氨基酸分子构象稳定性与光电离解离动力学的氢键效应*

本文综述了氨基酸分子内氢键种类和数目对分子构象稳定性和光电离解离动力学的各种效应：得出分子内含有N···H–O和C=O···H–O氢键的构象具有较高的热力学稳定性； N···H–O氢键导致分子第一电离能数值的增加，同时可以导致电离过程中的质子转移以及后续二氧化碳释放的解离过程。氨基酸分子正离子的稳定性或碳碳化学键断裂解离动力学也不尽相同，丝氨酸分子在电离阈值附近解离过程中表现出奇特的立体效应。

Hydrogen Bonding Effects on Conformational Stabilities and Dissociative Photoionization Dynamics of Amino Acids

Effects of types and numbers of hydrogen bonds in the isolated amino acids on both the relative stabilities of conformers and their photoionization dissociation dynamics are reviewed. The thermodynamic stabilities of the conformers are enhanced by the strong intramolecular N···H–O and C=O···H–O hydrogen bonds. Moreover, the N···H–O hydrogen bond leads to the high ionization energy of the specific conformer, and carbon dioxideis released after the intramolecular proton transfer in the ionization promotion. Cationic amino acids are distinctly different from the neutral, and some cations may be dissociated via the cleavages of carbon-carbon bonds. The remarkable stereo effects are observed in the threshold photoionization dissociation processes of serine conformers. Contents
1 Conformers and Hydrogen Bonds of Amino Acids
2 Intramolecular Hydrogen Bonds and Conformational Stabilities
3 Photoionization and Dissociation Dynamics
4 Conclusion