Synthesis, structural characterization, photo-physical and magnetic properties of cobalt salphen pseudo halide complexes showing meta-magnetic ordering

The solvo-thermal syntheses of [(CoSalphen)₂Co (SCN)₂]n (1), CoSalphen(NH₃)(N₃)(2), Na[Co^IIIsalphen(N₃)₂](3), Na[Co^IIIsalen(N₃)₂](4) and Co^IIIsalen(NH₃)(N₃) (5) {salphen = N,N'-o-phenylene-bis(salicylideneimine)} are reported. The structural studies using X-ray diffraction measurements revealed that 1 crystalizes in a monoclinic C2/c space group. Two cobalt (II) metal centers in penta-coordinated and octahedral local coordination environments are bridged via alternating O and μ1,3 SCN bridges resulting in a novel 2D layered coordination polymer. Compound 2 is a trivalent mononuclear cobalt azido complex with an octahedral coordination environment. The magnetic investigations of 1 revealed ferromagnetic coupling (J = +49.1 cm^-1) and meta-magnetic ordering. Time resolved photoluminescence studies of the complexes showed excited state lifetimes of (τ₁ = 0.4675 ns, τ₂ = 5.23 ns) for 1 and (τ₁ = 0.5078 ns, τ₂ = 6.79 ns) for 2.