The present invention relates to a new method of light induced photopolymerization under mild irradiation conditions, copper initiator complexes to be used in such method and a polymers obtained by such method.

Compounds of structure (I) are described wherein, R.sub.1, R.sub.2, R.sub.1a and R.sub.2a are independently selected from H, nitro, cyano, and an alkylsulfonyl, wherein at least two of R.sub.1, R.sub.2, R.sub.1a and R.sub.2a are independently selected from nitro, cyano, and an alkylsulfonyl, and X is not a halide, tosylate, trifluoromethylsulfonate, tetrafluoroborate, an aryl-substituted borates, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methane sulfonate, C-2 to C-20 linear unsubstituted alkyl sulfonates, naphthalenesulfonate, and camphorsulfonate. Also described are EUV negative and positive chemically amplified photoresist compostions containing said compound and the process of using these photoresist to pattern a substrate.

Alkoxylation reactions are performed in the presence of a phosphonium catalyst having the structure P.sup.+(XR.sup.1R.sup.2R.sup.3)A.sup.1 wherein R.sup.1 is a group having an unsubstituted or inertly substituted aromatic five-member ring having a direct bond between an atom of the aromatic five-member ring and the phosphorus atom, and each R.sup.2 is independently a group having an unsubstituted or inertly substituted, optionally heteroatomic, aromatic five- or six-member ring having a direct bond between a carbon atom of the optionally heteroatomic aromatic five- or six-member ring and the phosphorus atom. X is selected from fluorine, chlorine, bromine, iodine, C.sub.1-12 perfluoroalkyl, C.sub.1-12 alkyl, aryloxy and C.sub.1-12 alkoxy, and A is a weakly coordinating anion.