Multiple C−F Bond Activation:  Remarkable 4 to 4 Bond-Breaking/Bond-Making Reactions of Nb⁺ with Hexafluoro- and Tetrafluorobenzene

Abstract

Mass spectrometric reaction rate measurements are reported that show the remarkable occurrence of the breaking of four C−F bonds and the formation of four new Nb+−F bonds in gas-phase collisions of Nb+ with hexafluoro- and tetrafluorobenzene. A mechanism involving sequential intramolecular fluorine pick-up is proposed.

Catalysis and Organometallic Chemistry of Monometallic Species

“…108 An unusual reaction reported between Nb ϩ and C 6 F 6 in the gas phase gives multiple C-F bond cleavage leading to the formation of difluorohexatriyne and [NbF 4 ] ϩ that was analysed by mass spectrometry techniques. 109 …”

Carbon–fluorine bond activation—looking at and learning from unsolvated systems

“…The niobium cation, on the other hand, deserves special monitoring. Nb + undergoes a truly remarkable fourfold fluorine-atom abstraction from C 6 F 6 to form NbF + 4 in a single collision, 52 thus corresponding to the twofold C-F bond activation in one step by Pr +44 and the abovementioned behaviour of W + on surfaces. 31 Quantum-mechanical calculations of the niobium system suggest a sequential intramolecular fluorine abstraction from the hexafluorobenzene molecule 52 as shown in Fig.…”

11 Vanadium, niobium and tantalum

“…A mechanism has been proposed. 25 The X-ray crystal structure has been revised for NbOCl 3 . Contrary to an earlier report, two different Nb-O bond distances were observed.…”