Synthesis and properties of alkyl chain substituted naphthalenetetracarboxylic monoanhydride monoimides and unsymmetrically substituted naphthalene derivatives

1,4,5,8-Naphthalenedianhydride is converted to N-(2-ethylhexyl)-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (2a) and N-(2-hydroxyethyl)-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (2c) through the potassium salt prepared from a reaction with potassium hydroxide. N-Dodecyl-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (2b) was prepared by the condensation reaction of 1,4,5,8-naphthalenedianhydride with dodecylamine. Naphthalene-1,4-N-(2-ethylhexyl)-imide-N-ethyl-1H-benzo[d]imidazol-5-carboxylate and naphthalene-1,4-N-dodecyl-imide-N-ethyl-1H-benzo[d]imidazol-5-carboxylate were prepared by the condensation reaction of N-alkyl-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (alkyl = 2-ethylhexyl and dodecyl) with ethyl 3,4-diaminobenzoate. Molecular structures and electrochemical properties of all naphthalene derivatives were determined. Their thermal properties were also studied by thermal gravimetric analysis. © 2016, Chemical Publishing Co. All rights reserved.