Scandium-Terminal Boronylphosphinidene Complex.

The first isolation and structural characterization of a rare-earth metal-terminal imido complex were reported in 2010, but a rare-earth metal-terminal phosphinidene complex is still absent, to date. Herein, we report the synthesis and structure of the first example of a rare-earth-terminal phosphinidene complex, namely the scandium boronylphosphinidene complex. Single-crystal X-ray diffraction shows that the complex has a much shorter Sc-P bond length as compared to that in a related scandium boronylphosphido complex, 2.381(1) A vs 2.564(1) A. DFT calculations indicate the presence of a strong Sc-P π interaction in this complex, which is in striking contrast to the weak interaction found in the phosphido complex. A preliminary reactivity study demonstrates that the scandium-terminal boronylphosphinidene complex behaves as a nucleophilic phosphinidene complex.