1,3-propanediammonium [mu(4)-1,2,4,5-benzenetetracarboxylato(4-)]copper(II) dihydrate with a microporous structure

Crystal structure analysis of the title complex, (H3NC3H6NH3)[Cu{C6H2(COO)(4) }] center dot 2H(2)O, showed that the structure is built up from Cu(II) and tetradentate 1,2,4,5-benzenetetracarboxylate(4-) (btc) ions forming a 3D open-framework with two different channels extending parallel to the [110]/[1,-1,0] and [001] directions. The first, wider channels accommodate 1,3-propanediammonium cations, whereas the second ones are filled with H2O molecules. The Cu(II) ions are in a tetrahedrally distorted square-planar environment consisting of four carboxylate 0 atoms from four different btc ligands. The four uncoordinated O atoms from the same carboxylate groups are placed around Cu(H) at longer distances (approximate to 2.8 angstrom), forming a distorted sphenoid. The complex crystallizes in the orthorhombic space group Cc2m with a = 8.887(1), b = 11.493(2), c = 16.457(3) angstrom, V = 1680.9(5) angstrom(3) and Z = 4. Final agreement indices are: R-1 = 0.0303 for 1012 reflections with I > 2 sigma(I), wR(2) = 0.0493 for 1317 independent reflections and 123 refined parameters. The compound was also characterized by IR spectroscopy and TG/DSC analysis.