Synthesis and 2D H-bonded Cu(II) network structure of [Cu(2,2′bpy)(H2L1)](ClO4)2 [H2L1=1,2-bis((2-hydroxyethyl)amino)ethane]

Complex [Cu(2,2′-bpy)(H2L1)](ClO4)2 (1) has been self-assembled by the complexation of a potentially flexible tetradenate ligand 1,2-bis((2-hydroxyetheyl)amino)ethane (H2L1) and a chelating rigid ligand 2,2′-bipyridine (bpy) with Cu(II). Crystal analyses reveal that H2L1 acts as a tridenate ligand by the coordination of one alkoxyl O atom and two amino N atoms. Copper(II) coordinates additionally with the two N atoms of bipyridine, giving a distorted square pyramidal geometry. Each complex molecule is connected with four surrounding ones by hydrogen bonds along the ac plane, leading to 2D sheets constituted with 7.874×10.891 A˚ metallomacrocyclic rectangles. Each vertex of the rectangle is occupied by a copper atom. The four sides are comprised of multiple hydrogen bonds. Electronic spectra of complex 1 showed a band maximum at 661 nm; the EPR spectra of 1 in frozen DMF at 100 K showed an axial spectrum with four hyperfine peaks in the g∥ region, and g∥>g⊥, consistent with a distorted square pyramidal copper(II) coordination geometry. [Copyright &y& Elsevier]