Labilizing the Photoinert: Extraordinarily Facile Photochemical Ligand Ejection in an [Os(N^N)3]2+ Complex

Whilst [Os(N^N)3]2+ complexes are supposed to be photochemically inert to ligand loss, the complex [Os(btz)3]2+ (btz=1,1′-dibenzyl-4,4′-bi-1,2,3-triazolyl) undergoes unprecedented photolytic reactivity to liberate free btz (Φ363≈1.2 %). Further, both cis and trans isomers of the photodechelated ligand-loss solvento intermediate [Os(κ2-btz)2(κ1-btz)(NCMe)]2+ are unambiguously observed and characterized by NMR spectroscopy and mass spectrometry.