Taking (Me4N)2[Mo2S4(TDT)2] (1, TDT = 4-methyl-1,2-benzenedithiolate) as starting material, [Mo2Ag2S4](TDT)2(PPh3)2 (2) was obtained from the reaction of 1 with Ag(PPh3)3(NO3) by [2+1+1] mode. This is the 1st example for the compound containing [Mo2Ag2S4]4+ cluster core. The results of IR, UV-visible, a single crystal x-ray study and electrochem. CV curve for 2 are reported. When this cluster reacts with excess Cu(PPh3)2dtp (dtpH = HS2P(OEt)2), its Cu analog [Mo2Cu2S4](TDT)2(PPh3)2 was isolated. This reaction can be regarded as a metal replacement reaction, which is a novel type of reaction. Crystal data of 2: monoclinic, space group P21/n, a 1.7202(4), b 1.7632(3), c 1.9033(8) nm, b 99.24(3)? Z = 4, dc = 1.69 g/cm3 for 6158 reflections, R = 0.040, Rw = 0.048.

Key words: ULTRAVIOLET SPECTROPHOTOMETRY, INFRARED SPECTROPHOTOMETRY, CRYSTAL STRUCTURE, SILVER NITRATE, MOLYBDENUM COMPLEX, TRIPHENYLPHOSPHINE, SULFIDE, SILVER COMPLEX