A new recipe for the synthesis of diorganotin bis(O-alkylorganophosphonate)s, RSn{O(P)(O)(OR)R} [R = R = methyl (1); R = ethyl and R = methyl (2), allyl (3), 2-thienyl (4), benzyl (5)], has been developed from the direct reaction of elemental tin (powder) with organophosphonic acid dialkyl esters, RP(O)(OR), in the presence of a catalytic amount of potassium iodide under ambient conditions (130 °C, 18-20 h). The key steps in the proposed catalytic cycle involve the monodealkylation of phosphonate diester and in situ generation of a RSnI or RSnI intermediate via the oxidative addition of alkyl iodide on tin. Evidence in support of the formation of organotin species comes from the isolation of MeSn{O(P)(O)(OPr)Me} (6) from the direct reaction of tin metal with MeP(O)(OPr) in the presence of methyl iodide. The method has also been extended to isolate Zn{OP(O)(OMe)Me} (7) using metallic zinc as the precursor. All of the compounds have been characterized by IR and NMR studies as well as X-ray crystallography for 2, 4, 6, and 7.

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.

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.

The use of Internet has undergone revolutionary changes over the years. Earlier it was being used by limited number of people for accessing utility services but now its user base has changed all together. It is widely used by youth to access social media who have its 24*7 access via latest gadgets such as smartphones, PDAs etc. Moreover, social media is emerging as an important tool of marketing which has started influencing purchase decisions of the people. The aim of this paper is to examine the use of social media by university students and to study its impact on their purchase decisions. A sample of 90 students has been selected from Punjabi University, Patiala for the purpose of the study. The data have been collected by using a self-administered questionnaire. Various hypotheses have been formulated and tested using chi-square, t-test and ANOVA. The findings of the study have wide implications in the field of marketing.

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