(Pyrazol-1-yl)carbonyl and Ester-Functionalized Bis(pyrazol-1-yl)methide Carbonyl Tungsten Complexes

(3,5-Dimethylpyrazol-1-yl)­carbonyl- and n-butoxycarbonyl-functionalized bis­(3,5-dimethylpyrazol-1-yl)­methide carbonyl tungsten derivatives were unexpectedly formed, together with a bis­(3,5-dimethylpyrazol-1-yl)­acyl carbonyl tungsten complex, upon sequential treatment of bis­(3,5-dimethylpyrazol-1-yl)­methane with n-BuLi, tungsten carbonyl, and iodine. The resulting complexes were fully characterized using IR and NMR spectroscopy, and their structures were unambiguously determined by X-ray crystallography.