Abstract
Electronic absorption and emission properties of a new cytidine tethered zinc phthalocyanine 2 were used to probe the aggregation and guanosine/C60 derived de-aggregation of this nucleobase linked phthalocyanine. These experiments revealed that 2 aggregates even at low concentrations in a competitive solvent system (1.1×10−6 M in 20% DCM/toluene). Nucleobase–metal coordination and slipped co-facial π-stacking interactions are both important in aggregate formation. Guanosine 5, C60 6, and a guanosine-C60 chimera 4 were employed as potential aggregate disruptors. These experiments revealed that both guanosine and fullerene subunits are effective in disrupting the aggregate formed by 2. Such findings support the conclusion that base-pairing, π-stacking, as well as nucleobase–metal coordination interactions play important roles in the de-aggregation of 2.
Electronic absorption and fluorescence spectroscopies were used to study the aggregation and de-aggregation behavior of a novel cytidine tethered zinc phthalocyanine shown schematically above. De-aggregation of this conjugate, can be effected using guanosine, C60, as well as via the addition of a synthetic guanosine-C60 hybrid.
