Synthesis, Crystal Structure and Properties of trans-[Cu(sac) 2(en)2] (sac = Saccharinato and en = Ethylenediamine)

Abstract

The title complex trans -[Cu(sac) 2 (en) 2 ] (sac = saccharinato, en = ethylenediamine) has been obtained accidentally by the reaction of piperazine (ppz) with [Cu(sac) 2 (H 2 O) 4 ]·2H 2 O in butanol solution. During the reaction, ppz was presumably decomposed to produce en which then coordinated to copper(II) to yield the title complex. trans -[Cu(sac) 2 (en) 2 ] has been characterized by elemental analysis, IR, UV-VIS, magnetic measurements and single crystal X-ray diffraction. The compound crystallizes in space group (No. 2) and it consists of neutral units linked by bi- and trifurcated N-H⋯O hydrogen bonds into chains which are further connected by aromatic π-π stacking interactions forming a three-dimensional supramolecular network. The copper(II) ion in [Cu(sac) 2 (en) 2 ] sits on a inversion centre and is octahedrally coordinated by two neutral en and two anionic sac ligands. An elongated distorted octahedral geometry along the Cu-N sac bonds is a consequence of the Jahn-Teller effect. The en ligand acts as a bidentate (N,N′) chelating ligand, while sac is N -coordinated. IR and UV spectra and thermal analysis are in agreement with the crystal structure. © 2006 Taylor & Francis.