Cis-Dichlorido(1,3-dimesitylimidazolidin-2-yl-idene)(2-formyl-benzyl-idene- 2C,O)ruthenium diethyl ether solvate

Abstract

The title compound, [RuCl2(C8H6O)(C 21H26N2)]·C4H10O, contains a catalytically active ruthenium carbene complex of the second-generation Grubbs/Hoveyda type with Ru in a square-pyramidal coordination, the apex of which is formed by the benzyl-idene carbene atom with Ru=C 1.827 (2) Å. The complex shows the uncommon cis, rather than the usual trans, arrangement of the two chloride ligands, with Ru - Cl bond lengths of 2.3548 (6) and 2.3600 (6) Å, and a Cl - Ru - Cl angle of 89.76 (2)°. This cis configuration is desirable for certain applications of ring-opening metathesis polymerization (ROMP) of strained cyclic olefins. The crystalline solid is a diethyl ether solvate, which is built up from a porous framework of Ru complexes held together by π-π stacking and C - H⋯Cl and C - H⋯O interactions. The disordered diethyl ether solvent molecules are contained in two independent infinite channels, which extend parallel to the c axis at x,y = 0,0 and x,y =1/2,1/2 and have solvent-accessible void volumes of 695 and 464 Å3 per unit cell.