Fig. 2. Molecular structures of tweezers 4 as assessed by theory (sub-figure (a) and (c)) and crystal structural analysis (sub-figure (b) and (c)) and calculated structure of the supramolecular complex of Z-4 with aromatic guest molecule 5 (sub-figure (d)). (a) Molecular structures of E-4 and Z-4 optimized on the DFT (B3LYP/6-311G(d,p)) level of theory. The corresponding ESPs quantify the overall polarity distribution. (b) Structure of Z-4 in the crystalline state. Thermal ellipsoids are drawn at a 50% probability level. (c) Comparison of the structures of Z-4 assessed by theory (orange) and crystal structure analysis (turquoise). (d) Structure of the lowest energy Z-4·5 complex calculated on the B3LYP-GD3BJ/6-311G(d,p) level of theory.