Coordination of NO2- ligand to Cu(I) ion in an O,O-bidentate fashion that evolves NO gas upon protonation: a model reaction relevant to the denitrification process

[(2,6-(Ph2P(o-C6H4)CH=N)(2)C5H3N)(2)Cu-2](BF4)(2) (2) has been prepared by treating 2,6-(Ph2P(o-C6H4) CHQN)(2)C5H3N (1) with [Cu(NCMe)(4)]BF4. Reaction of 2 and [Ph3PNPPh3]NO2 produces (2,6-(Ph2P(o-C6H4) CHQN)(2)C5H3N) Cu(NO2) (3), with the nitrite ligand in a unique eta(2)-O,O coordination mode. Protonation of 3 releases NO gas, which mimics the reactivity of the Type 2 Cu-NiRs.