New photopolymerizable liquid crystalline dioxetane compounds are provided. having the general formula I: (I) wherein R1 and R2 are independently selected from straight or branched C1-C4 alkyl and hydrogen; X and X' are independently selected from oxygen, sulfur, a single covalent bond, -O-CO-, -CO-O-, and -O-CO-O-; Y and Y' are spacer groups having each independently 1 to 30 carbon atoms (linear or branched), in which the carbon chain may be interrupted by oxygen in the ether function or by sulfur in the thioether function; Z and Z' are independently selected from oxygen, sulfur, a single covalent bond, -O-CO-, -CO-O-, and -O-CO-O-; and M is any suitable mesogenic group. Also, compositions are provided containing one or more compounds of formula I, as well as methods of preparing said compounds and compositions. These compounds and compositions show excellent characteristics upon polymerization, such as improved non-shrinking properties, and are useful in a variety of applications, in particular in liquid crystal devices, sensors, and optical precision instruments.