Supramolecular structure of bis(1-methyl-1,3,5,7-tetraazatricyclo[3.3.1.13,7]decan-1-ium)2,5-dicarboxybenzene-1,4-dicarboxylate: Synthesis, spectral, structural and third-order nonlinear optical properties

Abstract

Single crystals of bis(1-methyl-1,3,5,7-tetraazatricyclo[3.3.1.13,7]decan-1-ium)2,5-dicarboxybenzene-1,4-dicarboxylate (I) were grown from an aqueous solution containing benzene-1,2,4,5-tetracarboxylic acid (BTCA) and hexamethylenetetramine (HMT) (1:4) under mild hydrothermal conditions. It was characterized by IR, 1H, 13C NMR, mass, DRS, PL, TG-DTA, powder and single crystal XRD. The characteristic peaks in HMT cation CN stretching mode appear at 1018 cm−1. 13C NMR shows the carboxylic acid carbon chemical shift is observed at 167.64 ppm. The compound is thermally stable up to ∼176 °C. Single crystal X-ray crystallography shows it crystallizes in the triclinic system with centric space group Pī. Powder X-ray diffraction scrutinizes, experimental and simulated from single-crystal diffractogram data have been matched. The existence of intramolecular (O–H•••O) and intermolecular (C–H•••O, C–H•••N) interactions helps to achieve crystal cohesion. The third-order nonlinear optical susceptibility (χ(3)) for the compound is found to be 7.67 × 10−7 esu. Hirshfeld surface analysis exposes the molecular interactions and their relative contributions.