Filik Jacob, Harvey Jeremy N, Allan Neil L, May Paul W, Dahl Jeremy E P, Liu Shenggao, Carlson Robert M K
School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
Spectrochim Acta A Mol Biomol Spectrosc. 2006 Jun;64(3):681-92. doi: 10.1016/j.saa.2005.07.070. Epub 2006 Jan 4.
A selection of diamondoid hydrocarbons, from adamantane to [121321] heptamantane, have been analysed by multi-wavelength laser Raman spectroscopy. Spectra were assigned using vibrational frequencies and Raman intensities were calculated by employing the B3LYP functional and the split valence basis set of Schafer, Horn and Ahlrichs with polarisation functions on carbon atoms. The variation of the spectra and associated vibrational modes with the structure and symmetry of the molecules are discussed. Each diamondoid was found to produce a unique Raman spectrum, allowing for easy differentiation between molecules. Using the peak assignments derived from the calculations we find that the low frequency region of the spectra, corresponding to CCC-bending/CC-stretching modes, is particularly characteristic of the geometric shape of the diamondoid molecules.
通过多波长激光拉曼光谱对一系列类金刚石烃进行了分析，这些烃类从金刚烷到[121321]庚烷。利用振动频率对光谱进行了归属，并采用B3LYP泛函以及舍费尔、霍恩和阿尔里希斯的分裂价基组并在碳原子上使用极化函数计算了拉曼强度。讨论了光谱及相关振动模式随分子结构和对称性的变化。发现每个类金刚石烃都能产生独特的拉曼光谱，便于区分不同分子。利用计算得出的峰归属，我们发现光谱的低频区域对应于CCC弯曲/CC拉伸模式，这对类金刚石分子的几何形状具有特别的特征性。
