A unique tetranuclear nickel(II) complex containing pyridine-2-carboxaldehyde derivative bearing an intramolecular acetato: Synthesis, crystal structure and magnetic property

The novel tetranuclear nickel(II) carboxylate complex formulated as [Ni4(L)2(m2-OAc)2 (m3-OAc)2]·CH3OH·H2O, (1) (where L = 2-oxo-1,2-di(pyridin-2-yl)ethyl picolinate) has been synthesized and characterized systematically. The complex crystallizes in orthorhombic system, consisting of a tetranuclear Ni(II) distorted cubane-like core, in which four Ni(II) ions are bridged by four acetato groups. Each Ni(II) ion is further ligated with nitrogen atoms of bridging pyridine-2-carboxaldehyde derivative, forming either Ni, N, N, O- or Ni, N, O-chelate macro-rings. Magnetic susceptibility studies indicate that the weak antiferromagnetic interaction is operating between the adjacent nickel ions bridged via the carboxylate oxygen atoms within the complex.