@phdthesis{Cota2010, author = {Cota, Smaranda}, title = {Contributions to the Chemistry of Higher-Coordinate Silicon: Synthesis, Structure, and Stereodynamics of New Penta- and Hexacoordinate Silicon(IV) Complexes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-52312}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2010}, abstract = {Im Vordergrund dieser Arbeit stand die Synthese und strukturelle Charakterisierung penta- und hexakoordinierter Silicium(IV)-Komplexe. Im Verlauf dieser Untersuchungen wurden die neutralen pentakoordinierten Silicium(IV)-Komplexe 38, 39, 43-48, 54 und 55 dargestellt. Weiterhin konnten die neutralen hexakoordinierten Silicium(IV)-Komplexe 33-36,49, 50, 52, 53, 56-62, 63, 64 und 65 synthetisiert werden. Die Charakterisierung aller Verbindungen erfolgte durch Elementaranalyse, NMR-Spektroskopie in L{\"o}sung (1H, 13C, 15N, 29Si) und im Festk{\"o}rper (13C, 15N, 29Si VACP/MAS NMR), sowie durch Kristallstrukturanalyse(außer 45, 47-49, 52, 53 und 63).}, subject = {Silicium}, language = {en} } @phdthesis{Dragota2005, author = {Dragota, Simona Olimpia}, title = {Contributions to the chemistry of higher-coordinate Silicon : synthesis, structure, and stereodynamics of new Silicon(IV) complexes with SiO2N2C, SiO4C, or SiO6 skeletons}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-15304}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2005}, abstract = {This thesis contributes to the field of silicon chemistry, with a special emphasis on the chemistry of penta- and hexacoordinate silicon.The spirocyclic zwitterionic Lambda5Si-silicates 1-6 with a (2,2,6,6-tetramethylpiperidinio)- methyl group and two identical bidentate chelate ligands derived from glycine, (S)-alanine, (S)-phenylalanine, (S)-valine, (S)-tert-leucine, or (S)-proline bound to the silicon(IV) coordination center were synthesized and structurally characterized for the first time.The hitherto unknown spirocyclic zwitterionic Lambda5Si-silicates 7-12 with an (ammonio)- methyl group and two identical bidentate chelate ligands derived from (S)-lactic acid, (S)-3- phenyllactic acid, or (S)-mandelic acid were synthesized and structurally characterized in the solid state (elemental analyses (C, H, N), crystal structure analyses, 15N and 29Si VACP/MAS solid-state NMR experiments) and in solution (except 10; 1H, 13C, and 29Si NMR experiments)The spirocyclic zwitterionic Lambda5Si-silicates 13, 15, and 16 with an (ammonio)methyl group and two bidentate meso-oxolane-3,4-diolato(2-) ligands bound to the silicon(IV) coordination center were synthesized for the first time. The already existent compound 14 was resynthesized in order to perform a crystal structure analysis. All compounds were characterized by elemental analyses (C, H, N), 29Si VACP/MAS solid-state NMR experiments, and solution NMR studies (1H, 13C, 15N, and 29Si NMR experiments), and compounds 14-16 were additionally studied by single-crystal X-ray diffraction.The already existent zwitterionic Lambda5Si-silicate 17 was synthesized by new methods, including a remarkable Si-C cleavage reaction with benzoin. To investigate the dynamic behavior of the known zwitterionic Lambda5Si-silicate 18 in solution, VT 1H NMR experiments in CD2Cl2 were performed in the temperature range -100 °C to 23 °C.The hexacoordinate silicon compounds 19-22 containing multidentate ligands derived from citric acid or (S)-malic acid were synthesized for the first time. The anionic Lambda6Si-silicates 19-22 were structurally characterized in the solid state by single-crystal X-ray diffraction and VACP/MAS NMR spectroscopy (13C, 15N, 29Si). Upon dissolution in water at 20 °C, spontaneous hydrolysis of the Lambda6Si-silicate anions was observed.}, subject = {Silicate}, language = {en} }