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Abstract

Attractive pi-pi interactions between two of the four outside cavity faces of 1,3-bis-pyridylmethylcalix[4]arene (1) and both faces of 1,4-diiodotetrafluorobenzene (2a) form infinite one-dimensional non-covalent ribbons where the two modules alternate. These ribbons are cross-linked by electron donor-acceptor interactions between picolyl nitrogen atoms of calixarene 1 in one chain and iodine atoms of perfluoroarene 2a in another chain and the two-dimensional supramolecular network 3a is formed. A similar behaviour is also shown by 1,4-dibromotetrafluorobenzene (2b). The halogen bonding and the attractive pi-pi interactions occur in directions which are nearly orthogonal each other. Diiodotetrafluorobenzene, being involved in both these interactions, appears to be a particularly interesting tecton. The ability of electron-poor arenes to elicit the exo-receptor potential of calixarene module by connecting their outside faces through pi-pi interactions may be developed as a new and general binding protocol in calixarene self-assembly processes.

The disorder of perfluoroalkyl chains in crystals: Two case histories of interpretation and refinement

“…Partial evaporation of equimolar solutions of TMPDA 1 and PFDIB 2a, or PFDIH 2b, affords colourless crystals 3a,b where starting modules are present in 1:1 ratio (as confirmed with 1 H/ 19 F NMR analyses in the presence of 2,2,2-trifluoroethyl ether as external standard [12]). Single crystal X-ray analyses of these solids (Fig.…”

Halogen Bonding: A Paradigm in Supramolecular Chemistry

“…But cases may also exist where the halogen bonding collaborates with another interaction to determine the packing of the module in the crystal lattice. For instance, in the co-crystal obtained starting from a 1,3-bis-(pyridylmethyl)calix[4]arene derivative and 1,4-diiodotetrafluorobenzene, [38] the two modules are held in a sandwich arrangement by the attractive p,p-interactions [39] occurring between the electron rich phenol ring faces directed outside the calixarene cavity and the two electron poor faces of 1,4-diiodotetrafluorobenzene, see Scheme 6. Scheme 6.…”

Reactions of Arylthiazylamides with Internal and External Fluoro Electrophiles − Formation of Products with Unusual Structures

“…[47] Both complexes 5e·9 and 8·C 10 F 8 feature face-to-face π-stacking of the areneϪpolyfluorene type. [26Ϫ28] Additionally, 8·C 10 F 8 shows another structural motif, namely an unprecedented π-stacking of the heptafluoronaphth-2-yl moieties with an interplanar separation of 350.1 pm (Figure 3), thus representing a new type of areneϪpolyfluoroarene complex.…”