关键词: 硫代双烯型镍络合物, 合成, 近红外吸收, 光稳定性, 热稳定性

Three bis-1,2-dithiolene nickel complexes with unsaturated substituted groups in the terminals, bis[4,5-di(4'-t-butylbenzyl)thio-1,3-dithion]nickel (2a), bis[4,5-dially-thio-1,3-dithion]nickel (2b) and bis[4,5-di(3'-phenyl-ally)thio-1,3-di-thion]nickel (2c) together with a bis-1,2-dithiolene nickel complexes with saturated substituted groups in the terminals, bis[4,5-didecylthio-1,3-dithion]nickel (2d), as a reference, were synthesized and characterized by ¹H NMR and MS. They were easily soluble in toluene with the maximum absorption wavelengths (λ_max) around 1000 nm, the effects of substituent groups in the terminals on λ_max were not so significant. Their λ_max in solid polymethyl methacrylate (PMMA) were around 1000 nm as well, and no broadening absorption bands could be observed in lower concentration. The solid cyclic voltammetry (CV) curves showed that the oxidation potentials would be increased by introduction of phenyl group in the terminals, thus their electrochemical stability could be improved. The results of thermal gravimetric analysis (TGA) indicated that the temperature of 5% weight-loss was higher than 200 ℃ for these compounds. Irradiated by xenon lamp (300 W) for 100 min, their absorbance was decreased less than 100% in toluene and 2% in solid polymethyl methacrylate (PMMA), respectively. The introduction of phenyl group in the terminals could improve the photo-stability for these molecules both in solution and solid PMMA.

Key words: bis-1,2-dithiolene nickel complexes, synthesis, near-infrared absorption, photo-stability, thermal stability