Electrochemistry of nickel(II) and copper(II) N,N′-ethylenebis(acetylacetoniminato) complexes and their electrocatalytic activity for reduction of carbon dioxide and carboxylic acid protons

Application of N,N′-ethylenebis(acetylacetoneiminato) Nickel (II) and Copper (II) Schiff Base Complexes as Acid–Base Sensing Materials and Indicators in Volumetric Titrations : Qualitative, Spectroscopic and Titrimetric Analyses

“…Similar to [Cu(L)], the spectral changes, upon adding HCl, are due to the different extent of [Ni(L)] protonation and Cl -association. These observations also support the hypothesis made regarding the differences in protonation of [Ni(L)] and similarities in electrocatalytic proton reduction by [Ni(L)] in trifluoroacetic acid and acetic acid[1].3.4 Colour and Spectroscopic Changes of Acidified[Ni(L)] in the Presence of Various Anions The UV-Vis spectral changes for [Ni(L)] complex on anion addition, are also similar to those for [Cu(L)]. Interestingly, no spectral changes were observed on the addition of anions (Cl -, Br -, I -, SCN -) as sodium or ammonium salts to a solution of [Ni(L)], if the solution was not preacidified with strong acid (pKa \ 2) (Figs.…”

“…1 H NMR spectra were obtained in MeOD-d 4 in the presence and absence of DCl using a 400 MHz Bruker DRX 400 spectrometer with a 5 mm broadband inverse probe and Z-gradients. Infrared (IR) spectra were recorded from NICOLET 6700 FT/IR spectrometer for dry KBr pellets of the complexes.…”

“…1 H NMR spectra were recorded for the complexes ([Cu(L)] and [Ni(L)]), dissolved in MeOD-d 4 , in the presence and absence of DCl.…”

“…N,N 0 -ethylenebis(acetylacetoneiminato) nickel (II) and copper (II) complexes (M(L)]) are well known as simple square planar Schiff base complexes, but the possible applications of these complexes have not been reported, except the recent publication on electrochemistry and electrocatalytic carbon dioxide reduction capacity of these complexes [1]. When we extended the electrocatalytic studies of [M(L)] complexes in the presence of different acids, surprisingly, it was always noticed that there was a reproducible change in the colour of the solution upon adding strong acid and base to alcoholic solutions of these complexes.…”

Ligand-Centered Electrochemical Processes Enable CO2 Reduction with a Nickel Bis(triazapentadienyl) Complex

“…An early kinetic study on the reduction of CO 2 indicates that the CO 2 anion radical initially forms (E° = -2.59 V vs. Fc +/0 , DMF), followed by (a) rapid bimolecular coupling to generate C 2 O 4 2or (b) sequential CO 2 /eaddition to produce equimolar amounts of CO and CO 3 2-. 16 More recently, several reported Mn, 17 Fe, [18][19] Ni, [20][21][22][23][24] and Cu [25][26] electrocatalysts have been developed, capable of reducing CO 2 into either C 2 O 4 2or CO/CO 3 2-in aprotic organic solvent. In particular, nickel-based electrocatalysts that convert CO 2 into CO/CO 3 2-or C 2 O 4 2are presented in Fig.…”