Structures of diethylenetriaminecopper(II) cations. Part IV. Crystal structure of µ-formato-diethylenetriaminecopper(II) formate

The crystal structure of µ-formato-diethylenetriaminecopper(II) formate has been determined by X-ray diffraction methods and refined by full-matrix least-squares procedure. Z= 4 in the orthorhombic unit cell, space group Pnam, with a= 8·954, b= 11·640, and c= 9·676 A. There are no discrete [Cu(dien)(HCO2)]+ ions in the crystal; chains of ions are formed parallel to a, the copper atoms being linked by formate groups in an anti–syn bridging arrangement. Each [Cu(dien)(HCO2)] group possesses mirror symmetry (space-group imposed) and the copper atom environment is essentially square-pyramidal. One oxygen atom co-ordinates to the copper atom at 2·035 A in the plane of the three equal copper–nitrogen bonds (2·012 A) and the apical position is occupied by a second oxygen atom 2·169 A from the copper atom.