Oxido- and Sulfidoniobium(V) N,N-Diethylcarbamates: Synthesis, Characterization and DFT Study

The N,N-diethylcarbamates NbE(O2CNEt2)3, E = O, S, have been prepared in high yields by treating NbOCl3 or NbSCl3(CH3CN)2 with CO2/NHEt2 in toluene at ca. 10 °C. The products have been characterized by spectroscopic techniques, elemental analysis and by X-ray diffractometry in the case of NbO(O2CNEt2)3. The molecular structure of the latter consists of a niobium centre coordinated to the oxo moiety and six O-atoms belonging to bridging and bidentate carbamates, in a slightly distorted pentagonal bipyramidal arrangement. The structures of both NbE(O2CNEt2)3 compounds have been reproduced by DFT calculations, showing substantial similarity despite the different nature of the chalcogen atom.