Investigating the synthetic mechanism of 3,5-diamino-1,2,4-triazole by using fibre optic ATR-IR spectroscopy combined with kernel independent component analysis

Abstract

In-line attenuated total reflection infrared (ATR-IR) combined with kernel independent component analysis (KICA) was applied to investigate the synthetic mechanism of 3,5-diamino-1,2,4-triazole (DAT). In the proposed method, the reaction process was first monitored by an in-line IR probe to acquire IR spectra at a precise period of time, and then KICA was used to directly estimate the spectrum of each component in the mixture without pre-separation and other prior information. The estimated IR spectra were used to monitor the reaction and deduce the reaction mechanism. The intermediates involved in the reaction process were further validated by the density functional theory (DFT) at the B3LYP level. The computational results obtained by the KICA approach are in good agreement with those by the quantum chemical calculation method, thereby demonstrating the reliability of the KICA method. The results show that in-line ATR-IR spectroscopy combined with KICA can be applied to study the synthetic mechanism of 3,5-diamino-1,2,4-triazole effectively.