Synthesis, structure and properties of the mixed-ligand tungsten(II) complex [WBr2(CO)3(tmpymt)] (tmpymt = 1,4,6-trimethylpyrimidine-2-thione)

The reaction of [{WBr(CO)4}2(μ-Br)2]2 1 with 1,4,6-trimethylpyrimidine-2-thione (tmpymt) affords the air-sensitive complex [WBr2(CO)3(tmpymt)] 2. The X-ray structure of 2·C3H6O reveals that the geometry surrounding the tungsten(II) atom is best described as a distorted capped trigonal prism with a bromine atom Br(1) in the unique capping position. The other bromine atom Br(2), the (N,S)-chelate and one carbonyl C(41) occupy the capped quadrilateral face. The complex has been additionally characterized by IR and NMR spectroscopy. The optimized molecular structure (RHF/LanL2DZ) supports the experimental data.