293～563K下甲醇结构的研究

The Structural Studies on Methanol up to 563 K under Pressure

利用金刚石压腔和拉曼光谱,研究了甲醇从室温到563K下的结构特征。结果表明:随着温度的升高,体系压力也在不断增大;νCH区伸缩振动和νOH区伸缩振动同时受到温度和压力的影响,但两种作用相反。由于压力效应大于温度效应,随温度压力的增大,νCH区伸缩振动的拉曼位移向高频方向移动,说明C—H键键能在增大;而O—H伸缩振动峰的相对面积随温度压力的增大而增大,说明对C—H键而言,O—H键总强度是增加的,由此推测在地质条件下,压力可能阻碍或延长了干酪根的降解生烃过程。

This paper investigates the structure of methanol by Raman spectrum in diamond anvil cell up to 563 K. The result shows that pressure increases at elevated temperature, but the effect of pressure on the stretching vibrational modes of C--H is inverse to that of temperature. The action of temperature is weaker than that of pressure. So the spectral profile of stretching vibrational modes of C--H gradually changes and the Raman shift moves to higher frequency with increasing temperature and pressure, indicating that the bonding energy of C--H bonding increases with temperature and psessure. In addition, the increase of the relative peak area of O--H stretch band with both the temperature and pressure indicates that the total intensity of O--H bonding is greater compared with that of C--H bonding. Thus, it can be inferred that the higher pressure might slow down the transforming process of kerogen to hydrocarbon under the geological condition.