Closed-shell Metal Complexes with New Bidentate Thioethers
Two new bidentate thioether ligands, the dialkylbis[(alkylthio)methyl]silanes Ph[subscript]2Si(CH[subscript]2SMe)[subscript]2 and Me[subscript]2Si(CH[subscript]2SBu[superscript]t)[subscript]2, have been synthesized and fully characterized. Reactivity studies led to the isolation of group 11 and 12 metal halide complexes, all of which have d[superscript]10 electronic configurations. The full characterization of these complexes, including NMR spectroscopy and elemental analysis, will be described in this thesis. Reactivity studies of R'[subscript]2Si(CH[subscript]2SR)[subscript]2 (R' = Ph, Me; R = Me, Bu[superscript]t) towards monovalent coinage metal ions have produced simple 1:1 and 1:2 complexes {R'[subscript]2Si(CH[subscript]2SR)[subscript]2}CuX (X = C1, Br, I), {R'[subscript]2Si(CH[subscript]2SR)[subscript]2}AgX (X = NO[subscript]3, OTf) and [Ag{R'[subscript]2Si(CH[subscript]2SR)[subscript]2}[subscript]2]X (X = BF[subscript]4, SbF[subscript]). With Ph[subscript]2Si(CH[subscript]2SMe)[subscript]2, the majority of these 1:1 complexes showed dimeric structures, similar in most cases to the Me[subscript]2Si(CH[subscript]2SMe)[subscript]2 analogues. It was concluded that changing substituents on silicon did not affect considerably the geometry of the complexes. However, the bulky substituents on the thioether Me[subscript]2Si(CH[subscript]2SBu[superscript]t)[subscript]2 preclude the generation of polymeric (or dimeric) species such as those isolated for R = Me and result instead in the formation of rare examples of three-coordinate trigonal planar Cu(I) thioether complexes. Furthermore, these are some of the first complexes exhibiting [CuS[subscript]2X] coordination spheres. In a similar vein, the dinuclear gold complexes Au[subscript]2{Me[subscript]2Si(CH[subscript]2SBu[superscript]t)[subscript]2}X[subscript]2 (X = C1, Br), each of which displays a weak intramolecular Au...Au aurophilic interaction and photoluminescent properties, are obtained instead of the polymeric species isolated for closely related but less sterically demanding thioether ligands [e.g., Me[subscript]2Si(CH[subscript]2SMe)[subscript]2]. The new complexes have been characterized by a variety of analytical and spectroscopic techniques, including electrospray ionization mass spectrometry (ESIMS). An overview of the coordination chemistry of R'[subscript]2Si(CH[subscript]2SR)[subscript]2 towards other transition metal ions such as Cd(II) and Hg(II) will be also discussed.