An unusual square planar open-lock shaped copper(II) metallaligand obtained from a hexadentate amine–amide–phenol ligand

The copper(II) complex, [Cu(LH -2 )] (4), asymmetrically coordinated by the tetradentate part of, 1,8-bis(2-hydroxybenzamido)-3,6-diazaoctane (L) is reported. Its structure involves a 1-D infinite chain that utilises hydrogen bonding between coordinated side amide carbonyl oxygen and uncoordinated metallaligand amide nitrogen atoms. Further complexation reaction of the metallaligand with [Cu(bpy)(MeOH) 2 ](ClO 4 ) 2 gives [Cu 2 (LH- 4 )(bpy)] (5).