Extended Data Fig. 6: Structural model of USTB-5a and corresponding N2 sorption isotherms.
From: Linkage conversions in single-crystalline covalent organic frameworks
(a) Structural model of USTB-5a containing three-fold interpenetration nets with all atoms in individual framework shown in pink, green, and blue color, respectively. Unit cell parameters are a = b = 32.6300 Å, c = 24.6860 Å, α = β = 90°, γ = 120°, and V = 22762.3 Å3 (Z = 18). (b) Hysteretic N2 sorption isotherms at 77 K with the first and second step corresponding to the flexible structure of USTB-5a and USTB-5, respectively. Inset: the structural difference between USTB-5a and USTB-5 along c axis, as mainly indicated by the different pitches for their double-strand helical secondary building blocks.
