Structure of the light-induced metastable state SII in Na2[Fe(CN)5NO]∙2H2O

Abstract

The structure of the light-induced metastable state SII of ${\mathrm{Na}}_2\left[\mathrm{Fe}{\left(\mathrm{C}\mathrm{N}\right)}_5\mathrm{N}\mathrm{O}\right]\bullet 2{\mathrm{H}}_2\mathrm{O}$ was investigated by single-crystal neutron diffraction. The population of SII of 16(3)% was determined by an in situ transmission measurement. The final structural refinement yields a side-on bonded configuration of NO in the metastable state SII with distances $\mathrm{Fe}\mathrm{O}$, $\mathrm{Fe}\mathrm{N}$, and $\mathrm{N}\mathrm{O}$ of $2.01\left(5\right)\mathrm{\AA }$, $1.96\left(5\right)\mathrm{\AA }$, and $1.11\left(8\right)\mathrm{\AA }$, respectively. The angle $\mathrm{Fe}\mathrm{N}\mathrm{O}$ is 77(4)°. The population determined from the refinement is 12(2)%, in good agreement with the value of 16(3)% determined from the independent in situ transmission measurement.