Nitrogen complexes reactions

NO formation occurs by a complex reaction network of over 100 free-radical reactions, and is highly dependent on the form of nitrogen in the waste. Nitro-compounds form NO2 first, and then NO, approaching equiHbrium from the oxidized side. Amines form cyano intermediates on their way to NO, approaching equiHbrium from the reduced side. Using air as the oxidant, NO also forms from N2 and O2. This last is known as thermal NO. ... 

Nitration. Because nitration frequentiy generates nitrogen oxides which can participate in oxidative transformations, the nitration of indole itself is a complex reaction. In strongly acidic media, the nitration of 2-substituted indoles can proceed through the conjugate acid (8). Because the aromatic system is thereby transformed to an a2astyrene, the 5-position is the primary site of reaction. 

If, however, the 7-position is blocked by a methyl group, then a more complex reaction ensues involving ring contraction, methyl migration and loss of the nitrogen function to give 4,6.6-trimethyl-2,3,5-triphenylcyclohexa-2,4-dienone (12% mp 198 C) and other unidentified... 

Aminomethylphosphines are convenient objects for a comparison of phosphorus and nitrogen donor ability in complexation reactions. Coordination compounds of heterocyclic aminomethylphosphines with metals are discussed in Section VII. In this section we present reactions of aminomethylphosphines with boranes (BH3). 

A germanium-nitrogen complex containing two Ge atoms disposed in an acyclic array was obtained via the formation of the intermediate germylene [(Me3Si)2N]GeCl, which was converted into a germanium(iv) adduct via an insertion reaction (Scheme 19).157... 

Interest in metal complexes able to bind molecular dinitrogen is mainly due to a desire to understand and reproduce in the laboratory the so-called nitrogen fixation reaction. This process, which in nature is catalysed by the metalloprotein nitrogenases, reduces the inert dinitrogen molecule to the metabolically useful NH3 ... 

A transition metal complex such as bpyNi(COD), generalized as LjNi, reacts with NCA in a complex reaction sequence that generates a propagating species XLV whose active center is a 5-membered amido-amidate metallacyclic complex. Propagation involves a nucleophilic attack by the amido nitrogen of the amido-amidate at the C-5 carbonyl of NCA. The... 

The reaction is exothermic, hence the highest equilibrium yield is obtained at low temperatures and high pressures. The catalyst functions by inducing the formation of a nitrogen complex with the catalyst surface this complex is far more readily hydrogenated to NH3 than is nitrogen with its triple bond (Somorjai and Salmeron, 1986). 

NADH reaction, 46 526 nitrogen complexes, 46 505-506 oxidation, 46 511-519 reduction, enzymatic, 46 524-525 reduction, nonenzymatic, 46 525-526 small ligands, 46 506-507 Fe(IV)=0... 

Another arylation method, in the case of nitrogen heterocycles, does not need a halogenated derivative but a heterocycle activated by triflic anhydride260,261 (reaction 22). Simple aryl halides usually do not react with phosphines and special methods therefore have to be used for their arylation. The most widely used is the complex salt method , in which an aryl halide is heated with a phosphine in the presence of a transition metal such as nickel (II)2e (reaction 23). The catalytic cycle probably takes place by means of a reduced nickel(I) complex, generated in situ from the starting nickel(II) salt this nickel(I) species could undergo an oxidative addition of the aryl halide to yield a transient nickel(III) adduct, which after the reductive elimination of the aryphosphonium affords the recovery of the first active-nickel(I) complex (reaction 24). 

In a mechanistically similar process, the neutral palladium(II) dipyridylamine complex (24), obtained by deprotonation of complex (23), underwent reaction with benzoyl chloride to give the substituted complex (25) together with some free ligand (Scheme 8).33 This particular reaction sequence could not be generalized because of the relative instability of other metal complexes related to compound (24). However, a more extensive series of electrophilic substitutions could be carried out on the neutral complex (26), which displayed ambident nucleophilic behaviour by reaction with benzyl chloride and benzoyl chloride at nitrogen and reaction with benzenediazonium fluoroborate at carbon (Scheme 9). 

---