Flexible chiral pyrazolate-based metal-organic framework containing saddle-type CuI4(pyrazolate)4 units

The syntheses and crystal structures of [Cu-2(I)(phbpz)]center dot MeOH (lp-CFA-9, lp = large-pore) and [Cu-2(I)(phbpz)] (np-CFA-9, np = narrow-pore; H-2-phbpz = 3,3', 5,5'-tetraphenyl-1H,1'H-4,4'-bipyrazole) are described. The copper(I)-containing metal-organic framework (termed Coordination Framework Augsburg University-9, lp-CFA-9) crystallizes in the trigonal crystal system, within the chiral space group P3(2)21 (no. 154) and with the following unit cell parameters: a = 18.2348(6), c = 16.3950(4) angstrom, and V = 4721.1(2) angstrom(3). Lp-CFA-9 features a 3-D microporous framework structure of Cu(4)pz(4) (pz = pyrazolate) SBUs with the D-2d (= (4) over bar 2m) symmetry connected by single bonds creating one-dimensional channels expanding in the c-direction of the crystal lattice. The framework flexibility of CFA-9 has been demonstrated by single-crystal and powder X-ray analyses as well as by sorption measurements. CFA-9 exhibits weak binding of carbon monoxide on Cu(I) centers. The reactivity of CFA-9 towards oxidizing agents, such as H2O2, t-BuOOH and Br-2 was also investigated. Additionally, CFA-9 shows luminescence upon exposure to UV radiation.