Porphyrinoid macrocycles: A cornucopia of novel chromophores

The porphyrins, due to their role as ''Pigments of Life'' (A. Battersby) to be regarded as functional dyes par excellence, have developed into an interdisciplinary area of research comprising chemistry, the biosciences, medicine and even material science. Guided by the [18]annulene model of porphyrin, which implies the presence of a (4n+2)pi conjugation pathway in the tetrapyrrolic macrocycle, we recently embarked on a systematic exploration of novel porphyrinoid chromophores. As a result of these efforts, a cornucopia of potential functional dyes and pigments - such as porphyrin isomers, dicationic tetraoxa-, tetrathia- and tetraselenaporphyrins, corrole isomers and, most recently, chiral cyclooctapyrroles - have been brought to light. In this report the tetra-and octapyrrolic porphyrinoid chromophores have been singled out for discussion.