Bonds to Nitrogen

Bonds to Nitrogen.—The chemistry of co-ordinated azides has been reviewed.  

J5T-Ray analysis has shown the compounds KNg, RbNa, CsNg, and TIN3 to be isostructural. They all crystallize in a tetragonal form of the CsCl type (space group lAlmcm) with unit-cell dimensions as indicated in Table 4. 

An electron-diffraction study of methyl azide, CH3N3, has provided the bond parameters listed in Table 5. Perhaps the most important point to note 

Prout and W. G. Sears, Imrg. Nuclear Chem. Letters, 1973, 9, 31. 

When equimolar amounts of a nitronium salt (NOjEFf) and an alkali-metal azide are mixed in an organic solvent (CCI4 or CHgCN) the resulting solution shows spectroscopic and chemical properties which are commensurate with the existence of nitryl azide, The pure compound was 

Bonds to Nitrogen.—Phosphorus (m) Compounds. From ab initio M.O. calculations on H2NPH2 the barrier to pyramidal inversion at phosphorus can be shown to be higher than that in phosphine.353 This is compatible with 

Steric effects and lone pair-lone pair repulsions appear to the most important contributors to the barrier to rotation about the P—N bond in the aminophosphines Me2NP(CF3)2, Me2NPCl(CF3), and Me2NPCI2.35 These conclusions are based on the results of recent lone-pair ionization-potential data obtained from photoelectron spectroscopy. 

An alternative route to the interesting two-co-ordinate phosphorus(m) compound (47) has been devised and follows equation (10).3,9a Contrary to the earlier report, the product appears to be stable at room temperature in daylight for long periods. On reaction with Me3SiN3, compound (47) gives 

An unusual ionic structure, [(Me2N)2P]+AlCl4, is assigned to the 1 1 adduct of aluminium chloride and bis(dimethylamino)chlorophosphine.361 The phosphorus atom in the cation is clearly shown to be again two-coordinate and to be involved in p -p bonding to nitrogen. 

The bicyclic diphosphine (52), on treatment with phosphorus(m) halides, breaks down via a monocyclic intermediate (53) to NN -bis(dihalogeno-phosphino)dimethylhydrazine (54) as shown in equation (ll).368 Imino-groups can be incorporated at each phosphorus atom of compound (52) by 

Shulz-Ekloff, K. Appell, D. Barcsel, W. Gellert, and W. Sarholz, Ber. Bunsengesellschaft phys. Chem., 1975, 79, 263. 

Second- and third-row Group VIII metals catalyse the decomposition of N3H at 323—363 K to give N2 and NH4N3. Metal-N-H surface sites appear to be intermediates in the catalysed decomposition. Fe, Co, and Ni react exothermically at ca. 373 K to give nitrides, which do not catalyse the decomposition, but this reaction provides the basis for a unique, low-temperature synthesis of these nitrides. Electronic absorption spectra indicate the formation of NH and NF2 intermediates in the pulse photolysis of N3H-N2F4 mixtures under adiabatic conditions. A reaction mechanism for the formation of these intermediates has been discussed.  

Alkyl halides gave 1,1-addition products with the N-silylated phosph(iii)azene as shown in equation (17), ° but with either silicon tetrachloride or tetrabromide there was formation of an intermediate 1,2-addition product, namely (Me3Si)2N-PX-N(SiX3)(SiMe3), which readily lost a molecule of halogeno-trimethylsilane, giving the PN2Si heterocycles (23). The final product of the 

Niecke, W. Flick, and S. Pohl, Angew. Chem. Intemat. Edn., 1976, 15, 309. 

A novel tetrazene which contains one phosphorus atom has recently been synthesized by the reaction shown in equation (18), the 2-phospha-l-tetrazene 

Cl2PNBu (SiMe3) + Me2NN(SiMe3)Li Me2N-N(SiMe3)P=NBu +LiCl + Me3SiCl (18) 

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Deuterium does not give a signal under the conditions of H NMR spectroscopy Thus replacement of a hydroxyl proton by deuterium leads to the disappearance of the OH peak of the alcohol Protons bonded to nitrogen and sulfur also undergo exchange with... 

Ammonium salts that have four alkyl groups bonded to nitrogen are called quaternary ammonium salts... 

NMR Similarly carbons that are bonded to nitrogen are more shielded than those bonded to oxygen as revealed by comparing the chemical shifts of methylamme and methanol... 

Saccharin was discovered at Johns Hopkins Uni versity in 1879 in the course of research on coal tar derivatives and is the oldest artificial sweetener In spite of Its name which comes from the Latin word for sugar saccharin bears no structural relationship to any sugar Nor is saccharin itself very soluble in wa ter The proton bonded to nitrogen however is fairly acidic and saccharin is normally marketed as its water soluble sodium or calcium salt Its earliest applications were not in weight control but as a... 

Xenon Bonded to Nitrogen. Several ligand groups form compounds containing xenon-nitrogen bonds (12). The first xenon-nitrogen... 

Several types of nitrogen substituents occur in known dye stmetures. The most useful are the acid-substituted alkyl N-substituents such as sulfopropyl, which provide desirable solubiUty and adsorption characteristics for practical cyanine and merocyanine sensitizers. Patents in this area are numerous. Other types of substituents include N-aryl groups, heterocycHc substituents, and complexes of dye bases with metal ions (iridium, platinum, zinc, copper, nickel). Heteroatom substituents directly bonded to nitrogen (N—O, N—NR2, N—OR) provide photochemically reactive dyes. 

Draw or build a molecular model of what you would expect to the most stable conformation of the piperidine derivative In which the hydro- gen bonded to nitrogen has been replaced by methyl. ... 

Lewis acid catalysts such as aluminum chloride and iron(III) halides also bond to nitrogen to strongly deactivate the ring toward Friedel-Crafts reactions and halogenation. 

The accessibility of the +4 and +6 oxidation states for sulfur and, to a lesser extent, selenium gives rise to both acyclic and cyclic molecules that have no parallels in N-O chemistry. Thus there is an extensive chemistry of chalcogen diimides RN=E=NR (E = S, Se, Te) (Section 10.4). In the case of Te these unsaturated molecules form dimeric structures reflecting the increasing reluctance for the heavier chalcogens to form multiple bonds to nitrogen. The acyclic molecule N=Sp3,... 

Mercury has a characteristic ability to form not only conventional ammine and amine complexes but also, by the displacement of hydrogen, direct covalent bonds to nitrogen, e.g. ... 

The two sulfonic acids, pyridine-3-sulfonic and sulfanilic (HL), react to form the Hg(I) compounds Hg2L2 with Hg2(N03)2 in H2O. In these derivatives in Hg atoms are bonded" to nitrogen atoms in L. 

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