Crystal structure of (3,5-dimethyl-1H-pyrrol-2-yl)di-phenyl-phosphine oxide

The title compound, C₁₈H₁₈NOP, was obtained during a search for new P,N-containing ligands with the potential to generate precatalysts with chromium(III) for selective ethyl-ene oligomerization. In the crystal, mutual pairs of N-H⋯O=P hydrogen bonds link two mol-ecules into a dimer with individual mol-ecules related by a twofold rotation axis. The P=O bond length of 1.4740 (15) Å is not elongated although the O atom is involved in hydrogen bonding. The crystal structure is further stabilized by van der Waals inter-actions between the dimers, linking the mol-ecules into a three-dimensional network structure.