中性和两性离子甘氨酸·H₂O配合物：理论与基质隔离傅里叶变换红外光谱研究
Neutral and zwitterionic glycine.H(2)O complexes: A theoretical and matrix-isolation Fourier transform infrared study.
作者信息
Ramaekers Riet, Pajak Joanna, Lambie Bert, Maes Guido
机构信息
Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
出版信息
J Chem Phys. 2004 Mar 1;120(9):4182-93. doi: 10.1063/1.1643735.
The H-bond interaction between glycine and H2O has been studied by a combined theoretical (DFT(B3LYP)/6-31++G(**)) and experimental (matrix-isolation FT-IR) methodology. The 1:1 and 1:2 complexes of the most stable conformation (I) of glycine appear to be neutral complexes which have been vibrationally characterized in detail. The higher stoichiometry complexes (glycine).(H2O)n with n larger than 3 are demonstrated to be zwitterionic H-bonded complexes. A set of characteristic IR absorption bands for this zwitterionic structure has been observed in low-temperature Ar matrices. This would be the first experimental IR evidence for proton transfer occurring between the NH2 and COOH groups of amino acids by a H-bonded water molecular channel in isolated conditions.
通过理论（DFT(B3LYP)/6-31++G(**)）与实验（基质隔离傅里叶变换红外光谱）相结合的方法，对甘氨酸与水之间的氢键相互作用进行了研究。甘氨酸最稳定构象（I）的1:1和1:2配合物似乎是中性配合物，已对其进行了详细的振动表征。已证明化学计量比更高的配合物（甘氨酸）·(H₂O)ₙ（n大于3）是两性离子氢键配合物。在低温氩基质中观察到了一组该两性离子结构的特征红外吸收带。这将是在孤立条件下，通过氢键水分子通道在氨基酸的NH₂和COOH基团之间发生质子转移的首个实验红外证据。
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