SYNTHETIC METHODS, PROPERTIES AND APPLICATION OF CONDENSATION PRODUCTS OF 1,8-NAPHTHALIC ANHYDRIDES WITH 1,2-DIAMINES (A REVIEW)

Abstract

The literary data concerning preparation methods and spectral properties of cyclocondensation products of 1,8-naphthalic anhydrides with aromatic and aliphatic 1,2-diamines and their use as luminescent materials have been summarized. The reaction of 1,8-naphthalic anhydrides with ortho-phenylenediamine results in the formation of 1,8-naphthoylene-1’,2’-benzimidazoles, which are widely used as materials for luminescent flaw detection, for synthesis of polymers with luminescent color, in organic light emitting diodes, as luminescent sensors for cations of various metals. Moreover, their cytotoxic activity is studied in relation to cells of various tumors. Acenaphthoquinone or 8-formyl-1-naphthoic acid can also be used as starting materials for synthesis of 1,8-naphthoylene-1’,2’-benzimidazoles. The spectral properties of 1,8-naphthoylene-1’,2’-benzimidazoles can be varied by the substituent introduction to naphthalene or/and phenyl moieties leading to luminescent materials with blue, green-yellow or red luminescence. Reaction of 4-substituted naphthalic anhydrides with o-phenylenediamine results in mixture of two constitutional isomers due to nonequivalence of two carbonyl groups in starting anhydride. The isomer ratio remains unchanged provided that syntheses are carried out under the same conditions, therefore the luminescent properties of such isomer mixtures are constant. 1,8-Naphthoylene-1’,2’-benzimidazoles with electron donating groups in positions 4 or 5 of naphthalene ring can be successfully obtained by nucleophilic aromatic substitution of halogen by amine or alcoholate. The introduction of electron donating substituents to positions 4 or 5 of naphthalene ring results in bathochromic shift of absorption and emission maxima compared to unsubstituted 1,8-naphthoylene-1’,2’-benzimidazole, corresponding shift is 10-20 nm larger for 5-isomer than for 4-isomer. There are few examples of applying amines other than o-phenylenediamine for cyclocondensation with naphthalic anhydrides, for instance naphthalene-2,3-diamine and ethylenediamine were used as starting materials.