Abstract: A azaporphyrin compound of the formula: ##STR1## wherein M is 2H, or a metal atom of Group VIII, Ib, IIb, IIIb, IVa, Va, VIa or VIIa of the Periodic Table or its oxide or halide, and each of A.sup.1, A.sup.2, A.sup.3, A.sup.4, B.sup.1, B.sup.2, B.sup.3 and B.sup.4 is a heterocyclic group, provided that A.sup.1 and B.sup.1, A.sup.2 and B.sup.2, A.sup.3 and B.sup.3, and A.sup.4 and B.sup.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.

Abstract: An optical recording material comprising a recording layer containing a substance with its optical properties changeable by irradiation with light in which information is recorded by irradiating the recording layer with light, said substance being an ethylene derivative having at its 1- and 2-positions heterocyclic groups which are cyclizable by irradiation with light to form a cyclohexadiene ring and thereby change the optical properties, and the other 1- and 2-positions connected to each other to form a ring.

Abstract: Novel diorganopolysiloxane-azobenzene alternating copolymers composed of repeat units having the formula ##STR1## wherein n has a value greater than or equal to 1; each R.sup.1 is independently selected from a group consisting of a hydrogen atom, a monovalent hydrocarbon group and an alkoxy group; each R.sup.2 is independently selected from a group consisting of a monovalent hydrocarbon group and an alkoxy group; each R.sup.3 is a linking group selected from a group consisting of an oxygen atom, C.sub.2 -C.sub.6 alkylene groups, --O(C.dbd.O)--, --R.sup.4 --N(R.sup.5)--(C.dbd.O)--, and --R.sup.6 --(C.dbd.O)--N(R.sup.7)--, are described. These copolymers undergo reversible photomediated changes in their viscosity and absorption specta. Also described are methods for preparing these novel copolymers.

Abstract: A spiroxazine compound represented by the formula: ##STR1## wherein R.sup.1 and R.sup.2 each represents an alkyl group, an allyl group, an aryl group or an aralkyl group; rings A and B each represents a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring or a substituted or unsubstituted heterocyclic ring; X represents an oxygen atom or a sulfur atom; and n represents an integer of from 1 to 6, and a photochromic composition containing said spiroxazine compound are disclosed. The compound is excellent in compatibility to and solubility in high molecular weight compounds, and the composition containing the same stably develops a color of high density upon irradiation of ultraviolet rays.

Abstract: A functional elastomer in which a viologen unit is introduced into a principal polymeric chain through cationic polymerization by using a bifunctional initiator, said elastomer being represented by the formula ##STR1## wherein X represents polyether and A represents an anion.