Abstract
A novel [Ni-4(mu(3)-O)(4)] twisted cubane complex, Ni4Cl2(NN)(2)(ONN)(2)(NNO)(2)(H2O)(2)center dot 2THF, was prepared from a crude mixture of three bidentate ligands. A mixture of ethyl 1-(hydroxymethyl)-3-methyl-1H-pyrazole-5-carboxylate (HONN) and ethyl 1-(hydroxyl-methyl)-5-methyl-1H-pyrazole-3-carboxylate (NNOH) were added to ethyl 3-methyl-1H-pyrazole-5-carboxylate (NNH) then mixed to NiCl2 center dot 6H(2)O solution under ambient conditions. Reaction progress was monitored via infrared and ultraviolet-visible spectroscopies and energy-dispersive X-ray spectroscopy was used to analyze the product. Reaction yields for cluster synthesis were very good. Single crystal structure determination for the cluster indicates a novel [Ni-4(mu(3)-O)(4)] twisted cubane structure with octahedral geometry around each of the Ni(II) centers in Ni4Cl2(NN)(2)(ONN)(2)(NNO)(2)(H2O)(2)center dot 2THF. The lattice is stabilized by hydrogen bonding and H-pi stacking. Hirshfeld surface analysis (HSA) corroborates the single crystal structure determination results. The cluster displays significant thermal stability under open atmosphere conditions; it decomposes in three steps at high temperature. The cluster demonstrates promising results as a catalyst; it promoted the complete oxidation of catechol to o-Quinone in under mild conditions.