Anion‐π Interaction: An Influential Force in Solid State Molecular Microstructures. Issue 16 (15th April 2013)

• Record Type: Journal Article
• Authors: Giese, Michael; Albrecht, Markus; Valkonen, Arto; Rissanen, Kari
• Is Part Of: European journal of organic chemistry. Issue 16(2013)
• Page Start: 3247
• Page End: 3253
• Publication Date: 2013-04-15
• Subjects: Anions -- Stacking interations -- Pi interations -- Solid‐state structures -- Fluorine­ -- Crystal engineering -- Crystal structure; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201201704
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: 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‐π interaction in a 1:1 mode with the pentafluorobenzene unit Z ‐configured, the bulkier anions iodide, tetrafluoroborate, 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‐π interactions induce a conformational change from the anti ‐form observed for the smaller anion to the tweezer‐like syn ‐form. Abstract : The solid‐state structures of a series of bis(pentafluorobenzyl)phosphonium salts reveal the crucial relevance of anion size in anion‐π interactions, leading to conformational control.