Synthesis, structure and magnetic properties of Ni(II) and Cu(II), [2 x 2] grid complexes of pyrimidine-based symmetric ditopic ligands

摘要

The successful synthesis of new pyrimidine based organic ligands with terminal carboxylate and oxime functional groups, followed by their employment in metallogrid self-assembly has yielded three tetranuclear [Ni-4(L-1)(4)]center dot 2CH(3)CN center dot 4CH(3)OH center dot 4H(2)O (1), [Cu-4(HL1)(4) ]center dot 8CH(3) OH center dot 28H(2)O (2) and [Ni-4(H2L2)(4)](CF3SO3 )(8)center dot 4CH(3)NO(2)center dot 8H(2)O (3), [2 x 2] metallogrid complexes. The complexes have been well characterized by elemental analyses, IR spectra, UV-vis spectra and X-ray structural analyses. Variable temperature magnetic measurements/studies done on these three complexes followed by magnetic data fitting suggest that all the three complexes are dominated by intramolecular antiferromagnetic exchange coupling.