次硝酸铋分子结构及热变性研究OA

To address the unresolved issues of molecular configuration and thermal stability mechanism of bismuth subnitrate,mid-infrared(MIR)spectroscopy,one-dimensional variable temperature mid-infrared(1D VT-MIR)spectroscopy(303～573 K)and two-dimensional mid-infrared(2D-MIR)spectroscopy were used to analyze the temperature-dependent characteristics of its molecular vibrations.The results show that the molecular structure of bismuth subnitrate mainly includes four infrared absorption modes:asymmetric telescopic vibration mode of NO3 functional group asymmetrical stretching vibration mode(νasNO3-bismuth subnitrate),NO3 functional group symmetrical stretching vibration mode(νsNO3-bismuth subnitrate),NO3 functional group out-of-plane bending vibration mode(rNO3-bismuth subnitrate)and NO3 functional group in-plane bending vibration mode(βNO3-bismuth subnitrate).In the temperature range of 303～573 K,the absorption intensity and frequency corresponding to the main functional groups of its molecular structure change significantly,and the 2D-MIR spectroscopy can effectively capture the information of the change of the absorption peaks of the main functional groups.This study clarifies the molecular structure characteristics and thermal denaturation law of bismuth subnitrate,and confirms that tertiary mid-infrared spectroscopy technology can be effectively applied to the molecular structure and thermal denaturation of bismuth subnitrate,which provides technical support and data reference for the related research of this type of inorganic fine chemicals.