VOLUMETRIC STUDY ON A CO(III) ROTAXANE COMPLEX IN AQUEOUS-SOLUTIONS AT 25-DEGREES-C

The standard partial molar volumes have been determined for [(en)(2)Cl Co(III)(don) Co(III)Cl(en)(2)] Br-4-[alpha-CDX]-rotaxane (Rotaxane) an d its component compounds, [(en)(2)ClCo(III)(don)co(III)Cl(en)(2)] Br- 4(Co(III)-II), and alpha-CDX, in aqueous solution at 25 degrees C V-0 (Rotaxane) is smaller than the sum of V-0(Co(III)-II) and V-0(alpha-CD X) by about 28 cm(3)-mol(-1). Some estimations were attempted; the num ber of methylene groups in the cavity of alpha-CDX, was estimated to b e six and the number of water molecules expelled from alpha-CDX cavity by hydrocarbon chain of the Rotaxane, is around four.