Syntheses, characterization and crystal structures of [Cu(PCHO)2(2,2′-bipy)][BF4], [Cu2(PCHO)4(4,4′-bipy)][BF4]2 and [Cu2(PCHO)4(bptz)] [BF4]2 (PCHO = o-(diphenylphosphino)benzaldehyde and bptz = 3,6-bis(2′-pyridyl)-1,2,4,5-tetrazine)

Treatment of [Cu(PCHO)2(NCMe)][BF4] (1) (PCHO = o-(diphenylphosphino)benzaldehyde) with 2,2′-bipyridine produces the complex [Cu(PCHO)2(2,2′-bipy)][BF4] (4), while the reactions of 1 with 4,4′-bipyridine and 3,6-bis(2′-pyridyl)-1,2,4,5-tetrazine (abbreviated as bptz) afford the dinuclear complexes [Cu2(PCHO)4(4,4′-bipy)][BF4]2 (5) and [Cu2(PCHO)4(bptz)][BF4]2 (6), respectively. The crystal structures of 4–6 have been determined by an X-ray diffraction study. The coordination about the Cu+ ion is trigonal for 5 and tetrahedral for 4 and 6, and there is no bonding between the aldehyde groups and the Cu+ ion in these compounds.