Organotin(IV) O-butyl carbonodithioates: Synthesis,characterization, in vitro bioactivities,and interaction with SS-DNA

Organotin(IV) O-butyl carbonodithioates [Me₂SnL₂], [Bu₂SnL₂], [Ph₂SnL₂], [Bu₃SnL], and [Ph₃SnL], where L = C₄H₉OCS ^–₂ , have been successfully synthesized and characterized by FT-IR, ¹H and ¹³C NMR, and single crystal X-ray analysis. The ligand coordinates to the tin atom via the carbonodithioate group. According to the X-ray diffraction data, the tin atom in [Me₂SnL₂] has distorted tetrahedral geometry. The synthesized compounds were screened in vitro for antibacterial, antifungal, antileishmanial, cytotoxic, and protein kinase inhibitory activities. The complexes [Bu₃SnL] and [Ph₃SnL] exhibited the highest anti-leishmanial activity that exceeded the activity of the reference drug amphotericin B, probably by blocking the function of parasitic mitochondria due to which it restricts further growth of the organisms. The ligand and the complexes have been shown to bind to DNA via intercalative interactions resulting in hypochromic effect with a minor red shift as confirmed by UV-Vis spectroscopic studies.

     

Syntheses,structural characteristics,and antimicrobial activities of new organotin(IV) 3-(4-bromophenyl)-2-ethylacrylates

New organotin(IV) carboxylates, [n-Bu₂SnL₂] (1), [Et₂SnL₂] (2), [Me₂SnL₂] (3), [n-Oct₂SnL₂] (4), [n-Bu₃SnL] _n (5), [Me₃SnL] _n (6), and [Ph₃SnL] _n (7), where L?=?3-(4-bromophenyl)-2-ethylacrylate, were synthesized and characterized by elemental analysis, FT-IR, and multinuclear NMR (¹H, ¹³C, and ¹¹⁹Sn). Spectroscopic studies confirm coordination of L to the organotin moiety via COO group. Single-crystal X-ray analysis reveals bridging mode of coordination in 6. Packing diagram established a supramolecular cage-like structure for 6 due to Sn–O interactions (3.287?Å). Subsequent antimicrobial activities proved them to be active biologically.     

Synthesis of stannic(IV) complexes: Their structural elucidation in solid and solution state and antimicrobial activity

A series of organotin(IV) thiocarboxylates have been synthesized with the general formula R₂SnL₂ and R₃SnL (R = Ph₂(I), Me₃(II), n‐Bu₃(III), Ph₃(IV), Cy₃(V), Me₂(VI), n‐Bu₂(VII), and L = piperidine‐1‐thiocarboxylic acid) in anhydrous toluene under the reflux conditions. The complexes were characterized by microanalysis, IR, ¹H and ¹³C NMR, mass spectrometry, and XRD. NMR data revealed that thiocarboxylic acid acts as bidentate, and complexes exhibit the four‐coordinated geometry in solution state. In solid state, diorganotin complexes exhibit the hexa‐coordinated geometry whereas the triorganotin(IV) compounds show the five‐coordinated geometry. These complexes were also tested for their antimicrobial activity along with the ligand against different animals, plant pathogens, and Artemia salina. All complexes with few exceptions show high activity as compared to the ligand. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:664–674, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20380     

Synthesis,characterization, and in vitro antimicrobial activities of organotin(IV) complexes of Schiff bases with ONO‐type donor atoms

A new series of diorganotin complexes of the type R₂SnL (L¹: N‐(2‐hydroxy‐5‐chlorophenyl)‐ 3‐ethoxysalicylideneimine, R = Me, (Me₂SnL¹), R = n‐Bu, (n‐Bu₂SnL¹), R = Ph, (Ph₂SnL¹), L²: N‐(2‐hydroxy‐4‐nitro‐5‐chlorophenyl)‐3‐ethoxysalicylideneimine, R = Ph, Ph₂SnL², L³: N‐(2‐hydroxy‐4‐nitrophenyl)‐3‐methoxysalicylideneimine, R = Me, (Me₂SnL³), R = n‐Bu, (n‐Bu₂SnL³), L⁴: N‐(2‐hydroxy‐4‐nitrophenyl)‐3‐ethoxysalicylideneimine, R = Me, (Me₂SnL⁴), R = n‐Bu, (n‐Bu₂SnL⁴)) were synthesized and characterized by elemental analysis, infrared (IR), ¹H, and ¹³C NMR mass spectroscopic techniques, and electrochemical measurements. Ph₂SnL¹ and Ph₂SnL² were also characterized by X‐ray diffraction analysis and were found to show a fivefold C₂NO₂ coordination geometry nearly halfway between a trigonal bipyramidal and distorted square pyramidal arrangement. The C Sn C angles in the complexes were calculated using Lockhart's equations with the ¹J(^117/119Sn‐¹³C) and ²J(^117/119Sn‐¹H) values from the ¹H NMR and ¹³C NMR spectra. Biocidal activity tests against several micro‐organisms and some fungi indicate that all the complexes are mildly active against Gram (+) bacteria and the fungi, A. niger and inactive against Gram (−) bacteria. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:373–385, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20628     

Synthesis,spectroscopic characterization,and biological activity studies of organotin(IV) derivatives of (E)‐3‐(3‐fluorophenyl)‐2‐phenyl‐2‐propenoic acid. Crystal and molecular structure of Et2Sn[OCOC(C6H5)CH(3‐FC6H4)]

The complexes Me₂SnL₂ ( I ), Me₃SnL ( II ), Et₂SnL₂ ( III ), n‐Bu₂SnL₂ ( IV ), n‐Bu₃SnL ( V ), n‐Oct₂SnL₂ ( VI ), Bz₂SnL₂ ( VII ), and Ph₃SnL ( VIII ), where “L” is ( E )‐3‐(3‐fluorophenyl)‐2‐phenyl‐2‐propenoate, have been prepared and structurally characterized by means of elemental analysis, infrared, mass, and multinuclear (¹H, ¹³C, ¹¹⁹Sn) NMR spectral techniques. The spectroscopic results showed that the geometry around the Sn atom in triorganotin(IV) derivatives is four‐coordinated in noncoordinating solvent and behaves as five‐coordinated linear polymers with bridging carboxylate groups or five‐coordinated monomers, both acquiring trans‐R₃SnO₂ geometry for Sn in the solid state. While all the diorganotin(IV) derivatives may acquire trigonal bipyramidal structures in solution due to collapse of the Sn←OCO interaction and octahedral geometries in the solid state, which have been confirmed by the X‐ray crystallographic data of the compound III . The crystal structure of Et₂SnL₂ ( III ) has been determined by X‐ray crystallography and is found skew‐trapezoidal bipyramidal, which substantiates that the ligand acts as an anisobidentate chelating agent, thus rendering the Sn atom six coordinated. The crystal is monoclinic with space group C2₁/n. All the investigated compounds have also been screened for biocidal and cytotoxicity data. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:420–432, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20243     

Synthesis,spectral, theoretical studies and in vitro antimicrobial activities of novel diphenyltin(IV) complexes of Schiff bases derived from phenacylamine

A series of new diphenyltin(IV) complexes of the type Ph₂SnL (L¹: N‐phenacyl‐5‐bromosalicylideneimine, Ph₂SnL¹; L²: N‐phenacyl‐3,5‐dichlorosalicylideneimine, Ph₂SnL²; L³: N–phenacyl‐4‐methoxysalicylideneimine, Ph₂SnL³) were synthesized and characterized by elemental analysis, IR, ¹H, ¹³C, ¹¹⁹Sn NMR spectroscopy and mass spectrometry techniques. The C―Sn―C angles in the complexes were calculated using equations with the ¹J(^117/119Sn―¹³C) values from ¹³C NMR spectra. The possible structures, NMR and electronic properties of the studied molecules were calculated through density functional theory and results compared with experimental data. All the complexes were found to be mildly active against several microorganisms and some fungi. Copyright © 2014 John Wiley & Sons, Ltd.     

Organotin(IV) esters of (E)‐3‐furanyl‐2‐phenyl‐2‐propenoic acid: Synthesis,investigation of the coordination modes by IR,multinuclear NMR (1H, 13C, 119Sn) and In Vitro biological studies

Complexes [Me₂SnL₂ ( I ), Me₃SnL ( II ), Et₂SnL₂ ( III ), n‐Bu₂SnL₂ ( IV ), n‐Bu₃SnL ( V ), n‐Oct₂SnL₂ ( VI )], where L is (E)‐3‐furanyl‐2‐phenyl‐2‐propenoate, have been synthesized and structurally characterized by vibrational and NMR (¹H, ¹³C and ¹¹⁹Sn) spectroscopic techniques in combination with mass spectrometric and elemental analyses. The IR data indicate that in both the di‐ and triorganotin(IV) carboxylates the ligand moiety COO acts as a bidentate group in the solid state. The ¹¹⁹Sn NMR spectroscopic data, ¹J[¹¹⁹Sn,¹³C] and ²J[¹¹⁹Sn, ¹H], coupling constants show a four‐coordinated environment around the tin atom in triorganotin(IV) and five‐coordinated in diorganotin(IV) carboxylates in noncoordinating solvents. The complexes have been screened against bacteria, fungi, and brine‐shrimp larvae to assess their biological activity. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:612–620, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20488     

Organotin esterification of (E)-3-(3-fluoro-phenyl)-2-(4-chlorophenyl)-2-propenoic acid: synthesis, spectroscopic characterization and in vitro biological activities. Crystal structure of [Ph3Sn(OC(O)C(4-ClC6H4) = CH(3-FC6H4))]

Nine organotin esters, Me₂SnL₂1, Me₃SnL 2, n-Bu₂SnL₂3, n-Bu₃SnL 4, Ph₃SnL 5, (PhCH₂)₂SnL₂6, [(Me₂SnL)₂O]₂7, Et₂SnL₂8 and n-Oct₂SnL₂9, of (E)-3-(3-fluorophenyl)-2-(4-chlorophenyl)-2-propenoic acid, HL have been synthesized and characterized by elemental analysis, IR, Multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn) and mass spectrometry. The geometry around the tin atom has been deduced and compared both in solution and solid states. The crystal structure of compound 5 has been determined by X-ray single crystal analysis, which shows a tetrahedral geometry around the tin atom with space group . These compounds have also been screened for bactericidal, fungicidal activities and cytotoxicity data.     

Synthesis,spectroscopic characterization,X-ray crystal structure,biological screening and catalytic studies of organotin(IV) carboxylates of 3-(4-cyanophenyl) acrylic acid

A series of six organotin(IV) carboxylates [Me₂SnL₂] (1), [n-Bu₂SnL₂] (2), [n-Oct₂SnL₂] (3), [Me₃SnL] (4), n-Bu₃SnL (5) and [Ph₃SnL] (6), where L = 3-(4-cyanophenyl) acrylic acid have been synthesized and characterized by elemental analysis, FT-IR and NMR (¹H, ¹³C). The complex (4) was also analyzed by single crystal X-ray analysis which showed distorted trigonal bipyramidal geometry with polymeric bridging behavior. The complexes 1–6 were screened for antimicrobial activities and cytotoxicity. The results showed significant activity with few exceptions. The catalytic activity of complexes was assessed in transesterification reaction of Brassica campestris oil (triglycerides) to produce biodiesel (fatty acid methyl esters). The results showed that triorganotin(IV) complexes exhibited good catalytic activity than their di-analogues.     

Biological evaluations and spectroscopic characterizations of 3-(4-ethoxyphenyl)-2-methylacrylate based organotin(IV) carboxylates derivatives

Six new organotin(IV) carboxylates, [Me₂SnL₂] (1), [n-Bu₂SnL₂] (2), [n-Oct₂SnL₂] (3), [Me₃SnL] (4), [n-Bu₃SnL] (5) and [Ph₃SnL] (6), where L = 3-(4-ethoxyphenyl)-2-methylacrylate, have been synthesized and characterized by FT-IR, NMR spectroscopy and elemental analyses. The synthesized compounds were tested for in vitro antibacterial and antifungal activities. The complexes 4–6 demonstrated higher activity than the complexes 1–3. UV-Vis absorption spectroscopy indicated that the ligand and its complexes interacted with DNA via partial intercalation as well as minor groove binding.

     

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.     

Biological studies of organotin(IV) complexes with 2-mercaptopyrimidine

The known organotin(IV) complexes with 2-mercaptopyrimidine (L) [Me₂SnL₂] (1), [Buⁿ ₂SnL₂] (2), [Ph₂SnL₂] (3), and [Ph₃SnL] (4) were synthesized using a new approach. The effect of the synthesized compounds on peroxidation of fatty acids (oleic and linoleic) was studied. Complexes 1–4 promote the peroxidation of oleic acid. Their effect on the enzymatic peroxidation of linoleic acid with lipoxygenase was compared with that of cisplatin and in vitro cytoxicity against sarcoma cancer cells was determined. The antiproliferative effect of complexes 2–4 was demonstrated. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 737–743, April, 2007.     

Structural properties and antibacterial potency of new supramolecular organotin(IV) dithiocarboxylates

A series of new organotin(IV) derivatives; Me₃SnL (1), Bu₃SnL (2), Ph₃SnL (3), Me₂SnClL (4), Bu₂SnClL (5), Ph₂SnClL (6), Et₂SnClL (7) and Et₂SnL₂ (8) where L = N-(2,3-dimethylphenyl)piperazine-1-carbodithioate have been synthesized and characterized by various analytical techniques. Among these techniques, ¹H and ¹³C NMR were carried out to asses solution structures whereas the solid state structures were confirmed by FT-IR and X-ray single crystal analysis (3, 5 and 8). Crystal structure of complex (3) and (5) showed distorted trigonal bipyramidal geometry and square pyramidal geometry, respectively. The inclination of the structure 5 towards square-pyramidal may be due to the presence of the Sn-Cl?HN-piperazine hydrogen bonds between the adjacent molecules. A supramolecular structure is shown by compound (8), with central tin atom exists in a distorted octahedral geometry. The antibacterial results indicated the profound activity of the compounds against various strains of bacteria. In addition to this, the triorganotin(IV) derivatives were found more active than diorganotin(IV) compounds.     

Organotin(IV) complexes derived from N-ethyl-N-phenyldithiocarbamate: Synthesis,characterization and thermal studies

Organotin(IV) dithiocarbamate complexes, RSnClL₂ and R₂SnL₂ (R = Me, Bu, Ph, and L = N-ethyl-N-phenyldithiocarbamate), have been synthesized by the reaction of mono- and disubstituted organotin(IV) with ammonium dithiocarbamate. The complexes were characterized by elemental analyses, and spectroscopic techniques (¹H, ¹³C NMR and FTIR). The structures of Me₂SnL₂ and Bu₂SnL₂ were further established by single crystal X-ray diffraction technique. The crystal structure analysis showed that both complexes (Me₂SnL₂ and Bu₂SnL₂) exist as monomers. One of the dithiocarbamate ligands formed a chelate, while the other dithiocarbamate bonded to the central tin atom through one of the sulfur atoms and the second sulfur atom existed as a pendant to form distorted trigonal bipyramidal geometry. The thermal stability of all the complexes was studied using simultaneous thermogravimetry (TG) and differential scanning calorimetry (DSC). The TG-DSC results showed that Me₂SnL₂, BuSnClL₂, Bu₂SnL₂, and PhSnClL₂ displayed similar decomposition pathway via isothiocyanate intermediate, while MeSnClL₂ and Ph₂SnL₂ showed decomposition pathways different from the rest of the complexes. All the complexes resulted in SnS as the final product of the thermal decomposition process.     

Neutral penta-coordinated diorganotin(IV) complexes derived from ortho-aminophenol Schiff bases: Synthesis, characterization and molecular structures

The one pot reactions carried among ortho-aminophenol, R₂SnO (R = Me or Ph) and acetyl acetone, 2-hydroxyacetophenone and 2-hydroxy-3-methylacetophenone led to six new diorganotin(IV) compounds Me₂SnL1 (1), Ph₂SnL1 (2), Me₂SnL2 (3) Ph₂SnL2 (4), Me₂SnL3 (5) and Ph₂SnL3 (6) (H2L1 = 2-(3-hydroxy-1-methyl-but-2-enylideneamino)-phenol, H2L2 and H2L3 = 2-[1-(2-hydroxyaryl)alkylideneamino]-phenol) in good yields. Combination of IR, ¹H, ¹³C and ¹¹⁹Sn NMR and X-ray diffraction techniques along with elemental analyses evidenced the formation of penta-coordinated monomeric species. The crystal structures of ligand H2L1 and complexes 1, 3 and 4 were determined by single crystal X-ray diffraction study. In the solid state, the ligand H2L1 exists as keto-enamine tautomeric form. There are N-H…O intra-molecular hydrogen bonds between amine and carbonyl groups. Diorganotin(IV) complexes 1, 3 and 4 are monomers with TBP (trigonal bipyramidal) geometry surrounding the tin atom. The O, N, O- tridentate ligand places its two oxygen donating atoms in the axial positions, and the nitrogen atom occupies one equatorial position. The two R groups attached to tin occupy the other two equatorial positions. The solution structures were predicted by ¹¹⁹Sn NMR spectroscopy.     

Syntheses,characterizations and crystal structures of triorganotin(IV) complexes with amine derivatives of 6-amino-1,3,5-triazine-2,4-dithiol

Four new triorganotin(IV) complexes: Me₃SnL¹SnMe₃ (1), Ph₃SnL¹SnPh₃ (2), [Me₃SnL²] _n (3), Ph₃SnL²SnPh₃ (4) have been synthesized from 6-anilino-1,3,5-triazine-2,4-dithiol (L¹H₂) and 6-(dibutylamino)-1,3,5-triazine-2,4-dithiol (L²H₂). All were characterized by elemental analyses, IR and NMR spectra and X-ray diffraction analyses. Crystal structures show that 1, 2 and 4 are monomers with one ligand coordinated to two triorganotin moieties; complex 3 is a helical chain. Significant C–H ··· π, N–H ··· π interactions and intermolecular hydrogen bonds stabilize these structures.     

Synthesis,spectral analysis and in vitro cytotoxicity of diorganotin (IV) complexes derived from indole-3-butyric hydrazide

A series ( 1–20 ) of diorganotin (IV) complexes with general formula R₂SnL were formed by the reaction of R₂SnCl₂ (where R = Me, Et, Bu and Ph) with Schiff base ligands ( H ₂ L ^1–4 ) derived from the reaction of indole-3-butyric hydrazide with the salicylaldehyde and its derivatives. The structure elucidation of compounds were done by using UV–Vis, FT-IR, NMR (¹H, ¹³C, ¹¹⁹Sn), Mass spectrometry and thermal gravimetric analysis. Spectroscopic evidences suggested tridentate nature (ONO) of Schiff base ligands and coordinated to the dialkyl/diaryltin (IV) moieties through nitrogen and oxygen donor sites giving pentacoordinated geometry to complexes. The compounds were tested for the antimicrobial activity against bacterial and fungal strains which showed promising biological activity with compound 20 (Ph₂SnL⁴) as most active against microbes. The in silico study of the compounds was carried and observed that the compounds are used as orally active drugs and promote the formation of different hydrazide based drugs. The synthesized compounds were tested against human carcinoma cell lines namely A549, MCF7 and one normal cell line IMR 90 using MTT assay. The diethyl and dibutyltin complexes of Schiff bases displayed good cytotoxic activities. Compound 3 (H₂L³) and 10 (Et₂SnL²) were most potent against cancer cell lines with lowest IC₅₀ values and 7–8 times less toxic against the normal cell line.     

Organotin(IV) 4-nitrophenylethanoates: Synthesis, structural characteristics and intercalative mode of interaction with DNA

Four new organotin(IV) carboxylates, [Bu₂SnL₂] (1), [Et₂SnL₂] (2), [Bu₃SnL]_n (3), [Me₃SnL]_n (4), where L = 4-nitrophenylethanoates, were synthesized and characterized by elemental analysis, FT-IR and multinuclear NMR (¹H and ¹³C). Spectroscopic results authenticated the coordination of ligand to the organotin moiety via COO group while X-ray single crystal analysis revealed bidentate chelating mode of coordination of ligand in complex 2 and a bridging behavior in complexes 3 and 4. Cyclic voltammetric (CV) technique was used to evaluate the electrochemical, kinetic and thermodynamic parameters of complexes 1-4, interacting with DNA. The linearity of the plots between the peak current (I) and the square root of the scan rate (ν^1/2) indicated the electrochemical processes to be diffusion controlled. The diffusion coefficients of the free (D_f) and DNA bound forms (D_b), standard rate constants (ks) and charge transfer coefficients (α) were determined by the application of Randle–Sevcik, Nicholson and Kochi equations. Furthermore, the binding constants evaluated from voltammetric data revealed the following increasing order of binding strength: 2 < 1 < 4 < 3. For 1 and 2, the activity against prostate cancer cell lines (PC-3) was found consistent with the order obtained from voltammetric behavior.     

Antifertility and biocidal activities of organometallics of silicon,germanium, titanium and zirconium derived from 2-acetylthiophene thiosemicarbazone

A comparative biochemical study of four Group IV element compounds with specific sulphur-containing organic substrates has been carried out and discussed. The structural characterizations of these organometallics, viz. Me₂SiLCl, Me₂SiL₂, Me₃SiL, Ph₂SiLCl, Ph₂SiL₂, Ph₃SiL, Ph₃GeL, Cp₂TiLCl, Cp₂TiL₂, Cp₂ZrLCl and Cp₂ZrL₂ (where LH?2-acetylthiophene thiosemicarbazone) had been deduced on the basis of various physico-chemical and instrumental techniques, viz., IR, UV, ¹H NMR, ¹³C NMR AND ²⁹SI NMR spectral studies. All the organometallics and the parent thiomine have been screened against a number of microbes and their sterilizing power in male mice tested. The results of these biocidal studies show that the organosilicon(IV) and organogermanium(IV) compounds are more active than the organotitanium(IV) and organozirconium(IV) derivatives. An attempt has also been made to correlate the structural aspects of the molecule with its biological activity.     

Synthesis and spectroscopic studies on organotin derivatives of biologically active Schiff bases

Some five- and six-coordinated di- and tri-n-butyl tin(IV) complexes of the type Bu₂SnL, Bu₂SnL₂ and Bu₃SnL (where L is the anion of a monofunctional bidentate or bifunctional tridentate Schiff base) have been synthesized and characterised on the basis of microanalyses, molecular weight determinations, IR, NMR (¹H, ¹³C, ¹¹⁹Sn) and ¹¹⁹Sn Mössbauer spectroscopy. These complexes are highly active towards bacteria.