Imides


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Imides

 

compounds having two acyl groups linked to an NH group. Open chain and cyclic imides are known. The latter are the most important ; they are derivatives of dibasic acids, for example, phthalimide (I; melting point, 233.5°-238°C), succini-mide (II; melting point, 125°-127°C), and the imide of o-sul-fobenzoic acid (III; saccharin, melting point, 226°-230°C):

Cyclic imides are obtained by the action of ammonia on the anhydrides of dibasic acids or by the heating of various derivatives of these acids, for example, ammonium salts or amides. Unlike amides, imides are quite devoid of basic properties and are weak acids. The hydrogen atom in the imino group is easily replaced by an atom of a metal or halogen. The metal salts and N-bromo derivatives of cyclic imides (for example, potassium phthalimide, N-bromosuccinimide) are widely used in organic synthesis. [10–417-1 ]

References in periodicals archive ?
The hydrogen-bonded imides of BPOB-1, BPOB-2 and BPOB-3 are calculated to be about 27%, displaying a slight increase with increasing ODA content, which is suggested to be caused by the slightly decrease of the "free" C=O due to the ether group in ODA moiety.
When SMA imide resins were used as coagulants with chemical recycled pulp and TMP, the retention of fines and fillers was measured to be high.
1]): 1780 (C=O of imide ring and COCI), 1720 (C=O of imide ring), 1600 (aromatic), 1390 (C--N), 1210 and 1180 ([CF.
The IR spectra of the polymers exhibit strong imide absorption bands in the ranges of 1786-1777 [cm.
The coating of SMI-1 shows some larger defects than SMI-2, related to coating strength and imide content.
1] due to symmetric and asymmetric stretching of C = O in the five membered imide ring indicates that the imide ring remained intact in the polymerization.
FT-IR spectra of these PEIs revealed the characteristic absorptions of imide and ester groups at 1777 and 1718 [cm.
It can be contributed to imide bond in PUI, which is difficult to decompose at high temperature [36].
1]) 610 Monosubstituted benzene deformation 645 C-O-C bonding 730 C-H vibration 753 Aromatic imide ring in dianhydride part 820 C-H vibration 852 Diamine nut; breathing 1124 C-N-C transverse vibration (imide III) 1272 C-O-C backbone 1395 C-N-C axial vibration (imide II) 1513 C=C bonding in the aromatic phenylene ring 1601 Ring vibration of carboxylic acid 1612 Aromatic imide ring in dianhydride part 1786 C-O asymmetric stretch (imide I)
The characteristic bands for imide rings at 1775, 1716, 1380, and 742 [cm.
As we know, the characteristic absorption bands of imide rings are 1778 c[m.
1] correspond to the C=O asymmetrical and symmetrical stretching of aromatic imide ring, respectively, and the peaks at 1365 [cm.