A mixed-ligand ternary complex of nickel(II): synthesis, characterization and catalytic investigation for the synthesis of pyranopyrazoles

作者：Ebrahimipour S Yousef^*; Ranjabr Zohre Rashid; Kermani Esmat Tavakolinejad; Amiri Behjat Pour; Rudbari Hadi Amiri; Sacca Alessandro; Hoseinzade Fatemeh

来源：Transition Metal Chemistry, 2015, 40(1): 39-45.

DOI：10.1007/s11243-014-9887-9

A new mixed-ligand Ni(II) complex, [Ni(L)(mimi)], was prepared by the reaction of Ni(OAc)(2)center dot 4H(2)O, 4-bromo-2-[(2-hydroxy-5-methylphenyl]iminomethyl]phenol [H2L] and 1-methylimidazole (mimi) in two forms of bulk and nanoparticle sizes using slow evaporation and ultrasonic irradiation, respectively. The complex was characterized by physicochemical and spectroscopic methods, and also by single crystal X-ray diffraction. The Ni(II) center is coordinated by the ONO donor ligand and the nitrogen of 1-methylimidazole. Scanning electron microscopy revealed that the particle size of the complex synthesized using ultrasonic irradiation was below 100 nm. Both the nano and bulk forms of [Ni(L)(mimi)] were found to be effective catalysts for four-component synthesis of dihydropyrano[2,3-c]pyrazoles from a stoichiometric mixture of ethyl acetoacetate, hydrazine hydrate, aldehyde and malononitrile in ethanol, and furthermore, the catalytic activity of the nano form of the complex is higher.

• 出版日期2015-2