Potential propelling and rotating functions of propeller-type complexes. III. Detection of the propelling motion in fac -tris( S -2,3-diaminopropionato)cobalt(III) in an aqueous solution upon IR irradiation

Circular dichroism spectra of the fac and mer isomers of tris-cobalt(III) complexes of S-2,3-Hdap (Hdap = diaminopropionic acid); fac and mer-[Co(S-dap)(3)] (Lambda or Delta), and [Co(en)(3)](3+) (Lambda or Delta, en ethylenediamine) in an aqueous solution without and upon IR irradiation were measured. The detection of the propelling motion that corresponds to circular dichroism spectral changes of the propeller-type complex,fac-[Co(S-dap)(3)] in an aqueous solution upon IR irradiation gave good agreement with the computer-simulation result, that is, the propelling ( translation and rotation) motion occurs in propeller-type metal complexes in aqueous solution as a consequence of an appropriate energy supply, which had been obtained by theoretical study based on molecular dynamics ( MD) simulations by the use of AMBER 6 program.