Instituto de Física Fundamental (IFF-CSIC), Group of Molecular Astrophysics, C/Serrano 121, 28006 Madrid, Spain.
Departamento de Química Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, 47011 Valladolid, Spain.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Mar 15;249:119320. doi: 10.1016/j.saa.2020.119320. Epub 2020 Dec 15.
Non-covalent interactions determine the three-dimensional structure and activity of biological molecules. In this work, the pyrrole-pyridine complex considered as a model of the NH⋯N hydrogen-bonded Watson-Crick base pairs has been generated in a supersonic expansion and characterized by chirped pulse Fourier transform microwave spectroscopy. The analysis of the unconventional spectral pattern of the 1:1 pyrrole-pyridine adduct and its C and N isotopologues reveal a non-planar complex, with a bent NH⋯N hydrogen bond and large amplitude motion of the pyrrole subunit. The bent structure is likely to arise from the stablishment of the secondary CH⋯N interaction between pyridine and pyrrole moieties.
非共价相互作用决定了生物分子的三维结构和活性。在这项工作中，我们生成了吡咯-吡啶复合物（被认为是 NH⋯N 氢键沃森-克里克碱基对的模型），并通过啁啾脉冲傅里叶变换微波光谱法对其进行了表征。对 1:1 吡咯-吡啶加合物及其 C 和 N 同位素的非常规光谱模式的分析表明，这是一个非平面复合物，具有弯曲的 NH⋯N 氢键和吡咯部分的大幅运动。弯曲的结构可能是由于吡啶和吡咯部分之间建立了次要的 CH⋯N 相互作用。
