Synthesis and spectroscopic characteristics of aryltrimethyl-silicon, -germanium, and -tin compounds

The synthesis and spectroscopic characteristics of 28 para-substituted aryltrimethyl-silicon, -germanium, and -tin compounds are described. The infrared spectra show characteristic bands at 1245-1165 (methyl bend), 840-765 (methyl rock), and 1105-1020 (in-plane aromatic H bend) cm^-1; the frequency of the last band was found to depend on the sum of the aromatic substituent masses, the presence or absence of metallic constituents in the substituent having little influence. The mass spectral fragmentation patterns are interpreted in terms of localization of positive charge on the metal atom, with subsequent bond cleavage behavior which obeys the rules for mass spectra of carbon compounds.