DETERMINATION OF THE TYPES OF SILICON BONDS WITH FUNCTIONAL GROUPS IN THE STRUCTURES OF ORGANIC SUBSTANCES OF PLANT ORIGIN USING THE DIFFUSE REFLECTION METHOD OF INFRARED SPECTROSCOPY

Abstract

The relevance of the study is caused by the disclosure of the possibility of determining Si bonds with C, H, N, O in the structures of coal and other carbonified substances by diffuse infrared spectroscopy in the range of 7500–350 cm–1. Then, the spectra are processed and spectral characteristics are determined by calculating values to define structural and genetic indicators and perform structural and group analysis. The use of structural and genetic indicators: Pm, Pv, PVt+L, PI, Pg, allows us to determine the influence of genetic factors on the formation of different types of silicon bonds and their amount in the structures of natural organic substances. The main aim: on the example of IR spectra of hard coals to show techniques for determining the types of Si bonds with elements C, H, N, O using reference spectrometric characteristics of simple chemical compounds of silicon and analyzing the pair correlation of the intensity values of the selected diffuse reflection bands with the Si content in coals; on the example of fossilized (herbarium, phytoleima) and carbonified (peat, kerogen, coal) substances to show the use of the detected types of bonds of organosilicon compounds in the structures of natural organic substances and the nature of their changes depending on carbon-petrographic and structural-genetic indicators. Objects: herbarium of horsetail swamps of the Tomsk region, phytoleums of horsetail, fern and kerogen of oil and gas deposits of Western Siberia of Jurassic age, peat of the Apache deposit in Kamchatka, coal grade D of the Two-arch Chernogorsky deposit of the Minusinsky basin, coal grade Z of the formation 39 of the Zhernovsky field of Kuzbass. Methods: infrared Fourier spectroscopy of diffuse reflection. Results. It was established that the using of reference tables of the spectrometric characteristics of Si and its correlation with intensity of diffuse reflection at frequencies with wave numbers of 800, 855, 868, 2070, 3391 cm–1, one can examine the compounds Si-H, SiCH3, Si(CH3)2, Si(C≡CH)4, Si2NH respectively. They reflect different types of Si bonds with functional groups and, as the experiment showed, with samples of horsetail herbarium, horsetail and fern phytoleims, kerogen, peat, coal. Their use with structural and genetic indicators allows determining the influence of genetic factors on the formation of different types of silicon bonds and their number in the structures of natural organic substances.

Keywords

• coalified substance
• structure
• functional groups
• si bond forms
• infrared spectroscopy