Møllendal Harald, Mokso Rajmund, Guillemin Jean-Claude
Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, NO-0315 Oslo, Norway.
J Phys Chem A. 2009 Mar 26;113(12):2821-5. doi: 10.1021/jp810810f.
The microwave spectrum of propargyl selenocyanate (HC[triple bond]CCH(2)SeC[triple bond]N) has been investigated in the 40-80 GHz spectral region at 0 degrees C. The spectra of the ground vibrational state of the (80)Se and (78)Se isotopologues of one conformer were assigned. The first vibrationally excited state of the torsion about the CC-Se bond was also assigned for the (80)Se isotopologue. The identified rotamer has a C-C-Se-C antiperiplanar conformation (C(s) symmetry). The microwave work has been augmented by ab initio calculations at the MP2/6-311++(3df,3pd) level and density functional theory calculations at the B3LYP/6-311G++(3df,3pd) level of theory. Both the ab initio and the B3LYP calculations predict that the identified rotamer is the global minimum and indicate the existence of an additional high-energy anticlinal form. The two theoretical methods predict rather different values for the H(2)C-Se bond length as well as for the C-C-Se-C dihedral angle of the high-energy anticlinal form.
在0摄氏度下，对炔丙基硒氰酸盐（HC≡CCH₂SeC≡N）的微波光谱进行了40 - 80 GHz光谱区域的研究。确定了一种构象体的（⁸⁰Se）和（⁷⁸Se）同位素异构体基态振动状态的光谱。还确定了（⁸⁰Se）同位素异构体围绕C-C-Se键扭转的第一振动激发态。所识别的旋转异构体具有C-C-Se-C反式共平面构象（Cₛ对称性）。微波研究通过MP2/6 - 311++(3df,3pd)水平的从头算和B3LYP/6 - 311G++(3df,3pd)水平的密度泛函理论计算得到补充。从头算和B3LYP计算均预测所识别的旋转异构体是全局最小值，并表明存在另一种高能反式构象。两种理论方法预测高能反式构象中H₂C-Se键长以及C-C-Se-C二面角的值有很大差异。
