| abstract |
A phthalocyanine compound of the formula:n wherein M is 2H, or a metal atom of Group VIII, Ib, lib, IIIb, IVa, Va, Via or VIIa of the Periodic Table or its oxide or halide, and each of A 1 , A 2 , A3, A4, B 1 , B 2 , B 3 and B 4 is a heterocyclic group, provided that A 1 and B 1 , A 2 and B 2 , A3 and B 3 , and A 4 and B 4 are, respectively, cyclizable by irradiation with light to form a cyclohexadiene ring and thereby change the optical properties, and an optical recording material using such a compound wherein information recording can be made by irradiation with light. |