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Stabilisation of [WF 5 ] + and WF 5 by Pyridine: Facile Access to [WF 5 (NC 5 H 5 ) 3 ] + and WF 5 (NC 5 H 5 ) 2
Author(s) -
Turnbull Douglas,
Hazendonk Paul,
Wetmore Stacey D.,
Gerken Michael
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202000424
Subject(s) - chemistry , adduct , raman spectroscopy , comproportionation , crystallography , spectroscopy , pyridine , nuclear magnetic resonance spectroscopy , ligand (biochemistry) , stereochemistry , medicinal chemistry , biochemistry , physics , receptor , organic chemistry , electrode , quantum mechanics , optics , electrochemistry
The enhanced reactivity of [WF 5 ] + over WF 6 has been exploited to access a neutral derivative of elusive WF 5 . The reaction of WF 6 (NC 5 H 5 ) 2 with [(CH 3 ) 3 Si(NC 5 H 5 )][O 3 SCF 3 ] in CH 2 Cl 2 results in quantitative formation of trigonal‐dodecahedral [WF 5 (NC 5 H 5 ) 3 ] + , which has been characterised as its [O 3 SCF 3 ] − salt by Raman spectroscopy in the solid state and variable‐temperature NMR spectroscopy in solution. The salt is susceptible to slow decomposition in solution at ambient temperature via dissociation of a pyridyl ligand, and the resultant [WF 5 (NC 5 H 5 ) 2 ] + is reduced to WF 5 (NC 5 H 5 ) 2 in the presence of excess C 5 H 5 N, as determined by 19 F NMR spectroscopy. Pentagonal‐bipyramidal WF 5 (NC 5 H 5 ) 2 was isolated and characterised by X‐ray crystallography and Raman spectroscopy in the solid state, representing the first unambiguously characterised WF 5 adduct, as well as the first heptacoordinate adduct of a transition‐metal pentafluoride. DFT‐B3LYP methods have been used to investigate the reduction of [WF 5 (NC 5 H 5 ) 2 ] + to WF 5 (NC 5 H 5 ) 2 , supporting a two‐electron reduction of W VI to W IV by nucleophilic attack and diprotonation of a pyridyl ligand in the presence of free C 5 H 5 N, followed by comproportionation to W V .