Diversity in Supramolecular Solid-State Architecture Formed by Self-Assembly of 1-(Diaminomethylene)thiourea and Aliphatic Dicarboxylic Acids

Abstract

A family of supramolecular complexes of 1-(diaminomethylene)thiourea with aliphatic dicarboxylic acids, HOOC(CH2)nCOOH, with odd and even numbers of methylene groups in the carbon chain of the acids has been characterized. Using solvent-assisted and evaporation-based techniques, crystallization of 1-(diaminomethylene)thiourea with aliphatic dicarboxylic acids from water solutions yielded ionic supramolecular complexes with base to acid ratio of 2:1 or 1:1. Malonic, succinic, adipic, and sebacic acids with 1-(diaminomethylene)thiourea form supramolecular complexes of 2:1 ratio (1, 2, 4, and 8), whereas glutaric, pimelic, azelaic, and suberic acids form supramolecular complexes of 1:1 ratio (3, 5, 6, and 7). Within all supramolecular complexes only one with adipic acid crystallizes as a hydrate containing water molecules of crystallization. In the hydrated crystal with adipic acid, the O–H···O chains of water molecules interact with adipiate(2-) anions forming anionic layers, and the charge is compensated b...