Curing combination for cationically polymerizable materials

A composition of matter obtainable by

• A) dissolving or dispersing a component i) in a component ii), component i) being a compound of the formula I
• [(R.sup.1)(R.sup.2 Fe.sup.II).sub.a ].sup.+na na X.sup.- (I)
• and component ii) being selected from the group consisting of a polycarboxylic acid, an anhydride based on a polycarboxylic acid, or a polyisocyanate, in which, in formula I, R.sup.1 is a .pi.-arene, R.sup.2 is a .pi.-arene or an anion of a .pi.-arene, a and n, independently of one another, are 1 or 2, and X is an anion [LQ.sub.m ].sup.- or an anion of an unfluorinated, partially fluorinated or perfluorinated aliphatic, cycloaliphatic, aromatic or araliphatic carboxylic acid or sulfonic acid, in which L is selected from the group consisting of B, P, As, Sb and Bi, Q is a halogen atom and m corresponds to the valency of L increased by one, and
• B) activating said solution or dispersion containing components i) and ii) by irradiation with actinic radiation or by heating, so that component i) is virtually no longer detectable in said solution or dispersion.