Aromatic polyimides as charge transfer complexes

High pressure visible spectroscopy of polyimide film

“…Studies of low molecular weight model imides supported this assumption (1 ), and spectroscopic examination of a series of polyimides indicated the presence of a low energy transition which was dependent upon the ionization potential of the diamine segment in the polymer backbone (2,3). One of the more interesting ramifications of this work has been the use of the charge transfer complex hypothesis to explain and predict structureproperty relationships of polyimides (4,5).…”

Thermo-oxidatively stable polyimides and their chemical structures

“…The B and C contained ether and carbonyl moieties in improved thermo-oxidative stability of the ethercarbonyl polyimide structure over the all ether or all carbonyl structures may also be explained by the formation of a change transfer complex (CT-complex) 22 caused by intermolecular charge transfer between the ether moiety and carbonyl moiety as shown in Figure 4. E-J were synthesized from diamines having both ether and carbonyl moieties in their chemical structures and commercially available tetracarboxylic dianhydrides such as PMDA, BTDA, and ODPA.…”

Absorption and Fluorescence Spectra and Thermal Properties of Novel Transparent Polyimides.

“…It is widely accepted that inter-and intramolecular charge transfer [1][2][3] are formed between imide moieties and diamine moieties in the usual aromatic polyimides which result in the coloration of poly im ides [4,5]. In recent years, with the demand of optical communication [6], liquid crystal display devices [7,8], transparent polyimides have become very important.…”