Kinetics of the electroreduction of tris(acetylacetonato)chromium(III) in nonaqueous solvents

Spectroelectrochemistry of Vanadium Acetylacetonate and Chromium Acetylacetonate for Symmetric Nonaqueous Flow Batteries

“…3 solutions in acetonitrile, assuming a mechanism for Reaction 1 with a = b = 1. 15 If a reaction with b/a = 2/3 is assumed when processing the data, consistent with Reaction 7, the diffusivity of Urbancyzyk and colleagues would become 2.7 × 10 -5 cm 2 s -1 , in close agreement with the present result. Given the evidence of ligand dissociation and the mechanistic complications arising from the presence of more than one reduction product, LSV and UV-visible absorbance measurements cannot eliminate the possibility that more than one acac -ligand dissociates from the Cr[III] center in Reaction 7.…”

“…Experimental efforts to clarify the electrochemistry of Cr(acac) 3 have been challenging because the reaction mechanism apparently varies with the choices of solvent, supporting electrolyte, and working electrode. [13][14][15][16][17] The literature describing nonaqueous Cr(acac) 3 electrochemistry does not provide a consensus about the mechanisms for either the first reduction or first oxidation of the neutral complex. The electrochemical response during reduction depends heavily upon solvent, with different behavior observed in dimethylsulfoxide, 13,15,18,19 N,N-dimethylformamide, 15 dichloromethane, 14 acetonitrile, 15,17,20 and others.…”

“…[13][14][15][16][17] The literature describing nonaqueous Cr(acac) 3 electrochemistry does not provide a consensus about the mechanisms for either the first reduction or first oxidation of the neutral complex. The electrochemical response during reduction depends heavily upon solvent, with different behavior observed in dimethylsulfoxide, 13,15,18,19 N,N-dimethylformamide, 15 dichloromethane, 14 acetonitrile, 15,17,20 and others. 15 Various mechanisms have been proposed for the first reduction, but the first oxidation mechanism has only received significant attention since Cr(acac) 3 was proposed for nonaqueous RFB applications.…”

“…The electrochemical response during reduction depends heavily upon solvent, with different behavior observed in dimethylsulfoxide, 13,15,18,19 N,N-dimethylformamide, 15 dichloromethane, 14 acetonitrile, 15,17,20 and others. 15 Various mechanisms have been proposed for the first reduction, but the first oxidation mechanism has only received significant attention since Cr(acac) 3 was proposed for nonaqueous RFB applications. 3,21 Most reports of Cr(acac) 3 electrochemistry describe experiments performed with Hg electrodes, which have been observed to form complexes with acac -ions.…”

Electroorganic reactions. Part 55.† Quinodimethane chemistry. Part 3. Transition metal complexes as inter- and intra-molecular redox catalysts for the electrosynthesis of poly(p-xylylene) (PPX) polymers and oligomers‡

“…It is reported 22 that cyclic voltammetry of Cr III (acac) 3 (acac = acetylacetonato) gives three cathodic waves with the first one reversible only in the presence of a 40-fold excess of Me 4 N(acac). It was proposed that dissociation is coupled to electron transfer (Scheme 1).…”