title: The chloride, bromide and iodide salts of 1-(diaminomethylene)thiouron-1-ium.
abstract: Crystals of 1-(diaminomethylene)thiouron-1-ium chloride, C(2)H(7)N(4)S(+) x Cl(-), 1-(diaminomethylene)thiouron-1-ium bromide, C(2)H(7)N(4)S(+) x Br(-), and 1-(diaminomethylene)thiouron-1-ium iodide, C(2)H(7)N(4)S(+) x I(-), are built up from the nonplanar 1-(diaminomethylene)thiouron-1-ium cation and the respective halogenide anion. The conformation of the 1-(diaminomethylene)thiouron-1-ium cation in each case is twisted. Both arms of the cation are planar and rotated in opposite directions around the C-N bonds involving the central N atom. The dihedral angles describing the twisted conformation are 22.9 (1), 15.2 (1) and 4.2 (1) degrees in the chloride, bromide and iodide salts, respectively. Ionic and extensive hydrogen-bonding interactions join oppositely charged units into a supramolecular network. The aim of the investigation is to study the influence of the size of the ionic radii of the Cl(-), Br(-) and I(-) ions on the dimensionality of the hydrogen-bonding network of the 1-(diaminomethylene)thiouron-1-ium cation. The 1-(diaminomethylene)thiouron-1-ium system should be of use in crystal engineering to form multidimensional networks.
authors.affiliation: Departamento de Fisica, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, CEP 35.400-000 Ouro Preto, MG, Brazil.
authors.forename: Genivaldo Júlio
authors.initials: GJ
authors.lastname: Perpétuo
authors.forename: Jan
authors.initials: J
authors.lastname: Janczak