Department of Physics, Sammilani Mahavidyalaya, E.M. Bypass, Baghajatin Station, Kolkata 700 075, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Oct;96:837-47. doi: 10.1016/j.saa.2012.07.106. Epub 2012 Aug 4.
Molecular structure and conformational properties of Isobutyl Cyanide (IBCN) have been studied by quantum chemical methods. The quantum chemical methods predict the existence of both the Trans-Gauche (TG) and Gauche-Gauche (GG) rotameric forms of the IBCN molecule. Fresh vibrational assignments corresponding to each of the 39 normal modes are proposed for both the TG and GG rotameric forms of the molecule. The origin of the internal rotational barrier of the TG form of the molecule has been studied by the relaxation effects and with the aid of nuclear virial and natural bond orbital (NBO) analyses technique. For the barrier to internal rotation of the methyl CH(3) (I)/CH(3) (II) groups of the TG form of the IBCN molecule; the combined relaxations of the C(2)-C(3)/C(2)-C(4) bond lengths and H(10)-C(3)-H(11)/C(2)-C(4)-H(13) angles together play a significant role.
已通过量子化学方法研究了异丁基氰（IBCN）的分子结构和构象特性。量子化学方法预测了 IBCN 分子存在两种反式- gauche（TG）和 gauche-gauche（GG）构象形式。为分子的 TG 和 GG 构象形式的每个 39 个正则模式提出了相应的新的振动分配。通过弛豫效应以及核维里和自然键轨道（NBO）分析技术研究了 TG 形式分子的内部旋转势垒的起源。对于 TG 形式的 IBCN 分子的甲基 CH(3)（I）/CH(3)（II）基团的内部旋转势垒；C(2)-C(3)/C(2)-C(4)键长和 H(10)-C(3)-H(11)/C(2)-C(4)-H(13)角度的联合弛豫共同起着重要作用。
