Facile Metalation of Silicon and Germanium Analogues of Thiocarboxylic Acids with a Manganese(II) Hydride Precursor

Synthesis and characterization of the first manganese(II)-containing heavier thiocarboxylate analogues, [(LSi)-Si-Dip(=S)OMnLDep] (4; L-Dip = CH[C(Me)N(2,6-iPr(2)C(6)H(3))](2), L-Dep = CH[C(Me)N(2,6-Et2C6H3)](2)) and [(LGe)-Ge-Dip(= S)OMnLDep] (5) are described. They are accessible through reaction of the silicon and germanium analogues of the respective thiocarboxylic acids [(LE)-E-Dip(=S)OH] (E=Si, Ge) with the beta-diketiminato (nacnac) manganese(II) hydride precursor [((LMn)-Mn-Dep)(2)(mu-H)(2)] (3) in high yield. The first Mn nacnac hydride 3 has been prepared by the reaction of manganese bromide [((LMn)-Mn-Dep)(2)(mu-Br)(2)] (2) with KBEt3H. Compounds 4 and 5 represent the first transition-metal heavier thiocarboxylates with the Si=S and Ge=S functionalities. All new compounds are paramagnetic and were characterized by elemental analysis, IR spectroscopy, MS (EI), and single-crystal X-ray diffraction analyses. Due to the N -> E (E=Si, Ge) and E=S -> Mn donor-acceptor interaction as well as the carboxylate-like p-electron delocalization within the E(S)O moieties, the E=S double bonds in these compounds are resonance stabilized.