Nitric oxide generation study of unsymmetrical β-diketiminato copper(ii) nitrite complexes

Abstract

The β-diketiminato copper(II) L1CuCl−L4CuCl and their nitrite complexes L1Cu(O2N) and L2Cu(O2N) has been synthesized and characterized. The X-ray structure of the L1CuCl−L4CuCl complexes clearly indicates towards the mononuclear structure with...

A Copper(II)‐Nitrite Complex Hydrogen‐Bonded to a Protonated Amine in the Second‐Coordination‐Sphere

“…Structurally characterized copper(II)-nitrite complexes typically exhibit k 2 -O,O' or k 1 -O binding modes of nitrite, whereas copper(I)-nitrite favors the k 1 -N binding mode (Figure 1). [17][18][19][20] Chemical and electrochemical reductions of isolated [Cu II ](k 2 -O,O'-nitrite) complexes have been demonstrated to flip the nitrite binding mode to k 1 -N. [21,22] Moreover, electrocatalytic reduction of nitrite to NO at copper(II) sites have been demonstrated in the recent past. [23,24] Examples of NO release from [Cu I ]-nitrite are well known under acidic conditions.…”

“…[35] [Cu II ]-nitrite complexes have been shown to react with Ph 3 P forming NO and Ph 3 PO through oxygen-atom-transfer pathway. [19,20,36,37] Electron deficient diketiminato [Cu II ](k 2 -O 2 N) complexe undergoes facile nucleophilic attack by thiol, alcohol, and amine, thereby resulting in nitrosation of the nucleophiles and [Cu II ]À OH. [38] Tricopper(II) nitrite complexes also catalyze nitrite reduction by thiol to afford NO and disulfide.…”

“…L‐ascorbic acid has been employed to reduce nitrite to NO and N 2 O at tripodal copper(II) sites [35] . [Cu II ]‐nitrite complexes have been shown to react with Ph 3 P forming NO and Ph 3 PO through oxygen‐atom‐transfer pathway [19,20,36,37] . Electron deficient diketiminato [Cu II ]( κ 2 ‐O 2 N) complexe undergoes facile nucleophilic attack by thiol, alcohol, and amine, thereby resulting in nitrosation of the nucleophiles and [Cu II ]−OH [38] .…”

An investigation on catalytic nitrite reduction reaction by bioinspired CuII complexes

“…Recently, a series of β-diketiminato Cu II -nitrito complexes reacted with thiol, and PPh 3 and CNAr also converted nitrite to NO (g) through an oxygen atom transfer reaction. [34][35][36][37] A Cu II complex bearing a proton-responsive outer coordination sphere ligand reported the phenol-mediated reduction which could convert nitrite to NO (g) . 38 These Cu I -nitro and Cu II -nitrito complexes are good bioinspired compounds and allow chemists to understand each step of the nitrite reduction mechanism; however, the catalytic aspects of copper-mediated nitrite reductions are rare, although there are a number of studies on bioinspired electro-catalysts used for nitrite reduction.…”

“…Recently, a series of β-diketiminato Cu II -nitrito complexes reacted with thiol, and PPh 3 and CNAr also converted nitrite to NO (g) through an oxygen atom transfer reaction. 34–37 A Cu II complex bearing a proton-responsive outer coordination sphere ligand reported the phenol-mediated reduction which could convert nitrite to NO (g) . 38…”