Crystal structures of the solvate and two tetralkylammonium inclusion compounds of [1, 2, 4, 5-tetra(4'-carboxyphenyl) - benzene

Abstract

This article reports [1, 2, 4, 5-tetra(4'-carboxyphenyl)-benzene] (1) and its tetraethyl ammonium and tetrabutylammonium inclusion compounds (C34H21O8 −·N+(C2H5)4·H2O (2) C34H21O8 −·N+(n-C3H7)4·H2O (3). Compound one eventually forms a "molecular column" along the direction of [110], and the solvent molecules are filled by two adjacent columns to form a stable crystal structure. In compound 2, the tetravalent host anion forms rectangular three-dimensional pores with water molecules by O-H… O hydrogen bonds, two tetraethyl ammonium ions are neatly arranged in the pores to form a tighter structure, In structure 3, the formation of the main skeleton mainly relies on O…H…O hydrogen bond formed by the contact between the proton H shared between the two host anions and the O-H…O generated by the water molecule and one of the two anions. In the three crystal structures, [1, 2, 4, 5-tetra(4'-carboxyphenyl)-benzene], as an “X” polycyclic polycarboxylate aromatic molecule, constructs a large 3 D hole by using its configuration feature. Corresponding solvent molecules and different guest molecules are contained in the 3 D pores, forming various stable crystal structures.