X-ray diffraction analysis of chiral (R,S)-(ON)Ru-salen complex: unusual unsymmetric conformation

The structure of chiral chloro nitrosyl (salen)ruthenium complex (1) has be en unambiguously determined by single crystal X-ray analysis. The salen lig and adopts a unique unsymmetrical nun-planar conformation: the one basal na phthalene ring is almost coplanar to the equatorial coordination plane and the other one is out of the plane. This characteristic conformation of the salen ligand in 1 is considered to be responsible for the unprecedented asy mmetric catalysis of 1 in epoxidation of olefins.