Containing More than One Nitrogen Atom

Compounds Containing More Than One Nitrogen Atom 

Only ring carbonyl derivatives of naphthyridines have been nitrated. The products 11.84-11.87 were obtained in high yield (75%) from the corresponding precursors (56JCS212 60JCS1794 72G253), with substitution occurring at the expected sites. 

With acetyl nitrate, the 1,10- (11.90) and 4,7-phenanthrolines (11.91) gave the 3- and 2-nitro products, respectively this was attributed to an addition-elimination mechanism (73RC2255), though it is possible here that direct nitration occurs on the free base. Nitration of 3,4-dihydro-4-methyl-3-oxo-4,7-phenanthroline (11.92) occurs in the 2-position (58-JCS825). This is the site that can conjugate with the nitrogen lone pair and substitution there involves the least interruption of benzenoid character in the transition state. 

Quinazoline (11.16) nitrates in the 6-position, and because theoretical calculations predict 8- 6-substitution (the 5- and 7-positions are each conjugatively deactivated by both nitrogens), it has been assumed that reaction must involve the hydrated quinazolinium cation (11.93) (47JOC405 49JCS1367). However, these calculations may not take sufficient account of inductive deactivation of the 8-position the deficiency of the calculations in this respect will be particularly marked if no auxiliary inductive parameter is used for the bridgehead carbon between the 1- and 8-positions. 

Variation in Isomer Distribution with Acidity in Nitration of Cinnoune  

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Many azamacrocycles, like cyclam [2] for instance, contain more than one nitrogen atom and therefore possess more than one pK. Therefore, in the discussion of the basicity of these compounds, it is not only the in- and OMt-orientation of the lone pair or the proton, respectively, that has to be considered. There is also an influence of the first on the second, third, etc. protonation. The developing Coulomb repulsions are very sensitive to the charge separation. In 15-membered rings this phenomenon has been investigated in detail (Arnaud-Neu et al., 1979). 

Some examples of nitrogen-containing heterocyclic compounds containing more than one nitrogen atom. 

B. Compounds Containing More Than One Nitrogen Atom... 

If the nucleus contains more than one nitrogen atom, the nucleus would be reduced at a less negative potential than the double bond no reports of electrolysis of such compounds have been published yet. 

When the heterocyclic ring contains more than one nitrogen atom, the initial reduction of the A-oxide may take place in the nucleus, or the reduction of the nucleus and the A-oxide function occurs simultaneously. The reduction of quinazoline-3-oxide,166 3-methoxy-2,5-... 

Morphine, also known as ascocaine, is also an addictive substance. The diacetate salt of morphine, heroin, is as addictive as morphine and cocaine. Many different alkaloids, such as nicotine and quinine, contain more than one nitrogen atom in their structure. Quinine is used in medicine to cure the disease malaria. Nicotine is a colorless, poisonous alkaloid present in large amounts in tobacco. As it is highly toxic, its salts are used as insecticides. 

Macallum reported that polymers prepared in this manner generally contained more than one sulfur atom per repeat unit (x in the range 1.0-1.3) (2). In addition the polymerization reaction was highly exothermic and difficult to control even on a small scale (3). Later Lenz and co-workers at Dow reported another synthesis of PPS (4,5,6) based on a nucleophilic substitution reaction involving the self-condensation of materials such as copper p-bromothiophenoxide. The reaction was carried out at 200-250°C under nitrogen in the solid state or in the presence of a reaction medium such as pyridine. It was quite difficult to remove the by-product, copper bromide, from polymers made by this process (7). These and other methods of polymerization have been reviewed by Smith (8). Polyphenylene sulfide resins have been described more recently by Short and Hill (9). 

There are very few thennochernical data for five-membered hetero-aromatics containing more than one hetero atom, and these are confined to nitrogen compounds. The heats of formation of gaseous imidazole, Fig. 12 (J), and pyrazole (//), have been derived... 

Heterocycle (Sections 15.5, 24.9) A cyclic molecule w hose ring contains more than one kind of atom. l or example, pyridine is a heterocycle that contains five carbon atoms and one nitrogen atom in its ring. 

Macrocycles containing nitrogen or sulfur atoms (e.g., 16 and 17) have similar properties, as do those containing more than one kind of hetero atom (e.g., 18, 19, or 20. ) Bicyclic molecules like 19 can surround the enclosed ion... 

This chapter provides an update of Chapter 8.33 in CHEC-II(1996) <1996CHEC-II(8)863>. The work carried out on the bicyclic ring systems with ring junction P, As, Sb, or Bi has focused primarily on phosphorus. Very little work has been done on the other heteroatoms and as such the synthesis and reactivity of these compounds have been reviewed as one section, Section 12.12.7. Most of the compounds in this class contain more than one heteroatom, the additional atoms usually being oxygen and nitrogen. 

Some ligands contain more than one atom that can function as an electron pair donor. For example, SCN is known to bond to some metal ions through the nitrogen atom but to others through the sulfur atom. In some instances, this situation is indicated in the name as thiocyanato-N- and... 

The simultaneous formation of 8 and 9 results in a situation in which all copper(I) ions are tetracoordinate and all of the ligands nitrogen atoms are bound to copper centers. Any other structures formed from this mixture of subcomponents would either contain more than one metal center (entropically disfavored) or have unsatisfied valences at either metal or ligand (enthalpically disfavored). 

In these nitrogen is the donor atom, and in most NO is bound as NO+ which is isoelectronic with CN and CO. The NO group can thus donate one extra electron to the metal this accounts for the stability of Co(NO)(CO)3 which has the same electronic pattern as Ni(CO)4 (p. 494). Co-ordination complexes of this type do not usually contain more than one NO group and they are generally of outer orbital (sp ) type (p. 134). 

Depending on the complex structure of the adsorbate molecule, simple atoms or spherical molecules can be assumed to behave as one-center interaction particle, i.e., they contain only one interaction site that involves in the interaction with the other atoms or molecules. Some adsorbates such as nitrogen and carbon dioxide contain more than one interaction site on each molecule. 

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