Infrared spectra amines

The progress of the photolysis can be followed either by observing the disappearance of the typical nitrite bands between 1600 and 1680cm (6.25 and 5.95 ju) in the infrared spectrum or by disappearance of the diphenyl-amine-sulfuric acid spot plate test. 

Medenwald suggests that the infrared spectrum of aminoaza-pyrene (238) favors the imino form. Di-(2-quinolyl) amine has been reported to exist in two modifications, one of which was the imino form 239, but this seems improbable. 

The reactions of arenediazonium ions with 7V-alkyl- or 7V-arylhydroxylamines were investigated by Bamberger (1920b, and earlier papers). Mitsuhashi et al. (1965) showed that the l,3-diaryl-3-hydroxytriazenes are tautomeric with 1,3-diaryltriazene-3-oxides (Scheme 6-16). Oxidation of 1,3-diaryltriazenes with peroxybenzoic acid in ether yields the same product as that from diazonium salts and TV-arylhydroxyl-amine. The infrared spectrum of the product obtained by coupling diazotized relabeled aniline with A/-phenylhydroxylamine indicates that the diaryltriazene-oxide is the preponderant tautomer. 

The infrared spectrum of erythromycin is commonly used for its identification. Figure 2 shows the spectrum of a 75 mg./ml. chloroform solution. The bands at 1685 and 1730 cm- are due to the ketone carbonyl and the lactone carbonyl, respectively. The absorption peaks between 1000 and 1200 cm-1 are due to the ethers and amine functions. The CH2 bending is evidenced by peaks between 1340 and 1460 cm-, and alkane stretching peaks appear between 2780 and 3020 cm-. Hydrogen bonded OH and water appear as bands between 3400 and 3700 cm-1. 

Amines (am) react with these bridged complexes to give mononuclear complexes of the type [RhX(am)(diene)] a similar complex is formed by triphenylphosphine, but not by triphenylarsine or diphenylsulphide. Cationic and anionic complexes of the type [Rh(diamine) (diene)]+ and [RhCl2(diene)] are readily formed. The stable acetate (XXVII X = OAc) is prepared from the corresponding chloride and potassium acetate its infrared spectrum indicates that each acetate group is symmetrically bound... 

The checkers observed, in two runs, that when w-butyralde-hyde is added after 10-15 minutes, the reaction is only mildly exothermic, and the white precipitate that forms does not dissolve. The infrared spectrum of the white crystalline product (19-20 g., m.p. 181-184° dec.) suggests that it may be the adduct of phenylhydroxylamine and N-phenylmaleimide formed by addition of the N—H bond of the amine to the olefinic bond of the imide however, the structure of the product was not further examined. 

Primary amines may be readily distinguished from secondary and tertiary analogues by the presence of two absorption bands in the infrared spectrum between 3320 and 3500 cm-1 (symmetric and antisymmetric NH str.). Secondary amines exhibit a single absorption band at about 3350 cm-1 (NH str.). In both cases deformation modes for the NH bond appear at about 1600 cm-1. There is no satisfactory absorption to allow a definitive characterisation in the case of tertiary amines. In the nuclear magnetic resonance spectrum of primary and secondary amines, the nitrogen-bound hydrogens are recognisable by their replaceability on the addition of deuterium oxide. 

The reaction with C02, as reported for the dried aminosilane polymer also occurs with immobilized aminosilane molecules. Culler43 reported that approximately half of the amine groups are reacting with C02 when silica samples modified with APTS in aqueous solution, are dried in air. Comparison with AEAPTS and a triaminosilane showed that only primary amines react with C02. The reaction product is evidenced by FTIR bands at 1630, 1575, 1488 and 1332 cm 1. Also after modification in dry conditions and drying at room temperature in humid air, the reaction with C02 may be observed. Characteristic infrared bands appear upon modification at high concentrations of APTS. Figure 9.32 shows the infrared spectrum of dry silica, modified with a 10% APTS/toluene solution, after air drying for 30 minutes. 

Infrared spectrum The IR shows a sharp peak around 3400 cm-1, possibly the N—H of an amine or the =C—H of a terminal alkyne. Because the MS suggests a nitrogen atom, and there is no other evidence for an alkyne (no C=C stretch around 2200 cm-1), the 3400 cm-1 absorption is probably an N — H bond. The unsaturated =C—H absorptions above 3000 cm-1, combined with an aromatic C = C stretch around 1600 cm-1, indicate an aromatic ring. 

Infrared spectrum of propan-1-amine. Note the characteristic N—H stretching absorptions at 3300 and 3400 cm-1. 

Fig. 1. The NH stretching region of the infrared spectrum of a 1.248M solution of diethyl-amine in a 1 1 mixture of CFCl a CFaBr—Cp2Br at difTerent temperatures. From M. C. Bcmard-Houplain, C. Bourdfcron, J. J. P6ton and C. San rfy, Chnn. Phys. Letters 11, 149 (1971). Reproduced with permission from the North-Holland Publishing Company...

The deacetylation of this product with sodium methoxide or hydroxyl-amine (mycolic acid esters react very slowly with hydroxylamine) gives, in rather low yield, a 6,6 -di-0-(3-hydroxy-x-methoxymycolanoyl)trehalose, m.p. 40-42°, [a]D -f 132°, CissHsvoOi 10 CH2 (9b), with an infrared spectrum identical with that of the natural cord-factor the biological activity of this compound was indistinguishable from that of natural cord-factor. ... 

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