Surface functionalization of cadmium sulfide quantum confined nanoclusters- 6: Evidence of facile electronic communication between remote surface sites

The preparation and derivatization of a series of surface functionalized si milar to 30 Angstrom cadmium sulfide nanoclusters possessing surfaces of va ried electron demand, tethered covalently to an electroactive fluorescent r uthenium polypyridyl complex, are described. Electrochemical analyses of th ese nanoclusters bearing ruthenium moieties yield a monotonic relationship between the Ru(II/III) oxidation potential and the electron withdrawing nat ure of the cluster surface, indicating that the electron density at the ele ctroactive ruthenium center is indeed influenced by remote electropositive and electronegative substituents attached to the nanocluster. Further evide nce of cluster mediated electronic interactions between remote surface moie ties presents itself in the form of a dependence of the integrated rutheniu m based MLCT emission intensity on the mole per cent of attached thiolate c apping agent possessing an electron withdrawing substituent in the position para to the point of cluster attachment. (C) 2000 Elsevier Science Ltd. Al l rights reserved.