Synthesis and solution structure of desoxotungsten(IV) and monooxotungsten(VI) benzenedithiolate complexes containing two intramolecular NH⋯S hydrogen bonds

摘要: Abstract Desoxotungsten(IV) and monooxotungsten(VI) benzenedithiolate complexes containing two intramolecular NH⋯S hydrogen bonds, (NEt4)[WIV{OSi(tBu)Ph2}(1,2-S2-3-tBuCONHC6H3)2] (1) (NEt4)[WVIO{OSi(tBu)Ph2}(1,2-S2-3-tBuCONHC6H3)2] (2), were synthesized by silylation of the parent mono- di-oxo compounds. The geometrical isomers, trans- cis-1, present at room temperature without any interconversion. 1H NMR spectra 2 showed only one set signals temperature, which separated into sets distinct upon cooling down to lower temperatures. These results suggest that pair enantiomers is in solution, are exchanged rapidly time scale via Bailar twist temperature. Subsequent structural analysis demonstrates isomer 2tc, where, bond trans terminal W O other cis O. Theoretical calculations revealed contribution molecular structure indicate 2tc most stable isomer.