N groups

Formaldehyde converts the basic NHj group into the neutral CH2 N group (Sorenson s reaction). 

Lactides, intermolecular cyclic esters, are named as heterocycles. Lactams and lactims, containing a —CO—NH— and —C(OH)=N— group, respectively, are named as heterocycles, but they may also be named with -lactam or -lactim in place of -olide. For example. 

Similarly, the —SOj—N= group as part of a ring is named by adding -sultam to the name of the hydrocarbon with the same number of carbon atoms. The —SOj— has priority over —N= for lowest-numbered locant. 

Asymmetric aryl isocyanate dimers, ia which the C=0 group of oae molecule reacts with the C=N group of another, have been postulated as labile iatermediates ia the formation of carbodiioiides (17) upoa heating isocyanates. 

Dyes. Sodium nitrite is a convenient source of nitrous acid in the nitrosation and diatozation of aromatic amines. When primary aromatic amines react with nitrous acid, the intermediate diamine salts are produced which, on coupling to amines, phenols, naphthols, and other compounds, form the important azo dyes (qv). The color center of the dye or pigment is the -N=N- group and attached groups modify the color. Many dyes and pigments (qv) have been manufactured with shades of the entire color spectmm. 

The pyra2olones may also be classified as a2o dyes siace each contains an —N=N— group. 

Phenyl isocyanate reacts with (82) to form (83) by ring enlargement (74JOC948). Reaction of oxaziridines with diphenylketene proceeds less obviously. Isolated products (84) and (85) contain only the R—N group of the starting material (69TL263). 

The eombination of aeid (-OH) and basie (-NH, -N(CH ), -N=N-) groups is also responsible for the properties of generated boron eomplexes. As a rule, sueh eompounds eomprise N B eoordination bond formed due to boron atom striving to eompensate the laek of eleetrons, and to the faet that nitrogen has a lone-eleetron pair on the other. 

Greenwood (1956) described the behaviour of an assembly of n groups of particles undergoing Ostwald ripening by solution-diffusion controlled transfer between particles according to a general relationship... 

Pure NI3 has not been isolated, but the structure of its well-known extremely shock-sensitive adduct with NH3 has been elucidated — a feat of considerable technical virtuosity.Unlike the volatile, soluble, molecular solid NCI3, the involatile, insoluble compound [Nl3.NH3] has a polymeric structure in which tetrahedral NI4 units are comer-linked into infinite chains of -N-I-N-I- (215 and 230 pm) which in turn are linked into sheets by I-I interactions (336 pm) in the c-direction in addition, one I of each NI4 unit is also loosely attached to an NH3 (253 pm) that projects into the space between the sheets of tetra-hedra. The stmcture resembles that of the linked Si04 units in chain metasilicates (p. 349). A further interesting feature is the presence of linear or almost linear N-I-N groupings which suggest the presence of 3-centre, 4-electron bonds (pp. 63, 64) characteristic of polyhalides and xenon halides (pp. 835-8, 897). 

Many heterocyclic compounds contain formally single-bonded P-N groups, the simplest being the cyc/o-diphosphazanes (X3PNR)2 and X(0,S)PNR 2. These contain P and have the structures shown in Fig. 12.22. A few... 

The first (white) product has been characterized by X-ray diffraction at —55° and features a linear F-Xe-N group and a planar N atom (Fig. 18.4). " ° On the basis of Raman and F nmr data, the cation of the final (pale yellow) product is believed to be essentially like the V-shaped [Xe2F3]+ cation but with the 2 terminal F atoms replaced by... 

The reaction series in which the N group is treated as a substituent. 

The Cg-amine, originally obtained by the methanolysis of kasugamycin, on treatment with lead tetraacetate or sodium periodate afforded a nitrile amine, with evolution of carbon dioxide, showing a maximum at 2200 cm.-1. This reaction is explained only by the structure (13). The -N-C=N group of the product can be formed by oxidative decarboxylation and can be easily rationalized by the present understanding of such reagents (2, 13) as shown below. On the other hand, the treatment... 

Pascal An SI unit of pressure the pressure exerted by the force of 1 newton on an area of 1 square meter, 104,635 Paschen series, 138 Pasteur, Louis, 601 Pauli exclusion principle, 141-143 Pauling, Linus, 185 Pentyl propionate, 596t Peptide linkage The—C—N—group... 

Our sincere appreciation goes to all the members of the K. C.N. group whose dedication, brilliance, and diverse ethnic background have made this group s contributions both possible and enjoyable. 

Trifluoroacetimidoyl chlorides reacted with compounds containing an active methylene group to give enamines that thermally cyclized in cumene to 2-trifluoromethylquinolines (89TL4821). With N.N -disubstituted trifluoroacetamidines, the N-group determined whether cyclization gave triazoles or quinazolones (90TL2717). 

The Os=N group has a strong frans-influence, reflected in both the labiliza-tion of the Irani-chloride (a similar reaction occurs with OsNBr3-) and in the pronounced lengthening of the fra s-Os-Cl bond (2.605 A versus 2.362 A). 

Phenols, alkali225, and some other substances226-228 serve as initiators of these reactions. In the case of poly(acrylonitrile) this role is played by a tertiary hydrogen which is activated by the C=N group. 

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