In situ attenuated total refletion-Fourier transform infrared spectroscopy（ATR-FTIR） was used to monitorand acquire spectral information on the synthesis of 4-amino-3,5-dimethyl pyrazole. Principal component analy-...In situ attenuated total refletion-Fourier transform infrared spectroscopy（ATR-FTIR） was used to monitorand acquire spectral information on the synthesis of 4-amino-3,5-dimethyl pyrazole. Principal component analy-sis（PCA） was used to determine the number of principle components（PCs）. The score vectors of the PCs were ana-lysed using the simple-to-use interactive self-modelling mixture analysis（SIMPLISMA） algorithm to obtain spectraland concentration profiles for the reactants, intermediates and product. The vibrational frequencies of the interme-diates were calculated via density ftmctional theory（DFT） at the level of the B3LYP/6-31 l＋＋G（d,p） basis set, and thegeometrical configurations of the intermediates were simultaneously optimized. Finally, a reasonable synthesismechanism for 4-amino-3,5-dimethyl pyrazole was determined based on the changes observed in the feature peaks.The results from the SIMPLISMA algorithm correlated well with the quantttm chemistry calculations. This provedthat the SIMPLISMA algorithm combined with ATR-FTIR can be used to detemfine the synthesis mechanism for4-amino-3,5-dimethyl pyrazole and can even provide a new, useful method to explore dynamic synthesis reactionmechanisms.展开更多
文摘In situ attenuated total refletion-Fourier transform infrared spectroscopy（ATR-FTIR） was used to monitorand acquire spectral information on the synthesis of 4-amino-3,5-dimethyl pyrazole. Principal component analy-sis（PCA） was used to determine the number of principle components（PCs）. The score vectors of the PCs were ana-lysed using the simple-to-use interactive self-modelling mixture analysis（SIMPLISMA） algorithm to obtain spectraland concentration profiles for the reactants, intermediates and product. The vibrational frequencies of the interme-diates were calculated via density ftmctional theory（DFT） at the level of the B3LYP/6-31 l＋＋G（d,p） basis set, and thegeometrical configurations of the intermediates were simultaneously optimized. Finally, a reasonable synthesismechanism for 4-amino-3,5-dimethyl pyrazole was determined based on the changes observed in the feature peaks.The results from the SIMPLISMA algorithm correlated well with the quantttm chemistry calculations. This provedthat the SIMPLISMA algorithm combined with ATR-FTIR can be used to detemfine the synthesis mechanism for4-amino-3,5-dimethyl pyrazole and can even provide a new, useful method to explore dynamic synthesis reactionmechanisms.
