The copper(II) complexes di-μ-bromo-bis{[2,6-bis(pyrazol-1-yl)pyridine]perchloratocopper(II)} and [2,6-bis(pyrazol-1-yl)pyridine]dibromocopper(II)

The two title compounds, di-mu-bromo-bis{[2,6-bis(pyrazol-1- yl-kappaN(2)) pyridine-kappaN](perchlorato-kappaO) copper(II)}, [Cu2Br2( ClO4)(2)(C11H9N5)(2)], (I), and [2,6-bis(pyrazol-1-yl) pyridine]dibromocopper( II), [CuBr2(C11H9N5)], (II), were synthesized by only slight modifications of the same reaction; compound ( II) was formed by adding one molar equivalent of pyrazole (C3N2H4) to the reaction mixture of (I). Compound (I) is a bromo-bridged dinuclear copper(II) compound stabilized by weak interactions with the perchlorate anions (ClO4-), while (II) is a related mononuclear species, which has a distorted square-pyramidal geometry.