Organic-inorganic hybrids are an important class of new materials that offer improved thermal and mechanical properties over normal polymers. They may be produced by either the sol-gel route or through the use of inorganic compounds possessing reactive functional groups. Polyhedral oligosilsesquioxanes (POSS) are completely defined molecules of nanoscale dimensions that may be functionalized with reactive groups suitable for the synthesis of new organic-inorganic hybrids. Here we report the synthesis and characterization of a novel POSS possessing eight isocyanate groups via the hydrosilylation of octakis(hydridodimethylsiloxy)octasilsesquioxane (Q8M8H) and m-isopropenyl-alpha,alpha'-dimethylbenzyl isocyanate (m-TMI). The suitability of this new macromer to the synthesis of a organic-hybrids has been explored by forming a new type of highly cross-linked polyurethane elastomer via reaction of the macromer with poly(ethylene glycol) using dibutyltin dilaurate catalyst.

The first member of a new family of tripodal thioether ligands, the methyltris[(alkylthio)methyl]silanes MeSi(CH(2)SR)(3) (R = Me), has been synthesized and characterized. Reactivity studies lead to the isolation of the complete series of group 6 metal carbonyl derivatives {eta(3)-MeSi(CH(2)SMe)(3)}M(CO)(3) (M = Cr, Mo, W), whose structures have been determined by single-crystal X-ray diffraction. The three complexes are isomorphous and display distorted octahedral structures with face-capping tridentate thioether ligands. {eta(3)-MeSi(CH(2)SMe)(3)}Cr(CO)(3) is monoclinic, P2(1)/c, a = 8.1658(2) Å, b = 15.0563(2) Å, c = 26.5791(3) Å, beta = 90.3653(6) degrees, V = 3267.74(8) Å(3), Z = 8. {eta(3)-MeSi(CH(2)SMe)(3)}Mo(CO)(3) is monoclinic, P2(1)/c, a = 8.34630(6) Å, b = 15.2747(2) Å, c = 27.1865(4) Å, beta = 90.8987(9) degrees, V = 3465.44(10) Å(3), Z = 8. {eta(3)-MeSi(CH(2)SMe)(3)}W(CO)(3) is monoclinic, P2(1)/c, a = 8.1582(2) Å, b = 14.9903(2) Å, c = 26.7268(4) Å, beta = 90.6568(8) degrees, V = 3268.30(9) Å(3), Z = 8.

The one-dimensional copper(I) coordination polymers Cu(3){MeSi(CH(2)SMe)(3)}(2)X(3) (X = Cl, Br) and [{MeSi(CH(2)SMe)(3)}Cu(NCMe)]Y (Y = OSO(2)CF(3), BF(4), PF(6)) were readily obtained in very good to excellent yields (80-95%) by reacting CuX or [Cu(NCMe)(4)]Y, respectively, with the tridentate thioether ligand MeSi(CH(2)SMe)(3) in acetonitrile. The new complexes were characterized by a combination of analytical and spectroscopic techniques, including electrospray ionization mass spectrometry and, for the bromo and hexafluorophosphate derivatives, single-crystal X-ray diffraction. Both complexes exhibit one-dimensional chain structures with approximately tetrahedral copper centers and bridging unidentate/bidentate thioether ligands.

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