Isolation and x-ray structure of a dinuclear copper-nitrosyl complex

Coordination chemistry of the HNO ligand with hemes and synthetic coordination complexes

“…Crystallographic characterization demonstrated that both had long N-O bonds (1.193 Å for the Fe complex and 1.211 Å for the Co) comparable to that in free HNO [132,17]. Similarly, a bridging NO À was obtained by reaction of NO + with a binuclear compound with Cu I in N 3 O ligation, used as models for the active site of Cu nitrous oxide reductases; the cationic product, ½Cu II 2 ðXYLÞðNO À Þ þ had a lower energy mNO at 1536 cm À1 but a much shorter N-O bond at 1.176 Å [133]. Another example of a bridging nitroxyl is found in [(Ir(COD)(Cl)(l-pz)) 2 ](NO À ), formed by several routes from Ir I precursors, which had a mNO of 1630 cm À1 [134].…”

“…Olabe [133]. Similarly, a nitroxyl adduct has been generated by the electrochemical reduction (E 1/2 ca.…”

A Peroxynitrite Dicopper Complex: Formation via Cu–NO and Cu–O2 Intermediates and Reactivity via O–O Cleavage Chemistry

“…31 In [Cu II 2 (XYL-O − )(NO − )] 2+ , the very low ν(N−O) value and structural aspects 31 of the complex indicate that a formal negative charge is located on the nitrosyl ligand; i.e., it is a nitroxyl-containing compound with a NO − moiety. 31 The considerably higher ν(N−O) value in 2 is thus more consistent with what is expected for a Cu I −NO (g) adduct (Figure 1a). …”

A peroxynitrite complex of copper: formation from a copper–nitrosyl complex, transformation to nitrite and exogenous phenol oxidative coupling or nitration

“…Here, key advances are described within a somewhat complementary chemical system: A new peroxynitrite complex, [Cu II (AN)(ONOO − )] + (see later), employs a tridentate and not a tetradentate ligand.In this new example, the synthesis instead begins with a copper–nitrosyl complex [2, 46–48], which is then exposed to O 2 .Density functional theory (DFT) calculations reveal that the nitrogen monoxide must dissociate from the Cu–NO moiety prior to Cu I /O 2 reaction and peroxynitrite formation.The new Cu II (O=NOO − ) species thermally transforms to a copper(II)–nitrito complex with evolution of O 2 . We observed this before with the thermal transformation of [(TMG 3 tren)Cu II (O=NOO − )] + ; yet this is another rather unusual case since most often peroxynitrite interacts with metal ions, leading to its isomerization to nitrate or effecting a substrate nitration.…”

“…In this new example, the synthesis instead begins with a copper–nitrosyl complex [2, 46–48], which is then exposed to O 2 .…”