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 (phi(363)approximate to 1.2%). Further, both cis and trans isomers of the photodechelated ligand-loss solvento intermediate [Os((2)-btz)(2)((1)-btz)(NCMe)](2+) are unambiguously observed and characterized by NMR spectroscopy and mass spectrometry.