Trichloro[2,5-bis[N-(4-isopropylphenyl)-P,P-diisopropylphosphorimidoyl-κN]pyrrole-κN]zirconium(IV)·Benzene

A new zirconium trichloride complex, supported by a monoanionic, pyrrole-based bisphosphinimine NNN-pincer ligand, [LZrCl3] (L = 2,5-[iPr2P=N(4-iPrC6H4)]2NH(C6H2) (1), is reported. Comparison with a related iminopincer complex reveals significant differences in bond lengths and angles between the atoms around the metal centre, largely due to the more electron donating phosphinimine (R3P=NR (R = alkyl, aryl)) functionality. The P=N bonds in complex (1•benzene) are longer than in the proteo ligand HL (L = 2,5-[Ph2P=N(4-iPrC6H4)]2NH(C6H2)), which is consistent with phosphinimine coordination to a metal. This is the only reported zirconium complex with this specific ligand scaffold; no analogous complexes have been reported for other group 4 metals. This structure expands the library of Zr pincer complexes that bear tridentate ligand frameworks and sets the stage for the preparation of related complexes.