Two new copper(II) complexes containing the benzene-1,3,5-tricarboxylic acid anion and 1,4,7-triazacyclononane

Two new copper(II) complexes, [Cu(tacn)(H₂BTC)₂]·2H₂O (1) and [Cu(tacn)(H₂BTC)(H₂O)](H₂BTC)·5H₂O (2), where H₂BTC^– = the benzene-1,3,5-tricarboxylic acid anion and tacn =1,4,7-triazacyclononane, have been synthesized and their structures determined. Copper(II) ions of both (1) and (2) are five-coordinate with three nitrogen atoms of tacn and two oxygen atoms of either H₂BTC^– or H₂O. Hydrogen bonds in these two complexes result in them being differently packed in the crystal cell.