Highly Selective Dissociation of a Peptide Bond Following Excitation of Core Electrons

详细信息    查看全文

• 作者：Yi-Shiue Lin ; Cheng-Cheng Tsai ; Huei-Ru Lin ; Tsung-Lin Hsieh ; Jien-Lian Chen ; Wei-Ping Hu ; Chi-Kung Ni ; Chen-Lin Liu
• 刊名：Journal of Physical Chemistry A
• 出版年：2015
• 出版时间：June 18, 2015
• 年：2015
• 卷：119
• 期：24
• 页码：6195-6202
• 全文大小：734K
• ISSN：1520-5215

文摘

The controlled breaking of a specific chemical bond with photons in complex molecules remains a major challenge in chemistry. In principle, using the K-edge absorption of a particular atomic element, one might excite selectively a specific atomic entity in a molecule. We report here highly selective dissociation of the peptide bonds in N-methylformamide and N-methylacetamide on tuning the X-ray wavelength to the K-edge absorption of the atoms connected to (or near) the peptide bond. The high selectivity (56鈥?1%) of this cleavage arises from the large energy shift of X-ray absorption, a large overlap of the 1s orbital and the valence 蟺* orbital that is highly localized on a peptide bond with antibonding character, and the relatively low bond energy of the peptide bonds. These characteristics indicate that the high selectivity on bond dissociation following core excitation could be a general feature for molecules containing peptide bonds.