Spectroscopic Characterization of Reaction Intermediates in a Model for Copper Nitrite Reductase

Abstract

A nitrous acid complex was identified by spectroscopic and kinetic analyses under stopped‐flow conditions as an intermediate in the reaction of copper(I) nitrite complex 1 with trifluoroacetic acid (see scheme). A reaction mechanism was proposed in which two protons are transferred in a stepwise manner to the nitrite anion. Intramolecular electron transfer from copper to the nitrite ligand occurs in the second protonation step.

An investigation into the unusual linkage isomerization and nitrite reduction activity of a novel tris(2-pyridyl) copper complex

“…The apparently rather simple active-site structure of CuNIR (a tripodal N-donor ligand which supports a copper centre undergoing a one-electron redox reaction) has led numerous groups of coordination chemists to attempt the synthesis of functional analogues of this enzyme [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Most of these complexes bind only one molecule of nitrite, but Woollard-Shore et al [20] have reported two examples where two nitrite molecules are bound to a single Cu centre.…”

Nitrite reduction by copper through ligand-mediated proton and electron transfer

“…While select systems have been shown to produce NO from a copper( i ) nitrite complex, 1c , 13 the mechanism by which these reactions proceed are often not fully resolved, thus precluding direct mechanistic comparisons to CuNiR. One reason for limited mechanistic insight has been the isolation of terminal copper( ii ) complexes which do not contain the inorganic products of nitrite reduction ( i.e.…”

Simultaneous Gas Storage and Catalytic Gas Production Using Zeolites—A New Concept for Extending Lifetime Gas Delivery

“…From many studies in solution and in polymers it is well known that the active metal for this reaction is Cu(I) [38][39][40]. Activity for the nitrite to NO reaction is in fact a rather sensitive test for the presence of Cu(I).…”

“…This occurs in bacterial nitrite reductase enzymes [37] and also in solution state [38,39] and polymer-bound models for this reaction [40]. Combining these two methods, gas storage and catalytic gas production, has the potential to significantly increase the lifetime of a gas delivery material beyond what is possible with gas storage alone.…”