Tetrakis[3,5-bis(pentafluorosulfanyl)phenyl]borate: A Weakly Coordinating Anion Probed in Polymerization Catalysis

Abstract

The novel weakly coordinating lipophilic anion tetrakis­[3,5-bis­(pentafluorosulfanyl)­phenyl]­borate ([S-BArF 4]−) was prepared by reaction of an aryl Grignard reagent from transmetalation with boron­(III) chloride. In other routes established for the synthesis of the trifluoromethyl analogue ([BArF 4]− with ArF = 3,5-(F3C)­C6H3), the SF5 substitution resulted in a distinctly different reactivity. Na­[S-BArF 4] as a solid is stable up to >250 °C according to thermogravimetric analysis. Single-crystal X-ray analysis of the novel cationic Ni­(II) complex [Ni­(allyl)­(mesitylene)]+[S-BArF 4]− shows a tetrahedral arrangement of the aryl units at the boron center. This complex is a catalyst precursor for butadiene polymerization in heptane with high activity and 1,4-cis selectivity (≥93%). In comparison to its [BArF 4]− analogue, the polymerization activity is 2-fold higher. Electrochemical and DFT studies further underline the weakly coordinating nature of [S-BArF 4]−.

When SF5 outplays CF3: effects of pentafluorosulfanyl decorated scorpionates on copper

“…For example, recent work by Mecking and co-workers illustrated the benefits of SF 5 over CF 3 groups on Ni( ii ) salicylaldiminato complexes in ethylene polymerization catalysis (to get more linear and higher molecular weight polymers), 6 a as well as on tetraphenylborate ions in Ni( ii ) mediated butadiene polymerizations. 8 In addition, SF 5 group has been utilized in luminescent transition metal complexes to minimize the aggregation in the solid-state, improve the solubility, and alter the emission features such as blue shifting of the phosphorescent emissions more significantly relatively to CF 3 bearing analogs. 2 b ,3 a ,9…”

MicroED characterization of a robust cationic σ-alkane complex stabilized by the [B(3,5-(SF5)2C6H3)4]− anion, via on-grid solid/gas single-crystal to single-crystal reactivity

“…Addition of sparingly soluble [NBu 4 ][S-BAr F 4 ] 17 to [Rh(Cy 2 PCH 2 CH 2 PCy 2 )Cl] 2 in CH 2 Cl 2 solvent, with excess NBD, leads to the precipitation of analytically pure microcrystals (∼1 to 10 μm) of [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(NBD)][S-BAr F 4 ], [1-NBD][S-BAr F 4 ], Fig. 1 .…”

“… 10 ], and two diagnostic signals in the alkene region in the latter [ δ 91.2, 84.1]. 20 While the insolubility of [1-NBD][S-BAr F 4 ] suggested desirable robustness, it counterpoints that of [Ni(allyl)(mesitylene)][S-BAr F 4 ] 17 and [1-NBD][BAr F 4 ] 10 which are soluble in CH 2 Cl 2 .…”

“…14 MOFs are also well documented to undergo SC-SC transformations using both solid/gas and solid/liquid reactivity. 15,16 We now report (Scheme 2) that by changing the anion in ) 17 increased C-H δ+ ⋯ δ− F-C non-covalent interactions 11 in the lattice lead to a robust, microcrystalline, σ-alkane complex, that shows improved stability characteristics under both thermal and solid/liquid reactivity conditions. This allows for catalytic ethene dimerisation/ isomerisation in a pentane slurry without decomposition to the zwitterion.…”

“…We now report ( Scheme 2 ) that by changing the anion in [1-NBA][BAr F 4 ] to Mecking's, recently reported, [B(3,5-(SF 5 ) 2 C 6 H 3 ) 4 ] − anion ([S-BAr F 4 ]) 17 increased C–H δ + ⋯ δ − F–C non-covalent interactions 11 in the lattice lead to a robust, microcrystalline, σ-alkane complex, that shows improved stability characteristics under both thermal and solid/liquid reactivity conditions. This allows for catalytic ethene dimerisation/isomerisation in a pentane slurry without decomposition to the zwitterion.…”