A Cu II Ni II Complex with Ethylenediamine: Crystal Structure and Ferromagnetic Behaviour of an Aqua‐Bridged Heterometallic Chain Containing Ambidentate Ni(OAc) 4 2– Blocks

Synthesis, crystal structure and magnetism of [Cu(cyclam)Ni(NCS)4(H2O)2]n

[Cu(cyclam)Ni(NCS)4(H2O)2]n(1) (cyclam = 1,4,8,11-tetraazacyclodecane) exhibits bent 1D crystal structure in which paramagnetic Cu(II) and Ni(II) atoms are linked by bridging μ2-NCS- ligands. The Cu(II) atom exhibit tetragonally elongated hexacoordination in the 4+2 form with one tetradentate macrocyclic cyclam ligands placed in the equatorial plane while the axial positions are occupied by S atoms from bridging NCS- ligands. The Ni(II) atom in NiN4O2donor set is deformed octahedrally coordinated by four isothiocyanato ligands among which two in trans positions are bridging in nature; additional aqua ligands occupy the remaining two positions in trans arrangement. Weak hydrogen bonding interactions of the O-H···S type links the formed chains into 3D supramolecular structure. The magnetism of 1 is dominated by a sizable single-ion anisotropy DNi/hc = +7.49 cm-1along with a weak exchange interaction of the ferromagnetic nature.