Preparation and spectroscopic studies of diorganotin(IV) complexes with adenosine and related compounds

Nine complexes of adenosine and related compounds (adenosine-5'-monophosphate, adenosine-5'-triphosphate, 1-methyl-adenosine, pyridoxal-5-phosphate and -nicotinamide-adenine-dinucleotide-phosphoric acid) with di-n-butyltin(IV) oxide and/or di-n-butytin(IV) dichloride were prepared in the solid state. The compositions of the complexes were determined by standard analytical methods. It was found that the complexes contain organotin(IV) moiety and the ligand in a ratio of 1:1 or 2:1. The FTIR spectra demonstrated that di-n-butyltin(IV) oxide reacts with the D-ribose moiety of the ligands, while di-n-butyltin(IV) dichloride is co-ordinated to the deprotonated phosphate group. The basic part of the ligands does not participate directly in complex formation. Comparison of the experimental Mössbauer QS values with those calculated on the basis of the PQS concept revealed that the organotin(IV) moiety has trigonal-bipyramidal, octahedral and in some cases tetrahedral geometry also. Some of the complexes contain the organotin(IV) cation in two different surroundings.     

Organotin(IV) coordination by oxime analogues of amino acids and peptides

The complexes of four oxime analogues of amino acids and peptides (containing {O,N} donor atoms) with Bu₂SnO were prepared, with ligand to metal ratios of 1 : 1 or 1 : 2, by two different methods. The FT-IR and Raman spectra clearly demonstrated that the organotin(IV) moieties react with the {O,N} atoms of the ligands. It was found that in most cases the -COO^- group is coordinated to the central metal ion in a monodentate mode. Complex formation was accompanied by a rearrangement of the hydrogen-bonding network existing in the ligands. The complexes probably have monomeric structures. Comparison of the experimental Mössbauer values with those calculated on the basis of the point charge model (pqs) formalism revealed that the organotin(IV) moiety has octahedral (oct) geometry, and in certain cases trigonal-bipyramidal (tbp) geometry too.     

Preparation and structural studies of organotin(IV) complexes formed with organic carboxylic acids

The complexes of six organic carboxylic acids (containing {O,O} donor atoms) with Bu₂Sn(IV)²⁺ and Ph₃Sn(IV)⁺ with ligand to metal ratios of 1 : 1 and 1 : 2, were prepared by two different methods. The FtIR and Raman spectra clearly demonstrated that the organotin(IV) moieties react with the {O,O} atoms of the ligands. It was found that in most cases the -COO^-group was chelated to the central metal ions, but monodentate coordination was also sometimes observed. Complex formation was accompanied by a rearrangement of the hydrogen-bonding network existing in the ligands. The complexes probably have polymeric structures. Comparison of the experimental Mössbauer D values with those calculated on the basis of the point charge model formalism revealed that the organotin(IV) moiety has a trigonal-bipyramidal (tbp) geometry, and in certain cases a tetrahedral (tetr) geometry too. Finally, the local structure of the maleic acid complex formed with Bu₂Sn(IV)²⁺ was determined by an EXAFS method.     

Preparation and XAFS studies of organotin(IV) complexes with adenosine and related compounds and calf thymus DNA

Complexes of adenosine and related compounds (adenosine-5’-monophosphate, adenosine-5’-triphosphate and pyridoxal-5-phosphate) with Bu₂SnO and/or BuSnCl₂ were prepared in the solid state. The compositions of the complexes were determined by standard analytical methods. It was found that the complexes contain the organotin(IV) moiety and the ligand in a ratio of 1:1. The FT-IR spectra demonstrated that Bu₂SnO reacts with the D-ribose moiety of the ligands, while Bu₂SnCl₂ is coordinated to the deprotonated phosphate group. The basic part of the ligands does not participate directly in complex formation. Comparison of the experimental Mössbauer Δ (quadrupole splitting) values with those calculated on the basis of the pqs concept revealed that the organotin(IV) moiety has Tbp and in some cases also T_h geometry. The adenosine complex contains the organotin(IV) cation in two different surroundings (Tbp and T_h). The local structures of the complexes were determined by means of EXAFS measurements. At the same time a number of organotin(IV) complexes containing different organo moieties of calf thymus DNA were also prepared. Similarly as above, EXAFS data were obtained for these compounds and analyzed by using multishell models up to 300 pm. These results are the first structural data (bond lengths) on complexes formed with organotin(IV)-DNA and related compounds.     

Coordination behavior of the carboxylate group in organotin(IV) derivatives of 2-[(2′,4′,6′-tribromophenylamido)]benzoic acid and 3-[(2′,4′,6′-tribromophenylamido)]propenoic acid: Spectroscopic studies

The complexes of two organic carboxylates (containing {O,O}-donor atoms) with Me₂Sn^(IV)Cl₂, n-Bu₂Sn^(IV)Cl₂, Bz₂Sn^(IV)Cl₂, Oct₂Sn^(IV)O, Me₃Sn^(IV)Cl, n-Bu₃Sn^(IV)Cl, Ph₃Sn^(IV)Cl, Ph₃Sn^(IV)Cl, and Bz₃Sn^(IV)Cl having ligand-to-metal ratios of 1: 2 and 1: 1 were prepared by two different methods. The FT-IR spectra clearly demonstrated that organotin(IV) moieties react with {O,O}-atoms of the ligands. It was found that in all cases the COO⁻ group was acting as bidentate in the solid state. The ¹¹⁹Sn NMR data revealed that the organotin(IV) moiety has a tetrahedral geometry in non-coordinating solvents. The biological activity of these compounds was compared with that of their precursors, and all the synthesized compounds show significant antibacterial activity. The antifungal activity of the complexes against six plant pathogens has been estimated. The complexes display marked toxicity against these fungi and are more fungitoxic than free acids. The compounds have also shown significant cytotoxicity against Brine Shrimp (Artemia salina). The article was submitted by the authors in English.     

Preparation and structural characterization of organotin(IV) complexes with ligands containing a hetero {N} atom and a hydroxy group or hydroxy and carboxyl groups

Twenty-two n-butyltin(IV) and t-butyltin(IV) complexes of ligands containing an -OH (-CO) group or -OH and -COOH groups and an aromatic {N} donor atom were prepared by metathetical reactions. On the basis of the FT-IR and Mössbauer spectroscopic data, molecular structures were assigned to these compounds. The binding sites of the ligands were identified by means of FT-IR spectroscopic measurements, and it was found that in most cases the organotin(IV) moiety reacts with the phenolic form of these ligands. In the complexes with -OH and -COOH functions, the -COOH group is coordinated to the organotin(IV) centres in a monodentate manner. The ¹¹⁹Sn Mössbauer and the FT-IR studies support the formation of trigonal bipyramidal (TBP) and octahedral (O_h) molecular structures. Furthermore, X-ray diffraction analysis has been performed on the n-butyltin(IV)- and t-butyltin(IV)-8-quinol 8-olato-O,N single crystals. The hexacoordinated tin centres exhibit cis-octahedral geometry in both complexes.     

Synthetic, structural, and antimicrobial studies of organotin(IV) complexes of semicarbazone, thiosemicarbazone derived from 4-hydroxy-3-methoxybenzaldehyde

Reaction of dibutyltin dichloride, dimethyltin dichloride, and tributyltin chloride with ligands derived from thiosemicarbazone and semicarbazone leads to the formation of a new series of organotin(IV) complexes of general formula R₂SnCl₂·L and R₃SnCl·L (where L ligands derived from the condensation of thiosemicarbazide and semicarbazide with 4-hydroxy-3-methoxybenzaldehyde). The authenticity of these ligands and their metal complexes have been established on the basis of elemental analysis, conductance measurements, molecular weight determinations, infrared, ¹H NMR, ¹³C NMR, ¹¹⁹Sn NMR, and UV spectral studies. These studies showed that the ligands coordinate to the metal atom in a bidentate. An octahedral structure is proposed for the organotin(IV) complexes. The ligands and its metal complexes are screened for their antimicrobial activities against some Gram-positive and Gram-negative bacteria, and fungus. The studies demonstrated that metalation can increase the antimicrobial activity rather than the free ligands.     

Synthesis,spectroscopic characterization (IR, 1H, 13C and 119Sn NMR,electrospray mass spectrometry) and toxicity of new organotin(IV) complexes with N,N′,O‐ and N,N′,S‐scorpionate ligands

New organotin(IV) derivatives containing the anionic ligands bis(3,5‐dimethylpyrazol‐1‐yl)dithioacetate [LCS₂]⁻ and bis(3,5‐dimethylpyrazol‐1‐yl)acetate [LCO₂]⁻ have been synthesized from reaction between (CH₃)₂SnCl₂ and lithium salts of the ligands. Mononuclear complexes of the type {[LCX₂](CH₃)₂SnCl} (X = S or O) have been obtained and fully characterized by elemental analyses and FT‐IR in the solid state and by NMR (¹H, ¹³C and ¹¹⁹Sn) spectroscopy, conductivity measurements and electrospray ionization mass spectrometry in solution. The acute toxicity of new organotin(IV) derivatives on rat was studied, comparing their effect with those of dimethyltin chloride (CH₃)₂SnCl₂. The comparison of LD₅₀ of organotin(IV) complexes and (CH₃)₂SnCl₂ administered intraperitoneally, as a single dose, evaluated in vivo on rats, showed that toxicity decreases as follows: (CH₃)₂SnCl₂ > LCO₂ > LCS₂. The effect of these organotin(IV) complexes on DNA was evaluated in vitro and in vivo on rats treated with different doses of these compounds (1/20 LD₅₀ and 1/100 LD₅₀). The lymphocyte DNA status was assessed by the comet assay, a rapid and sensitive single‐cell electrophoresis technique, used to detect primary DNA damage in individual cells. After 36 h from the start of treatment the two new organotin(IV) derivatives induced a significant rise in comet assay parameters, indicating an increasing presence of damaged DNA. Copyright © 2005 John Wiley & Sons, Ltd.     

Preparation and structural characterization of [Ph3Sn(IV)] complexes with pyridine-carboxylic acids or hydroxypyridine, -pyrimidine and -quinoline

A number of [Ph₃Sn(IV)]⁺ complexes formed with ligands containing -OH (-CO), or -COOH group(s) and aromatic {N} donor atom have been prepared. The binding sites of the ligands were identified by FT-IR spectroscopic measurements. In the complexes containing hydroxy and carboxylate functions, the carboxylato group is coordinated to the organotin(IV) centres in monodentate or bridging bidentate manner. It was also found that in the hydroxypyridine and -pyrimidine complexes the [Ph₃Sn(IV)]⁺ moiety in most cases reacts with the phenolic form of the ligands. The rationalisation of the experimental ¹¹⁹Sn Mössbauer nuclear quadrupole splittings, |Δ_exp| - according to the point charge model formalism - together with the FT-IR data support the formation of trigonal bipyramidal (Tbp) or octahedral (O_h) molecular structures. Furthermore, X-ray diffraction analysis has been performed on the triphenyltin(IV)-3-phenolato-2(1H)-pyridinone-O,O′ single crystals. The penta-coordinated tin center exhibits a Tbp geometry. In case of 2-picolinic acid, a trans-phenylation was observed during the complexation, resulting [Ph₂Sn(IV)]²⁺ complex and Ph₄Sn(IV).     

Organotin(IV) complexes of NSAID,ibuprofen, X-ray structure of Ph3Sn(IBF), binding and cleavage interaction with DNA and in vitro cytotoxic studies of several organotin complexes of drugs

This study encompasses the synthesis and characterization of organotin(IV) derivatives of non-steroidal anti-inflammatory drug ibuprofen (IBF), viz. [(Me₃Sn)(IBF)] ( 1 ), [(Bu₃Sn)(IBF)] ( 2 ), [Ph₃Sn(IBF)] ( 3 ), {[Me₂Sn(IBF)]₂O}₂ ( 4 ) and [Bu₂Sn(IBF)₂] ( 5 ). The crystal structure of complex 3 , [Ph₃Sn(IBF)], indicates a highly distorted tetrahedral (td) geometry with anisobidentate mode of coordination of the carboxylate group with tin atom, and a similar structure has been proposed for other two triorganotin(IV) derivatives. Moreover, the DFT (density functional theory) calculation and other studies have verified a dimer distannoxane type of structure for complex 4 , {[Me₂Sn(IBF)]₂O}₂. Complex 5 has been found to exhibit a highly distorted octahedral geometry around the tin atom. To investigate the DNA binding profile of the synthesized complexes, viscosity measurement, UV–vis and fluorescence titrations were performed, which revealed an intercalative type of binding with DNA for IBF and complex 5 and external binding in case of the complexes 1 and 2 ; complexes 3 and 4 could not be studied owing to their insufficient solubility in tris buffer. Plasmid DNA fragmentation studies of IBF and complexes 1 , 2 and 5 indicate that they cleaved the pBR322 plasmid potentially. Further, the drugs IBF {2-[4-(2-methylpropyl)phenyl]propanoic acid}, MESNA (sodium 2-mercaptoethane-sulfonate), warfarin [2H-1-benzopyran-2-one,4-hydroxy-3-(3-oxo-1-phenylbutyl)], sulindac (2-{5-fluoro-1-[(4-methanesulfinylphenyl) methylidene]-2-methyl-1H-inden-3-yl}acetic acid) and their corresponding organotin(IV) complexes 1–19 (complexes 6–19 were synthesized/reported previously) were screened in vitro for cytotoxicity against human cancer cell lines viz. DU145 (prostate cancer), HCT-15 (colon adenocarcinoma), Caco-2 (colorectal adenocarcinoma), MCF-7 (mammary cancer), LNCaP (androgen-sensitive prostate adenocarcinoma) and HeLa (cervical cancer), through MTT reduction assay and the cause of cell death was investigated through acridine orange/ethidium bromide staining of cells and DNA fragmentation assay. The probable structure–cytotoxicity relationship is also discussed. The major role of apoptosis along with small necrosis was also validated by flow cytometry assay using annexin V–fluorescein isothiocyanate and propidium iodide analysis.     

Organotin(IV) complexes with 2-hydroxynaphthaldehyde-N(4)-ethylthiosemicarbazone: Synthesis,characterization, and in vitro antibacterial activity

Four new organotin(IV) complexes with 2-hydroxynaphthaldehyde-N(4)-ethylthiosemicarbazone [(H₂DNET), (1)] of the type [MeSnCl(DNET] (2), [BuSnCl(DNET)] (3), [PhSnCl(DNET)] (4), and [Ph₂Sn(DNET] (5) have been synthesized by the direct reaction of H₂DNET (1) with organotin(IV) chloride(s) in the presence of potassium hydroxide in absolute methanol. All the compounds were characterized by elemental analyses, molar conductivity, UV-Vis, IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectral studies. The molecular structure of ligand (1) has been confirmed by X-ray single crystal diffraction. Spectroscopic data clearly suggested that Sn(IV) center is coordinated with the ONS tridentate ligand (H₂DNET) and exhibits a five-coordinate geometry in solution. Antibacterial studies were carried out in vitro against four bacterial strains. All organotin(IV) compounds (2–5) showed good activity against various bacteria but lower activity than the reference drug (Ciprofloxacin). The results demonstrate that organic groups attached to tin(IV) moiety have significant effect on their biological activities. Among them, diphenyltin(IV) derivative 5 exhibits significantly good activity than the other organotin(IV) derivatives (2–4).     

NEMATICIDAL,INSECTICIDAL, ANTIFERTILITY,ANTIFUNGAL AND ANTIBACTERIAL ACTIVITIES OF SALICYLANILIDE SULPHATHIAZOLE AND ITS MANGANESE,SILICON AND TIN COMPLEXES

A facile synthesis and studies on the stereochemistry and biochemical aspects of some organosilicon(IV), organotin(IV), and manganese(II) complexes derived from imine having N^∪N^∪O donor system is reported. The imine was prepared by the condensation of salicylanilide with sulphathiazole. This imine reacts with organosilicon(IV)chloride, organotin(IV)chloride, and hydrated manganese(II) chloride to yield compounds having M─O and M←N bonds. The structures of the compounds have been elucidated by physicochemical and spectral (IR, ¹H NMR, ¹³C NMR, ²⁹Si NMR, ¹¹⁹Sn NMR, and ESR) studies, which clearly point to a trigonal bipyramidal geometry around silicon(IV) and tin(IV), and tetrahedral geometry around manganese(II), as the active lone pair of the nitrogen is also included in the coordination sphere. In the search for better fungicides and bactericides, studies were conducted to assess the growth-inhibiting potential of the synthesized complexes against various pathogenic fungal and bacterial strains. These complexes are highly active against nematode (Meloidogyneincognita) and insect (Trogodermagranarium). The activity will be increased with increasing concentration. These studies demonstrate that the concentrations reached levels that are sufficient to inhibit and kill the pathogens. All compounds have also been found to act as sterilizing agents by reducing the production of sperm in male mice.     

Organotin(IV)n+ complexes formed with biologically active ligands: equilibrium and structural studies,and some biological aspects

The organotin(IV) cations form complexes with ligands containing {O}, {N}, {S}, or {phosphorus(O)} donor atoms with various composition and stability. The emergence of new experimental techniques (EXAFS, multinuclear ¹H-, ¹³C-, ¹¹⁹Sn-NMR, ¹¹⁹Sn Mössbauer, etc., spectroscopic techniques) provided useful information about the structure and stabilities of the complexes formed. We reviewed the literature on these type of complexes taking into account the biological aspects of the complexes discussed.     

Synthesis,characterization and antimicrobial activities of triorganotin(IV) complexes with azo-azomethine carboxylate ligands: crystal structure of a tributyltin(IV) and a trimethyltin(IV) complex

Triorganotin(IV) complexes with polyaromatic azo-azomethine carboxylate ligands viz. 2-{4-hydroxy-3-[(2/4-hydroxyphenylimino)methyl]phenylazo}benzoic acids [H₃L¹/H₃L²] were synthesized by reacting the ligands with either bis-tri-n-butyltin(IV) oxide (for 1 and 4) or trimethyltin(IV) chloride in presence of triethylamine (for 2 and 5) or triphenyltin(IV) hydroxide (for 3 and 6). The complexes were characterized by elemental analysis, UV, IR, NMR, and mass spectrometry. NMR spectroscopic studies of the compounds suggested that the complexes adopt four-coordinate tetrahedral geometry around tin in solution. Molecular structures of 1 and 2 were determined by single-crystal X-ray diffraction. Both complexes have distorted trigonal bipyramidal geometry around tin in the solid state. Compound 1 is a one-dimensional (1-D) double chain coordination polymer which can be described as two different 24- and 30-membered non-porous macrocyclic rings constructed from two tributyltin units and two ligand moieties. The structure of 2 comprises a discrete cyclic centrosymmetric dimer with two lattice water molecules per formula unit. In the dimer, two trimethyltin entities are bridged by two ligand moieties. The dimers are further interconnected with lattice water molecules by multiple O–H?O hydrogen bonds to form a 1-D H-bonded network. The complexes were also screened for their antimicrobial activities.     

Preparation and structural studies on dibutyltin(IV) complexes with pyridine mono- and dicarboxylic acids

A number of organotin(IV) complexes with pyridine mono- and dicarboxylic acids (containing ligating -COOH group(s) and aromatic {N} atoms) were prepared in the solid state. The bonding sites of the ligands were determined by means of FT-IR spectroscopic measurements. It was found that in most cases the -COO⁻ groups form bridges between two central {Sn} atoms, thereby leading to polymeric (oligomeric) complexes. On this basis, the experimental ¹¹⁹Sn Mössbauer spectroscopic data were treated with partial quadrupole splitting approximations. The calculations predicted the existence of complexes with octahedral (oh) and trigonal-bipyramidal (tbp) structures, but the formation of complexes with pentagonal-bipyramidal (pbp) structures could not be ruled out. Single-crystals of 2-picolinic and pyridine-2,6-dicarboxylic acid Bu₂Sn(IV)²⁺ complexes were obtained. The X-ray diffraction studies revealed that the central {Sn} atoms are in a pbp environment with bond distances characteristic of organotin(IV) compounds. The two butyl groups are located in axial positions. ¹¹⁹Sn NMR measurements in dmso solution and in the solid state indicated that the polymeric structures of the complexes are not retained in solution. The results of the solid-state ¹¹⁹Sn NMR measurements for compounds 1a, 2a and 6a are in agreement with the structures predicted by Mössbauer spectroscopy and revealed by X-ray diffraction.     

Spectral and biological studies of newly synthesized organotin(IV) complexes of 4-({[(E)-(2-hydroxyphenyl)methylidene]amino}methyl)cyclohexane carboxylic acid Schiff base

The new organotin(IV) complexes with 4-({[(E)-(2-hydroxyphenyl)methylidene]amino}methyl)cyclohexane carboxylic acid (HL, Schiff base) were synthesized by the reaction of di- and triorganotin salts in the presence of triethylamine as base or dioctyltin oxide using Dean and Stark trap for the removal of azeotropic water. All complexes were characterized by elemental analysis, IR, NMR (¹H and ¹³C) and mass spectrometry. The IR data indicate that in both di- and triorganotin(IV) carboxylates, the ligand moiety -COO acts as a bidentate group in solid state. Multinuclear NMR data show that triorganotin complexes exhibit the four-coordinated geometry, while diorganotin(IV) complexes show the coordination number greater than four, probably five or six, in solution state. These compounds were screened for antibacterial activities against six pathogenic bacterial strains. The activities were measured in terms of inhibition zones (mm). Antifungal activity was determined against six pathogenic fungal strains, cytotoxicity by the brine shrimp lethality assay. Results for antibacterial and antifungal activity, and cytotoxicity of these compounds demonstrate that complexes exhibit significant biological activity with few exceptions.     

Synthesis,Characterization, and Antibacterial Activities of Organotin(IV) Complexes with 2‐Acetylpyridine‐N(4)‐cyclohexylthiosemicarbazone (HAPCT)

The reaction of 2‐acetylpyridine‐N(4)‐cyclohexylthiosemicarbazone [(HAPCT), ( 1 )] ligand with organotin(IV) chloride(s) afforded the five new organotin(IV) complexes: [MeSnCl₂(APCT)] ( 2 ), [BuSnCl₂(APCT)] ( 3 ), [PhSnCl₂(APCT)] ( 4 ), [Me₂SnCl(APCT)] ( 5 ), and [Ph₂SnCl(APCT)] ( 6 ). The ligand ( 1 ) and its organotin(IV) complexes ( 2–6 ) have been synthesized and characterized by CHN analyses, molar conductivity, UV–vis, FT IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectral studies. The single crystal X‐ray diffraction studies indicated that [PhSnCl₂(APCT)] ( 4 ) is six coordinated and strongly adopts a distorted octahedral configuration with the coordination through pyridine‐N, azomethine‐N, and thiolato‐S atoms of the ligand. The compound crystallizes into a monoclinic lattice with the space group P21/n. The ligand ( 1 ) and its organotin(IV) complexes ( 2–6 ) were assayed for in vitro antibacterial activity against Staphylococcus aureus, Escherichia coli, Enterobacter aerogenes, and Salmonella typhi. The screening results have shown that the organotin(IV) complexes ( 2–6 ) have better antibacterial activity than the free ligand. Furthermore, it has been shown that the diphenyltin(IV) derivative ( 6 ) exhibits significantly better activities than the other organotin(IV) derivatives ( 2–5 ). © 2012 Wiley Periodicals, Inc. Heteroatom Chem 24:43–52, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21061     

Synthesis,characterization, and the antimicrobial and anthelmintic activities of some metal complexes with a new Schiff base 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one

The complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), dioxouranium(VI), and Th (IV) with a new Schiff base, 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one formed by the condensation of isatin (Indole-2.3-dione) with isophoronediamine(5-amino-1,3,3-trimethyl-cyclohexane methylamine) (IPDA) was synthesized and characterized by microanalysis, conductivity, UV-visi-ble, FT-IR, 1 H NMR,TGA, and magnetic susceptibility measurements. All the complexes exhibit 1: 1 metal to ligand ratio except for the dioxouranium(VI) and thorium(IV) complexes, where the metal: ligand stoichiometry is 1: 2. The spectral data revealed that the ligand acts as monobasic bidentate, coordinating to the metal ion through the azomethine nitrogen and carbonyl oxygen of the isatin moiety. Tetrahedral geometry for Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) complexes, square planar geometry for Cu(II) complexes, and the coordination numbers 6 and 8 for UO₂(VI) and Th(IV) complexes, respectively, are proposed. Both the ligand and the metal complexes were screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa, and the complexes are more potent bactericides than the ligand. The anthelmentic activity of the ligand and its complexes against earthworms was also investigated. This article was submitted by the authors in English.     

Organotin(IV) Complexes of 2-[(2′,4′,6′- Trichlorophenylamido)]benzoic Acid: Synthesis,Coordination Chemistry,and Semi-Empirical Study

A new series of organotin(IV) complexes of aniline derivatives, R₂SnL₂ and R₃SnL [where R = Me, n-Bu, n-Oct, and Ph], have been synthesized by the reaction of ligand acid with respective organotin halides in the presence of triethylamine as base or dioctyltin oxide using a Dean–Stark trap for the removal of water under reflux conditions. Experimental details for the preparation and characterization, including elemental analysis, IR, semi-empirical study, multinuclear NMR (¹H, ¹³C, and ¹¹⁹Sn spectra and EI mass spectral studies) of all reported complexes are provided. The IR data indicate that in both di- and triorganotin(IV) carboxylates, the ligand moiety ?COO acts as a bidentate group in the solid state. Multinuclear NMR data show that triorganotin complexes exhibits a four-coordinated geometry, while diorganotin(IV) complexes show a coordination number greater than four, probably five or six, in solution state.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis,Spectroscopic Characterization,and Antifungal Activity of Some Mixed Ligand Complexes of Zn(II), Cd(II), and Hg(II)

A series of new mixed ligand complexes of Zn(II), Cd(II), and Hg(II) with citronellal thiosemicarbazone [3,7-dimethyl-6-octene-1-a1 thiosemicarbazone (LH)] and N-phthaloyl amino acids (AH) have been synthesized by the reaction of metal(II) chloride with ligands citronellal thiosemicarbazone (DOTSC) and N-phthaloyl glycine [1,3-dihydro-1,3-dioxo-2H-isoindole-2-acetic acid (A₁H)] or N-phthaloyl alanine [1,3-dihydro-1,3-dioxo-α(methyl)-2H-isoindole-2-acetic acid (A₂H)] in 1:1:1 molar ratio in dry refluxing ethanol. All the complexes have been characterized by elemental analyses, molar conductance measurement, molecular weight measurement, IR, and multinuclear NMR (¹H and ¹³C{¹H}) spectral studies. IR, ¹H, and ¹³C{¹H} NMR spectral studies suggest the involvement of azomethine-N, thiol-S atoms of the thiosemicarbazone moiety and both carboxylate-O of N-phthaloyl amino acid moiety in coordination with central metal(II) ion, and four coordinated geometries have been assigned to these complexes. The free ligands and metal complexes have been screened for their antifungal activity against two fungal strains, Fusarium moniliformae and Macrophomina phaseolina, using the the radial growth method. The results of antifungal activity show that metal complexes show enhanced higher activity than the free ligands.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.