Revisiting ruthenium scorpionate chemistry : reactivity of bis(3,5-dimethylpyrazol-1-yl)acetic acid toward organoruthenium(II) precursorsRebernik Gracej, Mihaela (Avtor) Kitanovski, Nives (Avtor) Kjun, Jakob (Avtor) rutheniumscorpionate ligandp-cymene complexcrystal structureThe reactivity of the scorpionate ligand bis(3,5-dimethylpyrazol-1-yl)acetic acid (L1H) toward organoruthenium(II) precursors was investigated. Reactions of chlorido and bromido $p$-cymene ruthenium dimers afforded the corresponding complexes in which L1H acts as a neutral κ$^2$-N,N' donor. In the presence of acetonitrile and base, ligand deprotonation was accompanied by displacement of the $p$-cymene ligand, yielding a tris(acetonitrile)ruthenium(II) complex containing a κ$^3$-N,N',O-coordinated scorpionate ligand. Under ethanol-containing reaction conditions, in situ esterification of the coordinated carboxylic acid group was observed, yielding crystals of a new ruthenium complex 4 containing the ethyl ester derivative of the ligand. The compounds 1–3 were characterized by NMR, IR, HRMS, while the crystal structures of compounds 1·H$_2$O, 3·MeOH, and 4 were determined by single-crystal X-ray diffraction. The results demonstrate the influence of reaction conditions on the coordination mode and transformation of bis(pyrazolyl)acetate ligands in ruthenium chemistry.20262026-08-18 10:47:02Neznano185689sl