Synthesis, Raman and NMR studies are presented for the new octahedral trimetallic complexes with composition [IrCl(SnCl3)(HgCl)(CO)(PR3)2], R = p-XC6H4; X = H, CH3O, F, Cl. Only the isomer containing the Cl3SnIrHgCl fragment and trans phosphine ligands is observed. Force constants for the IrSn and IrHg bonds as well as 31P, 119Sn and 199Hg NMR data are reported. The presence of a spin-spin coupling