Rhenium Tris(pyrazolyl)Borate Oxothiolate Complexes: Syntheses and Structures

The rhenium complexes TpReOCl(StBu) (I), TpReO(StBu)2 (II), and TpReO(SnC3H7)2 (III) are synthesized using two methods by analogy to the known thiophenyl complexes. Complexes I–III having more electron-donating alkylthiolate ligands are characterized by IR and NMR spectroscopy. The structures of complexes I–III are determined by X-ray diffraction analysis (СIF files CCDC nos. 1892096 (I), 1892097 (II), and 1892098 (III)). The temperature dependence of the spectra of the bis(thiolate) complexes allows one to determine the activation energy for the hindered rotation about the Re–thiolate ligand bond. The by-product of the reaction of TpReOCl2 with NaS-tert-Bu, binuclear oxygen-bridged complex TpReIVCl(S-tert-Bu)O(S-tert-Bu)2ReIVTp, is isolated and structurally characterized (СIF file CCDC no. 1892099).