The detailed syntheses of a series of substituted bis (silirane) s (Me4C2SiR) 2 {R= Me (1a), Ph (1b), tert-butyl (1c)} are reported. The tert-butyl derivative (1c) shows steric congestion which results in conformational rigidity in solution with respect to Si–Si bond rotation. This contrasts with the methyl (1a) and phenyl (1b) analogs. The rotational barriers of all three bis (silirane) s were examined by Density Functional Theory (DFT) at the B3LYP/6-31G∗ level ...
