Abstract
Reaction of BI3 with carbodiphosphorane, C(PPh3)(2), gives a mixture of the dicationic compounds, methylenebis(triphenylphosphonium) diiodide dichloromethane disolvate, C37H32P2 (2+) 2I(-) 2CH(2)Cl(2) or [Ph3PCH2PPh3]I-2.2CH(2)Cl(2) (I), methylenebis(triphenylphosphonium) bis(tetraiodoborate), C37H32P2 (2+) 2BI(4)- or [Ph3PCH2PPh3](BI4)(2) (II). Solvents are the source of the protons at the ylidic C atom. The PCP angle is 124.1 (2)degrees for (I) and 121.7 (3)degrees for (II), while the two PC bond lengths are 1.804 (4) and 1.807 (5) angstrom in (I), and 1.817 (5) and 1.829 (5) angstrom in (II). In the crystal of (I), the protons of the central PCH2P C atom exhibit weak CH...I hydrogen bonds with the respective anions. The anions in turn are linked to the dichloromethane solvent molecules by CH...I hydrogen bonds. In the crystal of (II), one of the BI4- anions is linked to a phenyl H atom via a weak CH...I hydrogen bond.