Use of Melem as a Nucleophilic Reagent to Form the Triphthalimide C6N7(phthal)3—New Targets and Prospects

Abstract

Melem (1), as one of the most important representatives of the tri-s-triazine compounds, can be used as a nucleophilic reagent in reactions with phthalic acid derivatives. The synthesis of 2,5,8-triphthalimido-tri-s-triazine (C(6)N(7)(phthal)(3), 2) was investigated starting from phthalic anhydride or phthalic dichloride in various solvents, at different temperatures as well as in the solid state. NMR measurements (solution and solid state), IR spectroscopy and elemental analysis indicated the formation of a cyclic imide. Single-crystal structure analysis of a 1:1 adduct of 2 with nitromethane proved the molecular structure expected for a phthalimido-s-heptazine. DFT calculations were performed to obtain a better insight into the structural features of compound 2, especially the interaction of the carbonyl groups with the tri-s-triazine nitrogen atoms. The title compound 2 shows promising properties: it is thermally stable up to 500 °C in air and shows strong photoluminescence with a maximum emission at around 500 nm. The potential of the nucleophilic reaction of melem with other strong electrophiles provides new targets and prospects.