Hydrogen-Bonding Networks in a Bipodal Acyl-thiourea and Its Ni^II 2:2 Metallamacrocyclic Complex

The crystal structures of 3,3,3‘,3‘-tetra(2-hydroxyethyl)-1,1‘-isophthaloylbis(thiourea) (1) and its green metallamacrocyclic complex cis-[Ni(L-S,O)(pyridine)2]2 (2) are reported in the context of their supramolecular behavior dictated by the use of hydrogen-bonding end-groups on the ligand. In 1, each molecule forms a junction between two 4-fold chiral helices formed by the hydrogen bonding of hydroxyl moieties and sulfur atoms. The structure of 2 is laminar, consisting of layers of water-linked metallamacrocyclic cis-[Ni(L-S,O)(pyridine)2]2 units separated by layers of pyridine guest molecules. Thermogravimetric analysis of 2 shows that on heating the guest pyridine and water molecules are released at ca. 60 °C, followed quickly by the further release of coordinated pyridines from cis-[Ni(L-S,O)(pyridine)2]2 to yield cis-[Ni(L-S,O)]2.