Cu/Cd heterometallic solids with the motif (H2dea = diethanolamine): Exchange interactions through hydrogen bonding

The novel hybrid composites [Cu(Hdea)(H2dea)]2[CdX4], X = Br (1), I (2) have been prepared in reactions of zero-valent copper with cadmium halide in air-exposed solution containing the corresponding ammonium salt and diethanolamine (H2dea). X-ray crystallographic analysis reveals ionic solids of non-symmetric H-bonded dimeric View the MathML source cations and perhalocadmate anions. Further hydrogen bonding joins the dimers into ‘zig-zag’ like tetramers with copper–copper distances of about 5 Å for 1 and forms columns of the dimeric cations propagated along the b axis in 2 (copper–copper separations within the column are of not, vert, similar4.5 and 6 Å). In the crystal structure of 1, tetrahedral View the MathML source anions alternate with cationic tetramers in three dimensions, whereas View the MathML source anions form sheets parallel to the ab plane in 2. The exchange interactions between paramagnetic centres in the solid state, revealed by the triplet EPR spectra measured at X-band frequency, occur along the Cu–OH···O–Cu pathways, being mediated by hydrogen bonds established between OH and alkoxo groups of diethanolamine ligands.