trans-Diaquabis(pyridine-2-carboxamide-N¹,O)copper(II) Dichloride and Dibromide

Crystals of the title compounds, [Cu(C₆H₆N₂O)₂(H₂O)₂]Cl₂, (I), and [Cu(C₆H₆N₂O)₂(H₂O)₂]Br₂, (II), are isomorphic. The structures consist of centrosymmetrical complex cations and separate chloride or bromide ions linked by hydrogen bonding. The pyridine-2-carboxamide molecules (C₆H₆N₂O) are coordinated by the ring N atom and amide O atoms, forming the base of an elongated octahedron. Bond lengths in (I) and (II), respectively: short Cu-N bonds 1.960 (1), 1.965 (2); Cu-O 1.981 (1) and 1.981 (2); axial Cu-H₂O 2.418 (2) and 2.417 (3) Å.

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