Ammonia-nitromethane complex

Fig 5. Illustration of structures on the potential surface for an Ammonia-Nitromethane complex... 

Perhaps the obvious extension of the methodology is to replace the ammonia nucleophile with the carbon nucleophile nitromethane. The reaction of [Co(en)3]3+ with formaldehyde and nitromethane in the presence of a base gives complex 7.15 (Fig. 7-14). Con-... 

Turi, L., and Dannenberg, J.J., Molecular orbital studies of the nitromethane-ammonia complex. An unusually strong C—H "N hydrogen bond, J. Phys. Chem. 99, 639-641 (1995). 

Sarcophaginates can also be prepared by template condensation of bis-triamine metal complexes with formaldehyde and nitromethane or ammonia. Macrotricyclic and macrotetracyclic complexes of different structures have simultaneously been formed [148, 149],... 

The use of ammonia instead of nitromethane in the template condensation with [Co(tame)2] cation gave the macro tricyclic [Co(azatrisartame)]3+ heptazasarcophaginate (yield ca 30%). Like its nitromethane analog, this complex is remarkably stable in aqueous hydrochloric acid. Furthermore, treatment of [Co(azatrisartame)] + cation with trifluoromethanesulphonic acid for several days resulted in a triimine complex (ca 80%) with a ruptured aza-cap, but the methylene units and the four-membered rings remained... 

When nitromethane is used as the capping agent instead of ammonia, either the interaction of the nitromethane anion with coordinated ethyleneimine or the addition of nitroethylene to deprotonated coordinated amine yields an intermediate nitroethyl complex. Nitroethylene is formed by a base-catalyzed condensation of nitromethane and formaldehyde. The experimental data suggest that the mechanism of formation of the nitroethyl complex via coordinated imine by Scheme 106 is favoured [101]. 

The saturated silver silver chloride electrode [Ag/Ag(Cl(s), KCl(s) E = 0.197 V versus NHE, E = —0.045 V versus SCE] is especially convenient as it can be constructed by placing a silver wire in a solution of saturated potassium chloride, separated from the test solution by an agar plug and a glass filter. An analogous electrode may be employed in certain nonaqueous solvents, e.g., nitromethane ]202], acetic acid [210], and DMF [211], but is does not work well in others, such as ammonia or acetonitrile [212], in which complexes are formed that cause the potential to drift. 

They then turned to the less hindered reagent trimethyloxonium fluoroborate in nitromethane and obtained the desired salt (3). The product is rearranged to (4) on treatment with n-butyllithium, and reduction with sodium in liquid ammonia gives the squalenelike hydrocarbon (5). Desulfurization with Raney nickel gives complex mixtures in the case of allylic sulfides. 

The first type of electrophoretic buffer (nitromethane-acetic acid, absolute ethanol-dimethylformamide, sucrose in anhydrous formamide) has been used for the separation of sterols, fatty acids, dyes, nucleotide phosphates and oligonucleotides. High voltage electrophoresis in liquid ammonia has been applied to the separation of complexes of inorganic cations [66-69]. 

Generally, the two main template strategies exploited are sides + caps and caps + sides [5], of which the first is used more extensively. Thus the cage-like systems L824 and L825 (Eq. 4.1) are isolated in 40-90% yield by reaction of ethane-1,2-diamine complexes containing these metals with formaldehyde and ammonia or nitromethane [6-11]. 

ABSTRACT Work has begun at RARDE to attempt to elucidate the complex chemistry of reacting explosives using molecular orbital calculations to describe possible potential energy surfaces for decomposition. The well-known sensitising effect of amines on nitromethane is modelled by studies of the nitromethane/ammonia system. The calculations lead to a new proposal for a mechanism for decomposition. This mechanism is supported by experimental data. 

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