Green synthesis, characterization and optical properties of eutectics and 1:1 intermolecular compounds: $N,N$-dimethylaminobenzaldehyde–anthranilic acid and 2-(4-(dimethylamino)benzylideneamino)benzoic acid– $p$-nitroaniline systems

[摘要] Phase diagrams of $N,N$-dimethylaminobenzaldehyde (DMAB)–anthranilic acid (AA) and 2-(4-(dimethylamino)benzylideneamino)benzoic acid (DMABAB)–$p$-nitroaniline (PNA) systems, determined by the thaw-meltmethod, give two eutectics and a 1:1 intermolecular compound (IMC) in each case. Appropriate amounts (10 g) of each of the eutectics and the IMCs were prepared by a green synthetic method involving a solid state reaction without any solvent. These materials were characterized by X-ray diffraction, thermal and spectral methods and the optical properties of the pure components and the IMCs were studied.While negative values of heat of mixing in the case of a DMAB–AA system suggest clustering of molecules in both eutectic melts, those of positive value in E$_1$ and negative value in E$_2$ of the DMABAB–PNAsystem indicate the formation of a quasi-eutectic structure in E$_1$ melt and clustering of molecules in E$_2$ melt. The IMC of DMAB–AA system shows strong dual emission with two λmax one at 380 nm and the second at 450 nm with a total quantum efficiency of 0.49. The IMC of DMABAB–PNA system also shows a similar observation with two $\lambda_{\rm max}$ one at 390 nm and second at 435 nm with a total quantum efficiency of 0.31.

[学科分类] 材料工程

[关键词] Phase-diagram;inter-molecular compound;heat of fusion;powder XRD;optical properties.