Systematic investigation of the structure–property relationship of substituted p-alkoxy-azothiophenes

Abstract

Differently substituted p-alkoxy azothiophenes with increasing alkoxy chains were systematically investigated in terms of their structure–property relationships. In particular, it was observed that increasing the length of the alkoxy chain had an unusual effect on the melting point, which did not follow the expected odd–even effect. It was also shown that changing the length of the alkoxy chain did not significantly affect the thermal half-life, a finding that disagrees with results reported in other studies. These observations provide valuable insights into structure–property relationships with important implications for the design and development of azobenzenes as molecular materials for various applications. Furthermore, each p-alkoxy azothiophene was investigated in terms of neat solid-state photoisomerisation or photoinduced liquefaction, which is a critical parameter for application as a molecular solar thermal phase-change (MOST-PCM) energy storage system.