Probing furanose ring conformation by gas-phase computational methods:: Energy profile and structural parameters in methyl β-D-arabinofuranoside as a function of ring conformation
Probing furanose ring conformation by gas-phase computational methods:: Energy profile and structural parameters in methyl β-D-arabinofuranoside as a function of ring conformation
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DOI：
10.1021/jo000426w
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发表时间：
2000-08-11
影响因子：
3.6
通讯作者：
Hadad, CM
中科院分区：
文献类型：
--
作者：
Gordon, MT;Lowary, TL;Hadad, CM
利用从头算分子轨道（HF/6-31G*）和密度泛函理论（B3LYP/6-31G*），通过最小化10种可能的包络构象，研究了甲基β - d -阿拉伯糖醛酸苷(3)的势能面。局部势能面识别出整体能量最小和能量最低的北型为E-2。在HF计算中，E-2是最稳定的南方构象，而密度泛函理论方法确定E-4是本半球的局部最小值。在更高的理论水平上的额外计算表明，3的许多包络构象的b3lypp衍生能量依赖于所使用的基集。结果表明，B3LYP/G-31+G**//B3LYP/6-31G*单点能量与B3LYP/6-31+G**级全几何优化得到的能量基本相同。B3LYP/6-31+G**地表的北、南极小值分别为E-2和E-2构象。利用B3LYP/6-31G*几何结构研究了环构象与各种结构参数（键角、二面角、键长和原子间距离）的关系。
The potential energy surface of methyl beta-D-arabinofuranoside (3) has been studied by ab initio molecular orbital (HF/6-31G*) and density functional theory (B3LYP/6-31G*) calculations via minimization of the 10 possible envelope conformers. The partial potential energy surface identified that the global minimum and lowest energy northern conformer was E-2. In the HF calculations, E-2 was the most stable southern conformer, while the density functional theory methods identified E-4 as the local minimum in this hemisphere. Additional calculations at higher levels of theory showed that the B3LYP-derived energies of many of the envelope conformers of 3 are dependent upon the basis set used. It has also been demonstrated that B3LYP/G-31+G**//B3LYP/6-31G* single point energies are essentially the same as those obtained from full geometry optimizations at the B3LYP/6-31+G** level. The northern and southern minima of the B3LYP/6-31+G** surface are, respectively, the E-2 and E-2 conformers. The B3LYP/6-31G* geometries were used to study the relationship between ring conformation and various structural parameters including bond angles, dihedral angles, bond lengths, and interatomic distances.