Synthesis and Structure of Stable Tri-tert-butylgermyl-Substituted Stannylene and Germylene

Significant electron-donating effects of the germyl substituents in the first stable monomeric germyl(aryl)stannylene and germyl(aryl)germylene, which have the sterically encumbering 2,6-dimesitylphenyl group as the aryl substituent, were evidenced by the n → p transition bands appearing at very long wavelengths and the significant downfield shift of the 119 Sn NMR resonance in the stannylene.