In this paper we describe the synthesis of a nematic twin molecule with a lateral methyl substituent in the mesogenic group. This compound exhibits a broad nematic mesophase between -18 degreesC and 135 degreesC and can be supercooled into a liquid crystalline glass. The LC-phase was permanently fixed into a network by in-situ photopolymerization. The broad mesophase of the twin molecule allows the investigation of the photopolymerization behaviour by photo-DSC-measurements in a wide temperature range. The T-g of the polymer network was determined by TMA-measurements.