abstract in English: |
The novel coordination compound [CuI12(C16H16N4)6]·8DMAc, (2), (DMAc = N, N-dimethylacetamide) was prepared in solvothermal or microwave assisted reaction. It contains four metallamacrocyclic trinuclear copper(I) pyrazolate coordination units, which occupy four (opposite) faces of an imaginary metallosupramolecular octahedron. Six (4,4′-(1,2-phenylene)bis(3,5-dimethylpyrazol-1-ide) ligands (L12–) are placed at the corners of the octahedron. Crystals of the free ligand H2L1 [1,2-bis(3,5-dimethyl-1H-pyrazol-4-yl)benzene, (1)], and [CuI12(C16H16N4)6]·8DMAc (2), were characterized by single-crystal X-ray structure analyses. Lingand 1 crystallizes in the monoclinic crystal system, with: a = 9.0118(9), b = 14.0075(11), c = 11.7484(11) Å, β = 104.945(5)°, V = 1432.9(2) Å3, space group P21/c (no. 14). Compound 2 crystallizes in the tetragonal system, with: a = b = 19.506(5), c = 42.888(5) Å, V = 16318(6) Å3, space group I41/amd (no. 141). Compound 2 represents a porous structure, where each metallosupramolecular octahedron encloses a solvent-filled cavity of 889 Å3 (accounting for 6 DMAc molecules, 21.8 % of the cell volume). The incomplete crystal packing arrangement of adjacent [CuI12(C16H16N4)6] moieties in addition leads to solvent-filled interstitial voids accounting to 8.1 % of the cell volume. Removing solvent molecules in vacuo is accompanied by reversible structural changes, leading to a partial loss of porosity, as revealed by Ar-BET sorption analysis. Compounds 1 and 2 were further characterized by elemental and thermogravimetric analysis, X-ray powder diffraction, FTIR-, UV/Vis- and fluorescence spectroscopy. Preliminary results on the activation of molecular oxygen by compound 2 are presented. |