@b_schwederski

Noninnocence of Indigo: Dehydroindigo Anions as Bridging Electron-Donor Ligands in Diruthenium Complexes

, , , , , and . Inorganic Chemistry, 55 (6): 3105--3116 (2016)
DOI: 10.1021/acs.inorgchem.6b00038

Abstract

Complexes of singly or doubly deprotonated indigo (H2Ind) with one or two Ru(pap)22+ fragments (pap = 2-phenylazopyridine) were characterized exptl. mol. structure, voltammetry, EPR, and UV-visible-near-IR spectroelectrochem. and by time-dependent d. functional theory calcns. Ru(pap)2(HInd-)ClO4 (1ClO4) contains an intramol. NH...O hydrogen bond, whereas Ru(pap)22(m-Ind2-)(ClO4)2 (2(ClO4)2), isolated as the meso diastereoisomer with near-IR absorptions at 1162 and 991 nm, contains two metals bridged at 6.354 \AA distance by the bischelating indigo dianion. The spectroelectrochem. study of multiple reversible redn. and oxidn. processes of 2n (n = 4+, 3+, 2+, 1+, 0, 1-, 2-, 3-, 4-) reveals the stepwise addn. of electrons to the terminal p-accepting pap ligands, whereas the oxidns. occur predominantly at the anionic indigo ligand, producing an EPR-identified indigo radical intermediate and revealing the suitability of deprotonated indigo as a s- and p-donating bischelating bridge. on SciFinder(R)

Links and resources

Tags

community