A new method for synthesis of mesoionic methacrylates with various spacer lengths was developed. Copolymers with methyl methaerylate and cholesteric monomers were prepared; the latter showed liquid crystalline properties. The rate constant of the photocyclization to the bis(beta-lactame) structure of various spin-coated polymeric films was determined by irradiation with a HeCd laser (442 nm), whereby two different parameters controlling the rate constant could be found. It was shown that the length of the alkyl side chain on position 5 of the pyrimidinium-olate and the embedding of the mesoionic chromophore, which can be controlled by copolymerization with methyl methacrylate or liquid crystalline methacrylates, causes significant changes in the rate constant. In addition, heating of a polymer film caused a strong acceleration of the photoreaction above the glass transition temperature.