Anion-pi Interaction: An Influential Force in Solid State Molecular Microstructures

作者：Giese Michael; Albrecht Markus^*; Valkonen Arto; Rissanen Kari

来源：European Journal of Organic Chemistry, 2013, 2013(16): 3247-3253.

DOI：10.1002/ejoc.201201704

• Anions
• Stacking interations
• Pi interations
• Solid-state structures
• Fluorine
• Crystal engineering
• Crystal structure

The crystal structures of simple triphenyl(pentafluorobenzyl)phosphonium salts provide crucial data on the influence of anion size on the molecular structure of bis(pentafluorobenzyl)phosphonium cations containing two adjacent electron-deficient moieties. Whereas the bromide anions interact by anion-pi interaction in a 1: 1 mode with the pentafluorobenzene unit Z-configured, the bulkier anions iodide, tetrafluoro-borate, and hexafluorophosphate result in a 1: 2 tweezer-like anti-configuration in which one anion interacts simultaneously with two pentafluorobenzene units. When spatial separation of the two electron-deficient rings match the size of the anion, anion-pi interactions induce a conformational change from the anti-form observed for the smaller anion to the tweezer-like syn-form.

• 出版日期2013-6