Synthesis and characterisation of a linear [Cu(pyr)2]2+ complex in siliceous ferrierite

The linear [Cu(pyr)(2)](2+) complex has been synthesized in situ within the internal pore architecture of siliceous ferrierite. The structure of the product was determined by single crystal X-ray diffraction [formula Cu0.964F1.2(Si36O72). 4C(5)H(5)N, space group Pmnn, a = 18.775(1), b = 14.086(1), c = 7.4296(6) Angstrom, V = 1964.9(4) Angstrom(3), Z = 1, R(F) = 3.88, Rw(F) = 4.31%]. The complex consists of a Cu2+ cation located at the center of the 8-ring window bound to one pyridine molecule residing in the cage that forms part of the 8-ring channel and another pyridine molecule in the main 10-ring channel. Evidence for the presence of this complex is also provided by EPR. The charge of the complex is balanced by F- anions, which were found in the crystal structure to be present in SiO4F- units, and SiO3O- defect sites in the zeolite framework. The presence of both the SiO4F- units and the SiO3O- defect sites was confirmed by NMR spectroscopy.