Adjacent Tin Atoms Research Articles

Exploration of organotin(IV) derivatives for medicinal applications: Synthesis, spectroscopic characterization, structural elucidation and molecular docking study

Organotin (IV) derivatives of carboxylate ligand, 4-(4-methoxyanilino)-4-oxobutanoic acid, have been synthesized and characterized by FTIR, NMR, CHN analysis, mass spectrometry and X-ray crystallography. Single crystal data of four compounds (1–4) displayed a distorted trigonal bipyramidal environment around Sn with the three equatorial positions occupied by alkyl group. In compounds 1–3, carboxylate oxygens of ligand play the role of a bridge between the adjacent tin atoms symmetrically giving a polymeric chain structure. In compound 4, oxygen of the amide carbonyl moiety perform the same function and bridges the adjacent tin atoms [SnO = 2.155 (3) and 2.428 (3) Å, respectively], with the three phenyl ipso-C atoms defining the trigonal plane and the axial positions occupied by O atoms [O1SnO3 = 177.62 (11) Å]. The τ values calculated for complexes 1–4 are 0.78, 0.77, 0.82 and 0.92, respectively, also confirm the trigonal bipyramidal geometry. The antimicrobial results of the synthesized compounds illustrate their use as a potential antimicrobial agent. The DNA interaction study performed by UV–visible spectroscopy as well as by molecular docking suggests the tested compounds interact with DNA through intercalation mode. The compounds were screened for anticancer activity performed against lung carcinoma and Vero cell lines resulting in activity that is almost equivalent to that of the standard, vincristine. The biological significance of these compounds is that there affect on the normal cell line is very small i.e., <27.1%. The compounds also exhibit good inhibition of urease enzyme. A good correlation was observed between the docking scores and biological activities of these compounds.

Pharmacological investigations and Petra/Osiris/Molinspiration (POM) analyses of newly synthesized potentially bioactive organotin(IV) carboxylates

A series of organotin(IV) carboxylate complexes: [Me2SnL2] (1), [n-Bu2SnL2] (2), [n-Oct2SnL2] (3), [Me3SnL] (4), [n-Bu3SnL] (5) and [Ph3SnL] (6), where L=3-(4-fluorophenyl)acrylic acid, have been successfully synthesized and characterized by FT-IR, NMR (1H, 13C) and single crystal analysis. The ligand coordinates to tin atom via carboxylate group. Compound 4 was also analyzed by single crystal XRD analysis. Crystallographic data for trimethyltin(IV) complex showed that the tin has approximate trigonal bipyramidal geometry with the CH3 groups in the trigonal plane. The carboxylate groups bridge the adjacent tin atoms, resulting in polymeric chains. FT-IR and NMR data also support the 5-coordination geometry for the triorganotin(IV) derivatives. In the case of the diorganotin(IV) derivatives a six-coordinate geometry at the tin atom is proposed from spectroscopic data. The Me–Sn–Me bond angle in complexes 1 and 4 was determined from the 2J[119Sn–1H] value as 138.4° and 111° that falls in the range of 5-coordinated trigonal bipyramidal and 6-coordinated octahedral geometries, respectively. The synthesized compounds were screened for their biological activities including antibacterial, antifungal and cytotoxicity. The compounds 4–6 exhibit excellent antibacterial, antifungal and cytotoxic activities. The cytotoxicity data reveals that the HL and 1–3 are almost non-toxic and exhibited LD50 values in the range 73.45–675.1μg/mL while 4–6 are found to be cytotoxic to mildly cytotoxic with LD50 values in the range 6.43–13.49μg/mL. The compound interacts with DNA via intercalation of aromatic ring into the base pairs of DNA resulting in hypochromism and minor red shift.

Potentially bioactive organotin(IV) compounds: Synthesis, characterization, in vitro bioactivities and interaction with SS-DNA

Fourteen new organotin(IV) complexes with general formula R2SnL2 or R3SnL where R = CH3, C2H5, C4H9, C6H5, C6H11, CH2–C6H5, C(CH3)3, C8H17 and L = N-[(2-methoxyphenyl)]-4-oxo-4-[oxy]butanamide were synthesized and characterized by elemental analyses, FT-IR, NMR (1H, 13C and 119Sn), mass spectrometry and single crystal X-ray structural analysis. Crystallographic data for four triorganotin(IV) complexes (R3SnL, R = CH3, C2H5, C4H9, CH2–C6H5) showed the tin has approximate trigonal bipyramidal geometry with the R groups in the trigonal plane. The carboxylate groups of ligands L bridge adjacent tin atoms, resulting in polymeric chains. In case of the diorganotin(IV) derivatives a six-coordinate geometry at the tin atom is proposed from spectroscopic evidence. The Me–Sn–Me bond angle in complex 7 was determined from the 2J[119Sn–1H] value as 166.3° that falls in the range of six-coordinate geometry. The ligand and its complexes (1–14) were screened for their antimicrobial, antitumor, cytotoxic and antileishmanial activities and found to be biologically active. The ligand and its complexes bind to DNA via intercalative interactions resulting in hypochromism and minor bathochromic shifts as confirmed by UV–visible spectroscopy. Based on in vitro studies such as the potato disc method, the synthesized compounds were found to possess significant antitumor activity. Also, from cytotoxicity and DNA interaction studies, these compounds can also be used for the prevention and treatment of cancer. Gel electrophoresis assay was used to investigate the damage to double stranded super coiled plasmid pBR322 DNA by the synthesized compounds and compounds 1 and 7 were found to cause the maximum damage. All the synthesized compounds exhibit strong antileishmanial activity that was even higher than that of Amphotericin B, with significant cytotoxicity. This study, therefore, demonstrated the potential use of these compounds as source of novel agents for the treatment of leishmaniasis.

Synthesis and Characterization of Some Triphenyltin(IV) Complexes from Sterically Crowded [((E)-1-{2-Hydroxy-5-[(E)-2-(aryl)-1-diazenyl]phenyl}methylidene)amino]acetate Ligands and Crystal Structure Analysis of a Tetrameric Triphenyltin(IV) Compound

Four new triphenyltin(IV) complexes containing [((E)-1-{2-hydroxy-5-[(E)-2-(aryl)-1-diazenyl]phenyl}methylidene)amino]acetate ligands (L) have been synthesized with formulations of Ph3SnLH. They have been studied by multinuclear (1H, 13C, 119Sn) NMR, 119Sn Mössbauer and IR spectroscopy. A full characterization of one complex, Ph3SnL1H (1), was accomplished by single crystal X-ray crystallography, which revealed the compound to be a macrocyclic tetramer. In the tetramer, the five coordinate tin atoms have distorted trigonal bipyramidal geometries with the three phenyl groups occupying equatorial positions, while an oxygen atom of the carboxylate group of one L ligand and the oxide O-atom (formerly the hydroxy group) of a second L ligand in an apical positions. The carboxylate ligands bridge adjacent tin atoms and coordinate in the zwitterionic form with the phenolic proton moved to the nearby nitrogen atom. 119Sn NMR results indicate that the tetrameric structures of the complexes in the solid state, in which the tin atoms are five-coordinated, dissociate in solution to yield four coordinate monomeric species.

Synthesis and structure of a novel tetranuclear 32-membered macrocycle of triphenyltin complex with pyridine-4-carboxylic acid N-oxide

Abstract The 32-membered stereoregular triphenyltin macrocycle: [Ph3Sn (OCOC5H4NO)]4·3(CH2Cl2) has been synthesized by the reaction of triphenyltin chloride with pyridine-4-carboxylic acid N-oxide. The complex was characterized by elemental analysis, FT-IR, NMR (1H, 119Sn) spectra and X-ray crystallography. Single crystal X-ray diffraction data reveal that the complex is highly symmetrical tetranuclear cyclic complex with the ligand pyridine-4-carboxylic acid N-oxide bridging the adjacent tin atoms. All four tin atoms are five-coordinated resulting in trigonal bipyramidal geometry. And the complex showed good thermal stability and high antitumor activity.

Synthesis, structure and biological activity of organotin derivatives with pyridylmethylthiobenzoic acid

Reaction of 2-(2-pyridylmethylthio)benzoic acid ( 1) with R 2SnO (R = Et or n Bu) in a 1:1 molar ratio gives the dimeric compounds {[(2-PyCH 2SC 6H 4CO 2)SnR 2] 2O} 2. A similar reaction of 2-(4-pyridylmethylthio)benzoic acid ( 2) with Et 2SnO yields an analogous result. However, treatment of 2 with n Bu 2SnO in a 1:1 molar ratio only gives the diorganotin dicarboxylate (4-PyCH 2SC 6H 4CO 2) 2Sn( n Bu) 2. X-ray crystal structure analyses indicate that the pyridyl nitrogen atoms do not coordinate to the tin atoms in the dimer, whilst in the diorganotin dicarboxylate the tin atom has a seven-coordinate distorted pentagonal-bipyramidal geometry, and this compound forms a linkage coordination polymer through the interactions of the pyridyl nitrogen atoms with the adjacent tin atoms. In addition, treatment of 1 or 2 with (Ph 3Sn) 2O in a 2:1 molar ratio affords triphenyltin carboxylates, in which the tin atoms also show different coordination environments. In the solid state, triphenyltin 2-(2-pyridylmethylthio)benzoate is a monomer and the pyridyl nitrogen atom does not participate in coordination to the tin atom either, while the interactions between the pyridyl nitrogen atoms and the adjacent tin atoms link triphenyltin 2-(4-pyridylmethylthio)benzoate into a coordination polymer. Preliminary in vitro tests for fungicidal activity show that all these compounds display good activity to Physolospora piricola in a low concentration. Moreover, the triphenyltin carboxylates show a higher inhibition percentage than the diorganotin carboxylates.

Synthesis of Diorganotin Esters of 5-Bromonicotinic Acid: X-ray Crystal Structure of Polymeric 5-Bromonicotinatodiorganotin

Two types of diorganotins [R2Sn(OCOC5H3N-3-Br-5)2] n and {[R2Sn(OH2)(OCOC5H3N-3-Br-5)2]2} n (R= Me, n-Bu, Ph, n-Oc), are prepared from 5-Br-omonicotinic acid and diorganotin oxides. All the compounds, 1–8, are characterized by elemental analysis as well as IR and 1H-NMR spectroscopy. The crystal structures of [R2Sn(OCOC5H3N-3-Br-5)2] n (2) and {[R2Sn(OH2)(OCOC5H3N-3-Br-5)2]2} n (8) were determined by single crystal X-ray diffraction. In compound 2, each carboxylate moiety of 5-Br-omonicotinic acid is involved in coordination to one Sn atom via two O-atoms, and the N-atom of one pyridine-ring coordinates to the neighboring Sn atom which leads to a polymeric chain. And the N-atom of the other pyridine-ring is dissociative. In compound 8, the compound proves to be dinuclear macrocyclic compounds with 5-Br-omonicotinic acid bridging the adjacent tin atoms with a 12-member ring. The hydrogen bonds ( $$\hbox{N}\ldots\hbox{H}-\hbox{O}$$ ) are observed in the compound 8. These intermolecular hydrogen bonds form another ring, and lead to a polymeric chain in the lattice at the same time.

Calculation of the electronic and optical properties of indium tin oxide by density functional theory

Abstract Density functional theory (DFT) was used to calculate the bulk electronic and optical properties of indium tin oxide (ITO). The ITO model was constructed replacing indium atoms with tin atoms in the cubic unit cell of indium oxide. To allow more possibilities for tin atom substitution than afforded by the forty-atom primitive cell of indium oxide all eighty atoms of the unit cell were included in the stoichiometry (In32−xSnxO48) using periodic boundary conditions. A number of properties of ITO were calculated including the optical band gap, charge carrier density and plasma frequency. The dependence of the electronic and optical properties of ITO on a variety of parameters such as the tin content, cubic lattice parameter and the distance between adjacent tin atoms was investigated. The electronic and optical properties agreed well with experimental data and allowed insight into the origin of the electronic and optical properties of ITO.

The electron density distribution in alpha -tin from powder X-ray data by the maximum-entropy method

The electron density distribution map of alpha -tin has been drawn by the maximum-entropy method (MEM) with 11 independent and two combined structure factors, which were determined by the powder pattern decomposition from X-ray data. The final R and Rw factors were 0.80% and 0.89%, respectively, though a small amount of beta -tin was contained in the specimen. The obtained map indicates that the bonding electrons are clearly seen between the two adjacent tin atoms in the (110) plane with the 0.6 e AA-3 level. This value was about twice that of germanium. The structure factor F(222)e-M for the 222 forbidden reflections at 293 K calculated from the MEM density is +0.4350. The results are discussed by comparing with the electron density maps of C (diamond), Si and Ge.

A NEW STRUCTURAL FORM OF TIN AS A DOUBLE CUBE. A HEPTANUCLEAR TIN-SULFUR CLUSTER

Abstract Recently, we reported new classes of organooxotin compounds in the form of cubes, 1.2 drums,3-6 and oxygen-capped cluster.2,6,7 The faces of these clusters consist of either four- or six-membered Sn-O rings. The cube and the drum have the same empirical composition, [R'Sn(O)O2PR2] n n = 4 and 6, respectively, whereas the oxygen-capped cluster, [(R'Sn(OH)O2PR2)3O][R2PO2], resembles a cube with one corner missing. 119Sn NMR spectra show that the drum6 and the cube2 forms undergo hydrolysis in solution giving oxygen-capped clusters. Heating the latter regenerates the starting drum6 or cube,8 thus showing the reaction to be reversible. In all of these compositions, tin is hexacoordinated, and chelating phosphinate or phosphate ligands span adjacent tin atoms.

A new structural form of tin as a double cube. A heptanuclear tin-sulfur cluster

Abstract Recently, we reported new classes of organooxotin compounds in the form of cubes, 1.2 drums,3-6 and oxygen-capped cluster.2,6,7 The faces of these clusters consist of either four- or six-membered Sn-O rings. The cube and the drum have the same empirical composition, [R'Sn(O)O2PR2] n n = 4 and 6, respectively, whereas the oxygen-capped cluster, [(R'Sn(OH)O2PR2)3O][R2PO2], resembles a cube with one corner missing. 119Sn NMR spectra show that the drum6 and the cube2 forms undergo hydrolysis in solution giving oxygen-capped clusters. Heating the latter regenerates the starting drum6 or cube,8 thus showing the reaction to be reversible. In all of these compositions, tin is hexacoordinated, and chelating phosphinate or phosphate ligands span adjacent tin atoms.

Crystal and molecular structure of dimethylchlorotin 2-pyridinecarboxylate

The crystal and molecular structure of the title compound has been determined using Patterson and Fourier techniques from diffractometer data. Crystals are monoclinic, space group P2 1/ c with a 10.805(7), b 20.292(15), c 10.804(8) Å, β 113.20(5)°, U 2177.37 Å 3. D m 1.85, D c 1.87 mg m −3 for Z = 8, with two independent molecules in the asymmetric unit. The structure has been refined using 1153 observed reflections to a final R = 0.075 and R′ = 0.080. The 2-pyridinecarboxylate ligand bridges adjacent tin atoms to give a polymeric structure consisting of chains which run parallel to the a axis. The pyridine ring is orientated to facilitate a close approach of the nitrogen atom to tin and the SnN distances of 2.468(20), 2.505(25) Å indicate the presence of a significant interaction. The resulting coordination about each tin atom is that of a distorted octahedron.

Investigation into diphosphine oxides as ligands in diorganotin(IV) adducts. Part 1. Synthesis and spectroscopic characterization of 1,2-bis(diphenylphosphoryl)ethane tin complexes and X-ray structure of [1,2-bis(diphenylphosphoryl)ethane]di-n-butyldichlorotin(IV)

1,2-Bis(diphenylphosphoryl)ethane (dppoe) forms complexes with diorganotin(IV) chlorides of the type SnR2Cl2(dppoe)(R = Prn, Bun, or Ph), the i.r. and tin-119 Mossbauer spectra of which have been recorded. The crystal structure of SnBun2Cl2(dppoe) has been determined from single-crystal X-ray data collected by counter methods and refined by full-matrix least-squares techniques to R= 0.0461 for 2 430 observed reflections. Crystals are triclinic, space group P, with unit-cell dimensions a= 11.775(5), b= 15.987(7), c= 11.006(5)A, α= 102.12(5), β= 114.55(6), γ= 101.69(5)°, and Z= 2. Tin is bonded to two Cl– ions, to two C atoms and to two O atoms, to one more loosely than the other. The weaker co-ordination of one of the two OP groups is also reflected in distortions of the geometry of the co-ordination polyhedron. The structure is polymeric in that the dppoe ligand forms bridges between adjacent tin atoms. Tin-119 Mossbauer spectra have been recorded for the three SnR2Cl2(dppoe) complexes in the temperature range 77–150 K, and for the complex (SnPh3Cl)2(dppoe) at 77 K. Quadrupole-splitting data for the former are consistent with a trans-SnC2X4 arrangement about the tin atom in each case. Recoil-free fraction temperature coefficients, a, have also been determined for the three SnR2Cl2 complexes; root-mean-square amplitudes of vibration, 〈x〉, and absolute recoil-free fractions, ƒ, have been estimated at various temperatures for SnBun2Cl2(dppoe).

Derivatives of bivalent germanium, tin, and lead. Part 21. Tin(II) formate: a reinvestigation

The structure of the title compound has been determined from diffractometer data using Patterson and Fourier methods. Crystals are triclinic, P, with unit-cell dimensions a= 5.303(2), b= 8.834(3), c= 5.271 (2)A, α= 104.38(2), β= 105.75(2), and γ= 82.82(2)°. Refinement has been carried by full-matrix least squares to a final R value of 0.050 3 for 1 309 independent non-zero reflections. Crystals consist of infinite two-dimensional sheets in which all the formate groups bridge adjacent tin atoms. Tin forms two short [2.14(1) and 2.20(1)A] and two long [2.36(1)A] bonds in a pseudo-trigonal-bipyramidal arrangement with the tin lone pair occupying the remaining equatorial site. The structure is disordered such that the formate groups occupy equally two sets of positions between the tin atoms. Vibrational and tin-119m Mossbauer spectra have been recorded, and together with the unit-cell data are compared with data reported previously.

Derivatives of bivalent germanium, tin, and lead. Part X. Tin(II) bis(phenoxides), bis(O-methyl dithiocarbonate), and bis(diethyidithiocarbamate)

Tin(II) bis(phenoxides), Sn(OR)2(I), have been synthesised in high yield from bis(methylcyclopentadienyl)tin and 2 mol of phenol in benzene or tetrahydrofuran (thf); o-aminophenol yields a compound of composition Sn2(OR)3 due to some Sn–N covalent bond formation. The reaction of Sn(OMe)2 with phenols does not give (I), but [(p-MeC6H4O)SnOSn(OC6H4Me-p)], (IV), has been isolated from the reaction with p-cresol. Mossbauer spectra of the compounds (I) and (IV) indicate the presence of polymeric lattices in which adjacent tin atoms are bridged by oxide and phenoxide oxygen atoms in an infinite array. Tin(II) bis(diethyldithiocarbamate), [Sn(S2CNEt2)2], and bis(O-methyl dithiocarbonate), [Sn(S2COMe)2], have been obtained by metathesis between tin(II) chloride and K[S2CNEt2] or K[S2COMe]. The Mossbauer parameters for the dithiocarbonate are substantially different from those for the diethyldithiocarbamate which is known to possess a structure based on a distorted trigonal bipyramid with the tin lone pair occupying a sp2 hybrid orbital, and suggests a structure in which dithiocarbonate chelates the tin atoms in such a way that the four sulphur atoms are disposed almost tetrahedrally about the metal.