Tri‐tert‐butyl(trimethylgermyl)cyclobutadien und Tri‐tert‐butyl(trimethylgermyl)tetrahedran

Small Rings, 80[1]. — Tri‐tert‐butyl(trimethylgermyl)cyclobutadiene and Tri‐tert‐butyl(trimethylgermyl)tetrahedrane In the course of our research on silyl‐substituted diazo compounds as precursors of cyclobutadienes and tetrahedranes the synthesis of the title compounds 16 and 17 has also been accomplished. Their properties are comparable to those of the silyl‐substituted homologous compounds. Tri‐tert‐butyl(trimethylgermyl)tetrahedrane (17) melts without decomposition at 143°C and thus proves to be as stable as tri‐tert‐butyl(trimethylsilyl)tetrahedrane. The interconversion of the rectangular forms of tri‐tert‐butyl(trimethylgermyl)cyclobutadiene (16) proceeds with an activation energy below 4 kcal/mol, which is nearly the same as of tri‐tert‐butyl(trimethylsilyl)cyclobutadiene.