کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1250329 | 970813 | 2009 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The terahertz spectrum and quantum chemical assignment of 2,2′-bithiophene in cyclohexane The terahertz spectrum and quantum chemical assignment of 2,2′-bithiophene in cyclohexane](/preview/png/1250329.png)
The room temperature solution-phase terahertz (THz, 7 to 165 cm−1) spectrum of 2,2′-bithiophene in cyclohexane is reported. Density functional theory (B3LYP) and ab initio (MP2) methods employing the 6-311++G(2d,2p) and aug-cc-pVDZ basis sets are used to assign the THz vibrational structure and determine the relative populations of the cis and trans conformations, as well as the trans–trans rotational barrier height and the effects of the cyclohexane solvent on the predicted molecular geometries and vibrational frequencies. Significant differences are seen in the performance of the different theoretical methods, with the best performing method dependent upon the molecular property of interest. The best fit model of the experimental THz spectrum is achieved using MP2/aug-cc-pVDZ, which places the relative trans and cis populations at 54% and 46%, respectively.
Journal: Vibrational Spectroscopy - Volume 49, Issue 2, 18 March 2009, Pages 124–132