Fig. 4: Crystal structure from neutron data showing the occupation of CO₂ molecules into the channels in TAMOF-1.

a Detail of the CO₂ positions within the Cu₃ triangles in the largest void space of TAMOF-1. The distances O1C-Cu1(zxy) and O2C-Cu1 are 2.7726(1) and 2.7068(1) Å, respectively. The view direction is along [111]. Cu1, Cu1(zxy) and Cu1(yzx) are related by a crystallographic three-fold axis, which also relates the CO₂ molecule at C1C to two others, which are not shown. C1C/O1C/O2C and its two congeners have site occupancy factors of 1/3 as a result of disorder about the symmetry axis. Color code: Cu, deep blue; O, red; N, light blue; C, gray; H, white. b View along [111] of the TAMOF-1 open framework (green stick representation) and the positions occupied by the guest CO₂ molecules (red van der Waals’ radii representation) in the TAMOF-1 channels, with the two components shown together (left) and individually (right). View along [100] (c) and view along [111] (d), of parts of the complex void structure that accommodates the guest CO₂ in TAMOF-1. The voids are represented as lighted areas for exterior surfaces and as shadowed areas for interior surfaces of the void boundaries.