Preparation of methylsilyl methyl ether and a base strength study of the monomethoxy derivatives of methylsilane

Abstract

Notes 1741 tion is probably due to the formation of diand trisubstituted borazines which decompose more readily than the monosubstituted derivative. The formation of polysubstituted borazines is indicated from the observation that alcohol was always consumed faster than borazine even when the initial alcohol to borazine ratio was greater than unity.The most abundant ions produced by fragmentation in the mass spectrum of borazine are B3N3H6+, B3N2-H2+, B2N2H3+, B2NH2+, and BNH3+.7 In the mass spectrum of B-monomethoxy-and B-monoethoxyborazine major ion fragments occur in positions corresponding to the base groups in borazine shifted to higher masses due to the substitution of an alkoxy group for an H atom. Ion fragments in the alkoxy derivatives also arise by splitting off segments of the side chain.

Synthesis and base strengths of some (.omega.-methoxyalkyl)silanes and -germanes

“…The yield was 70% based upon the Br(CH2)40CH3 used in the reaction, mass spectrum of the germanium-containing ether showed no bromide contaminant was present. Major peaks in the mass spectrum occur at m/e values of 15 (50%), 27 (26%), 28 (17%), 29 (37%), 41 (19%), 45 (100%), 55 (21%), and 58 (17%). Major peaks in the ir spectrum are found at 2918, 2847, 2813 (m), 2057 (s), 1132 (s), and 835 cm"1 (vs).…”

Siloxane Coordination Revisited: Si−O Bond Character, Reactivity and Magnificent Molecular Shapes

“…Matching with the material properties of (polymeric) siloxanes, it was found in a number of studies that the electron‐donating capacity of the oxygen atom decreases in the sequence C−O−C>C−O−Si>Si−O−Si [16–30] . Even though silicon is a neighbour of carbon in the periodic table, the nature and reactivity of Si−O bonds are obviously different to C−O bonds, especially in terms of coordination and host‐guest chemistry.…”

“…This results in limited donor capacities and a lowered basicity. This type of backbonding has been the explanation for a lower basicity of siloxanes for decades, especially in the above‐mentioned hydrogen bonding studies [16,18–25,27] . Over time, the 3 d ‐orbitals were identified to be too high in energy.…”

“…Instead, they have, not least due to their water repellent properties, evolved into a completely different research area than host‐guest chemistry. Conclusively, many studies were published since the 1960s which have examined the binding properties of Si−O donors in comparison to C−O donors [16–30] . Basicity of cyclic and acyclic siloxanes were intensely investigated in terms of hydrogen bonding and proton affinity.…”

“…Basicity of cyclic and acyclic siloxanes were intensely investigated in terms of hydrogen bonding and proton affinity. Especially IR spectroscopic investigations on hydrogen bonding towards the Si−O−Si linkage had been established as the method of choice [16–30] …”