SPHINO-2-PHENYL-1,2-DICARBA-CLOSO-DODECABORANE(12)

The two crystallographically independent molecules of the title compou nd, 1-[(C6H5)(2)P]-2-C6H5-1,2-C2B10H10 (C20H25B10P), in the asymmetric fraction of the unit cell are highly congruent. The conformation of t he cage phenyl groups is defined by theta = 1.15 degrees and the avera ge C1-C2 distance is 1.744 (8) Angstrom which is significantly longer than that usually found for 1,2-C2B10H10 compounds. The PPh(2) substit uent is tilted away from an idealized radial position on C1 as a resul t of intramolecular crowding.