Steric Effects in Heteroboranes. III. 1‐Ph‐2‐Me‐1,2‐closo‐C2B10H10

The crystallographically determined structure of 2-methyl-1-phenyl-1,2-dicarba-closo-dodecaborane(12), C 9 H 18 B 10 , is reported. The 12-vertex polyhedron is relatively undistorted although the phenyl substituent is twisted by ca 73° from its electronically preferred orientation by steric pressure from the methyl group, resulting in a C−C(cage) separation of 1,695 (5) A