The contribution of silaalkylphosphonic acids Me3SiCH2P(O)(OH)2 (1) and Me3SiC(CH3)2P(O)(OH)2 (2) as ligands was demonstrated for the first time by the isolation of new diorganotin(IV) phosphonates Et2Sn{OP(O)(OH)CH2SiMe3}(OSO2Me) (3), (Et2Sn)6{O3PC(CH3)2SiMe3}4(OSO2Me)4 (4), and Et2Sn(O3PCH2SiMe3) (5). X-ray crystallographic studies of 1-4 are presented. The structures of 1 and 2 adopt extended motifs by virtue of P-OH···O═P-type hydrogen bonding interactions. The molecular structure of 3 is composed of a dimer formed by bridging hydrogen phosphonate groups, while the sulfonate group appended on each tin atom acts in a μ2-bridging mode to afford the formation of one-dimensional coordination polymer featuring alternate eight-membered [-Sn-O-P-O-]2 and [-Sn-O-S-O-]2 rings. The asymmetric unit of 4 is composed of two crystallographically unique trinuclear tin phosphonate clusters with a Sn3(μ3-PO3)2 core linked together by coordinative association of a μ2-sulfonate group, while the remaining sulfonates are involved in the construction of a two-dimensional self-assembly. The identity of 1-5 in solution was established by IR and multinuclear ((1)H, (13)C, (31)P, (119)Sn) NMR spectroscopy. The presence of silaalkyl group in 5 imparts unusual solubility in hydrocarbon, aromatic, and ether solvents. As a consequence, the formation of colloidal particles of 5 featuring rodlike morphology was achieved by ultrasonication of a solution in ethanol-chloroform mixture.

A one-pot reaction between di-n-butyl/diethyl/dimethyltin dichloride and dimethylphosphite (MeO)2P(O)H in a solvent free medium (120 °C, 18 h) proceeds smoothly to yield the corresponding diorganotinbis(O-methylphosphite)s, [R2Sn(OP(O)(OMe)H)2]n [R = n-Bu (1), Et (2), Me (3)]. The identity of 1-3 has been established by IR, multinuclear ((1)H, (13)C, (31)P, (119)Sn) NMR, powder X-ray diffraction (PXRD) and X-ray crystallography. The coordination framework in each case adopts a one-dimensional structural motif comprising an infinite array of eight-membered [Sn-O-P-O]2 cyclic rings, with the phosphite ligands acting in a bridging bidentate mode. The structures are extended to two- (for 1) and three-dimensional (for 2, 3) assemblies by virtue of C-H···O hydrogen bonding interactions. The stability and bulk properties of 1-3 have been investigated upon exposure to humid laboratory conditions using (1)H NMR, PXRD and SEM studies. The results conform to a unique chemical modification of 1-3 involving selective de-esterification of P-OMe bonds and the formation of corresponding diorganotinbis(phosphite)s, [R2Sn(OP(O)(OH)H)2]n (1a-3a), as insoluble solids. The results obtained from impedance studies (σ = 10(-4)-10(-6) S cm(-1); E(a) = 0.33-0.42 eV) reveal potential application of 1a-3a as proton conducting materials.

This study presents the synthesis of diorganotin(IV) phosphonates,Et or Ph] and Sn {O 3 P(CH 2 ) 3 SiR 1 R 2 2 } 2 featuring rod, rosette and spherical morphologies. The presence of silaalkylphosphonate ligands in the structural framework facilitates the transformation of bulk samples into a nano/ colloidal domain by a facile solution based approach. The colloidal particles show enhanced antimicrobial activity against B. Subtilis bacteria as compared to their bulk counterparts. 2 9606136 † Electronic supplementary information (ESI) available: Experimental details and characterization of the samples. See

Di-n-butyltinbis(O-methylmethylphosphonate), 1 exhibits the formation of slender micro crystallites with unique bending features and iodine-induced modulation of crystal morphology to cubic shaped single crystals.