Perpétuo, Genivaldo JulioJanczak, Jan2015-03-162015-03-162008PERPÉTUO, G. J.; JANCZAC, J. Supramolecular architectures in crystals of melamine and aromatic carboxylic acids. Journal of Molecular Structure, v. 891, p. 429-436, 2008. Disponível em: <http://www.sciencedirect.com/science/article/pii/S0022286008002937>. Acesso em: 20 fev. 2015.0022-2860http://www.repositorio.ufop.br/handle/123456789/4666Two crystals containing melamine (M), melaminium (MH+), and aromatic carboxylic acids are synthesized and characterized by single-crystal X-ray diffraction analysis: melamine–melaminium 3,4,5-trihydroxybenzoate (THB_) dihydrate (1), and melamine–melaminium 2-acetylbenzoate (AB_) dihydrate (2). In the crystal structures protonated (MH+) and non-protonated melamine (M) molecules are interconnected via NAH___N hydrogen bonds into a planar dimer in (1) and one-dimensional polymer in (2). The NAH___O hydrogen bonding interaction between the protonated nitrogen atom of MH+ and the carboxylate oxygen atom of the corresponding anion is observed in both structures. However, only in (1) it results in an almost planar ionic unit (THB_MH+) where additional p–p interactions between the anions appear, that are missing in (2). The water molecules act as donor and as acceptor of hydrogen bonds linking the substructures observed in the (1) and (2) crystals into 3D supramolecular networks.en-USCrystalsMelamineSupramolecular architectureHydrogen bondCarboxylic acidArtigo publicado em periodicoO periódico Journal of Molecular Structure concede permissão para depósito do artigo no Repositório Institucional da UFOP. Número da licença: 3566050502197.https://doi.org/10.1016/j.molstruc.2008.04.032