Cacciapaglia Roberta, Di Stefano Stefano, Mandolini Luigi
Dipartimento di Chimica and ICCOM CNR-Sezione di Roma, Università La Sapienza, Box 34-ROMA 62, 00185 Roma, Italy.
J Am Chem Soc. 2003 Feb 26;125(8):2224-7. doi: 10.1021/ja029331x.
Reversible phototuning of the catalytic efficiency of the bis-barium complex of azobis(benzo-18-crown-6) in the basic ethanolysis of anilide derivatives has been achieved by light-induced cis right arrow over left arrow trans interconversion of the azobenzene spacer unit of the catalyst. The geometry of the productive catalyst-substrate complex is more favorable when the concave cis form of the catalyst is involved. Continuous photoregulation of the catalytic activity at any intermediate value between the "HIGH" and "LOW" levels was achieved by proper adjustment of the excitation wavelength or the irradiation time. The complete and relatively fast interconvertibility of photostationary states allowed the activity of the catalyst to be repeatedly photoswitched "HIGH" and "LOW" in the course of the same run.
通过光诱导催化剂偶氮双（苯并 - 18 - 冠 - 6）双钡配合物中偶氮苯间隔单元的顺式⇌反式相互转化，实现了其在苯胺衍生物碱性醇解反应中催化效率的可逆光调节。当涉及催化剂的凹形顺式形式时，活性催化剂 - 底物复合物的几何结构更有利。通过适当调整激发波长或照射时间，可在“高”和“低”水平之间的任何中间值实现催化活性的连续光调节。光稳态的完全且相对快速的相互转换使得催化剂的活性在同一次运行过程中能够反复光切换为“高”和“低”状态。
