Supramolecular assembly of linear trinickel complexes incorporating metalloporphyrins: a novel one-dimensional polymer and oligomer

One-dimensional polymeric or oligomeric chains, in which various linear trinickel complexes linked to the axial sites of metalloporphyrins by the combination of self-assembly and coordination chemistry, have been constructed. A carboxylate group of carboxylpyridine was attached to the end of linear trinickel complexes to produce the linear building blocks, Ni3(dpa)4X2 [X = 4-PyCOO- (1) or 3-PyCOO- (2)], which was then reacted with metalloporphyrins to form stable polymers or oligomers. The new self-assembled oligomeric chain, [Ni3(dpa)4(4-PyCOO)2][ZnTPP]2 (3), and two novel self-assembled one-dimensional polymeric chains, {[Ni3(dpa)4(4-PyCOO)2][MnTPP]}n(ClO4)n (4), and {[Ni3(dpa)4(3-PyCOO)2] [MnTPP]}n(ClO4)n (5), [dpa-= di(-pyridyl)amido anion; TPP =meso-tetraphenylporphyrinato dianion], have been synthesized and their structures were determined by X-ray diffraction. The UV/vis spectra indicate the absence of any noticeable interactions between the linear trinickel units and metalloporphyrins in these chains. The magnetic susceptibility measurements in the solid state show that both polymers 4 and 5 have a very weak ferromagnetic interaction.