Synthesis and structural characterisation of three dicyanamide complexes with Mn(II), Zn(II) and Cd(II): Supramolecular architectures stabilised by hydrogen bonding

Three new dicyanamido [N(CN)2]− (dca) compounds of the formula [Mn(ac)(tptz)(dca)(H2O)] · (H2O)2 (1), [Zn(tptz)(dca)2] · (H2O)2 (2) and [Cd2(tptz)2(dca)2(H2O)2] · (ClO4)2 (3), (where ac = acetate anion and tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine) have been synthesised. X-ray diffraction analysis revealed that the manganese atom in 1 is seven-coordinated with a pentagonal-bipyramidal environment, in 2 zinc is penta-coordinated square pyramidal and in 3 the cadmium atom is six-coordinated octahedral. dca is found to act as an end-to-end bridging ligand in the dimer 3, whereas in 1 and 2 it acts as a monodentate terminal ligand. All the complexes exhibit supramolecular architectures by hydrogen bonding interactions involving lattice water (for 1 and 2) or coordinated water molecules (for 3).

Graphical abstractThree new dicyanamide complexes with Mn(II), Zn(II) and Cd(II) have been synthesised at ambient temperature. Complexes 1 and 2 are mononuclear and 3 is a dicyanamide bridged dinuclear species, which is rare in the literature. All three structures exhibit supramolecular frameworks resulting from the numerous hydrogen bonding interactions involving the constituent materials.Figure optionsDownload full-size imageDownload as PowerPoint slide