Crystal structure determination and studies on self assembled supramolecular structures of some organic organic and inorganic organic acid base salts

Abstract

The thesis presents the structure and supramolecular networks of fourteen acid-base salts prepared from phthalic acid, DL-malic acid, orthophosphoric acid and perchloric acid with different amines. All the compounds presented in the thesis were prepared by taking suitable proportions of acids and bases and crystallized by slow evaporation method using methanol, ethanol and mixed solvents and their structures were solved by direct methods and refined using full-matrix least squares technique using SHELX 97 program package. The compounds 2-hydroxyanilinium hydrogen phthalate (2HAHP) and 3-hydroxyanilinium hydrogen phthalate (3HAHP) crystallize in monoclinic space group P21/c whereas 4-ethoxyanilinium hydrogen phthalate (4EAHP) crystallizes in triclinic space group P-1. The hydrogen phthalate anions in the 2HAHP, 3HAHP and 4EAHP are almost planar with distinctly asymmetric intramolecular O H O hydrogen bond between the carboxyl (COOH) and carboxylate (COO-) group. The cyclohexylaminium cation through N H O hydrogen bonds with hydrogen phthalate anions forms molecular channel along the [0 0 1] direction in which the solvent water molecules are trapped. The supramolecular networks of the present work are compared with a list of structures deposited in Cambridge Structural Database (CSD). The hydrogen phthalate and hydrogen malate salts can form tunable selfassembled supramolecular architectures. Dihydrogenphosphate salts have the tendency of formation of inorganic layered architectures and can be used in the construction of host lattices for accommodating guest molecules. The involvement of HClO4 - in specific ladder type super-molecule construction is the significance of perchlorate salts. newline newline newline