Peroxo Complexes of Molybdenum(VI) Containing Mannich Base Ligands

The molybdenum(VI)-peroxo complexes containing Mannich base ligands having a formula as [MoO(O2)2(L-L)] [where L-L＝morpholinobenzyl benzamide (MBB), piperidinobenzyl benzamide (PBB), morpholinobenzyl urea (MBU), piperidinobenzyl urea (PBU), morpholinobenzyl thiourea (MBTU), piperdinobenzyl thiourea (PBTU)] have been synthesized and characterized by physico-chemical, electrochemical techniques and TGA/DTA studies. The complexes have been prepared by stirring ammonium molybdate and excess of 30% aqueous-H2O2 and then treatment with ethanolic solution of the ligand. Studies revealed that these complexes were non-electrolytes and diamagnetic in nature. The ligands are bound to metal in a bidentate mode through carbonyl oxygen/thiocarbonyl sulphur and the ring nitrogen. The cyclic voltammograms of the complexes show two quasi-reversible steps involving complexes. The complexes have also been tested for antibacterial activity against Salmonella and Kleibsella. The antibacterial study of the ligands and complexes indicate that the complexes exhibit higher activity than the free ligands.     

Diperoxo Complexes of Vanadium(V) Containing Mannich Base Ligands

The vanadium(V) peroxo complexes containing Mannich base ligands having composition Na[VO(O₂)₂(L‐L)]·H₂O [where L‐L=morpholinobenzyl acetamide (MBA), piperidinobenzyl acetamide (PBA), morpholinobenzyl benzamide (MBB), piperidinobenzyl benzamide (PBB), morpholinomethyl benzamide (MMB), piperidinomethyl benzamide (PMB), morpholinobenzyl formamide (MBF), piperdinobenzyl formamide (PBF)] have been reported. The complexes have been prepared by stirring vanadium pentoxide with excess of 30% aqueous‐H₂O₂ followed by treatment with ethanolic solution of the ligand and finally maintained the pH of the reaction mixture by adding dilute solution of sodium hydroxide. The synthesized complexes have been characterized by various physico‐chemical techniques, via elemental analysis, molar conductivity, magnetic susceptibility measurements, infra red, electronic, mass, ¹H NMR spectral and TGA/DTA studies. These studies revealed that the synthesized complexes are uni‐univalent electrolytes and diamagnetic in nature. The ligands are bound to metal in a bidentate mode through carbonyl oxygen and the ring nitrogen. Thermal analysis result provides conclusive evidence for the presence of one molecule of lattice water in the complexes. Mass spectra confirm the molecular mass of the complexes.     

Synthesis and characterization of peroxo complexes of uranium(VI) with some Mannich base ligands

Abstract  

Uranium(VI) peroxo complexes of composition [UO(O₂)L–L(NO₃)₂], where L–L are the Mannich base ligands morpholinobenzyl urea, piperidinobenzyl urea, morpholinobenzyl thiourea, piperidinobenzyl thiourea, morpholinomethyl thiourea, piperidinomethyl thiourea, or morpholinomethyl urea, are reported. The synthesized complexes were characterized by use of a variety of physicochemical techniques, viz. elemental analysis, molar conductivity, magnetic susceptibility measurements, IR, electronic, mass, ¹H NMR, and ¹³C NMR spectroscopy, and TGA/DTA studies. These studies revealed that the complexes are both non-electrolytic and diamagnetic in nature. The ligands are bound to the metal in a bidentate mode through carbonyl oxygen or thiocarbonyl sulfur and the ring nitrogen. Mass spectra confirm the molecular mass of the complexes. The antifungal activity of the complexes is greater than that of the corresponding free ligands.     

Peroxo complexes of uranium(VI) containing nitrogen and oxygen donor ligands

The uranium(VI) peroxo complexes containing Mannich base ligands having composition [UO(O₂)L-L(NO₃)₂] {where L-L = morpholinobenzyl acetamide (MBA), piperidinobenzyl acetamide (PBA), morpholinobenzyl benzamide (MBB), piperidinobenzyl benzamide (PBB), morpholinomethyl benzamide (MMB), piperidinomethyl benzamide (PMB), morpholinobenzyl formamide (MBF)}, piperidinobenzyl formamide (PBF) are reported. In a typical reaction UO₂(NO₃)₂ · 6H₂O (1 mmol, 0.502 g) was dissolved in methanol. An equimolar (1 mmol) methanolic solution (30 mL) of the ligand (Mannich bases) was added to a solution of uranyl nitrate followed by addition of potassium hydroxide (KOH) (2 mmol, 0.1122 g). The solution was refluxed for 15 min and then 10 mL of 30% hydrogen peroxide (H₂O₂) was added dropwise and was refluxed for an additional 1 h. The synthesized complexes have been characterized by various physico-chemical techniques, viz. elemental analysis, molar conductivity, magnetic susceptibility measurements, infra red, electronic, mass spectral and TGA/DTA studies. These studies revealed that the synthesized complexes are non-electrolytic and diamagnetic in nature. The ligands are bound to metal in a bidentate mode through carbonyl oxygen and the ring nitrogen. Thermal analysis result provides conclusive evidence for the absence of water molecule in the complexes. Mass spectra confirm the molecular mass of the complexes. Antibacterial activity of complexes revealed enhanced activity of complexes as compared to corresponding free ligands. Molecular modeling suggests pentagonal bipyramidal structure for complexes.     

Synthesis and characterization of tungsten carbonyl complexes containing N-methyl substituted urea and thiourea ligands

Six new mixed-ligand tungsten carbonyl complexes containing N-methyl substituted urea and thiourea of the type W(CO)₄[RCH₂N-(C=X)NH₂] where X?=?O or S and R?=?morpholine, piperidine and diphenylamine are reported. These have been prepared by refluxing hexacarbonyl tungsten(0) with corresponding ligands in THF to produce cis-disubstituted products, [(L-L)W(CO)₄] where L-L?=?a chelating bidentate ligand, morpholinomethyl urea (MMU), morpholinomethyl thiourea (MMTU), piperidinomethyl urea (PMU), piperidinomethyl thiourea (PMTU), diphenylaminomethyl urea (DAMU) and diphenylaminomethyl thiourea (DAMTU). The compounds have been characterized by elemental analysis, IR, electronic and ¹³C NMR spectra, magnetic moments and conductivity measurements. The IR spectra suggests that in all the complexes, the ligands are bidentate chelating, coordinating the metal through carbonyl oxygen or thiocarbonyl sulphur and the ring nitrogen or tert-nitrogen of diphenylamine. The CO force constants and CO–CO interaction constants for these derivatives have also been calculated using Cotton–Kraihanzel secular equations, which indicate poor π-bonding ability of the ligands. ¹³C NMR and electronic spectra reveal loss of cis-carbonyl ligands to produce cis-disubstituted tetracarbonyl derivatives. Molecular modeling studies have been carried out using Hyperchem release 7.52 which suggest a distorted octahedral geometry for these complexes.     

Synthesis and magnetic properties of μ-phenolato copper (Ⅱ) binuclear complexes with different exogenous bridges

The syntheses and magnetic properties are reported for a series of copper(Ⅱ) complexes prepared from a pentadentate binucleating ligand 2,6-diformyl-4-methylphenol di(benzoyl-hydrazone) (H3L). These complexes incorporate different exogenous ions (X-) into a bridging position to form copper(Ⅱ) binuclear complexes of the formula [Cu2(H2L)X]2+, where X-= Br-(1), Cl-(2), HO-(3), C2H5O-(4) and C3H3N2- (5). The complexes have been characterized with variable temperature magnetic susceptibility (4.2-300 K) and the observed data were fit to those from a modified Bleaney-Bowers equation by least-squares method, giving the exchange integral 2J = -6.2 cm-1 for 1, -76.4 cm-1 for 2, -241.9 cm-1 for 3, -231.1 cm-1 for 4 and -343.8 cm-1 for 5. This suggested that there is an antiferromagnetic interaction between the Cu(Ⅱ) ions and the sequence of the effect of some exogenous bridging ligands on magnetic coupling is corresponding to that in spectrochemical series.     

Impact of the anion and chalcogen on the crystal structure and properties of 4,6‐dimethyl‐2‐pyrimido(thio)nium halides

By the reaction of urea or thiourea, acetylacetone and hydrogen halide (HF, HBr or HI), we have obtained seven new 4,6‐dimethyl‐2‐pyrimido(thio)nium salts, which were characterized by single‐crystal X‐ray diffraction, namely, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium bifluoride, C₆H₉N₂O⁺·HF₂^? or (dmpH)F₂H, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium bromide, C₆H₉N₂O⁺·Br^? or (dmpH)Br, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium iodide, C₆H₉N₂O⁺·I^? or (dmpH)I, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium iodide–urea (1/1), C₆H₉N₂O⁺·I^?·CH₄N₂O or (dmpH)I·ur, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium bifluoride–thiourea (1/1), C₆H₉N₂S⁺·HF₂^?·CH₄N₂S or (dmptH)F₂H·tu, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium bromide, C₆H₉N₂S⁺·Br^? or (dmptH)Br, and 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium iodide, C₆H₉N₂S⁺·I^? or (dmptH)I. Three HCl derivatives were described previously in the literature, namely, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium chloride, (dmpH)Cl, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium chloride monohydrate, (dmptH)Cl·H₂O, and 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium chloride–thiourea (1/1), (dmptH)Cl·tu. Structural analysis shows that in 9 out of 10 of these compounds, the ions form one‐dimensional chains or ribbons stabilized by hydrogen bonds. Only in one compound are parallel planes present. In all the structures, there are charge‐assisted N⁺—H…X^? hydrogen bonds, as well as weaker C_Ar⁺—H…X^? and π⁺…X^? interactions. The structures can be divided into five types according to their hydrogen‐bond patterns. All the compounds undergo thermal decomposition at relatively high temperatures (150–300 °C) without melting. Four oxopyrimidinium salts containing a π⁺…X^?…π⁺ sandwich‐like structural motif exhibit luminescent properties.     

Synthesis,structures, and characterization of copper(II), nickel(II), and cobalt(III) metal complexes derived from an asymmetric bidentate Schiff-base ligand

An asymmetric bidentate Schiff-base ligand (2-hydroxybenzyl-2-furylmethyl)imine (L–OH) was prepared. Three complexes derived from L–OH were synthesized by treating an ethanolic solution of the appropriate ligand with an equimolar amount of metallic salt. Three complexes, Cu₂(L–O^?)₂Cl₂ (1), Ni(L–O^?)₂ (2) and Co(L–O^?)₃ (3), have been structurally characterized through elemental analysis, IR, UV spectra and thermogravimetric analysis. Single crystal X-ray diffraction shows metal ions and ligands reacted with different proportions 1?:?1, 1?:?2 and 1?:?3, respectively, so copper(II), nickel(II), and cobalt(III) have different geometries.     

Catalytic Potential of Pyrazolone Based Dioxidomolybdenum(VI) Complexes for Multicomponent Biginelli Reactions,Epoxidation of Olefins and Oxidative Bromination of Phenol Derivatives

Three different types of dioxidomolybdenum(VI) complexes of 4-acetyl-3-methyl-1-phenyl-5-pyrazolone (Hmp, I )), 3-methyl-1-phenyl-4-propionyl-5-pyrazolone (Hpp, II ), 4-butyryl-3-methyl-1-phenyl-5-pyrazolone (Hbutp, III ), and 4-isobutyryl-3-methyl-1-phenyl-5-pyrazolone (isobutp, IV ) have been isolated and characterized by various spectroscopic (FT-IR, UV/Vis, ¹H and ¹³C NMR) techniques, thermal analysis and single crystal X-ray analysis. These complexes adopt a distorted six-coordinate octahedral geometry where ligands act as bidentate, coordinating through the two O atoms. These complexes have been used as catalysts to explore a single pot multicomponent (benzaldehyde or its derivatives, urea/thiourea and ethyl acetoacetate/phenyl acetoacatate) Biginelli reaction producing biologically active 3,4-dihydropyrimidin-2-(1H)-one and 3,4-dihydropyrimidin-2-(1H)-thione based biomolecules under solvent-free conditions. Presence of H₂O₂ improves the yield of dihydropyrimidin-2-(1H)-one but it acts as poison for the later molecule. Epoxidation of internal and terminal alkenes mainly resulted in the formation of the corresponding epoxide. The catalytic oxidative bromination of thymol, a reaction facilitated by vanadium dependent haloperoxidases, resulted in the formation of three product namely 2-bromothymol, 4-bromothymol and 2,4-bromothymol. Other phenol derivatives have also been brominated effectively.     

Self‐assembly properties of Salamo‐type trinuclear Cu(II) and Co(II) complexes based on the regulation of H+/OHˉ

A novel naphthalenediol‐based bis(salamo)‐type tetraoxime compound (H₄L) was designed and synthesized. Two new supramolecular complexes, [Cu₃(L)(μ‐OAc)₂] and [Co₃(L)(μ‐OAc)₂(MeOH)₂]·4CHCl₃ were synthesized by the reaction of H₄L with Cu(II) acetate dihydrate and Co(II) acetate dihydrate, respectively, and were characterized by elemental analyses and X‐ray crystallography. In the Cu(II) complex, Cu1 and Cu2 atoms located in the N₂O₂ sites, and are both penta‐coordinated, and Cu3 atom is also penta‐coordinated by five oxygen atoms. All the three Cu(II) atoms have geometries of slightly distorted tetragonal pyramid. In the Co(II) complex, Co1 and Co3 atoms located in the N₂O₂ sites, and are both penta‐coordinated with geometries of slightly distorted triangular bipyramid and distorted tetragonal pyramid, respectively, while Co2 atom is hexa‐coordinated by six oxygen atoms with a geometry of slightly distorted octahedron. These self‐assembling complexes form different dimensional supramolecular structures through inter‐ and intra‐molecular hydrogen bonds. The coordination bond cleavages of the two complexes have occurred upon the addition of the H⁺, and have reformed again via the neutralization effect of the OH^?. The changes of the two complexes response to the H⁺/OH^? have observed in the UV–Vis and ¹H NMR spectra.     

Preparation and characterization of oxoperoxo tungsten(VI) complexes with morpholinomethyl urea and related ligands

The monooxodiperoxo complexes of tungsten(VI) of the type [WO(O₂)₂ L-L] (where L-L = morpholinomethyl urea, morpholinomethyl thiourea, piperidinomethyl urea, piperidinomethyl thiourea, pyrrolidinomethyl urea, and pyrrolidinomethy thiourea) have been synthesized and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility, and conductivity measurements, in addition to TGA/DTA. The energy-minimized structures of these complexes have been obtained by molecular modeling using Hyperchem release 7.52. The text was submitted by the authors in English.     

Synthesis reactivity and electrochemical properties of substituted cyclopentadienyl cobalt (III) complexes

Cyclopentadienyl cobalt complexes (η⁵‐C₅H₄R) CoLI₂ [L = CO,R=‐COOCH₂CH=CH₂ (3); L=PPh₃, R=‐COOCH₂‐CH=CH₂ (6); L=P(p‐C₆H₄O₃)₃, R = ‐COOC(CH₃) = CH₂ (7), ‐COOCH₂C₆H₅ (8), ‐COOCH₂CH = CH₂ (9)] were prepared and characterized by elemental analyses, ¹H NMR, ER and UV‐vis spectra. The reaction of complexes (η⁵‐C₅H₄R)CoLI₂ [L= CO, R= ‐COOC(CH₃) = CH₂ (1), ‐COOCH₂C₆H₅(2); L=PPh₃, R=‐COOC (CH₃) = CH₂ (4), ‐COOCH₂C₆H₅ (5)] with Na‐Hg resulted in the formation of their corresponding substituted cobaltocene (η⁵‐C₅H₄R)₂ Co[R=‐COOC(CH₃) = CH₂ (10), ‐COOCH₂C₆H₅ (11)]. The electrochemical properties of these complexes 1–11 were studied by cyclic voltammetry. It was found that as the ligand (L) of the cobalt (III) complexes changing from CO to PPh₃ and P(p‐tolyl)₃, their oxidation potentials increased gradually. The cyclic voltammetry of α,α′‐substituted cobaltocene showed reversible oxidation of one electron process.     

Supramolecular networks constructed by cationic copper(II) complexes incorporating hybrid water–anionic polymeric assemblies

Two complexes, [Cu₂(TFSA)(2,2′-bpy)₄]?·?TFSA?·?8H₂O (1) and {[Cu(4,4′-bpy)(H₂O)₂]?·?TFSA?·?6H₂O} _n (2) (H₂TFSA?=?tetrafluorosuccinic acid, 2,2′-bpy?=?2,2′-bipyridine, and 4,4′-bpy?=?4,4′-bipyridine), have been synthesized and structurally characterized by X-ray structural analyses. Complex 1 is a binuclear molecule bridged by TFSA ligands; 2 is a 1-D chain bridged by 4,4′-bpy ligands. The asymmetric units of the two complexes are composed of cationic complexes [Cu₂(TFSA)(2,2′-bpy)₄]²⁺ (1) and [Cu(4,4′-bpy)(H₂O)₂]²⁺ (2), free TFSA anion, and independent crystallization water molecules. A unique 2-D hybrid water–TFSA anionic layer by linkage of {[(H₂O)₈(TFSA)]^2?} _n fragments consisting of 1-D T6(0)A2 water tape and TFSA anionic units by hydrogen bonds in 1 was observed. Unique 2-D hybrid water–TFSA anionic layer generated by the linkage of {[(H₂O)₆(TFSA)]^2?} _n fragments consisting of cyclic water tetramers with appended water molecules and TFSA anionic units, and 1-D metal–water tape [Cu–H₂O?···?(H₂O)₆?···?H₂O^?] _n in 2 were found. 3-D supramolecular networks of the two complexes consist of cationic complexes and water–TFSA anionic assemblies connected by hydrogen bonds.     

Synthesis and characterization of nitrogen-containing Lewis base adducts of bis(O,O′-dialkylmonoselenophosphato)cobalt(II) complexes

The adducts of bis(O,O′-dialkylmonoselenophosphato)cobalt(II) complexes, Co{O(Se)P(OR)₂}₂(L)₄ (where R?=?n-Pr, i-Pr; L?=?C₅H₅N, NC₅H₄Me-2, NC₅H₄Me-3), were synthesized by in situ reactions of CoCl₂?·?6H₂O, Lewis base, and NaO(Se)P(OR)₂. The single crystal structure of Co{O(Se)P(OⁱPr)₂}₂(C₅H₅N)₄ shows distorted octahedral geometry around cobalt(II) and monoselenophosphates are trans. The CoN₄ forms a square plane. These bis(O,O′-dialkylmonoselenophosphato)cobalt(II) adducts were characterized by elemental analyses, spectroscopic techniques (UV-Vis, infrared, ¹H and ³¹P), and magnetic moment measurements.     

Synthesis,structure, and DNA binding of three reduced amino-acid Schiff-base zinc(II), nickel(II), and cadmium(II) complexes

Three new reduced amino-acid Schiff-base complexes, [Zn(HL)₂] · H₂O (1), [Ni(HL)₂] · H₂O (2), and [Cd(HL)₂] · H₂O (3), where H₂L is a reduced Schiff base derived from condensation of N-(2-hydroxybenzaldehyde) and L-histidine, have been synthesized and characterized by elemental analysis, UV-Vis absorption spectra and single crystal X-ray diffraction. Complexes 1–3 are isostructural. All metal centers are six-coordinate with O₂N₄ donor sets in slightly distorted octahedra. Unlike its Schiff-base counterpart, the deprotonated monoanionic ligand HL^? has a more flexible backbone and two HL^? are tridentate to one metal. Moreover, the binding interactions of these complexes with calf thymus DNA (CT-DNA) have been investigated by UV-Vis spectra and fluorescence quenching, which show that the complexes bind in an intercalative mode.     

REACTION BETWEEN [PdCl4]2- AND 5,5-DIMETHYL-2-THIOXOIMIDAZOLIDIN-4-ONE

Abstract

The reaction between 5,5-dimethyl-2-thioxoimidazolidin-4-one (H2L) and [PdCl₄]^2- has been studied in aqueous solution by potentiometric and spectrophotometric measurements. In the presence of the palladium salt, H₂L is completely monodeprotonated (HL^?); from spectrophotometric measurements, only two complexes having 1:1 and 1:2 Pd/ligand mol ratios have been identified. Potentiometric titrations, carried out on solutions with 1:1, 1:2, 1:3 and 1:4 metal/ligand mol ratios, show that these complexes must be formulated as Pd(HL)₂ and [Pd₂(HL)₂(μ-H₂O)(μ-OH)]⁺. Ionization constants of the pure ligand and formation constants of the complexes give pH distribution curves of the various species and the spectra of the two complexes. From MeOH, S-coordinated Pd(H₂L)_nCl₂ (n = 2–4) complexes have been separated in the solid state; from water, two complexes of formula Pd(H₂L)(HL)Cl and Pd(HL)Cl have been obtained with HL^? N,S-coordinated to the metal.     

Synthesis,characterization, and biological activity studies of copper(II)–metal(II) binuclear complexes of dipyridylglyoxal bis(2-hydroxybenzoyl hydrazone)

A new series of copper(II) mononuclear and copper(II)–metal(II) binuclear complexes [(H₂L)Cu] ? H₂O, [CuLM] ? nH₂O, and [Cu(H₂L)M(OAc)₂] ? nH₂O, n = 1–2, M = Co(II), Ni(II), Cu(II), or Zn(II), and L is the anion of dipyridylglyoxal bis(2-hydroxybenzoyl hydrazone), H₄L, were synthesized and characterized. Elemental analyses, molar conductivities, and FT-IR spectra support the formulation of these complexes. IR data suggest that H₄L is dibasic tetradentate in [(H₂L)Cu] ? H₂O and [Cu(H₂L)M(OAc)₂] ? nH₂O but tetrabasic hexadentate in [CuLM] ? nH₂O (n = 1–2). Thermal studies indicate that waters are of crystallization and the complexes are thermally stable to 347–402°C depending upon the nature of the complex. Magnetic moment values indicate magnetic exchange interaction between Cu(II) and M(II) centers in binuclear complexes. The electronic spectral data show that d–d transitions of CuN₂O₂ in the mononuclear complex are blue shifted in binuclear complexes in the sequences: Cu–Cu > Cu–Ni > Cu–Co > Cu–Zn, suggesting that the binuclear complexes [CuLM] ? nH₂O are more planar than the mononuclear complex. The structures of complexes were optimized through molecular mechanics applying MM ⁺force field coupled with molecular dynamics simulation. [(H₂L)Cu] ? nH₂O, [CuLM] ? nH₂O, and the free ligand were screened for antimicrobial activities on some Gram-positive and Gram-negative bacterial species. The free ligand is inactive against all studied bacteria. The screening data showed that [CuLCu] ? H₂O > [(H₂L)Cu] ? H₂O > [CuLZn] ? H₂O > [CuLNi] ? 2H₂O ≈ [CuLCo] ? H₂O in order of biological activity. The data are discussed in terms of their compositions and structures.     

Nano‐synthesis and spectral,thermal, modeling,quantitative structure–activity relationship and docking studies of novel bioactive homo‐binuclear metal complexes derived from thiazole drug for therapeutic applications

Seven novel homo‐binuclear Cr(III), Fe(III), Cu(II), ZrO(II), Sn(II), Pb(II) and Ce(III) nanosized complexes of a thiazole drug (H₂L) were synthesized for chemotherapeutic applications. H₂L was prepared via a condensation reaction between 2‐(4‐aminobenzenesulfonamido)thiazole and 2‐hydroxybenzaldehyde. The structures of H₂L and its metal complexes were investigated by various means. These included microanalysis, ¹H NMR, ¹³C NMR, Fourier transform infrared, UV–visible, electron spin resonance and mass spectroscopies, transmission electron microscopy (TEM), powder X‐ray diffraction (XRD), thermogravimetric analysis (TGA) and molar conductivity. The measurements revealed that H₂L coordinates with the metal ions through two chelating centers, indicating its behavior as a dibasic tetradentate ligand. The first center involves the nitrogen of azomethine (CH═N) and the α‐hydroxyl oxygen while the other center is the thiazole nitrogen and the sulfonamide oxygen. From spectroscopic and analytical data, the Cr(III), Fe(III) and Ce(III) complexes have octahedral geometries, whereas the Cu(II), ZrO(II), Sn(II) and Pb(II) complexes have tetrahedral geometries. TEM and XRD measurements unambiguously showed the nanometric particle sizes of the complexes. The activation thermo‐kinetic parameters, E*, ?H*, ?S* and ?G*, of the various decomposition steps of the complexes were determined mathematically from the TGA curves. Gaussian09 and quantitative structure–activity relationship modeling studies were utilized to verify the biological and structural feature relationships. Docking studies were performed to throw more light on the biological priority of the proposed drugs, using microorganism protein receptors. The antitumor and antimicrobial efficiencies of the H₂L drug and its complexes were determined to estimate their potential therapeutic utility. In general, the complexes showed greater antitumor and antimicrobial efficiencies than the H₂L drug. The Fe(III) complex exhibited efficient antimicrobial activities against Candida albicans and Staphylococcus aureus and its efficiency is equivalent to that of standard drugs. The Cu(II) complex showed the greatest cytotoxic activity towards HEPG2.