Image forming element

Abstract

An image forming element utilizing the photoreduction of a cobalt complex is disclosed. The image forming element comprises a support having thereon a layer comprising a cobalt complex compound represented by Formula 1 or Formula 2; ##STR1## wherein lig is a coordinating compound capable of forming a cobalt complex compound with a cobalt cation; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each independently an aryl group, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aralkyl group, a heterocyclic group or a cyano group, provided that at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aralkyl group, a heterocyclic group or a cyano group, the above groups represented by R.sup.1, R.sup.2, R.sup.3 or R.sup.4 are each may have a substituent; X is a monovalent or bivalence anion; m is 1, 2 or 3, when m is 2 or 4, a plurality of lig may be the same or different; n is 2 or 3; and s is 0, 1 or 2; and m, n and s are selected so as the valence of the cobalt complex compound to be zero; ##STR2## wherein Dlig is a coordination compound capable of forming a cobalt complex compound with a cobalt cation; p is 1, 2 or 3, when p is 2 or 3 a plurality of Dlig may be the same or different, provided that at least one of Dlig is a coodination compound having a moiety of a dye or a moiety of a dye precuror; R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are each independently an aryl group, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aralkyl group, a heterocyclic group or a cyano group, groups represented by R.sup.5, R.sup.6, R.sup.7 and R.sup.8 each may have a substituent; q is 1, 2 or 3; X is a monovalent or bivalent; r is 0, 1 or 2; and p, q and r are selected so that the valence of the cobalt complex compound to be zero.