Electron Transfer‐Induced Coordination Changes in Organometallic Complexes with Noninnocent Hemilabile Ligands

Structure and Spectroelectrochemical Response of Arene–Ruthenium and Arene–Osmium Complexes with Potentially Hemilabile Noninnocent Ligands

“…In the crystallographically characterized (Table and Table S1 (Supporting Information), Figures – and Figures S1–S4 (Supporting Information)) neutral compounds 1 – 6 the metal exhibits a formal 16-valence-electron count. Such coordinative unsaturation was observed before for metal catecholate compounds of, e.g., Cr, W, Mn, Re, Rh, and Ir; ,,− it is attributable to the strong σ and π donation from the catecholate dianion. The bond parameters of the neutral compounds are very similar (Table ) and are well reproduced for 1 – 5 by DFT calculations (Tables S2 and S3 (Supporting Information)).…”

“…As noted earlier, , the oxidation of the complex may affect predominantly the noninnocent ligand (see below) but the fractional amount δ of the charge change at the metal results in additional coordination of the hemilabile ligand. The additional binding of the thio- and selenoether donors in systems 1 / 1 + and 3 / 3 + , respectively, appears reasonable but raises further questions: How does an O -ether function respond, are coordination situations comparable for solids and dissolved complexes, and which options are there in the absence of suitable complementary donor atoms within the noninnocent ligand?…”

“…8%) but non-negligible spin density transfer from the ligand to the metal as a crucial feature . Modifications including rhodium analogues and the effect of thioether/ether (S/O donor) substituent exchange were studied, using the noninnocent amidophenolate/iminosemiquinone/iminobenzoquinone redox systems as represented by o -iminosemiquinonate ligand intermediates Q SMe •– and Q OMe •– (see Chart ).…”