Syntheses and structures of two novel “doubledecker” silicon complexes [R-Si(o-O-p-OMe-C6H3- C(Ph)=N-(CH2)2-N=C(Ph)-C6H3-p-OMe-o-O)-CH2-]2 (R = Ph, p-tBu-C6H4-O) with the silicon atoms hexacoordinated by two salen-type tetradentate 〈ONNO〉-chelating ligands are described. Hydrogen bonding between the halves of the bridged complexes as well as with chloroform solvate molecules determines the conformation. Compared with analogous mononuclear silicon complexes these ”doubledeckers” show bathochromically shifted Vis-absorption.
Alkynylsilanes bearing one to four alkynyl groups at silicon, with organyl groups (Me, Ph, Vin), H, Cl at silicon, and with substituents H, nBu, tBu, Ph, C6H4-4-Me, 3-thienyl, CH2NMe2 at the C≡C bond, were prepared, and their 13C and 29Si NMR data are reported. The results of X-ray structure analyses of three representative derivatives [di(phenylethynyl)dimethylsilane, di(phenylethynyl) methyl(phenyl)silane, and tri(phenylethynyl)methylsilane] are presented. The chemistry of mono- and dialkynylsilanes was further developed to prepare compounds with alternating Si atoms and C≡C bonds, affording new dialkynylsilanes as well as numerous new vinylsilanes which have also been characterized by 13C and 29Si NMR spectroscopy in solution. In the case of ethynyl(triphenylsilylethynyl) dimethylsilane, the molecular structure was determined by X-ray diffraction.