Porphyrin Arrays Responsive to Additives. Fluorescence Tuning

The application of low-flux sunlight begins with the synthesis of effective antenna systems. This requires the development of dye integrates with optimized dye orientation for effective energy transfer. We here report a series of peptide-linked porphyrin arrays, denoted by Boc−(PorZn,S)n−OBut (n = 2, 4, and 8), that change their dye orientation to increase fluorescence responsively to additive reagents. The B-band absorption (AB) regions of the arrays show blue shifts (dimer, 407.6 nm; tetramer, 408.2 nm; octamer, 407.8 nm) in organic solvents as compared to that of Boc−PorZn,S−OBut (monomer, 422.6 nm) and the fluorescence yield Φ′ of the arrays decreases with increasing n, obeying the relationship Φ′ = 0.03/n1.5; however, the arrays are tuned up in fluorescence emission by the addition of 1,2-diaminoethane (en). The addition of a sufficient amount of en increases the fluorescence of the porphyrins in monomer, dimer, tetramer, and octamer by ∼5, ∼12, ∼12, and >730 times, respectively, when compared with t...