Electronic absorption and emission properties of a new cytidine tethered zinc phthalocyanine 2 were used to probe the aggregation and guanosine/C-60 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 x 10(-6) M in 20% DCM/toluene). Nucleobase-metal coordination and slipped co-facial pi-stacking interactions are both important in aggregate formation. Guanosine 5, C-60 6, and a guanosine-C-60 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, pi-stacking, as well as nucleobase-metal coordination interactions play important roles in the de-aggregation of 2. (c) 2005 Elsevier Ltd. All rights reserved.
- phthalocyanine aggregation
- phthalocyanine de-aggregation
- non-covalent interactions
- electronic spectra