Synthesis, Characterization, and Lewis Acid Behavior of [W(NC₆F₅)F₄]_x and Computational Study of W(NR)F₄ (R = H, F, CH₃, CF₃, C₆H₅, C₆F₅), W(NC₆F₅)F₄(NCCH₃), and W(NC₆F₅)F₄(NC₅H₅)_n (n = 1, 2)

Abstract

Amorphous [W­(NC6F5)­F4] x has been synthesized by the reaction of [C5H5NH]­[W­(NC6F5)­F5] with AsF5 in CH2Cl2. The reaction of [W­(NC6F5)­F4] x with CH3CN yields monomeric W­(NC6F5)­F4(NCCH3), whereas reaction with a sub-2-fold excess of C5H5N in CH3CN results in quantitative conversion to W­(NC6F5)­F4(NC5H5). Meanwhile, the reaction of W­(NC6F5)­F4(NCCH3) with a large excess of C5H5N results in the precipitation of W­(NC6F5)­F4(NC5H5)2. These compounds have been characterized in the solid state by Raman spectroscopy and in solution by multinuclear NMR spectroscopy. The crystal structures of W­(NC6F5)­F4(NCCH3) and W­(NC6F5)­F4(NC5H5), as well as improved structures of WOF4(NC5H5) n (n = 1, 2), have been obtained at low temperatures. Furthermore, density functional theory (DFT-B3LYP) calculations have been conducted on the W­(NR)­F4 (R = H, F, CH3, CF3, C6H5, C6F5) series as well as W­(NC6F5)­F4(NCCH3) and W­(NC6F5)­F4(NC5H5) n (n = 1, 2), providing optimized gas-phase geometries, vibrational frequencies, molecular orbitals, fluoride-ion affinities, and natural bond orbital (NBO) analyses.

Stabilisation of [WF5]+ and WF5 by Pyridine: Facile Access to [WF5(NC5H5)3]+ and WF5(NC5H5)2

“…360.38,c alcd. 360.48), and no displacemento ft he tungsten centre from the plane.Asimilar coordination geometry has been observed for the adducts of WOF 4 [17,18] and W(NC 6 F 5 )F 4 [18] with two molar equivalents of C 5 H 5 N. Adducts of WOF 4 with chelating diphosphines are also pentagonal-bipyramidal;h owever,t he donor atoms occupy adjacent sites in the pentagonal plane. [19] The WXF 4 (NC 5 H 5 ) 2 (X = O, F) adducts are isomorphic, but can be distinguishedb yt heir unit-cellp arameters (WOF 4 (NC 5 H 5 ) 2 : a = 8.2014(5) , b = 11.1972(5) , c = 13.5387(9) , b = 107.256(7)8)a nd disorder between the axial W=Oand WÀFbonds in WOF 4 (NC 5 H 5 ) 2 resulting in an averaged bond length (1.834(2) ).…”

“…[19] The WXF 4 (NC 5 H 5 ) 2 (X = O, F) adducts are isomorphic, but can be distinguishedb yt heir unit-cellp arameters (WOF 4 (NC 5 H 5 ) 2 : a = 8.2014(5) , b = 11.1972(5) , c = 13.5387(9) , b = 107.256(7)8)a nd disorder between the axial W=Oand WÀFbonds in WOF 4 (NC 5 H 5 ) 2 resulting in an averaged bond length (1.834(2) ). [18] To our knowledge,o nly one other heptacoordinate fluoridotungsten(V) complex is known, i.e., K 2 [WF 7 ], in which the anion is found to adopt an edge-disordered, monocapped-trigonal-prismatic geometry. [20] Comparison of WF 5 (NC 5 H 5 ) 2 and [WF 7 ] 2À reveal insignificant differences between their WÀFb ond lengths( 1.8936(14)-1.9191(11) and 1.882(16)-1.943 (19) ), [20] respectively), though large errors in the latter prevent more precise analysis.…”

Crystal structure of an ordered [WOF5]− salt: (1,10-phen-H)[WOF5] (1,10-phen = 1,10-phenanthroline)

“…Turnbull et al, 2019b]. The W-F eq bonds in [Xe 2 F 11 ][WOF 5 ](Bortolus et al, 2020) are also of similar lengths to those in the title compound, although one terminal W-F eq bond [1.848(2)Å ] is significantly shorter in the [Xe 2 F 11 ] + salt, and one bridging bond significantly longer [1.900 (2) Å ].…”