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Abstract: The 1-oxa-4,6-dithia-, 1,3,6-trithia-, 1-aza-4,6-dithia-, 1-aza-4,6-dioxa-, 1-thia-4,6-dioxa- and 1,3,6-trioxametallocanes possess a strong 1,5 transannular interaction through an acceptor atom M [Ge(IV), Sn(IV), Pb(IV), As(III), Sb(III) and Bi(III)] and an X donor (O, S, NR). The conformation adopted by the metallocane ring has exhibited various conformations along with the extreme conformations boat–boat, boat–chair and chair–chair. The structural diversity observed in these eight-membered rings results in a variety of coordination numbers, as well as in the presence of polymeric structures. The purpose of the present review is to highlight the relationship between the strength of the transannular bonding and the resulting molecular structures. Factors such as coordination number, electronegativity and steric effects are revised. [Copyright &y& Elsevier]

Reports on the isolation of Sn(nBu)(Cl)((OCH2CH2S)2Sn(nBu)) from the reaction of nBuSnCl3 and Na2(SCH2CH2O). Trimetallic tin(IV) compound connection via oxygen atom bridges, forming distannoxane units; Different arrangement from the previous ladder or staircase structure.

We report the synthesis and spectroscopic characterization of the first organotin(IV) complexes with cyclic seven-membered dithiocarbamate ligands: the azepane-1-carbodithioate and the homopiperazine-1,4-bis-carbodithioate with two different organotin entities, di-n-butyltin and tri-cyclohexyltin: [(C4H9)2Sn{S2CN(CH2)6}2] (3), [(C6H11)3Sn{S2CN(CH2)6}] (4), and [(C6H11)3Sn}2 (μ-S2CN(C5H10)NCS2)] (5). Compounds (3–5) are air-stable both in solid-state and in solution, and were characterized by elemental analyses, IR, FAB+–MS, and multinuclear NMR (1H, 13C, and 119Sn) spectroscopy. Their molecular structures were unambiguously established by single-crystal X-ray diffraction studies. The geometrical arrangement around the tin atom can be described as distorted octahedral for (3) and distorted trigonal bipyramid for (4) and (5). The coordination mode for both ligands is considered as asymmetric bidentate, as happens in other organotin(IV) dithiocarbamates. Furthermore, (4) and (5) do not exhibit intermolecular secondary interactions, while (3) presents intermolecular interactions between the tin and a sulfur atom with the reciprocally neighboring molecule, giving rise to a zig-zag polymeric structure. [ABSTRACT FROM AUTHOR]

Four new optically active organotin(IV) O,O'-di-(-)-menthyldithiophosphates: Me3SnS2P(OMen)2 1, Ph3SnS2P(OMen)2 2, Me2Sn[S2P(OMen)2]2 3 and Ph2Sn[S2P(OMen)2]2 4 (Men = Menthyl) have been prepared in ethanol from sodium O,O'-(-)-dimenthyldithiophosphate and the corresponding tri- or diorganotin(IV) chlorides. All the compounds display optical activity and were characterized by elemental analyses, IR, EM FAB+, and multinuclear NMR, (1H, 13C, 19P 119Sn). In addition, the molecular structures of 3 and 4 were determined by X-ray single crystal analyses. Both complexes consist of discrete molecules, where tin is bonded to two carbon atoms and the four sulfur atoms of two anisobidentate dithiophosphate ligands. The environment around the central tin atom exists in skew-trapezoidal bipyramidal geometry. [ABSTRACT FROM AUTHOR]

Abstract: Sodium tetraphenylimidodiphosphinochalcogenide salts Na[(Ph2P(X)NP(X)Ph2)] (X=S, Se), react with 15-crown-5 ether to give two complexes [Na(15C5)][(Ph2P(X)NP(X)Ph2)] (X=S, Se), 1 and 2 respectively. The crystal and molecular structures of the resulting compounds were determined by X-ray diffractometry. The compounds are isostructural showing sodium–sulfur and sodium–selenium interactions, respectively, forming discrete inorganic (carbon free) chelate rings. These are different from the complex from the oxygen homolog which is an aggregated poly-ion, containing sodium ions with different coordination environments. [Copyright &y& Elsevier]

Abstract: Herein we report on the preparation of hydrated ammonium salts of the dithiophosphonic acids (RO)(Fc)P(S)(SH) (R=derivative of benzyl) featuring [(NH4 ·H2O)2]2+ cations formed by N–H⋯O hydrogen bonds. Interaction of these cations with the PS2 − units gives rise to unprecedented 2D networks, formed solely by hydrogen bonds. These unique networks containing two- and three centered hydrogen bonds are valuable examples of the acceptor properties of sulfur atoms. [Copyright &y& Elsevier]

Abstract: The synthesis of the four disubstituted organotellurium (IV) compounds, C4H8Te[S2P(OCH2)2CEt2]2 (1), C4H8Te[S2P(OCH2)2CMe- n Pr]2 (2), C4H8OTe[S2P(OCH2)2CEt2]2 (3), C4H8OTe[S2P(OCH2)2CMe- n Pr]2 (4), and one monosubstituted compound C4H8OTe(I)[S2P(OCH2)2CMe- n Pr] (5), was achieved. All compounds were characterized by IR, EI, MS, and multinuclear NMR (1H, 13C, 31P, 125Te). In addition, the molecular structures of 2 and 3 were determined by X-ray analyses. Both structures are monomeric and the tellurium atom is bonded to two carbon atoms and to one sulfur atom of each one of the two anisobidentate dithiophosphate ligands. In 2, the geometry around Te(IV) is as that of a sawhorse structure in which the lone pair is apparently stereochemically active and occupying an equatorial position in a ψ-trigonal bipyramid. However, when the second sulfur atom of the dithiophosphate ligand is included in the coordination sphere, the environment about tellurium in the compound 2 can be described as bicapped ψ-trigonal bipyramid. Whereas in 3 it is a distorted octahedral structure in which the lone pair is stereochemically inactive. [Copyright &y& Elsevier]

The crystal and molecular structures of substituted difluorenyl-(dimethyl)silanes Me2Si(CR′R2)(CR″R2) (R′=H, R″=Me 1 and R′=R″=Me 2, CR2=fluorenyl) have been determined by X-ray diffraction and compared with the conformations available in the gas phase. 1 and 2 crystallize in the P2(1)/m and P2(1)/c space groups with the cell parameters: a=7.191 A˚, b=17.658 A˚, c=8.982 A˚, α=γ=90°, β=101.880° (1) and a=13.132 A˚, b=7.463 A˚, c=24.438 A˚, α=γ=90°, β=99.73° (2), respectively. Both compounds as well as the unsubstituted parent silane Me2Si(CHR2)2 (3) exhibit extensive intramolecular and intermolecular C&z.sbnd;H⋯π interactions leading to supramolecular associations. Gas phase conformations predicted on the basis of AM1 semiempirical molecular orbital calculations support the existence of these intramolecular interactions and correlate well with the temperature dependent proton NMR spectra. [Copyright &y& Elsevier]