Potential propelling and rotating functions of propeller-type complexes. II. Preparation and molecular dynamics simulation of tris(5-carboxy-2,2′-bipyridine)cobalt(III)

Isolation of four optically active isomers of the 5-substituted 2,2'-bipyridine complexes [Co(cbpy)(3)](3+) (cbpy=5-carboxy-2,2'-bipyridine) was achieved using cation-exchange column chromatography (SP-Sephadex C-25) eluting with either sodium (-)-O,O'-dibenzoyltartrate or sodium ((+)-tartrato)antimonate(III). Structure optimization and molecular dynamics (MD) simulations of the system consisting of the propeller-type complex fac-[Co(cbpy-H)(3)] (cbpy-H = 2,2'-bipyridine-5-carboxylate anion) and 80 water molecules were performed using the AMBER 6 program. Results of the MD simulation revealed that distinct translating and rotating behaviors can be obtained in this complex in aqueous solution upon IR irradiation.