Formation and characterization of the ionic salts {3[Ξ—BPMTU]+Β·3[X]-Β·nH2O} (BPMTU = 1,3-Bis(3-pyridylmethyl)-2-thiourea and X = Cl, Br, I). A novel supramolecular architecture based on OΒ·Β·Β·Cl- bonding interactions and strong chargeassisted OHΒ·Β·Β·Cl- and NHΒ·Β·Β·Cl- hydrogen bonding network