. These results, along with the FMO characterization of ligand–receptor interactions, represent important information to support the design of new and potent hCA II inhibitors. [ABSTRACT FROM AUTHOR]

G-quadruplexes (G4s) are non-canonical nucleic acid secondary structures that have gathered significant interest in medicinal chemistry over the past two decades due to their unique structural features and potential roles in a variety of biological processes and disorders. Traditionally, research efforts have focused on stabilizing G4s, while in recent years, the attention has progressively shifted to G4 destabilization, unveiling new therapeutic perspectives. This review provides an in-depth overview of recent advances in the development of small molecules, starting with the controversial role of TMPyP4. Moreover, we described effective metal complexes in addition to G4-disrupting small molecules as well as good G4 stabilizing ligands that can destabilize G4s in response to external stimuli. Finally, we presented antisense strategies as a promising approach for destabilizing G4s, with a particular focus on 2′-OMe antisense oligonucleotide, peptide nucleic acid, and locked nucleic acid. Overall, this review emphasizes the importance of understanding G4 dynamics as well as ongoing efforts to develop selective G4-unfolding strategies that can modulate their biological function and therapeutic potential. [ABSTRACT FROM AUTHOR]

Free radicals can improve the reaction rate, but most of them are unstable due to unpaired electrons. Simultaneously maintaining their stability and activity is challenging. Herein, taking sulfur (S) radicals as an example, we propose a strategy in which solvated metal complexes constructed by Al(acetylacetonate)3 and different solvents can stabilize high concentrations of S radicals with good activity through ion-dipole interactions. Based on this strategy, it is first demonstrated that S4·- is selectively stabilized by controlling the configurations of the solvated complexes. As a result, the reaction rate of S-Li2S is increased by 8 times, and the energy efficiency and rate capability of the Li-S batteries are significantly improved, especially the 5-fold increase in cell capacities at a low electrolyte/sulfur ratio. This work provides an important strategy in which solvated metal complexes balance the activity and stability of free radicals to accelerate reactions and their application in various fields. [ABSTRACT FROM AUTHOR]

Due to their notable antimicrobial activity and optical properties, Schiff base ligands, along with their lanthanide and transition metal complexes, have seen extensive use in various applications. However, despite their potential, a comprehensive investigation into lanthanide and transition metal complexes using the same Schiff base ligand has not been reported to date. In this study, coordination compounds of lanthanide and transition metal ions were synthesized from the Schiff base ligand salicylaldehyde‐dipropylenetriamine. These complexes were characterized by elemental analysis, 1H and 13C NMR, mass spectroscopy, Fourier‐transform infrared spectroscopy ultraviolet–visible spectroscopy (UV–Vis), fluorescence spectroscopy, molar conductivity measurements, and thermogravimetric studies. Furthermore, the molecular structure of the Co (II) complex was determined by means of X‐ray crystallography. Thermogravimetric studies illustrated endothermic and non‐spontaneous degradation pathways of the complexes. UV–Vis spectra showed a new absorption band attributed to the ligand‐to‐metal charge transfer peak supporting the complexation between the ligand and metals. The lanthanide complexes exhibited distinctive luminescence emissions in the Sm (III), Tb (III), and Eu (III) complexes. This observation suggests that the ligand possesses the capability to absorb and efficiently transfer energy to the metal center of these lanthanide ions, thereby resulting in their characteristic luminescent properties. Additionally, antimicrobial investigations revealed that transition metal complexes generally exhibited antimicrobial activity against both gram‐positive and gram‐negative bacterial strains compared to lanthanide metal complexes, in most cases. However, it is noteworthy that the Dy (III) complex displayed the lowest minimum inhibitory concentration and minimum biocidal concentration values of 16 μg/ml against Staphylococcus epidermidis, indicating its potential as a candidate for the treatment of this pathogenic bacterium. The main purpose of this article is to investigate the variations in the synthesis and characterization of lanthanide and transition metal complexes utilizing the same Schiff base ligand suitable for applications in the pharmaceutical industry and optical material sciences. [ABSTRACT FROM AUTHOR]

The new Schiff base ligand was designed from a condensation reaction of isatin with 5‐amino‐2‐hydroxy benzoic acid. Then, the metal complexes were prepared. The structures of the prepared compounds were framed from thermogravimetric analyses (TG–DTG), mass spectrometry, elemental analyses, 1H‐NMR, IR, electronic spectra, UV–vis, and conductivity measurements. Surface and size morphology have been studied by X‐ray powder diffraction and scanning electron microscope (SEM) analysis. The IR spectra suggested that the ligand acted as bidentate coordinated with metal ions through deprotonated carboxylate oxygen atom and oxygen of phenolic group. With the exception of the complexes of Cr (III), Fe (III), and Cd (II), which were non‐electrolytes, the molar conductivities demonstrated the electrolytic behavior of all the rest complexes. The X‐ray diffraction (XRD) analysis patterns for the Schiff base complexes indicated their crystalline nature except the Co (II) complex which had amorphous structure. The ligand and its metal complexes were screened for their antimicrobial activities against two G‐positive, two G‐negative bacteria and against Aspergillus fumigatus and Candida albicans fungi. Additionally, the compounds were evaluated against the MFC‐7 breast cancer cell line for their anticancer activity. The outcomes demonstrated their strong antitumor activity. [Fe(HL)Cl2(H2O)2]0.5H2O complex has the lowest IC50 value = 9 μg mL−1. Molecular modeling studies for the ligand and its Co (II) and Fe (III) complexes were accomplished from density functional theory (DFT) analysis. From molecular docking study, the electrophilic moieties in both complexes displayed good binding interactions with the CDK6, aminoglycoside phosphotransferase, and CYP51 targeted proteins. [ABSTRACT FROM AUTHOR]

This study focuses on the synthesis of azo‐thiosemicarbazone ligand, which is designed by reacting 2‐hydroxy‐5‐(phenyldiazenyl)benzaldehyde with hydrazine carbothioamide. Hence, this ligand was exploited for chelation with nickel and cupric salts in (1 M:1 L) molar ratio. These synthetics were structurally investigated using a variety of physical, analytical, and spectroscopic (1D/2D‐NMR, UV–Vis, FT‐IR, and E‐mass) tools as well as theoretically. The finding demonstrated that the resulting azo‐thiosemicarbazone (H4Azo‐TSC) bonded with the nickel and cupric ions as mono/di‐basic tridentate chelators, binding them via deprotonated phenolic oxygen, imino nitrogen, and thionic/thiol sulfur atoms adopting square planar geometry. The theoretical investigation was examined by DFT/B3LYP/LanL2dZ, including energetic parameters, HOMO‐LUMO energy gap, dipole moment, and geometrical optimization, which were applied to support the complexes' geometrical structure. The in vitro microbicidal activities of the azo‐thiosemicarbazone, compared with its Ni2+ and Cu2+ complexes, display superior activity over the metal complexes against different bacterial and fungal species. The anticancer efficacy of the synthetics was tested against human lung fibroblast (WI38) and mammary gland breast cancer (MCF‐7) compared with Doxorubicin as a standard drug. The cytotoxic efficiency of metallic complexes exceeded that of un‐chelated azo‐thiosemicarbazone. The most effective complex is Ni2+ complex with IC50 equal to 11.75 and 14.05 μg/ml, respectively. It has been demonstrated that Ni2+ and Cu2+ complexes are more biocompatible than free azo‐thiosemicarbazone; this finding may be related to the chelation process. [ABSTRACT FROM AUTHOR]

Spin‐orbit natural transition orbital (SO‐NTO) methodology, recently developed in our group for complete and restricted active space (CAS/RAS) wavefunction calculations, is applied to analyze triplet‐to‐singlet emission in transition metal complexes. The lowest‐energy (longest‐wavelength) spin‐forbidden transition T1→S0 ${{{\rm T}}_{1}\to {{\rm S}}_{0}}$ is studied for for [Ir(pbt)2(acac)] and [Re(CO)4(pbt)] and the complexes [W(CO)4(bpy)] and [Mo(CO)4(bpy)]. For the latter complexes, spin‐forbidden transitions from higher spin‐triplet levels are additionally analyzed. SO‐NTOs are compared with spin‐free NTOs for the transitions under consideration. The major assignment of a spin‐forbidden transition is obtained from the spin‐free NTO analysis, while the source of intensity of the electronic transition is revealed by the SO‐NTOs. [ABSTRACT FROM AUTHOR]

Macrocyclic complexes play a crucial role in various emerging fields, including electrocatalysis, catalysis, sensor technology, pharmaceuticals, and biological applications. In this study, we synthesized a tetraaza-macrocyclic cavity capable of hosting transition metals, specifically MnII and NiII, forming the MnN4 and NiN4-macrocyclic complexes, respectively. Structural analyses were performed to propose the configuration of these complexes. Additionally, electrochemical studies were conducted to assess their redox potential and electron transfer kinetics. Furthermore, the biological activity of the complexes as antibacterial agents against a broad spectrum of microorganisms was investigated. The findings revealed that these complexes exhibit favorable redox properties with rapid electron transfer kinetics. The cyclic voltammogram was showed interesting results by eliminating ligand oxidation redox couple were observed as comparable in DMSO with shifting of 0.13 V peak potential in -ve peak potential range with the decreament in peak height. These results underscore the multifaceted applications of tetraaza-macrocyclic complexes in diverse fields, highlighting their importance in both fundamental research and practical biomedical interventions. [ABSTRACT FROM AUTHOR]