doiSerbia

1,3-Propanediammonium [μ4-1,2,4,5-benzenetetracarboxylato(4-)]copper(II)dihydrate with a microporous structure

Poleti Dejan D. (Tehnološko-metalurški fakultet, Beograd)
Karanović Ljiljana Č. (Rudarsko-geološki fakultet, Beograd)

Crystal structure analysis of the title complex, (H3NC3H6NH3)[Cu{C6H2(COO)4}] ·2H2O, 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 O atoms from four different btc ligands. The four uncoordinated O atoms from the same carboxylate groups are placed around Cu(II) at longer distances (≈2.8Ǻ), 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)Ǻ, V=1680.9(5)Ǻ3 and Z=4. Final agreement indices are: R1=0.0303 for 1012 reflections with I>2σ(I), wR2=0.0493 for 1317 independent reflections and 123 refined parameters. The compound was also characterized by IR spectroscopy and TG/DSC analysis.

Keywords: transition metal complexes, copper(II), 1,2,4,5-benzenetetracarboxylateion, 1,3-propanediammonium ion, crystal structure, thermal properties