Syntheses, characterization and crystal structures of copper(I) o-(diphenylphosphino)benzaldehyde complexes

The complexes [Cu(PCHO)2(NCMe)][BF4] (1) and [Cu(PCHO)3][BF4] (2) have been prepared by treating [Cu(NCMe)4][BF4] with two and three equivalents of Ph2P(o-C6H4)C(double bond; length as m-dashO)H (abbreviated as PCHO) at room temperature, respectively. The reaction of 1 and (Ph2PC5H4)2Fe (abbreviated as DPPF) affords [Cu(PCHO)(DPPF)][BF4] (3). The molecular structures of 1–3 have been determined by an X-ray diffraction study. The aldehyde groups in 1 are pendant, while one of the formyl groups in 2 is weakly coordinated to the copper ion through the oxygen atom. On the other hand, the copper atom in 3 is strongly chelated by both DPPF and PCHO ligands.