New Insights into Hexacoordinated Silicon Complexes with 8- Oxyquinolinato Ligands: 1,3-Shift of Si-Bound Hydrocarbyl Substituents and the Influence of Si-Bound Halides on the 8-Oxyquinolinate Coordination Features

• DOI: 10.5560/znb.2014-4170
• Publication Date: 2014-12-08T16:38:41Z
• Authors: Erik Wächtler; Alexander Kämpfe; Katrin Krupinski; Daniela Gerlach; Edwin Kroke; Erica Brendler; Jörg Wagler
• Keywords: Moiety

Abstract The transsilylation reaction between allyltrichlorosilane and 8-trimethylsiloxyquinoline in the molar ratio 1 : 3 yields hexacoordinated silicon tris-chelate (oxinate) 2 Si(adho) (“oxinate” = 8- oxyquinolinate, “adho” di-anion of 2-allyl-1,2-dihydro-8-oxyquinoline) comprising an SiO N skeleton. identity this complex was established by single-crystal X-ray diffraction analysis 29 Si CP=MAS NMR spectroscopy its chloroform solvate. Benzyltrichlorosilane dibenzyldichlorosilane, benzyl (Bn) as “aromatically stabilized allyl moiety” did not undergo such rearrangement. Instead, complexes SiBnCl SiBn were obtained even upon using three equivalents 8-trimethylsiloxyquinoline. We determined crystal structure a non-disordered bis-chelate with Sibound hydrocarbyl halogen substituents (the previously published SiMeCl disordered alternative Me=Cl site occupancies). (Oxinate) exhibits surprisingly poor response N-Si bonds to different trans-disposed Si-X (X=Bn, Cl) bonds. For comparison deeper insights into coordination chemistry oxinato halide substituents, we structures SiPhCl·CHCl , SiCl SiF ·1.5(CHCl ), (8-oxyquinaldinate) . Furthermore, BnSiCl Bn (and dibromo analog) are reported. influence Si-C-C-C torsion angles group on shift benzylsilanes (which is noticeably upfield respect analogous methyl silanes) analyzed quantum-chemical calculations.