Metal-Siloxy Condensation Reactions
MICHIGAN STATE UNIV EAST LANSING
Pagination or Media Count:
In search for a prototype inorganic condensation reaction that could be used later for study of inorganic polycondensation reactions, it was found that the reaction of NaOSiPhi3 with Phi3SnCl, n-C4H92SnCl2, and CH32SnCl2 in an aprotic solvent is consistent with the overall equations Phi3SnCl NaOSiPhi3 Phi3SiOSnPhi3 NaCl n-C4H93SnCl2 2NaOSiChi3 n-C4H92SnOSiPhi32 2NaCl CH32SnCl2 2NaOSiPhi32 2Nacl with no evidence that significant side reactions occur. These reactions appear to go to completion as shown by quantitative determination of NaCl and the stannosiloxane product. The sodium chloride by-product forms immediately, indicating that these reactions at room temperature in benzene are extremely rapid. Quantitative rate measurements could not be made but the stoichiometry of the reaction was established. In the course of the study, several new stannosiloxanes were prepared and characterized by infrared spectroscopy and elemental analysis. The preparation, characterization, and some properties are reported for siloxy derivatives of bis cyclopentadienyltitaniumIV. Monosiloxy derivatives were prepared by the reaction of the appropriate sodium silanolate with biscyclopentadienyl titanium dichloride in toluene at 75-90C under anhydrous conditions. The compounds prepared and characterized were trimethylsiloybiscyclopentadienyltitanium chloride, methyldiphenylsiloybiscyclopentadienyltitanium chloride, and triphenylsiloxybiscyclopentadienyltitanium chloride. These Ti-O-Si compounds are orange crystalline substances the triphenylsiloxy derivative melts at 201-204 C. Replacement of C6H5 by CH3 groups markedly lowers the melting points and thermal stabilities. Bistriphenylsiloxybiscyclopentadienyltitanium was prepared in toluene at 75-90 C from biscyclopentadienyltitanium dihalide and sodium triphenylsilanolate or triphenylsilanol.
- Inorganic Chemistry