2 TRIMETHYLPHENYLPHOSPHONIUM IODIDES

wThe structures of trimethylphenylphosphonium iodide, C9H14P+.I-, and (p-dimethylaminophenyl)trimethylphosphonium iodide, C11H19NP+.I-, have been determined at 100K in order to study the substituent perturbatio n of the trimethylphosphonium group and the additional effect of a p-d imethylamino group. Trimethylphenylphosphonium iodide crystallizes in the orthorhombic space group Pca2(1) with two independent molecules in the asymmetric unit. The p-dimethylamino-substituted compound has a p lanar amino group with an N-C(phenyl) bond distance in the double-bond range, Both structures contain short C-H ... I distances below the su m of the van der Waals radii.