Structural Characterization of a Cage Ligand Fragmentation Reaction

Abstract

The room temperature X-ray single-crystal structural characterization of a protonated copper(II) complex of a ligand artefact, L′, of L = N-Me₆sar (described in an accompanying paper) is recorded, the new ligand L′ being generated formally by elimination of a CH₂CH₂ bridge between a pair of nitrogen donor atoms of L. The complex, [ ClCu (H₂L′) (ClO₄)₃.2H₂O, is orthorhombic, Pccn , a 22.528(7), b 10.544(3), c 13.748(6) Ǻ, Z = 4 formula units, R being 0.053 for 1133 independent 'observed' [I > 3σ(I)] reflections. The cation, containing five-coordinate square-pyramidal ClCuN₄ copper, is disposed with the Cu- Cl bond [2.458(3)Ǻ] lying on a crystallographic 2 axis; Cu-N distances are 2.094(8) and 2.093(8)Ǻ.