Diorganotin(IV) and triorganotin(IV) derivatives of diphenic acid

The diorganotin(IV) and triorganotin(IV) derivatives R₂SnA (R = Me, n-Pr, n-Bu, n-Oct) and (R₃Sn)₂A [R = Me, Ph, cyclohexyl (Cyh); A = an anion of diphenic acid] have been prepared and characterized by elemental analysis, IR, ¹H and ¹³C NMR spectroscopies. Tetrahedral tin forms a part of a diphenate cyclic ring in the diorganotin complexes with unidentate carboxylates, which have further been used for the synthesis of cyclic acid anhydrides. The soluble dinuclear triorganotin complexes (Me, Ph) possess symmetrically bonded carboxylates while the less soluble compound (Cyh₃Sn)₂A has two asymmetrically bonded carboxylates. All have a trigonal bipyramidal structure with R₃Sn units remote from each other.     

Bioactive versatile azomethine complexes of organotin(IV) and organosilicon(IV)

Diorganotin(IV) and diorganosilicon(IV) derivatives of the types R₂MCl(TSCZ) and R₂M(TSCZ)₂ (where TSCZ is the anion of a thiosemicarbazone ligand, R=Ph or Me and M=Sn or Si) have been synthesized and characterized by elemental analyses, molecular weight determinations and conductivity measurements. The mode of bonding has been established on the basis of IR and ¹H, ¹³C ²⁹Si and ¹¹⁹Sn NMR spectroscopic studies. Some of the representative complexes have also been evaluated for their antimicrobial effects on different species of pathogenic fungi and bacteria in vivoas well as in vitro.The results of these investigations are reported. © 1998 John Wiley & Sons, Ltd.     

Synthesis and characterization of di- and triorganotin(IV) complexes of 2-tert-butyl-4-methyl phenol

The di- and trialkyltin(IV) complexes of composition R₂SnCl_2−x (OAr), and n-Bu₃Sn(OAr) (R = n-Bu and Me; x = 1 and 2; OAr = OC₆H₃Bu ^t -2-Me-4) have been synthesized by the reactions of di-n-butyl and dimethyltin dichlorides and tri-n-butyltin(IV) chloride with 2-tert-butyl-4-methylphenol and triethylamine in tetrahydrofuran. The reaction of triphenyltin chloride with trimethylsilyl-2-t-butyl-4-methylphenoxide in the same solvent however, gives a complex of composition Ph₃Sn(OAr). The complexes have been characterized by microanalyses, molar conductance measurements, molecular weight determinations and IR and ¹H, ¹³C and ¹¹⁹Sn NMR and mass spectral studies. Thermal behaviour of the complexes has been studied by TGA and DTA techniques. From the non-isothermal TG data, the kinetic and thermodynamic parameters have been calculated employing Coats-Redfern equation and the mechanism of decomposition has been computed using non-isothermal kinetic method. Thermal investigations on the blends of poly(methylmethacrylate). PMMA, with organotin(IV)-2-tert-butyl-4-methylphenoxides have shown increased thermal stability compared to pure PMMA suggesting thereby their potential as additives towards PMMA.     

Organosilicon(IV) and organotin(IV) complexes as biocides and nematicides: synthetic,spectroscopic and biological studies of N∩N donor sulfonamide imine and its chelates

A brief account is given of the synthesis and stereochemistry and the antibacterial, antifungal, nematicidal and insecticidal behaviour of organosilicon(IV) and organotin(IV) complexes of a biologically potent ligand, 2‐acetylfuransulfaguanidine. The unimolar and bimolar substitution products have been characterized by elemental analyses, conductance measurements, molecular weight determinations, and spectral studies, viz. IR, ¹H NMR, ¹³C NMR, UV, ²⁹Si NMR and ¹¹⁹Sn NMR spectra. The data support the binding of the nitrogen atom to the metal atom in R₃M(N^∩N), [R₂M(N^∩N)₂ and R₂M(N^∩N)Cl [(R = Me/Ph and M = Si(IV) and Sn(IV)] types of complex. Based on these studies, with coordination number five and six a trigonal bipyramidal and an octahedral geometry have been proposed for the resulting derivatives. The free ligand (N^∩NH) and its respective metal complexes were tested in vitro against a number of microorganisms to assess their antimicrobial properties. The results are indeed positive. In addition to these studies, the complexes also show good nematicidal and insecticidal properties. The results of these findings have been discussed in detail. Copyright © 2004 John Wiley & Sons, Ltd.     

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).     

Synthesis and coordination chemistry of organotin(IV) complexes of 2,3-methylenedioxyphenylpropenoic acid

The synthesis, spectroscopy, and antitumor behavior of organotin(IV) complexes of 2,3-methylenedioxyphenylpropenoic acid are described. The spectroscopic data indicate 1 : 2 and 1 : 1 metal to ligand stoichiometry in case of di- and trioganotin(IV) compounds and hypervalency of Sn(IV) in trigonal bipyramidal and octahedral modes. Mass spectrometric and elemental analysis data support the solid and solution spectroscopic results. The complexes have been evaluated in vitro against crown gall tumor and bio-activity screenings showed in vitro biological potential. The nature of covalent attachments (methyl, ethyl, n-butyl, phenyl, and n-octyl) of Sn(IV) played a decisive role for bioactivity. All the compounds have been studied in solution by NMR (¹H, ¹³C) and also in solid state using FTIR, mass spectrometry, and by X-ray crystallography. The molecular structure of Et₂Sn(IV) and Me₃Sn(IV) derivatives confirm the behavior of di- and tri-organotin(IV) compounds in solid state. Mono-organotin derivatives are octahedral both in solid and solution.     

The First Butyltin(IV) Homo- and Heterobimetallic Diethanolaminates

Equimolar reactions of BuSn(OPrⁱ)₃ with diethanolamines, RN(CH₂CH₂ OH) ₂ (abbreviated as RdeaH₂, where R = H or Me), afford dimeric isopropoxo-bridged six-coordinate butyltin(IV) complexes [{Bu(η³-Rdea)Sn(μ-OPrⁱ)}₂] (R = H ( 1 ), Me ( 2 )). Interactions between BuSn(OPrⁱ)₃ and diethanolamines (RdeaH₂) in a 1:2 molar ratio yield monomeric derivatives of the type [BuSn(Rdea)(RdeaH)] (R = H ( 3 ), R = Me ( 4 )). These homometallic complexes on 1:1 reactions with an appropriate metal alkoxide form monomeric heterobimetallic complexes of the type [BuSn (Rdea)₂ {M(OR′)_n}] (R = H, M = Al, R′ = Prⁱ, n = 2 ( 5 ); R = H, M = Ti, R = Prⁱ, n = 3 ( 6 ); R = H, M = Zr, R′ = Prⁱ, n = 3 ( 7 ); R = Me, M = Al, R′ = Prⁱ, n = 2 ( 8 ); R = Me, M = Ti, R′ = Prⁱ, n = 3 ( 9 ); R = Me, M = Ge, R′ = Et, n = 3 ( 10 )). The driving force behind this work was (i) to explore the utility of homometal complexes ( 1 ) –( 4 ) in assembling a metal alkoxide fragment via a condensation reaction and (ii) to gain insights into the structures of new compounds by NMR spectral data. All of these derivatives have been characterized by elemental analysis, spectroscopic (IR, NMR; ¹H, ²⁷Al, and ¹¹⁹Sn) studies, and molecular weight measurements. ¹¹⁹Sn NMR spectral studies indicate that both the homometallic ( 3 ) and ( 4 ) and heterobimetallic ( 5 ) – ( 9 ) complexes exist in a solution in an equilibrium of six- and five-coordinated tin(IV) species.     

Synthesis and characterization of diorganotin(IV) derivatives from rhodanine (HRd): crystal structures of [(PhCH2)2Sn(Rd)(μ-OH)]2 and [n-Bu2Sn(Rd)(μ-OH)]2

The diorganotin(IV) complexes, [R₂Sn(Rd)(μ-OH)]₂ (R?=?Me (1), PhCH₂ (2), n-Bu (3), Ph (4); HRd?=?rhodanine), have been synthesized and characterized by IR and multinuclear (¹H, ¹³C, ¹¹⁹Sn) NMR spectroscopy. The structures of complexes 2 and 3 have been determined by single-crystal X-ray diffraction. Both crystal structures of 2 and 3 show the presence of asymmetrically bridging hydroxy groups leading to an Sn₂O₂ unit. Each atom in complex 1 is also coordinated by an N atom of ligand and two C atoms of the alkyl groups, so the Sn environment is based on a trigonal bipyramid. While in complex 2, a weak intermolecular Sn–O interaction has also been found between the two adjacent molecules, so the geometry of the Sn atom can be best described as six-coordinate octahedral. The salient feature of the supramolecular structure of complex 3 is that of a 1D polymer, in which the discrete molecules are connected through weak intermolecular Sn?···?O interactions.     

Diorganotin(IV) complexes with 2-benzoylpyridine and 2-acetylpyrazine N(4)-phenylthiosemicarbazones: Synthesis, crystal structures and biological activities

Four diorganotin(IV) complexes [(Me)₂Sn(L¹)(CH₃COO)]·CH₃CH₂OH (1), [(Ph)₂Sn(L¹)(CH₃COO)]·CH₃CH₂OH (2), [(Me)₂Sn(L²)Cl] (3) and [(Ph)₂Sn(L²)(CH₃COO)] (4) where HL¹ = 2-benzoylpyridine N(4)-phenylthiosemicarbazone and HL² = 2-acetylpyrazine N(4)-phenylthiosemicarbazone have been synthesized and characterized by elemental analysis, IR MS, ¹H NMR and single-crystal X-ray diffraction studies. Schiff bases in their deprotonated forms coordinate to tin(IV) via pyridine/pyrazine nitrogen atom and the nitrogen atom and sulfur atoms of the thiosemicarbazone moiety. The tin atom is seven-coordinated in 1, 2 and 4 containing one acetato group, respectively, and six-coordinated in 3 containing one chloride ion. Biological studies, carried out in vitro against selected bacteria and K562 leukaemia cells, respectively, have shown that different substituted groups attached at the thiosemicarbazone moieties and different diorganotin(IV) groups showed distinctive differences in the biological property.     

Chromatographic behaviour of metal ions on tin(IV) and titanium(IV) antimonate papers

Summary The chromatographic behaviour of 49 metal ions has been studied on papers impregnated with Sn(IV) and Ti(IV) antimonates in aqueous HNO₃ and mixed solvent systems containing dimethyl sulphoxide. Numerous separations have been achieved and the Alberti equation, for Sn(IV) and Ti(IV) antimonate papers, in the modified form: –nloga K⁺=R_M + constant (a K⁺=activity of K⁺), has been verified. The effect of the concentration of impregnating reagents on these papers has been determined and compared with other papers. The effect of pH on R_f, R_i, log R_f and R_M values of metal ions has also been examined in aqueous systems.     

Synthesis and characterization of tin(IV)/organotin(IV) complexes with 2-benzoylpyridine-N(4)-cyclohexylthiosemicarbazone [HBPCT]: X-ray crystal structure of [SnCl3(BPCT)]

Four new tin(IV)/organotin(IV) complexes, [SnCl₃(BPCT)] (2), [MeSnCl₂(BPCT)] (3), [Me₂SnCl(BPCT)] (4), and [Ph₂SnCl(BPCT)] (5), have been synthesized by the direct reaction of 2-benzoylpyridine-N(4)-cyclohexylthiosemicarbazone [HBPCT, (1)] and stannic chloride/organotin(IV) chloride(s) in absolute methanol under purified nitrogen. HBPCT and its tin(IV)/organotin(IV) complexes (2–5) were characterized by CHN analyses, molar conductivity, UV-Vis, FT-IR, and ¹H NMR spectral studies. In all the complexes, tin(IV) was coordinated via pyridine-N, azomethine-N, and thiolato-S from 1. The molecular structure of 2 has been determined by X-ray single-crystal diffraction analysis. Complex 2 is a monomer and the central tin(IV) is six-coordinate in a distorted octahedral geometry. The crystal system of 2 is monoclinic with space group P121/n1 and the unit cell dimensions are a?=?8.3564(3)?Å, b?=?23.1321(8)?Å, c?=?11.9984(4)?Å.     

Some Tribenzyl Tin(IV) Complexes with Thiohydrazides and Thiodiamines. Synthesis,characterization and thermal studies

Tribenzyl tin(IV) chloride complexes of morpholine N-thiohydrazide (L¹), aniline-N-thiohydrazide (L²),N-(morpholine-N-thio)-1,3-propanediamine (L³) and (aniline-N-thio)-1,3-propanediamine (L⁴) of the type (C₆H₅CH₂)₃Sn(L)Cl (where L=L¹, L², L³ and L⁴) have been synthesised in dioxane and in H₂O and acetone mixture. These were characterized by C,H,N-analysis, UV, IR and ¹HNMR spectral studies. In both the complexes ligands act as bidentate, coordinating through sulphur and terminal nitrogen. The complexes are 1:1 metal ligand complexes. Various thermodynamic parameters have been calculated for the decomposition steps using TG/DTA curves in air as well as nitrogen atmosphere. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis of coordination compounds of dibutyltin(IV) with Schiff bases having nitrogen donor atoms

The new dibutyltin(IV) complexes of Schiff bases is designed & synthesis from the interaction between various substituted amines and aromatic aldehyde with general formula Bu₂Sn(L^1-7)₂Cl₂. Where L¹: (E)-4-chloro-N-(thiophen-2-ylmethylene) aniline; L²: (E)-2-chloro-N-(3,4,5-trimethoxybenzylidene) aniline; L³: (E)-N-((1H-indol-3-yl) methylene)-4-chloro-2-nitroaniline; L⁴: (E)-4-nitro-N-(3,4,5-trimethoxybenzylidene) aniline; L⁵: (E)-N-(3,4,5-trimethoxybenzylidene) aniline; L⁶: (E)-4-nitro-N-(thiophen-3-ylmethylene) aniline; L⁷: (E)-4-chloro-2-nitro-N-(pyridin-3-ylmethylene) aniline. Analytical and spectroscopic methods, such as molar conductance measurement, UV–Vis, IR, NMR, and DFT studies, have been used to describe newly synthesised compounds. The DFT studies have also provided confirmation regarding the complexes' geometry. The results of the Tauc equation indicate that the fundamental band gap of the compound [Bu₂Sn(L⁵)₂Cl₂] is 2.670 eV, which is in agreement with the findings of DFT studies, which indicate that the band gap is 2.657 eV. The bactericidal effects of Schiff bases and their dibutyltin(IV) complexes were tested. The antibacterial activity of organotin(IV) complexes is enhanced in comparison to that of the free ligands.     

Synthesis and characterization of pentagonal bipyramidal organotin(IV) complexes of 2,6-diacetylpyridine Schiff bases of S-alkyl- and aryldithiocarbazates

New organotin(IV) complexes with empirical formula Sn(SNNNS)R₂, where SNNNS is the dianionic form of 2,6-diacetylpyridine Schiff bases of S-methyldithiocarbazate (H₂dapsme) or S-benzyldithiocarbazate (H₂dapsbz) and R = Ph or Me, have been prepared and characterized by IR, UV-Vis, NMR and Mössbauer spectroscopic techniques and conductance measurements. The molecular structures of the Sn(dapsme)R₂ (R = Ph and Me) have been determined by single crystal X-ray diffraction techniques. Both complexes have a distorted pentagonal-bipyramidal geometry in which the tin is coordinated by a dinegatively charged pentadentate chelating agent via pyridine nitrogen, two azomethine nitrogens, and two thiolate sulfurs. The five donors (N₃S₂) provided by the Schiff base occupy the equatorial plane close to a pentagonal planar array while the carbanion ligands occupy axial sites.     

Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid. Synthesis, spectroscopic characterization, in vitro antimicrobial activity and X-ray crystallography

Triorganotin(IV) complexes of the 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid (HL), Me₃SnL(H₂O), (1), [n-Bu₃SnL]₂(H₂O), (2), Ph₃SnL(MeOH), (3), were synthesized by reacting the amino acid with organotin(IV) hydroxides or oxides in refluxing methanol. The complexes have been characterized by elemental analysis, ¹H, ¹³C and ¹¹⁹Sn NMR, IR, Raman and ¹¹⁹Sn Mössbauer spectroscopic techniques. Single crystal X-ray diffraction data were obtained for compounds (2) and (3). Ph₃SnL(MeOH) presents a trigonal bipyramidal structure with the organic groups on the equatorial plane and the axial positions occupied by a ligand molecule, coordinated to tin through the carboxylate, and a solvent molecule, MeOH. A similar structure is proposed for Me₃SnL(H₂O) on the basis of analytical and spectroscopic data. The tributyltin(IV) derivative, [n-Bu₃SnL]₂(H₂O), is characterized by two different tin sites with similar tbp geometry featured by butyl groups on the equatorial plane. Sn(1) and Sn(2) atoms are axially bridged by a ligand molecule binding through the N(4) and the carboxylate group; the two coordination spheres are saturated by another ligand molecule, binding the metal through the carboxylate group, and a water molecule, respectively. Antimicrobial tests on compounds 1 and 2 showed in vitro activity against Gram-positive bacteria.     

Thermal studies on some organotin(IV) complexes with piperidine and 2-aminopyridine dithiocarbamates

The complexes of piperidine dithiocarbamate, 2-aminopyridine dithiocarbamate and organotin(IV) of the type R₃Sn(L¹), R₂Sn(L¹)₂, R₃Sn(L²), R₂Sn(L²)₂, [R=C₆H₅CH₂ (benzyl), p-ClC₆H₄CH₂ (p-chlorobenzyl), L ¹=sodium piperidine dithiocarbamate and L ²=sodium 2-aminopyridine dithiocarbamate] have been synthesised and characterised by spectral studies (IR, UV, ¹H NMR). Thermogravimetric (TG) and differential thermal analytical (DTA) studies have beeen carried out for these complexes and from the TG curves, the order and apparent activation energy for the thermal decomposition reactions have been elucidated. The various thermal studies have been correlated with some structural aspects of the complexes concerned. From DTA curves, the heat of reaction has been calculated.     

Synthesis, Spectroscopic Properties and Crystal Structures of Dibenzyltin（IV） Dithiobenzoate and Chlorodibenzyltin（IV） Thiobenzoate

Two dibenzyltin(IV) complexes with thiobenzoate ligand, (PhCH2)2Sn(SOCPh)2 (1) and (PhCH2)2Sn(C1)SOCPh (2), have been synthesized by the reaction of dibenzyltin(IV) dichloride with thiobenzoic acid in the presence of organic base Et3N and characterized by IR, ^1H NMR spectroscopy and elemental analysis. Their crystal structures were determined by X-ray single crystal diffraction analysis. In the crystals of 1, the tin atom is six-coordinated in a distorted octahedron configuration. In the crystals of 2, the molecular packing in unit cell reveals that the two adjacent molecules are symmetrically linked to each other to form a dimer with intermolecular Sn…C1 distances of 0.3591 (2) nm and the tin atom is five-coordinated in a distorted trigonal bipyramid configuration.     

Synthesis,spectroscopic characterization,crystal structure,and anti-bacterial activity of diorganotin(IV) complexes with 5-bromo-2-hydroxybenzaldehyde-N(4)-ethylthiosemicarbazone

Three new diorganotin(IV) complexes, [Me₂Sn(BDET] (2), [Bu₂Sn(BDET)] (3), and [Ph₂Sn(BDET)] (4), were synthesized by reacting R₂SnCl₂ (R = Me, Bu, and Ph) with 5-bromo-2-hydroxybenzaldehyde-N(4)-ethylthiosemicarbazone [H₂BDET, (1)] in the presence of KOH in absolute methanol. The newly synthesized complexes were characterized by elemental analysis, molar conductivity, UV–vis, FT-IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectroscopies. The molecular structure of 4 was confirmed by X-ray crystallography. X-ray crystallography revealed that the doubly deprotonated O,N,S-tridentate thiosemicarbazone coordinates to tin(IV), resulting in a distorted trigonal bipyramidal geometry. Their ¹H, ¹³C, and ¹¹⁹Sn NMR spectra support a five-coordinate tin(IV) in solution for all complexes, in accord with the solid-state X-ray structure determined for 4. Compounds 1–4 were evaluated for their antibacterial activities against Staphylococcus aureus, Enterobacter aerogenes, Escherichia coli, and Salmonella typhi. The results exhibited that 2–4 were active with comparable potency compared to the standard drug. Antibacterial studies also indicated that the complexes have potential for biological evaluation.     

Nitrosubstituted hydroxamate ligands in new triphenyltin(IV) complexes as prospective antimicrobial agents

New triphenyltin(IV) hydroxamate complexes, [Ph₃Sn(4-NO₂CnH)] and [Ph₃Sn(4-NO₂BzH)] have been synthesized by the reactions of Ph₃SnCl with potassium 4-nitrocinnamo hydroxamate [4-NO₂C₆H₄CHCHCONHOK] (KHL¹) and potassium 4-nitro benzohydroxamate [4-NO₂C₆H4CONHOK] (KHL²). The complexes were synthesized in 1:1 molar ratio in MeOH?+?C₆H₆ and characterized by physicochemical and IR, ¹H NMR, and mass spectrometry. The bidentate hydroxamate involving bonding through carbonyl and hydroxamic oxygen (O, O coordination) has been inferred from IR spectra. The electrochemical behavior of complexes has been analyzed. Quasi-irreversible two electron metal-centered cathodic process of type Sn^IV/Sn^II redox couple was indicated by cyclic voltammetric technique. The thermal behavior of 1 and 2 studied by TGA has shown continuous decomposition to yield Sn + 0.5SnO₂ and SnO₂ as final residues. The in vitro antimicrobial activity assays of 1 and 2 against pathogenic Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Salmonella typhi and Pseudomonas aeruginosa), and fungi (Aspergillus fumigatus and Alternaria alternata) were done by MIC method. The complexes have exhibited appreciable antimicrobial activity relative to the respective standard Gentamycin and Nystatin drugs.     

Synthesis,characterization and antimicrobial activity of triorganotin(IV) derivatives of some bioactive Schiff base ligands

Triorganotin(IV) complexes of the type Me₃Sn[OC(R¹):CH(CH₃)C:NR²OH] and Ph₃Sn[OC(R′):CH(CH₃)C:NR″OH] (R′ = ─CH₃, ─C₆H₅; R″ = ─(CH₂)₂─, ─(CH₂)₃─) have been synthesized by the reactions of trimethyl/phenyltin(IV) chloride with the sodium salt of corresponding Schiff base ligands in unimolar ratio in refluxing tetrahydrofuran. All these compounds have been characterized using elemental analyses and their probable structures have been proposed on the basis of infrared, ¹H NMR, ¹³C NMR, ¹¹⁹Sn NMR and mass spectroscopic studies. In the trimethyltin(IV) derivatives the central tin atom is tetracoordinated, whereas in the analogous triphenyltin(IV)derivatives the central tin atom is pentacoordinated. All these ligands, metal precursors and corresponding triorganotin(IV) complexes have been screened for antimicrobial activities. A comparison of activities of the ligands and their corresponding triorganotin(IV) derivatives has been made. Attempts have also been made to relate the activity to the structure of these compounds.