A porphyrin square: synthesis of a square-shaped π-conjugated porphyrin tetramer connected by diacetylene linkages
Abstract
A square-shaped π-conjugated porphyrin tetramer has
prepared: the excitation energies of both the Soret and Q bands, 19880
(503) and 15180 cm−1 (659 nm), respectively, are quite low
compared with those for the monomer and reported cyclic