Abstract +An aggregation‐induced emission‐based, luminescent Zinc (II) coordination complex of bisimidazolyl phenol ( Zn‐BDI ) is prepared. The thermal stability of the complex Zn‐BDI is attributed to the twisted conformation, and the rigid molecular structure of the ligand BDI resulted from the incorporation of the Zn‐metal atom. The maximum emission of the Zn‐BDI appears to be at 475 nm and emits strong cyan fluorescence. The light emission performance of the prepared zinc complex in organic light‐emitting diodes (OLEDs) indicates fairly good electroluminescence properties (max. brightness 13500 cd/m 2 , max. EQE=3.8 %). Moreover, these Zn‐BDI can emit strong cyan‐blue luminescence with a high quantum efficiency (0.83), and hence, latent fingerprint (LFPs) investigation exhibited permanent, immutable, and unique pores that are distributed on the ridges. Collectively, the prepared Zn complex offers a new avenue for the OLED and LFP applications.
The absorption and emission spectra of fluorescent thiophene dye, namely, 2,5-di-(5-tert-butyl-2-benzoxazolyl) thiophene, have been recorded at room temperature in solvents of different polarities. The excited state dipole moments (μ e ) were estimated from Lippert’s, Bakhshiev’s, and Kawski–Chamma–Viallet’s equations using the variation of Stoke’s shift with the solvent dielectric constant and refractive index. The optimized geometry of the molecule and μ g were calculated theoretically by Gaussian 03 software using B3LYP/6-31g* level of theory. The μ g and μ e were calculated by means of solvatochromic shift method and μ e was determined in combination with μ g . It was observed that μ e were higher than those of the μ g , indicating a substantial redistribution of the π-electron densities in a more polar excited state for the selected thiophene dye. Further, the change in the dipole moment (Δμ) was calculated both from solvatochromic shift method and on the basis of microscopic empirical solvent polarity parameter [Formula: see text] and values are compared.