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)

The reactions of [Cu(PCHO)2(NCMe)][BF4] with 2,2′-bipyridine, 4,4′-bipyridine and bptz afford [Cu(PCHO)2(2,2′-bipy)][BF4] (4), [Cu2(PCHO)4(4,4′-bipy)][BF4]2 (5) and [Cu2(PCHO)4(bptz)][BF4]2 (6), respectively. The coordination about the Cu+ ion is trigonal for 5 and tetrahedral for 4 and 6.