Nucleophilic attacks dinitrogen

Whereas heating [Pt(terpy)(N3)]+ in the gas phase gives dinitrogen, heating in solution in acetonitrile or benzonitrile gives the tetrazolato complexes 14 (R = Me, Ph), presumably by nucleophilic attack by RCN at coordinated azide and subsequent closure of the N4C ring (401). 

Finally, the idea of the coupling between nucleophilic attack and proton transfer in the reaetions just discussed provides an interpretive framework for another important atmospheric reaction, namely the hydrolysis of dinitrogen pentoxide N2O5, thought to play an important role in mid-latitude global ozone depletion. 28,29 Indeed a related mechanism was suggested in ref 5 for the low acidify condition hydrolysis. 

The ligand NNR has been referred to as alkyl- or arylazo, diazo, or diazenato, but diazenido is preferred. The aryl compounds are commonest they can be obtained from diazonium compounds (ArN2) and from hydrazines such as PhNNH2 or ArC(0)NNH. They are also formed by electrophilic or nucleophilic attacks on dinitrogen compounds, for example,... 

Diazomethylenephosphorane 21 can also be used as a synthetic equivalent of "naked carbon". Indeed, when a toluene solution of 21 was heated (70°C) in the presence of excess elemental sulfur, the chlorophosphine was obtained along with CS2 (88 % yield). Carbon disulfide formally results from the trapping of naked carbon by sulfur. However, it is quite clear that the first step of the reaction is the nucleophilic attack of the ylidic carbon at sulfur, as observed in the reaction of elemental sulfur with Wittig ylides. The transient adduct 22 could then eliminate the chlorophosphine, giving the thioxodiazomethane 23 which finally reacts with sulfur with loss of dinitrogen (Scheme 9). 

At this point, it only remains to report on an alternative synthesis for nitride clusters Equation (3.33), which is based on a different approach as the previously described cleavage of NO. A nucleophilic attack by Nj on coordinated CO followed by the elimination of dinitrogen will generate a coordinated isocyanate ligand. The subsequent step to form the nitride is based on the observation that the preformed [Ru4(CO)i3(NCO)]" isocyanate substituted carbonyl cluster slowly converts into the [Ru4(m4-N)(CO)i2] nitride derivative on standing in solution. [268, 363]... 

SeUmann D, Weiss W. The first reaction of the N2 hgand with bases reduction of coordinated dinitrogen by nucleophilic attack. Angew Chem Ini Ed Engl. 1977 16 880-881. 

The reactions of [W(N2)2(diphos)2] with RBr are clearly catalyzed by visible light. The homolytic fission of the R— Br bond that takes place at the metal center is preceded by the loss of one N2 molecule. The resulting C—bond is formed by an alkyl radical attack on the remaining coordinated dinitrogen. Product distribution in these photocatalyzed reactions depends on the solvent and the stability of the free radical. This mechanism is strongly supported by flash photolysis experiments. When gem-dibromides are used in the photo-catalyzed reaction, diazoalkanes are produced. With CH2Br2 for example, the diazomethane complex [WBr(diphos)2(N2CH2)]Br is obtained. More recently it has been shown that some of the diazoalkanes do not react with protonic acids, but that the unique carbon atom is attacked by nucleophiles such as MeLi to yield diazenido complexes. ... 

Cyclopentadienyl Carbonyl and Related Complexes.—Successive attack of CHs and CH3+ on [CpMn(CO)2(N2>] yields the azomethane complex [CpMn(CO>2 N-(Me)=NMe ], which can also be synthesized by oxidation of [CpMn(CO)2 MeN-(H)NHMe ]. Similar nucleophilic and electrophilic attacks on the dinitrogen complex using Ph and H+ gives [CpMn(CO)a N(Ph)=NH ]. The pyrrolyl nitrogen atom of [(> -C4H4N)Mn(CO)3] acts as a donor in the formation of the complexes [(OC)3Mn( -C4H4N)M(CO)2Cp] (M = Mn or Re).i The adducts RsP.CSa (R=Bu or Cy) have been assessed as reagents for the preparation of thiocarbonyl complexes. Unfortunately reactions such as [CpMn(CO)2(as-cyclo-octene)] with R3P,CSa lead mainly to [CpMn(CO)2(PR3)] with very low yields of [CpMn(CO)2(CS)].i ... 

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