ABSTRACT: A new tridentate thioether ligand, methyltris[(methylthio)methyl]silane MeSi(CH2SMe)3, has been synthesized with the goal of investigating the coordination chemistry of acyclic polythioethers. This ligand represents the first member of a new family of face-capping, tridentate thioether ligands which are related to the well known macrocyclic thioether 1,4,7-trithiacyclononane and also to the anionic tetrakis[(methylthio)methyl]borates. Initial reactivity studies of the newly synthesized thioether ligand resulted in the successful isolation and structural characterization of the complete series of group 6 carbonyl derivatives ([eta symbol3]-MeSi(CH2SMe)3)M(CO)3(M = Cr, Mo, W). The copper(I) coordination polymers Cu3(MeSi(CH2SMe)3)2X3(X = Cl, Br) and [(MeSi(CH2SMe)3)Cu(NCMe)]Y (Y = OSO2CF3, BF4, PF6) were isolated by reacting CuX or [Cu(NCMe)4]Y, respectively, with the ligand. The reaction of the ligand in a 1:1 molar ratio with CuI yielded (MeSi(CH2SMe)3)CuI, which has been structurally characterized and found to form a dimer in the solid state. Related silver(I) derivatives based on the thioether ligand were also synthesized and characterized. The investigation of the behavior of these complexes in acetonitrile solution was conducted using electrospray ionization mass spectrometry (ESI-MS). Reactions of the ligand with BiX3(X = Cl, Br) afforded complexes of stoichiometry Bi2(MeSi(CH2SMe)3)2X6 and the chloride derivative was also found to be polymeric.