Diorganotin Dicarboxylates Research Articles

Tuning the Supramolecular Structure through Variation of the Ligand Geometry and Metal Substituents–Diorganotin Macrocycles and Coordination Polymers Derived from cis- and trans-1,2-, 1,3-, and 1,4-Cyclohexanedicarboxylic and cis,cis-1,3,5-Cyclohexanetricarboxylic Acid

cis- and trans-1,2-chdcaH2, 1,3-chdcaH2, and 1,4-chdcaH2 (chdcaH2 = cyclohexanedicarboxylic acid) as well as cis,cis-1,3,5-chtcaH3 (chtcaH3 = cyclohexanetricarboxylic acid) have been treated with dimethyl- and di-n-butyltin reagents, and for the case of 1,4-chdcaH2 additionally with di-tert-butyltin dichloride, to determine whether macrocyclic or polymeric diorganotin dicarboxylates are formed dependent of the spatial orientation of the coordinating ligand functions and the organic substituents at the metal atom and to analyze conformational and topological variations in the resulting supramolecular aggregates. The single-crystal X-ray diffraction studies showed that besides the ligand geometry the substituents at the metal center are key elements for the formation of either monomeric, cyclo-oligomeric, or polymeric assemblies. Two of the compounds characterized by X-ray diffraction analysis exhibited macrocyclic ring structures, [{Me2Sn(cis-e,a-1,4-chdca)}2] and [{nBu2Sn(cis-e,a-1,4-chdca)}4]. For most o...

Bis{2-[(E)-(5-tert-butyl-2-hydroxyphenyl)diazenyl]benzoato}dimethyltin(IV)

In the title diorganotin dicarboxyl­ate, [Sn(CH3)2(C17H17N2O3)2], the tin(IV) atom is six-coordinated by four O atoms derived from asymmetrically coordinating carboxyl­ate ligands, and two methyl-C atoms. The resulting C2O4 donor set defines a skew-trapezoidal bipyramid with the Sn—C bonds disposed over the weaker Sn—O bonds. Within each carboxyl­ate ligand, the hydroxyl-H atom forms bifurcated O—H⋯(O,N) hydrogen bonds with carboxyl­ate-O and azo-N atoms. The dihedral angles between the benzene rings in the two ligands are 10.44 (11) and 34.24 (11)°. In the crystal, centrosymmetric dimers are formed through pairs of Sn⋯O inter­actions [2.8802 (16) Å], and the dimers are linked into supra­molecular layers in the ac plane by C—H⋯π inter­actions.

Thermokinetic studies of organotin(IV) carboxylates derived from para-methoxyphenylethanoic acid

Thremogravimetric (TG) studies of a new series of organotin(IV) carboxylates of the general formula RnSnL4-n (where R = CH3, C2H5, C4H9, C6H5, C6H11 and C8H17, n = 2, 3 and L = para-methoxyphenylethanoate anion) have been carried out. Horowitz and Metzger method has been used to calculate thermokinetic parameters. It has been found that diorganotin dicarboxylates have larger activation energy than those of corresponding triorganotin carboxylates. Furthermore, the activation energy, Gibb’s free energy, entropy and enthalpy of diorganotin compounds shows the following trend, (CH3)2SnL2 < (C2H5)2SnL2 < (C4H9)2SnL2 < (C8H17)2SnL2. This is attributed to steady increase in chain length of the alkyl groups. However, triorganotin compounds do not show such behavior.

Self-assembly of a novel 2D network polymer: Syntheses, characterization, crystal structure and properties of a four-tin-nuclear 36-membered diorganotin(IV) macrocyclic carboxylate

The novel macrocyclic complex (n-Bu 2SnL) 4·2C 6H 6 1 (LH 2 = naphthalene-1,4-dicarboxylic acid, C 6H 6 = benzene) has been synthesized by the reaction of di-n-butyltin oxide and rigid naphthalene-1,4-dicarboxylic acid. Single crystal X-ray diffraction analyse shows that complex 1 has a centrosymmetric tetranuclear diorganotin dicarboxylate with 36-membered macrocycle, which is formed by n-Bu 2Sn and ligand alternately linking. All four Sn atoms are hexacoordinated, and the coordination environment can be considered as a skew-trapezoidal bipyramidal with an anisobidentate coordination mode of the carboxylate groups. Luminescent property study of complex 1 has shown that the fluorescent peak was blue-shifted and the fluorescent intensity strengthened markedly compared with ligand. Pilot studies indicated that complex 1 has shown good antitumor activities. This complex 1 is likely to serve as a new model for further investigation on the structure–antitumor activity relationship.

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.

Disproportionation reactions of (methoxy/hydroxy)diorganotin(IV) methanesulfonates with carboxylic acids: Synthesis and structure of new diorganotin(IV) carboxylates

Disproportionation reactions between equimolar quantities of R 2Sn(X)OSO 2Me [X=OMe or OH] and ethylmalonic/maleic acid in acetonitrile under mild conditions afford new diorganotin dicarboxylates, R 2Sn(O 2CR′COOH) 2 [R′=CHEt, R= n-Pr ( 3a), n-Bu ( 3b); R′=CHCH, R= n-Pr ( 3c), n-Bu ( 3d)] along with R 2Sn(OSO 2Me) 2 [R= n-Pr ( 4a), n-Bu ( 4b)]. Similar reactions of the tin precursors with pyridine-2-carboxylic acid provide an access to novel trinuclear tin complexes, R 6Sn 3(O 2CC 5H 4N-2) 3(OSO 2Me) 3 [R= n-Pr ( 5a), n-Bu ( 5b)]. These have been characterized by IR and multinuclear ( 1H, 13C, 119Sn) NMR spectroscopies. The molecular structures of 3b, 4b and 5b have been determined by X-ray crystallography. Compound 3b is monomeric with bicapped tetrahedron geometry by virtue of anisobidentate coordination of one carboxylate group of each ligand, while the other carboxylic acid group remains free. The polymeric structure of 4b features centrosymmetric eight-membered rings comprising bridging methanesulfonate groups and nearly perfect octahedral geometry around each tin atom. Compound 5b crystallizes as 5b·2H 2O·Et 2O. Its molecular structure comprises of mixed ligand tin ester, n-Bu 2Sn(O 2CC 5H 4N-2)OSO 2Me and its disproportionated products, n-Bu 2Sn(O 2CC 5H 4N-2) 2 and n-Bu 2Sn(OSO 2Me) 2 which are coordinatively associated by varying bonding modes of pyridine-2-carboxylate groups. A possible rationalization of these results are discussed in terms of the intermediacy of mixed ligand tin complexes, R 2Sn(L)OSO 2Me (L=carboxylate) formed by the selective substitution of SnOMe group or by the dehydration of SnOH group in the tin precursors with the carboxylic acid.

Review: Organotin compounds and their therapeutic potential: a report from the Organometallic Chemistry Department of the Free University of Brussels

AbstractAn overview of the development of antitumour organotin derivatives is presented and discussed for selected classes of compounds, such as tetraorganodicarboxylatodistannoxanes and related diorganotin dicarboxylates, and for triorganotin carboxylates. Among the carboxylate groups used are steroidcarboxylates and other biologically relevant carboxylates. High to very highin vitroactivities have been found, sometimes equalling that of doxorubicin. Solubility in water is an important issue, dominating thein vivotesting of compounds. Polar substituents, like fluorine or polyoxaalkyl moieties, improve the water solubility. Although organotin derivatives constitute a separate class of compounds, the comparison with cisplatin is inevitable. Among the observed toxicities, neurotoxicity, known from platinum cytostatics, and gastrointestinal toxicity, typical for many oncology drugs, have been detected, but to a lower extent. Further research to develop novel useful organotin antitumour compounds needs to be carried out. Copyright © 2002 John Wiley &amp; Sons, Ltd.

Synthesis, Characterization and Biological Activity of DimethyltinDicarboxylates Containing Germanium

A series of diorganotin dicarboxylates of the general formula (CH3)2Sn(OCOCHR3CHR2GeR1)2 where R1=(C6H5)3, (P-CH3C6H4)3, N(CH2CH2O)3, R2=C6H5, H, CH3, P-CH3OC6H4, P-ClC6H4, P-CH3C6H4, R3=CH3 and H, have been synthesized by the reaction of dimethyltin oxide with germanium substituted propionic acid in 1:2 molar ratio in toluene. The H2O formed was removed azeotropically using a Dean and Stark apparatus. All the compounds have been characterized by IR, multinuclear (1H, 13C, 119Sn) NMR, mass and Mössbauer spectroscopies. All compounds were found to have potential activity against bacteria.

Redistribution reactions of diorganotin dicarboxylates and diorganotin dihalides: A convenient method for the preparation of halo-diorganotin carboxylates

Organotin compounds with the general formula R2(X)SnL (where R=Me, Et, n-Bu, Ph; L=the trans-3-(2-furanyl)-2-propenoate anion or the trans-3-(3-methylphenyl)-2-propenoate anion; and X=Cl) have been prepared by redistribution reactions between the R2SnL2 and R2SnX2 compounds. These compounds were characterized by elemental analyses and various spectroscopic techniques such as 1H, 13C, 119Sn NMR, Mass, Mössbauer, and IR spectroscopies. On the basis of these spectroscopic data, it is suggested that these compounds adopt the cis-R2(X)SnO2 geometry. © 1997 John Wiley & Sons, Inc. Heteroatom Chem 8: 273–278, 1997.

Synthesis and crystal structure of di- n-butylbis(2-amino-5-chlorobenzoato)tin(IV)

Reaction of di- n-butyltin oxide with 2-amino-5-chlorobenzoic acid in 1:2 stoichiometry yields the title compoind which crystallizes as the six-coordinate diorganotin dicarboxylate monomer. The crystal structure of the compound reveals the tin atom situated on a crystallographic two-fold axis in a skew-trapezoidal bipyramid geometry. The trapezoidal plane is defined by two asymmetrically chelating carboxylate groups; SnO bonds are 2.123(4) and 2.484(5) Å and the CSnC angle is 141.7(6)°. The nitrogen atom of the amino group of the carboxylate ligand does not participate in any significant interactions with the tin atom.

Silicone curing and polyurethane preparation promoted by latent organotin catalysts

AbstractThe use of new latent organotin cataylsts has been investigated for silicone curing and polyurethane preparation. These functional tetraorganotins are inactive at room temperature and liberate in situ the active species, diorganotin dicarboxylates, when heated. They confer long pot‐lives to the mixtures in which they are incorporated. Upon heating, these mixtures are rapidly cured or polymerized after a short activation period.

Crystal structure of trans-C2SnO5 pentagonal bipyramidal dibutylbis(phenylacetato)tin(IV) hydrate

The Lewis acidity of tin in a diorganotin dicarboxylate is demonstrated in this first example of a 1/1 adduct of the ester with a neutral ligand. The structure of dibutyltin bisphenylacetate hydrate [(C4H9)2Sn(O2CCH2C6H5)2·H2O] has been determined from 1211 ∥F 0∥≥6σ∥F c ∥ MoKα reflections and refined to anR F of 0.061 [space groupP2/a witha=8.416(2),b=10.391(5),c=14.28(1) A,β=98.42(4)° andZ=2]. TheC α atoms [Sn-C 2.101(8) A; C-Sn-C 169.9(5)°] make up the apices and the Ocarboxylate [Sn-O 2.234(5), 2.439(7) A; O-Sn-O 55.7(2)°] and Owater [Sn-O 2.342(8) A] atoms the equatorial points of thetrans-C2SnO5 pentagonal bipyramid around the Sn atom. The molecular symmetry isC 2, and the Sn and Owater atoms lie along a crystallographic twofold axis. The aqua ligand forms donor H-bonds with neighboring carboxylato groups to link the molecules into a double zigzag chain running parallel toa.

Structural chemistry of organotin carboxylates IV. Synthesis and spectroscopic properties of diorganotin(IV) complexes with o-anisic acid. The crystal and molecular structure of [ nBu 2Sn(2-MeOC 6H 4COO)] 2O 2

Reactions of diorganotin(IV) oxides with o-anisic acid in 1 1 and 1 2 stoichiometry afford complexes of the type [R 2Sn(2-MeOC 6H 4COO)] 2O 2 (I) and [R 2Sn(2-MeOC 6H 4COO) 2] (II) (R = Me, Et, nPr, nBu), respectively. These complexes have been characterized by elemental analyses, IR and NMR ( 1H, 13C and 119Sn) spectroscopy, and I shown to adopt a dimeric ladder structure whereas II has the usual monomeric diorganotin dicarboxylate structure. The oxygen atom of the methoxy group of the ligand does not participate in bonding to the tin atom. This conclusion is supported by an X-ray diffraction study. The compound [ nBu 2Sn(2-MeOC 6H 4COO)] 2O 2, (Id), showed that in solid Id there are two unique, centrosymmetric dimers in the asymmetric unit. The individual molecules conform to the tetraorganostannoxane structure, with six-coordination being assigned to both the endocyclic and exocyclic tin atoms after consideration of close intermolecular tin to oxygen contacts. Crystals are triclinic with space group P 1 and unit cell dimensions a 13.503(3), b 24.226(4), c 11.917(1) Å, α 102.21(1), β 108.54(2), and γ 89.92(1)°. The structure was refined by a blocked-matrix least-squares procedure to final R = 0.052 for 5505 reflections with I ⩾ 2.5σ( I).

New latent organotin catalysts: preparation and mechanism of the thermal decomposition of bis[2-(acyloxy)alkyl]diorganotins

New organotin compounds, bis(2-(acyloxy)-alkyl)diorganotins, can be thermally decomposed into di-organotin dicarboxylates. The substituent effects on the reaction parameters are studied, and a possible mechanism for the decomposition is proposed. These tetra-organotins can be regarded as latent catalysts for silicone curing and polyurethane preparation

Exchange reactions of organotin carboxylates

Triorganotin carboxylates were found to react with diorganotin dichlorides according to the following reactions: ▪ (R = CH 3 or C 6H 5; R′ = CH 3, C 6H 5 or n-C 4H 9 and R″ = CH 3, CH 2Cl, or C 6H 5). In addition, reaction of R 2SnCl(OOCR″) with R′ 3Sn(OOCR″) in a 1 1 mole ratio was found to give R 2Sn(OOCR″) 2. These reactions were followed by use of NMR techniques as well as by isolation of the products. These reactions afford a convenient method for the synthesis of diorganotin halide carboxylates and diorganotin dicarboxylates. The scope of these reactions as well as the IR spectra of the products are discussed.