Helical twisting powers of a series of ruthenium complexes with screw-like , chirality were investigated in N-(4-Methoxybenzylidene)-4-butylaniline (MBBA). -[Ru(acac)(2)(trop)] (acac = acetylacetonate, trop = tropolonate) shows a fairly low HTP of 18 mu m(-1), while we found that the HTP increased almost double by connecting with an achiral bulky unit [Ru(Cp)(dppe)] (Cp = cyclopentadienyl, dppe = 1,2-bis(diphenyl)phosphinoethane) that was found to behave as a molecular picket fence to force the orientation of surrounding MBBA molecules.