A Convenient Solvothermal Synthesis of Group 6 PNP Pincer Tricarbonyl Complexes

The solvothermal synthesis of a series of zerovalent Cr, Mo, and W complexes of the type [M­(PNP)­(CO)3] featuring PNP pincer ligands based on 2,6-diaminopyridine is described. We demonstrate that the solvothermal synthesis technique presented provides a powerful, simple, and practical synthetic method resulting in high isolated yields in a short time. In particular, Cr and W complexes are not readily accessible via conventional methods. Moreover, this study allows a direct comparison of steric and electronic properties of group 6 metal PNP pincer tricarbonyl complexes.