Pentacene-fused diporphyrins.

In this work, we report the synthesis, spectroscopic characterization, and theoretical analysis of a linearly conjugated pentacene-fused porphyrin dimer and cross-conjugated quinone-fused dinaphtho[2,3]porphyrins. These multichromophoric systems display non-typical UV-visible absorptions of either porphyrins or pentacenes/quinones. UV-visible, emission and magnetic circular dichroism (MCD) spectroscopy suggest strong electronic interactions among the multichromophores in the system. DFT calculations revealed the delocalization of the HOMOs and LUMOs spanning the entire dimer and linker assembly. The pentacene-fused porphyrin dimer is significantly more stable than both the corresponding pentacene and the heptacene derivatives. The availability of these huge π-extended and electronically highly interactive multichromophoric systems promises unprecedented electronic and photophysical properties.