Hydrogen-bonding network in the crystal of 1-(diaminomethylene)thiouron-1-ium picrate

The single crystals of 1-(diaminomethylene)thiouron-1-ium picrate were grown using a solution growth technique. The compound crystallises in the centrosymmetric C2/c space group of the monoclinic system. The conformation of the 1-(diaminomethylene)thiouron-1-ium cation is almost planar, while the conformation of the picrate(−) anion is non-planar. Both NO2 groups linked in ortho positions in relation to the phenolate oxygen are oppositely turned in relation to the ring plane. Arrangement of the oppositely charged components, i.e. 1-(diaminomethylene)thiouron-1-ium cations and picrate(−) anions in the crystal is mainly determined by ionic and hydrogen bonding interactions forming pseudo-one dimensional chains. The compound was also characterised by the FT-IR and Raman spectroscopy. The characteristic bands of the NH2, NO2, CS and CarO groups as well as of skeletal groups are discussed.