Pentafluorphenylioddifluorid: alternative Darstellungsmethoden, Molekülstruktur und Eigenschaften

Abstract

Es wird die Darstellung von C6F5IF2 (1) aus C6F5I (2) durch oxidative Fluorierung mit ClF, CF3OCl, BrF5, C6F5BrF2 und C6F5BrF4 beschrieben. Höchste Reinheit und Ausbeute an 1 wurde durch eine modifizierte Tieftemperaturfluorierung mit F2 erhalten. Die Thermolyse von 1 lieferte Perfluoriodcyclohexadien‐1,4 und Perfluoriodcyclohexen neben 2. Die Röntgenstrukturanalyse von 1 zeigt dessen Fluoriddonor‐ und Fluoridakzeptoreigenschaft. 1 wird spektroskopisch charakterisiert durch NMR (19F, 13C), IR und Ra. Diskutiert wird der Einfluß der Änderung der Oxidationszahl von Iod in 2, 1 und C6F5IF4 (3) auf strukturelle und spektroskopische Ergebnisse. Die Geometrien und Ladungsverteilungen im Energieminimum wurden für 1, 2 und verwandte Moleküle berechnet (RHF, LANL2DZ).

Straightforward Syntheses of Hypervalent Iodine(III) Reagents Mediated by Selectfluor

“…The I−F bond lengths are approximately equal (2.025(3), 1.995(3) Å and 2.023(3), 1.992(3) Å to each independent iodine atom). These bond lengths are very similar to those in C 6 F 5 IF 2 (2.029, 1.954 Å) and CF 3 IF 2 (1.982(2) Å), which clearly demonstrates that the structure of 4b is not unusual as previously thought. The F−I−F array is not linear (171.0 and 174.4°) and is a result of the large space requirements of the lone pairs and intermolecular interactions (vide infra).…”

Chemistry of Polyvalent Iodine

“…A variety of other powerful fluorinating reagents, such as F 2 , ClF, CF 3 OCl, BrF 5 , C 6 F 5 BrF 2 , C 6 F 5 BrF 4 , and XeF 2 /BF 3 , can be used for the preparation of (difluoroiodo)arenes derived from polyfluoro-substituted iodoarenes. − A convenient procedure for the preparation of (difluoroiodo)benzene and 4-(difluoroiodo)toluene consists of direct fluorination of the respective iodoarenes with the commercially available fluorinating reagent Selectfluor in acetonitrile solution . Various mixed (fluoroiodo)arene triflates, ArIF(OTf), can be generated in situ by fluorination of the respective iodoarenes with xenon fluorotriflate, FXeOTf. , …”

“…Theoretical studies of CF 3 IF 2 by ab initio and DFT calculations have also been reported . The structure of pentafluorophenyliododifluoride, C 6 F 5 IF 2 , has been investigated by single crystal X-ray crystallography and by multinuclear NMR, IR, and Raman spectroscopy . The X-ray crystal and molecular structures of p -(difluoroiodo)toluene and m -(difluoroiodo)nitrobenzene had been reported in a Ph.D. dissertation in 1996…”

Recent Developments in the Chemistry of Polyvalent Iodine Compounds

“…(Difluoroiodo)arenes are potentially useful fluorinating reagents, but they have found only limited practical application due to the low stability and lack of convenient methods of preparation . They are commonly prepared by the reaction of (dichloroiodo)arenes with aqueous hydrofluoric acid and mercuric oxide or by the electrochemical oxidation of para -substituted iodobenzenes in the presence of Et 3 N· 3HF. − Polyfluoro-substituted (difluoroiodo)benzenes can also be prepared by fluorination of the respective iodoarenes with fluorine, xenon difluoride, or other powerful fluorinating reagents. − Frohn and co-workers investigated the preparation of C 6 F 5 IF 2 and related iododifluorides by oxidative fluorination of the appropriate iodides using F 2 , ClF, CF 3 OCl, BrF 5 , C 6 F 5 BrF 2 , C 6 F 5 BrF 4 , and XeF 2 . , The highest purity and yield of C 6 F 5 IF 2 was achieved by a low-temperature fluorination with F 2 84a. Prepared in this work, C 6 F 5 IF 2 was fully characterized by multinuclear NMR, IR, Raman spectroscopy and X-ray structural analysis 84a.…”