C6F5XeF, ein Schlüsselsubstrat in der Xenon-Kohlenstoff-Chemie: Synthese symmetrischer und asymmetrischer Pentafluorphenylxenon-Derivate

Abstract

„Nacktes Fluorid“ [NMe4]F setzt sich in CH2Cl2 mit der salzartigen Verbindung [C6F5Xe][AsF6] in 70 % Ausbeute zum asymmetrisch hypervalenten Molekül 1 um. Dank seiner hohen Fluoriddonorfähigkeit und seines permanenten Dipolmoments reagiert 1 in guten Ausbeuten mit Cd(C6F5)2 zu 2 und mit Me3SiCN zu 3.

Synthesis, NMR spectroscopic characterisation and reactions of 2,6-difluorophenylxenon fluoride, 2,6-F2C6H3XeF

“…As recently described, bis(pentafluorophenyl)xenon, Xe(C 6 F 5 ) 2 , can either be generated via the reaction of XeF 2 and Me 3 SiC 6 F 5 in the presence of catalytic quantities of [NMe 4 ]F [8,10] or the reaction of C 6 F 5 XeF and Cd(C 6 F 5 ) 2 [9]. Cadmium reagents were also employed in the syntheses of 2,4,6-F 3 C 6 H 2 XeC 6 F 5 and Xe(2,4,6-F 3 C 6 H 2 ) 2 [12].…”

“…NMR spectra and chemical behaviour make 2,6-F 2 C 6 H 3 XeC 6 F 5 unambiguous (Table 1). 19 F NMR chemical shifts were detected in the region of those reported for Xe(C 6 F 5 ) 2 [8][9][10] and Xe(2,4,6-F 3 C 6 H 2 ) 2 [12], significantly shifted from those of salt-like fluorophenylxenon derivatives (e.g. [6,12,16,17]).…”

“…In the case of the cyanide, results match well with those given for C 6 F 5 XeCN [9], while those obtained for 2,6-F 2 C 6 H 3 XeNCO to our knowledge appear to be unique so far.…”

“…The first examples of organoxenon compounds with two Xe-C bonds were those of Xe(C 6 F 5 ) 2 [8][9][10] and Xe(C 6 F 5 )CN [9]. In a recent publication [12] Frohn and Theißen proved the existence of 2,4,6-F 3 C 6 H 2 XeC 6 F 5 and Xe(2,4,6-F 3 C 6 H 2 ) 2 by 19 F and 129 Xe NMR spectroscopic means and supported their results by theoretical calculations.…”

“…While ligand exchange reactions with less or low co-ordinating anions have been a major part of investigations [3][4][5][6][7], attempts to prepare hypervalent [10-Xe-2] remained of lower success [8][9][10][11][12].…”