Synthesis and spectroscopic properties of novel meso-cyano boron-pyridyl-isoindoline dyes

meso-Cyano boron-pyridyl-isoindoline dyes with asymmetrical structures were synthesized through a facile two-step reaction. Broad envelopes of intense vibrational bands were observed for the main spectral bands in the absorption and emission spectra. Moderate fluorescence quantum yields were obtained in solution, with significant intensity also observed in film, powder and crystal forms. An analysis of the structure-property relationships was carried out based on X-ray crystallography, optical spectroscopy, and theoretical calculations.