Cordeiro João M M, Soper Alan K
ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0QX, United Kingdom.
J Phys Chem B. 2009 May 14;113(19):6819-25. doi: 10.1021/jp902053y.
The structure of N-methylformamide (NMF) in liquid state has been investigated using a combination of neutron diffraction measurements augmented with isotopic substitution and empirical potential structure refinement computer simulations. The reference potential used was optimized previously and consisted of Coulomb and 6-12 Lennard-Jones interactions for the atoms. The results show that the three-dimensional model of the liquid structure constructed at the correct atomic number density is consistent with the diffraction experimental data. The liquid structure is orientated by the hydrogen bonds among the molecules. Each NMF molecule is, on average, hydrogen bonded to two others. The findings indicate that dimers and "linear" trimers are very stable species in the liquid bulk. Because of that, the liquid is strongly structured into a chain-like structure. Neighboring chains are stabilized with respect to each other by weak O...H(C) hydrogen bonds. The results are consistent with the known physicochemical properties of the liquid.
利用中子衍射测量结合同位素取代以及经验势结构精修计算机模拟的方法，对液态N-甲基甲酰胺（NMF）的结构进行了研究。所使用的参考势先前已进行了优化，由原子间的库仑相互作用和6 - 12 Lennard-Jones相互作用组成。结果表明，在正确的原子数密度下构建的液体结构三维模型与衍射实验数据一致。液体结构由分子间的氢键定向排列。平均而言，每个NMF分子与另外两个分子形成氢键。研究结果表明，二聚体和“线性”三聚体在液体主体中是非常稳定的物种。因此，液体强烈地形成链状结构。相邻的链通过弱的O...H(C)氢键相互稳定。这些结果与该液体已知的物理化学性质一致。
