The syntheses and crystal structures of [Cu I 2 (phbpz)]·MeOH (lp-CFA-9, lp = large-pore) and [Cu I 2 (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 C _oordination F _ramework A _ugsburg 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) Å, and V = 4721.1(2) Å 3 . Lp-CFA-9 features a 3-D microporous framework structure of Cu 4 pz 4 (pz = pyrazolate) SBUs with the D 2d (= 42m) 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 H 2 O 2 , t-BuOOH and Br 2 was also investigated. Additionally, CFA-9 shows luminescence upon exposure to UV radiation. CrystEngComm, 2016, 18, 7883-7893 | 7883 This journal is † Electronic supplementary information (ESI) available: Ortep-style plot of the asymmetric units; topology analysis; XRPD patterns of lp-and np-CFA-9; and IR spectrum and gas sorption measurements of CFA-9. CCDC 1488850 and 1488851. For ESI and crystallographic data in CIF or other electronic format see