Transition metal bifluorides

Abstract

A c c e p t e d M a n u s c r i p t HighlightsSince their discovery four decades ago, transition metal bifluoride complexes have long been considered as unwanted byproducts, a necessary evil, on the route to access fluoride complexes. Until recently, reports on this chemistry almost always presented these complexes as a fluke discovery. However, with the recent increase in reports and applications involving such species, a renewed interest in these complexes has been observed. Most of the work done in this area, so far, has been directed toward the synthesis and quite challenging characterization of these complexes, yet mostly neglecting the behavior of such species and their influence on catalytic processes. The aim of this work is to present a summary of the various preparation methods, characterization techniques and applications of reported transition metal bifluoride complexes. It is our hope that by centralizing all information available on such species, future efforts aimed at exploiting the full potential of transition metal bifluoride species can be facilitated.

Synthesis, Characterisation and Hydrogen Bonding of Isostructural Group 10 Metal Halido Complexes Bearing a POCOP Ligand

“…However, after 2 d we observed quantitative conversion of the chlorido complex to a single fluoride‐containing new species, as evidenced by a doublet in the 31 P NMR spectrum at δ = 180.8 ppm ( J = 25.8 Hz) caused by coupling of two equivalent phosphorus nuclei to the nickel‐bound fluorine atom. Further analysis of the 1 H and 19 F NMR spectra suggested the presence of a bifluorido complex ( 1 H: δ = 10.8 ppm, d, J FH = 430 Hz; 19 F: δ = –185.2 ppm, d, J FH = 430 Hz) . Formation of a similar POCOP Ni bifluorido complex with P i Pr 2 donor sites was described before by Zargarian et al; the spectroscopic features are in good agreement with the herein‐reported example .…”

“…ATR‐IR analysis of 1‐FHF and comparison of the spectra with HF‐free 1‐F showed the presence of two prominent bands at 1751 and 2752 cm –1 ; the latter band can be assigned to the terminal H–F bonds (cf. free HF: ν̃ = 3960 cm –1 ) . This is indicative of an unsymmetric bifluorido ligand and in contrast to bifluoride salts, which typically show a single band at much lower wavenumbers.…”

A C^N Cycloplatinated(II) Fluorido Complex: Photophysical Studies and Csp3‒F Bond Formation

“…The emission band of the frozen solution (77 K) appears at 480 nm with a slight blue shift and more structured shape compared with that of at 298 K ( Figure S14). 487, 522 max , 554 sh (350), Solid (298 K) 6.9 31.0 4.49×10 4 10.0×10 4 a kr and knr were calculated according to the equations kr = Φ/τ and knr = (1/τ)-kr respectively.…”

“…The emission band of the frozen solution (77 K) appears at 480 nm with a slight blue shift and more structured shape compared with that of at 298 K (Figure S14). 487, 522 max , 554 sh (350), Solid (298 K) 6.9 31.0 4.49×10 4 10.0×10 4 a kr and knr were calculated according to the equations kr = Φ/τ and knr = (1/τ)-kr respectively. Interestingly, in solid state the similar emission bands but with decreased intensities were observed from 2 to 1c (F to I), while 1c is practically non-emissive (Figure 3 and Table 1).…”

“…1 2 As a result, transition metal complexes usually show interesting halide effect in reactivity and properties such as luminescence. While transition metal complexes with Cl, Br, and I ligands are very common, the F containing analogues are much less available, especially for late transition metals cations in low oxidation states, [2][3][4][5] thus preventing a complete study across the group. For example, halide ligands (Cl, Br, I) have been shown to largely influence the emission properties of Pt(II) [6][7][8][9] , Pt(IV) 10,11 , and Cu(I) [12][13][14][15] complexes.…”