Department of Chemistry, University of California, Davis, California 95616, USA.
J Am Chem Soc. 2012 Feb 1;134(4):1950-3. doi: 10.1021/ja210239k. Epub 2012 Jan 19.
We report here a new phenomenon of dynamic enhancement of chemical reactions by nanomaterials under hard X-ray irradiation. The nanomaterials were gold and platinum nanoparticles, and the chemical reaction employed was the hydroxylation of coumarin carboxylic acid. The reaction yield was enhanced 2000 times over that predicted on the basis of the absorption of X-rays only by the nanoparticles, and the enhancement was found for the first time to depend on the X-ray dose rate. The maximum turnover frequency was measured at 1 × 10(-4) s(-1) Gy(-1). We call this process chemical enhancement, which is defined as the increased yield of a chemical reaction due to the chemical properties of the added materials. The chemical enhancement described here is believed to be ubiquitous and may significantly alter the outcome of chemical reactions under X-ray irradiation with the assistance of nanomaterials.
我们在这里报告了一种新的现象，即在硬 X 射线辐照下纳米材料会动态增强化学反应。纳米材料为金和铂纳米粒子，所采用的化学反应是香豆素羧酸的羟化反应。反应产率比仅基于纳米粒子吸收 X 射线预测的产率提高了 2000 倍，并且首次发现增强取决于 X 射线剂量率。最大周转率频率在 1×10(-4)s(-1)Gy(-1)下进行测量。我们将这个过程称为化学增强，它被定义为由于添加材料的化学性质而导致化学反应产率增加。这里描述的化学增强被认为是普遍存在的，并且可能会在纳米材料的协助下，显著改变 X 射线辐照下化学反应的结果。
