Synthesis, optical characterization and crystal and molecular X-ray structure of a phenylazojulolidine derivative

The synthesis, spectroscopic characterization, and X-ray crystal structure of [4-(2,3,6,7-tetrahydro-1H,5H-pyrido[3,2,1-ij]quinolin-9-ylazo)-phenyl]-methanol azodye are reported. A 37–47 nm bathochromic shift has been observed by comparison with analogous azodyes where diethylamino or dimethylamino groups act as donor moiety in agreement with the larger electronic donating properties of julolidine. The azobenzene skeleton adopts a planar trans-configuration and intra- and inter-molecular hydrogen bonds have been detected. A correlation between the spectroscopic and the molecular features has been attempted.

► Single crystal of a new phenylazojulolidine derivative was obtained and studied.
► Fluorescence emission was detected both in solution and in the solid state.
► Presence of H-bonds and planarity around N(17) are evidenced by X-ray analysis.
► A correlation between spectroscopic and molecular features was attempted.
► This functional building block can be used in DSC and all-optical poled NLO-dyes.