Mesitylgold complexes: synthesis and reactivity; crystal structure of [{(Ph 3 P)Au(µ-mes)Ag(tht)} 2 ][SO 3 CF 3 ] 2 (mes = mesityl, tht = tetrahydrothiophene)

The complex [AuCl(AsPh3)] reacted with MgBr(mes)(mes = mesityl) to give the corresponding gold(I) derivative [Au(mes)(AsPh3)], which undergoes substitution reactions with neutral ligands to give the neutral complexes [Au(mes)L](L = Ph2PCH2PPh2, PPh3 or PPh2Me) or with QX to afford anionic complexes Q[Au(mes)X][X = Cl. Q = P(CH2Ph)Ph3; X = Br, Q = N(PPh3)2]. The latter reacted with X2(X = Cl or Br) to give gold(III) complexes, Q[Au(mes)X3][X = Cl, Q = P(CH2Ph)Ph3; X = Br, Q = N(PPh3)2]. The reaction of [Au(mes)(PPh3)] with [Ag(OSO2CF3)L][L = PPh3 or tetra-hydrothiophene (tht)] afforded [{(Ph3P)Au(µ-mes)AgL}n][SO3CF3]n(L = PPh3, n= 1; L = tht, n= 2). The structure of [{(Ph3P)Au(µ-mes)Ag(tht)}2][SO3CF3]2 has been determined by a single-crystal X-ray diffraction study, which shows an Au–Ag distance of 2.8245(6)Å.