Scattergood Paul A, Elliott Paul I P
Department of Physical and Life Sciences & Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
Inorg Chem. 2024 Sep 16;63(37):17287-17297. doi: 10.1021/acs.inorgchem.4c03154. Epub 2024 Sep 5.
Facial and meridional isomerism of metal complexes is known to result in fundamental differences in photophysical properties. One may also envisage differences in their photochemical reactivity and therefore predict different outcomes of their light-triggered transformations. The - and -isomers of the complex [Ru(pytz)] (- & -, pytz = 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole) were separated and isolated. - undergoes a predicted pytz photodechelation process in acetonitrile to yield -[Ru(κ-pytz)(κ-pytz)(NCMe)] () whereas unfavorable interligand steric interactions are predicted to, and indeed do prevent comparable photoreactivity for -. Reversible photoisomerization of - and - is also observed, however. The differences in photochemical reactivity of the two isomers can be rationalized based on structural programming of the preferential accessibility of particular MC excited states due to differences in their interligand steric interactions. Here we present an initial predictive thought experiment, subsequent experimental verification, and computational rationalization of the differences in photochemical reactivity of these two isomeric complexes.
已知金属配合物的面式和经式异构会导致光物理性质的根本差异。人们还可以设想它们在光化学反应性方面的差异，因此预测它们光触发转变的不同结果。配合物[Ru(pytz)]（- & -，pytz = 1-苄基-4-(吡啶-2-基)-1,2,3-三唑）的 - 异构体和 - 异构体被分离并提纯。 - 在乙腈中经历预测的pytz光脱螯合过程，生成 -[Ru(κ-pytz)(κ-pytz)(NCMe)]（），而不利的配体间空间相互作用预计会，并且实际上确实阻止了 - 的类似光反应性。然而，也观察到了 - 和 - 的可逆光异构化。基于由于它们配体间空间相互作用的差异导致特定MC激发态优先可及性的结构规划，可以解释这两种异构体光化学反应性的差异。在这里，我们展示了一个初步的预测性思想实验、后续的实验验证以及对这两种异构配合物光化学反应性差异的计算合理化。
