Optically active phthalocyanines

Optically active phthalocyanines (Pcs) reported to date have been reviewed. These are classified into three groups: (i) Pcs containing chiral carbons in the side chain. This type of Pc is further divided into two groups, i.e. Pcs with eight long alkyl chains attached directly or indirectly onto the periphery of the Pc core, and Pcs linked with small cyclic compounds. The former always form liquid crystals; (ii) Pcs with optically active aromatic molecules. This group includes helicene and binaphthyl-substituted species; (iii) Pcs with planar asymmetry. Synthesis, characterization and some spectroscopic properties have been summarized, and an outlook for future chiral phthalocyanines given. (C) 2001 Elsevier Science B.V. All rights reserved.