Ultrafast kinetics of linkage isomerism in Na₂[Fe(CN)₅NO] aqueous solution revealed by time-resolved photoelectron spectroscopy

Azhr A. Raheem^1,2,3, Martin Wilke^1,2, Mario Borgwardt^1,2, Nicholas Engel^1,2, Sergey I. Bokarev^4,a), Gilbert Grell⁴, Saadullah G. Aziz⁵, Oliver Kühn⁴, Igor Yu. Kiyan², Christoph Merschjann^1,2,b), and Emad F. Aziz^1,2,6,c)

Structural Dynamics 4, 044031 (2017); doi: http://dx.doi.org/10.1063/1.4990567

The kinetics of ultrafast photoinduced structural changes in linkage isomers is investigated using Na₂[Fe(CN)₅NO] as a model complex. The buildup of the metastable side-on configuration of the NO ligand, as well as the electronic energy levels of ground, excited, and metastable states, has been revealed by means of time-resolved extreme UV (XUV) photoelectron spectroscopy in aqueous solution, aided by theoretical calculations. Evidence of a short-lived intermediate state in the isomerization process and its nature are discussed, finding that the complete isomerization process occurs in less than 240 fs after photoexcitation.