Biphenylyl triphenylphosphine gold(I) complexes (4-biphenytyl, 4B; 2-biphenylyl, 2B) having the Au-C bond are synthesized. The 4B complex is found to exhibit intense blue phosphorescence (Phi(p) = 0.24 and tau(T) = 117 mu s) at room temperature originated from the locally excited triplet of the biphenyl moiety ((LE)-L-3) in both solid states and a degassed 2-methyltetrahydrofuran solution. 2B, however, is nonluminescent. The homolytic cleavage of the Au-C bond in dichloromethane solution of 4B upon UV irradiation is also reported. (c) 2007 Elsevier B.V. All rights reserved.