A redetermination of bis(ethylenediamine-N,N prime )bis(perchlorato-O)copper(II)

Reaction of copper(II) perchlorate with excess ethylenediamine (en) in aqueous solution gave the title complex, [Cu(ClO4)2(C2H8N2) 2]. The cation is centrosymmetric with a mean Cu - N distance of 2.016 (2) A. There are semi-coordinate bonds to the perchlorate ions with a Cu - O distance of 2.579 (4) A. The N - Cu - N angle is 84.69 (9)°, as expected for chelating en. The structure is stabilized by hydrogen bonds from three of the perchlorate O atoms to amino H atoms within each molecule and between molecules, linking them into chains.