Complexes containing the diradical 1,2,3,4-tetraphenylbuta-1,3-diene-1,4-diyl; crystal structure of [AuCl(C₄Ph₄)(phen)]

The reaction between [{AuCl(C4Ph4)}2](C4Ph4= 1,2,3,4-tetraphenylbuta-1,3-diene-1,4,diyl) or [AuCl(C4Ph4)(tht)] and neutral unidentate ligands L gives rise to bridge cleavage or to displacement of the tetrahydrothiophen ligand (tht) yielding neutral complexes of the type [AuCl(C4Ph4)L][L = pyridine, PPh3, P(C6H11)3, or CNBut]. The reaction of the dimeric complex with NEt4Cl leads to the anionic complex [NEt4][AuCl2(C4Ph4)]. The use of bidentate ligands allows the preparation of two different types of complexes : [Au(C4Ph4)(L–L)][AuCl2(C4Ph4)][L–L = 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), or Ph2P(CH2)2PPh2(dppe)] and [AuCl(C4Ph4)(L–L)][L–L = phen or 2,2′-biquinolyl (bquin)]. Preparations of the probably non-heterocyclic [Pd2Cl2(C4Ph4)(bipy)2] and two gold(I) complexes [Au2(C4Ph4)(PPh3)2] and [Au2(C4Ph4)(dppe)] are also described. The crystal structure of [AuCl(C4Ph4)(phen)] has been determined : space group P, a= 11.040(2), b= 12.283(2), c= 13.670(3)Å, α= 99.76(2), β= 113.58(2), γ= 101.94(2)°, R= 0.030. Distorted five-co-ordination is observed [Au–N 2.184(4) and 2.755(4)Å].