Inorganic Chemistry, Vol.54, No.5, 2100-2102, 2015
Concept for Enhancement of the Stability of Calcium-Bound Pyrazolyl-Substituted Methanides
Metalation of bis(3-thiophen-2-ylpyrazol-1-yl)phenylmethane [2, which is accessible from the reaction of bis(3-thien-2-ylpyrazol-1-yl)methanone (1) with triphosgene] with [(thf)(2)Ca{N(SiMe3)(2)}(2)] in tetrahydrofuran and subsequent crystallization from a mixture of toluene and 1,2-dimethoxyethane yield [(dme)Ca{C(Pz(th))(2)Ph}{N(SiMe3)(2)}] (3). The alpha,alpha-bis(3-thiophen-2-ylpyrazol-1-yl)benzyl ligand exhibits a kappa N-2,kappa C-coordination mode with a Ca-C sigma-bond length of 262.8(2) pm. The crystalline compound is stable if air and moisture is strictly excluded; however, in solution; this calcium complex slowly degrades.