A MOLECULAR MECHANICS VALENCE FORCE-FIELD FOR SULFONAMIDES DERIVED BY ABINITIO METHODS
A MOLECULAR MECHANICS VALENCE FORCE-FIELD FOR SULFONAMIDES DERIVED BY ABINITIO METHODS
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DOI：
10.1021/j100177a038
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发表时间：
1991-11-28
影响因子：
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通讯作者：
HOPFINGER, AJ
中科院分区：
文献类型：
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作者：
NICHOLAS, JB;VANCE, R;HOPFINGER, AJ
在RHF/6- 31 G ~* 水平上用从头算方法计算了磺酰胺基SO_2NH的分子力学价力场参数。 力场参数设计为与MM 2/MMP 2力场的现有参数结合使用。 证明了新的参数，以准确地再现从头算优化的几何形状的四个分子，含有磺酰胺基团。 讨论了力场参数化的策略。 磺酰胺基团的构象灵活性进行了研究。 在RHF/6- 31 G * 水平上的计算表明存在两种稳定的构象，并且相互转换是通过氮的反转而不是围绕S-N键的旋转实现的。 讨论了将基组扩展到6- 31 G * 和加入电子关联的MP2和MP3修正的能量效应。 还报道了从头算优化结构的几何形状和Mulliken电荷。
Molecular mechanics valence force field parameters for the sulfonamide group, SO2NH, have been derived from ab initio calculations at the RHF/6-31G* level of theory. The force field parameters were designed to be used in conjunction with existing parameters from the MM2/MMP2 force field. The new parameters are demonstrated to accurately reproduce the ab initio optimized geometries of four molecules that contain the sulfonamide group. The strategy used in force field parametrization is discussed. The conformational flexibility of the sulfonamide group has been investigated. Calculations at the RHF/6-31G* level reveal the existence of two stable conformers and that interconversion is achieved by nitrogen inversion rather than rotation about the S-N bond. The energetic effects of expanding the basis set to 6-31G* and of including MP2 and MP3 corrections for electron correlation are discussed. The geometries and Mulliken charges for the ab initio optimized structures are also reported.