Department of Physics, Science Faculty, Anadolu University, Eskişehir 26470, Turkey.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 May;90:109-17. doi: 10.1016/j.saa.2011.12.048. Epub 2012 Jan 18.
FT-IR and FT-Raman spectra of 1-cyclobutylpiperazine (1cbpp) have been experimentally reported in the region of 4000-10 cm(-1) and 4000-50 cm(-1), respectively. The optimized geometric parameters, conformational equilibria, normal mode frequencies and corresponding vibrational assignments of 1cbpp (C(8)H(16)N(2)) are theoretically examined by means of B3LYP hybrid density functional theory (DFT) method together with 6-31++G(d,p) basis set. Furthermore, reliable vibrational assignments have been made on the basis of potential energy distribution (PED) and the thermodynamics functions, highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO) of 1cbpp have been predicted. Calculations are employed for four different conformations of 1cbpp, both in gas phase and in solution. Solvent effects are investigated using chloroform and dimethylsulfoxide. All results indicate that B3LYP method is able to provide satisfactory results for predicting vibrational frequencies and the structural parameters, vibrational frequencies and assignments, IR and Raman intensities of 1cbpp are solvent dependent.
FT-IR 和 FT-Raman 光谱分别在 4000-10 cm(-1) 和 4000-50 cm(-1) 范围内对 1-环丁基哌嗪（1cbpp）进行了实验报道。采用 B3LYP 杂化密度泛函理论（DFT）方法和 6-31++G（d，p）基组，对 1cbpp（C8H16N2）的优化几何参数、构象平衡、正则振动频率及相应的振动归属进行了理论研究。此外，还基于势能分布（PED）和热力学函数对 1cbpp 的最高占据和最低未占据分子轨道（HOMO 和 LUMO）进行了预测，并对 1cbpp 的四种不同构象（气相和溶液）进行了可靠的振动归属。采用氯仿和二甲亚砜研究了溶剂效应。所有结果表明，B3LYP 方法能够提供令人满意的结果，用于预测振动频率和结构参数、振动频率和归属、IR 和拉曼强度，1cbpp 的溶剂依赖性。
