A Monometallic Bis(cyaphido) Complex

Abstract

The first example of a bis(cyaphido) complex, trans-[Ru(dppe)2(CºP)2], is described, unequivocally demonstrating the synthetic accessibility and stability of complexes that feature more than one cyaphido ligand. Synthesis is achieved from the precedent cation [Ru(dppe)2(CΞP)]+ via sequential coordination and desilylation of the phosphaalkyne Me3SiCΞP. The heteroleptic analogue trans-[Ru(dppe)2(CΞN)(CΞP)] is also prepared from the same cation and NaCN; both cyaphido complexes are structurally characterized, enabling the first direct comparison of cyaphide with cyanide, its isoelectronic and isolobal counterpart. This demonstrates an enhanced p-acidity for -CΞP over -CΞN, while computational studies reveal also a degree of p-donor character for the cyaphido ligand.

Keywords: Coordination chemistry; Ruthenium; Structure; cyanide; cyaphide.