We report on the ultraviolet photodissociation (UVPD) chemistry of protonated tyrosine, iodotyrosine, and diiodotyrosine. Distonic loss of the iodine creates a high-energy radical at the aromatic ring that engages in hydrogen/proton rearrangement chemistry. Based on UVPD kinetics measurements, the appearance of this radical is coincident with the UV irradiation pulse (8 ns). Conversely, sequential UVPD product ions exhibit metastable decay on ca. 100 ns timescales. Infrared ion spectroscopy is capable of confirming putative structures of the rearrangement products as proton transfers from the imine and β-carbon hydrogens. Potential energy surfaces for the various reaction pathways indicate that the rearrangement chemistry is highly complex, compatible with a cascade of rearrangements, and that there is no preferred rearrangement pathway even in small molecular systems like these.

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我们报告质子化酪氨酸，碘酪氨酸和二碘的紫外光解离（UVPD）化学酪氨酸。碘的tontonic损失会在芳香环上产生一个高能自由基，从而参与氢/质子重排化学反应。根据UVPD动力学测量，该自由基的出现与UV照射脉冲（8 ns）一致。相反地​​，顺序的UVPD产物离子在ca上表现出亚稳态衰减。100 ns时标。红外离子光谱能够确定重排产物的假定结构，因为质子从亚胺和β-碳氢转移而来。各种反应路径的势能表面表明，重排化学非常复杂，可与级联重排兼容，即使在像这样的小分子系统中也没有优选的重排路径。

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