Site-Specific Photo-oxidation of the Isolated Adenosine-5′-triphosphate Dianion Determined by Photoelectron Imaging
Site-Specific Photo-oxidation of the Isolated Adenosine-5′-triphosphate Dianion Determined by Photoelectron Imaging
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DOI：
10.1021/acs.jpclett.0c02089
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发表时间：
2020-10-01
影响因子：
5.7
通讯作者：
Verlet, Jan R. R.
中科院分区：
文献类型：
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作者：
Castellani, Maria Elena;Avagliano, Davide;Verlet, Jan R. R.
激发到 (1)pi pi* 态的分离的腺苷-5'-三磷酸双阴离子的光电子成像表明，电子发射主要平行于光的偏振轴，并且由亚皮秒电子隧道穿过排斥库仑势垒 (RCB) 产生。计算的 RCB 显示最可能的电子发射位点位于腺嘌呤的氨基上。这与光电子成像一致：对 (1)pi pi* 态的激发导致主要平行于腺嘌呤长轴分布的对齐系综；随后的电子隧道位置沿着该轴；带负电的磷酸基团主要沿着该轴长距离引导出射电子。聚阴离子电子隧道成像与计算化学相结合，可以为探测固有光氧化位点和动力学以及复杂孤立物质的整体结构提供通用途径。
Photoelectron imaging of the isolated adenosine-5'-triphosphate dianion excited to the (1)pi pi* states reveals that electron emission is predominantly parallel to the polarization axis of the light and arises from subpicosecond electron tunneling through the repulsive Coulomb barrier (RCB). The computed RCB shows that the most probable electron emission site is on the amino group of adenine. This is consistent with the photoelectron imaging: excitation to the (1)pi pi* states leads to an aligned ensemble distributed predominantly parallel to the long axis of adenine; the subsequent electron tunneling site is along this axis; and the negatively charged phosphate groups guide the outgoing electron mostly along this axis at long range. Imaging of electron tunneling from polyanions combined with computational chemistry may offer a general route for probing the intrinsic photo-oxidation site and dynamics as well as the overall structure of complex isolated species.