Related Experiment Video
Updated: Jul 16, 2025
Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
Interrelations between Linkage Isomers of an Efficient Square-planar Nickel(II) Nitrite Photoswitch in the Solid
Kinga Potempa1, Krystyna A Deresz1, Joanna Jankowska1,2
1Department of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland.
Abstract:
An efficient nitrite nickel(II) photoswitch, with the 1-phenyl-2-hydroxyimino-3-[(2'-dimethylamino)ethyl]imino-1-propanone moiety used as the ancillary ligand, is reported. In the ground-state ('dark') crystal structure, the studied compound exists predominantly as the nitro-(η1 -N(O)2 ) isomer, however, traces of the exo- and endo-nitrito-(η1 -ONO) forms are detected both at 100 K (4-5 % each) and under ambient conditions (~9 % each). When excited with the 405-530 nm LED light, the nitro-to-nitrito isomerization takes place. The total conversion exceeds 90 %. The exo-nitrito linkage isomer constitutes the dominant photo-generated form, whereas the relative population of both nitrito species depends on temperature. The reaction is fully reversible and reproducible. The photo-products are stable up to 200 K. The system constitutes a good model case for the reaction mechanism studies. Thus, experimental and theoretical investigations on the photo-isomerism were conducted and are presented in detail. Eventually, the nitro→exo-nitrito→endo-nitrito reaction pathway is proposed.
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