Synthetic, spectral, and antimicrobial aspects of biologically relevant coordination compounds of dioxomolybdenum(VI) and oxovanadium(V)

Heterocyclic ketimines, 5-nitro-3-(indolin-2-one)hydrazinecarbothioamide (L¹H), 5-nitro-3-(indolin-2-one)hydrazinecarboxamide (L²H), 6-nitro-3-(indolin-2-one)hydrazinecarbo-thioamide (L³H), and 6-nitro-3-(indolin-2-one) hydrazinecarboxamide (L⁴H), were prepared by the condensation of thiosemicarbazide and semicarbazide hydrochloride (in the presence of sodium acetate) in ethanol with the respective ketones. The dioxomolybdenum(VI) complexes and oxovanadium(V) complexes have been prepared by mixing dioxobis(2,4-pentanedinato)molybdenum(VI) in 1: 2 molar ratios and vanadium oxytrichloride in 1: 1 and 1: 2 molar ratios with monobasic bidentate ketimines. The resulting complexes have been characterized by elemental analysis, conductance measurements, and spectral studies, including IR, ¹H NMR, and UV spectra. The ketimines and their corresponding metal complexes have been tested on a number of pathogenic bacteria and fungi in order to assess their growth inhibition potency at different concentrations. The article was submitted by the authors in English.     

Coordination chemistry of oxovanadium(V) complexes with active Schiff bases: synthetic,spectral, and antimicrobial approach

The Schiff bases, 3-(indolin-2-one)hydrazinecarbothioamide (L¹H), 3-(indolin-2-one)hydrazinecarboxamide (L²H), 5,6-dimethyl-3-(indolin-2-one)hydrazinecarbothioamide (L³H), and 5,6-dimethyl-3-(indolin-2-one)hydrazinecarboxamide (L⁴H), have been synthesized by the condensation of ¹ H-indol-2,3-dione and 5,6-dimethyl-1H-indol-2,3-dione with the corresponding hydrazinecarbothioamide and hydrazinecarboxamide, respectively. The complexes of oxovanadium and ligands have been characterized by elemental analyses, melting points, conductance measurements, molecular weight determinations, and IR, ¹H NMR and UV spectral studies. These studies showed that the ligands coordinated to the oxovanadium in a monobasic bidentate fashion through oxygen or sulfur and the nitrogen donor system. Thus, penta-and hexacoordinated environment around the vanadium atom has been proposed. All the complexes and their parent organic moieties have been screened for their biological activity on several pathogenic fungi and bacteria and were found to possess appreciable fungicidal and bactericidal properties. The article was submitted by the authors in English.     

Structural Studies with Antimicrobial and Antifertility Activity of a Monofunctional Bidentate Ligand with its Boron(III), Palladium(II), and Platinum(II) Complexes

The reaction of the sulfur donor Schiff base ligand, 7-nitro-3-(indolin-2-one) hydrazinecarbo-thioamide, with phenyldihydroxyboron in benzene, palladium(II)chloride, and platinum(II) chloride, in ethanol, gave the mononuclear tetracoordinated and hexacoordinated complexes. The Schiff base ligand coordinated to the boron atom in 1:1 and 1:2 molar ratios and to the palladium and platinum metals in only 1:2 molar ratios in the presence of an acidic and basic medium. Tentative structural conclusions are drawn for reaction products based upon elemental analysis, electrical conductance, and spectral (electronic, infrared, ¹ H NMR, ¹³ C NMR, and ¹¹ B NMR) data. The antifertility activity of the ligand and its nonmetal/metal complexes are discussed with a comparative study in an effective manner.     

Palladium(II) and platinum(II) derivatives of benzothiazoline ligands: Synthesis, characterization, antimicrobial and antispermatogenic activity

A series of Pd(II) and Pt(II) complexes with two N(∩)S donor ligands, 5-chloro-3-(indolin-2-one)benzothiazoline and 6-nitro-3-(indolin-2-one)benzothiazoline, have been synthesized by the reaction of metal chlorides (PdCl2 and PtCl2) with ligands in 1:2 molar ratios. All the synthesized compounds were characterized by elemental analyses, melting point determinations and a combination of electronic, IR, 1H NMR and 13C NMR spectroscopic techniques for structure elucidation. In order to evaluate the effect of metal ions upon chelation, both the ligands and their complexes have been screened for their antimicrobial activity against the various pathogenic bacterial and fungal strains. The metal complexes have shown to be more antimicrobial against the microbial species as compared to free ligands. One of the ligands, 5-chloro-3-(indolin-2-one)benzothiazoline and its corresponding palladium and platinum complexes have been tested for their antifertility activity in male albino rats. The marked reduction in sperm motility and density resulted in infertility by 62-90%. Significant alterations were found in biochemical parameters of reproductive organs in treated animals as compared to control group. It is concluded that all these effects may finally impair the fertility of male rats.     

Synthesis and nematicidal activities of 1,2,3-benzotriazin-4-one containing 4,5-dihydrothiazole-2-thiol derivatives against Meloidogyne incognita

Abstract

A series of novel 1,2,3-benzotriazin-4-one derivatives containing 4,5-dihydrothiazole-2-thiol were synthesized and characterized by ¹H NMR, ¹³C NMR, ¹⁹F NMR and HRMS. The bioassay results showed that compounds 3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)-7-methoxybenzo[d][1–3]triazin-4(3H)-one, 3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)-6-nitrobenzo[d][1–3]triazin-4(3H)-one, 7-chloro-3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)benzo[d][1–3]triazin-4(3H)-one exhibited good control efficacy against the cucumber root-knot nematode disease caused by Meloidogyne incognita at the concentration of 10.0?mg L^?1 in vivo. Compound 7-chloro-3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)benzo[d][1–3]triazin-4(3H)-one showed excellent nematicidal activity with inhibition 68.3% at a concentration of 1.0?mg L^?1. It suggested that the structure of 1,2,3-benzotriazin-4-one containing 4,5-dihydro-thiazole-2-thiol could be optimized further.     

Rapid synthesis and bioactivities of 3-(nitromethylene)indolin-2-one analogues

A new synthesis method of 3-(nitromethylene)indolin-2-one analogues is described, using the Henry reaction of isatin and N-substituted isatins with nitromethane followed by dehydration of the nitroaldol adduct with mesyl chloride. The use of diethylamine (rather than DBU) as the base catalyst in a solvent-free Henry reaction gave the nitroaldol adduct in sufficient purity as to allow its direct dehydration to nitroalkene. Overall yields for this two-step synthesis are satisfactory (typically 50–77 % after chromatographic purification). 3-(Nitromethylene)indolin-2-one analogues are valued protective agents against H₂O₂-induced apoptosis using PC12 cells, and for their cytotoxicity against the A549 and P388 lung cancer cell lines. One compound, (E)-1-benzyl-3-(nitromethylene)indolin-2-one (VIII), exhibited potent activity in the latter assay.     

Synthesis of 4′-[3-methyl-5-thioxo-1H-1,2,4-triazol-4(5H)-yl]-2′,5′-diphenyl-2′,4′-dihydro spiro[indolin-3,3′[1,2,4]triazol]-2-one derivatives

In this paper 1,3-dipolar cycloaddition reaction has been studied. An efficient synthesis of 4′-[3-methyl-5-thioxo-1H-1,2,4-triazol-4(5H)-yl]-2′,5′-diphenyl-2′,4′-dihydro spiro(indolin-3,3′[1,2,4]triazol)-2-one derivatives using triethylamine in MeCN at room temperature is reported. The structures of the obtained compounds were confirmed by means of elemental analysis, MS and spectral (IR, ¹H, and ¹³C NMR) methods.     

Ultrasound-assisted synthesis of 3-(1-(2-(1H-indol-3-yl)ethyl)-2-aryl-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydro-1H-indol-3-yl)indolin-2-ones by novel core-shell bio-based nanocatalyst anchoring sulfonated L-histidine on magnetized silica (SO3H-L-His@SiO2-nano Fe3O4)

An efficient synthesis of 3-(1-(2-(1H-indol-3-yl)ethyl)-2-aryl-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydro-1H-indol-3-yl)indolin-2-ones is reported via a one-pot three-component reaction of 3-phenacylidenoxindoles, tryptamine, and dimedone under ultrasound irradiation using a newly prepared core-shell nanostructure. The utilized nanocatalyst is obtained by anchoring sulfonated L-histidine amino acid shell, as the bio part, on silica-nanomagnetite core (SO₃H-L-His@SiO₂-nano Fe₃O₄) and characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy (¹H NMR), field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric/differential thermal analysis, vibrating sample magnetometer measurements, transmission electron microscopy, and back-titration. The protocol contains several advantages, such as relatively short reaction times, simple work-up procedure by separation of the catalyst with an external magnet, the use of economical and environmentally friendly ultrasonic waves, and reusability and recoverability of the core-shell nano-promoter for three runs without significant activity loss.     

Coordination behavior and biopotency of N and S/O donor ligands with their palladium(II) and platinum(II) complexes

Some metal complexes of Schiff bases have been prepared by the interactions of palladium(II) and platinum(II) chloride with 5-chloro-1,3-dihydro-3-[2-(phenyl)-ethylidene]-2H-indol-2-one-hydrazinecarbothioamide(L¹H) and 5-chloro-1,3-dihydro-3-[2-(phenyl)-ethylidene]-2H-indol-2-one-hydrazinecarboxamide(L²H), in bimolar ratios. All the new compounds have been characterized by elemental analyses, conductance measurements, molecular weight determinations, IR and ¹H NMR spectral studies. The spectral data are consistent with a square planar geometry around Pd(II) and Pt(II) in which the ligands act as neutral bidentate and monobasic bidentate ligands, coordinating through the nitrogen and sulfur/oxygen atoms. Free ligands and their metal complexes were screened for their antimicrobial activity on different species of pathogenic fungi and bacteria and their biopotency has been discussed.     

New Schiff Bases Containing Silicon and Their Co(II) and Cu(II) Complexes: Synthesis,Complexation, Characterization,and Antimicrobial and Electrochemical Properties

Two novel Schiff base ligands, 4-((3-(trimethoxysilyl)propylimino)methyl)benzene– 1,2,3-triol (L¹H) and 4-((3-(triethoxysilyl)propylimino)methyl)benzene–1,2,3-triol (L²H), have been synthesized by the reaction of 2,3,4-trihydroxybenzaldehyde with 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane, respectively. The mononuclear Co^II and Cu^II complexes of these Schiff bases were prepared. The complexes of the Schiff bases are formed by coordination of N, O atoms of the ligands. The proposed structures were confirmed by elemental analyses, FT-IR, and UV-visible spectroscopy, magnetic susceptibility, and conductance measurements; the ¹H NMR spectra of the ligands were also recorded. The analytical data show that the metal to ligand ratio in the complexes containing silicon is 1:2. The electrochemical properties of the complexes have been investigated at 100 mVs^?1 scan rate in DMSO. In addition, the antimicrobial activity of L¹H and L²H Schiff ligands, and their [M(L¹)2] and [M(L²)2] type coordination compounds, were investigated.     

Aluminum(III) complexes containing O,O chelating ligand

The stoichiometric reactions of trimethylaluminum with 2,6‐(MeOCH₂)₂C₆H₃OH (LH) revealed compounds L₃Al ( 1 ) and L₂AlMe ( 2 ). On the other hand reaction of 1 equiv. of LH with trimethylaluminum did not lead to the formation of complex LAlMe₂ ( 3 ), rather 2 together with Me₃Al were observed as a result of a disproportionation of 3 . Compounds 1 and 2 were characterized by elemental analysis, ¹H and ¹³C NMR spectroscopy and in the case of 1 by X‐ray diffraction. Derivative 2 underwent transmetalation with Ph₃SnOH, giving LSnPh₃ ( 4 ) as the result of a migration of ligand L from the aluminum to the tin atom. The identity of 4 was established by elemental analysis, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy and ¹H, ¹¹⁹Sn HMBC experiments. The system 2 and B(C₆F₅)₃ in a 1:1 molar ratio was shown to be active in the polymerization of propylene oxide and ε‐caprolactone. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis and characterization of novel oxime-imine ligands and their heteronuclear ruthenium(III) complexes

Vicinal carbonyl oxime (HL¹) and oxime-imine (H₂L²) ligands and their mononuclear Ru(III) and Cu(II), heterodinuclear Ru(III)-Mn(II), Ru(III)-Ni(II), Ru(III)-Cu(II), and heterotrinuclear Ru(III)-Cu(II)-Ru(III) chelates were synthesized and characterized by elemental analysis, molar conductivity, IR, ESR, ICP-OES, magnetic moment measurements, and thermal analyses studies. The free ligands were also characterized by ¹H NMR spectra. The carbonyl-oxime ligand coordinates through the oxygen of =N-OH to form a six-membered chelate ring. The quadridentate tetraaza ligand (H₂L²) obtained by condensing of the bidentate ligand 1-p-diphenylmethane-2-hydroxyimino-2-(1-naphthylamino)-1-ethanone (HL¹) with 1,2-phenylenediamine coordinates with Ru(III) through its nitrogen donors in the equatorial position with the loss of one of the oxime protons and concomitant formation of an intramolecular hydrogen bond. Stoichiometric and spectral results of the metal complexes indicated that the metal: ligand ratios in the mononuclear complexes of the ligand (HL¹) were found to be 1: 2, while these ratios were 1: 1 in the mononuclear complexes of the ligand (H₂L²). The metal: ligand ratios of the dinuclear complexes were found to be 2: 1, and this ratio was 3: 2 in the trinuclear complex. The article is published in the original.     

Synthesis and spectral studies of macrocyclic Pb(II), Zn(II), Cd(II) and La(III) complexes by template reaction of 1,2-bis(2-formylphenyl)ethane with metal nitrate and various diamine

Eight new macrocyclic complexes were synthesized by template reaction of 1,4-bis(3-aminopropoxy)butane or (±)-trans-1,2-diaminocyclohexane with metal nitrate and 1,2-bis(2-formylphenyl)ethane and their structures were proposed on the basis of elemental analysis, FT-IR, UV-Vis, molar conductivity measurements, ¹H NMR and mass spectra. The metals to ligand molar ratios of the complexes were found to be 1: 1. The complexes are 1: 2 electrolytes for Cd(II), Pb(II) and Zn(II) complexes and 1: 3 electrolytes for La(III) as shown by their molar conductivities (Λ_m) in DMSO at 10⁻³ mol L⁻¹. Due to the existence of free ions in these complexes, such complexes are electrically conductive. The configurations of Cd(II) and Zn(II) complexes were proposed to probably tetrahedral, La(III) complexes are octahedral and Pb(II) complexes are octahedral geometry in the L¹ complex and tetrahedral geometry in the L² complex.     

Heteronuclear complexes of oxorhenium(V) with Fe(III), Co(II), Ni(II), Cu(II), Cd(II) and UO2(VI) and their biological activities

Heteronuclear complexes containing oxorhenium(V), with Fe(III), Co(II), Ni(II), Cu(II), Cd(II) and UO₂(VI) ions were prepared by the reaction of the complex ligands [ReO(HL¹)(PPh₃)(OH₂)Cl]Cl (a) and/or [ReO(H₂L²)(PPh₃)(OH₂)Cl]Cl (b), where H₂L¹?=?1-(2-hydroxyphenyl)butane-1,3-dione-3-(5,6-diphenyl-1,2,4-triazine-3-ylhydrazone) and H₃L²?=?1-(2-hydroxyphenyl)butane-1,3-dione-3-(1H-benzimidazol-2-ylhydrazone), with transition and actinide salts. Heterodinuclear complexes of ReO(V) with Fe(III), Co(II), Ni(II), Cu(II) and Cd(II) were obtained using a 1?:?1 mole ratio of the complex ligand and the metal salt. Heterotrinuclear complexes were obtained containing ReO(V) with UO₂(VI) and Cu(II) using 2?:?1 mole ratios of the complex ligand and the metal salts. The complex ligands a and b coordinate with the heterometal ion via a nitrogen of the heterocyclic ring and the nitrogen atom of the C=N⁷ group. All transition metal cations in the heteronuclear complexes have octahedral configurations, while UO₂(VI)?complexes have distorted dodecahedral geometry. The structures of the complexes were elucidated by IR, ESR, electronic and ¹H NMR spectra, magnetic moments, conductance and TG-DSC measurements. The antifungal activities of the complex ligands and their heteronuclear complexes towards Alternaria alternata and Aspergillus niger showed comparable behavior with some well-known antibiotics.     

Synthesis,characterization and mass spectral studies on acrocyclic schiff base complexes of Pb(II), Zn(II) and La(III)

Six new macrocyclic complexes were synthesized by template reaction of (±)-1,4-bis(3-aminopropoxy)butane with metal(II) nitrate and 1,10-bis(2-formylphenyl)-1,4,7,10-tetraoxadecane or 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane and their structures were proposed on the basis of elemental analysis, FT-IR, UV-Vis, molar conductivity measurements, ¹H NMR and mass spectra. The metals to ligand molar ratios of the complexes were found to be 1: 1. The complexes are 1: 2 electrolytes for Pb(II) and Zn(II) complexes and 1: 3 electrolytes for La(III) as shown by their molar conductivities (Λ_m) in DMSO at 10⁻³ mol L⁻¹. Due to the existence of free ions in these complexes, such complexes are electrically conductive. The configurations of La(III) and Zn(II) complexes were proposed to probably octahedral.     

Structural characterization and cytotoxicity studies of ruthenium(II)–dmso–chloro complexes of chalcone and flavone derivatives

A synthetic precursor cis-[Ru^IICl₂(dmso)₄] is complexed separately with 3-(4-benzyloxyphenyl)-1-(2-hydroxylphenyl)-prop-2-en-1-one (L¹H) and 2-(4-benzyloxyphenyl)-3hydroxy-chromen-4-one (L²H). The resulting complexes are assigned the composition fac-[RuCl(S-dmso)₃(L¹)] 1 and fac-[RuCl(S-dmso)₃(L²)] 2 using elemental analyses, FAB mass data and spectroscopic (IR, ¹H NMR, UV–Vis, emission) spectral properties. The X-ray diffraction analysis shows that complexes self-associate through non-covalent interactions and provide 1D and 2D supramolecular structures. These complexes are assayed for their cytotoxicity studies on Dalton Lymphoma cell lines.     

Synthesis,crystal structure and spectral characterization of Co(II) complexes with acylpyrazolone ligands

The three new Cobalt(II) complexes [Co(L¹)₂(H₂O)₂] (1), [Co(L²)₂(H₂O)₂] (2), and [Co(L³)₂(H₂O)₂] (3) have been synthesized by interaction of acyl pyrazolone ligands, 4-(4-chlorobenzoyl)3-methyl1-phenyl1H-pyrazole5(4H)-one (HL¹), 4-(4-chlorobenzoyl)1-(3-chlorophenyl)3-methyl1H-pyrazole5(4H)-one (HL²) and 5-methyl4-(4-methylbenzoyl)2-phenyl2,4-dihydro3H-pyrazole3-one (HL³) with CoCl₂.6H₂O. The complexes were screened using FTIR, UV–Vis, TGA, and Single Crystal X-ray diffraction spectroscopic techniques. A relative study of the ligands’ FTIR spectra and their metal complexes reveal the formation, sifting, and disappearance of several bands during complexation. Other interpretations stipulated that these three complexes are mononuclear and exhibited octahedral geometry around Co²⁺.Triclinic crystal system, Distortion in Octahedral geometry, and Intermolecular hydrogen bonding confirmed by Single-crystal XRD analysis of [Co(L³)₂(EtOH)₂] complex.     

Synthesis and characterization of copper(II), cobalt(II), nickel(II), and iron(III) complexes with two diamine Schiff bases and catalytic reactivity of a chiral diamine cobalt(II) complex

New transition metal complexes of Co(II), Cu(II), Ni(II), and Fe(III) of the ligands 6,6′-(1E,1′E)-(4,5-dimethyl-1,2-phenylene)bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(7-hydroxy-5-methoxy-2-methyl-4H-chromen-4-one) H₂L¹ and 6,6’-(1E,1′E)-cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(7-hydroxy-5-methoxy-2-methyl-4H-chromen-4-one) H₂L² have been prepared and characterized using physio-chemical and spectroscopic methods. The results obtained for the complexes indicated that the geometries of the metal centres are either square planar or octahedral. Cyclopropanation reactions of unactivated olefins by ethyldiazoacetate (EDA) in the presence of [L¹Cu]·H₂O, [L²Cu]·2H₂O and [L²*Co]·2H₂O as catalysts were examined. The results showed that only [L²*Co]·2H₂O can act as a catalyst for the cyclopropanation reaction of unactivated olefins with very high selectivity (up to 99% based on EDA).     

Synthesis,Spectroscopic Characterization,and In Vitro Antimicrobial Potency of Sulfur-Bonded Complexes of Boron(III)

The present article describes the synthesis and characterization of tetracoordinated boron (III) complexes with monobasic bidentate ligands (L ¹ H, L ² H, L ³ H, L ⁴ H, L ⁵ H, and L ⁶ H) having the general formulae PhB(L)(OH) and PhB(L) ₂ . The 1:1 and 1:2 reactions of phenyl boronic acid with monobasic bidentate ligands resulted in the formation of colored solids. The complexes have been characterized by elemental analysis, molecular weight determinations, and IR and NMR ( ¹ H, ¹³ C and ¹¹ B) spectroscopy, as well as UV-vis spectral studies. Based on these studies, a tetrahedral geometry has been proposed for the resulting complexes. The ligands, along with their complexes, have been screened in vitro against a number of pathogenic fungal and bacterial strains. The studies indicate that the boron chelates are more potent than the parent ligands.     

Preparation and alkylation of regioisomeric tetrahydrophthalimide-substituted indolin-2(3H)-ones

A series of novel regioisomeric tetrahydrophthalimide-substituted indolin-2-ones has been prepared via the Sommelet-Hauser type cyclization of appropriately substituted anilines as potential herbicides. The resultant indolin-2-ones were then regioselectively alkylated at N-1 and C-3 to give 1,3,3-trisubstituted indolin-2-ones. The most active series was also prepared by the bis-nitration of m-fluorophenylacetic acid followed by reduction and cyclization to give 6-amino-5-fluoroindolin-2-one. Elaboration to the tetrahydrophthalimide-substituted indolin-2-one was followed by C- and N-alkylation to give the desired compounds.