Specificity and Selectivity in Photoluminescent Properties of π-Conjugated Benzheterazole Molecules

Benzheterazole derivatives with ethylene and phenyl linkers have been studied as model compounds to understand the role of (i) aromatic and heteroaromatic rings on the photophysical properties, (ii) extended π-structure and the proximity of heteroatoms in the aromatic rings, and (iii) substitutional effect of benzheterazoles at the 1,2-position of the ethylene and 1,2- and 1,4-position of the phenyl linkers. In this study we highlight the crucial parameters that govern selective white light emission against the other spectral colors emitted by the benzheterazole derivatives. Distinguishably, benzothiazoles substituted at 1,2-positions in both ethylene and phenyl linkers show pronounced broad-band emission against several other molecules which show a dominant blue or green or red emission. The electroluminescent properties of the model molecules 1,2-bis(benzothiazolyl)ethylene (1,2-BBE—sample 1a) and 1,2-bis(benzothiazolyl)benzene (1,2-BBB—sample 2a), showing white light emission, are demonstrated. The dev...