摘要
应用密度泛函理论中的ω-B97XD/6-311+G(d,p)方法,对甲醛分子团簇[CH2O]n(n=1~4)的空间结构进行了优化,得到了这些团簇的基态结构,并对其红外光谱,核磁共振谱的性质进行了研究.结果表明,当甲醛分子构成稳定的多分子团簇时,团簇中的每个分子仍然为平面结构,分子间将形成氢键,并且团簇中的各个分子共面.与单分子甲醛相比,多分子团簇的红外光谱,会出现许多与分子间氢键振动有关的新的吸收峰.当甲醛分子形成团簇时,13C核和17O核的核磁共振谱线会发生劈裂现象,这与电荷分布的对称性的破缺有关;而1H的核磁共振谱中将会出现新的条纹,这是由分子间的氢键的形成引起的.本文的研究可为甲醛团簇的识别、检测及性质研究提供理论依据.
With Density Functional Theory( DFT) and ω-B97 XD/6-311 + G( d,p) method,the spatial structure of formaldehyde molecule clusters[CH_2O]n( n = 1 ~ 4) at ground state were obtained in this study. The infrared spectrum and Nuclear Magnetic Resonance( NMR) spectrum of these clusters were also studied. This study shows that intermolecular hydrogen bonds arise and formaldehyde molecules stay in planar structure when forming into the cluster. the molecule planes would be coplanar. Compared with the single molecule case,multi-molecular clusters will generate more absorption peaks in the infrared spectrum,which are related to the vibration of its hydrogen bonds and the interaction among molecules in the cluster. Moreover,as formaldehyde molecules form into a cluster,NMR spectrum lines of 13C and 17O will split; a new spectrum line will appear in the NMR spectrum of 1H,which is also due to intermolecular hydrogen bonds. The results of this study may serve as a theoretical reference for the identification,detection,and isolation of formaldehyde clusters.
出处
《广州航海学院学报》
2017年第4期53-56,70,共5页
Journal of Guangzhou Maritime University
基金
广州航海学院创新强校平台项目(2014E057
2014E059)
关键词
分子团簇
密度泛函理论
红外光谱
核磁共振谱
[CH2O]n(n = 1 ~ 4) clusters
Density Functional Theory
infrared spectrum
Nuclear Magnetic Resonance
