Pentafluorophenyl receptor

Fig. 30 CPK representation of the single-crystal X-ray structure of the pentafluorophenyl receptor. The receptor adopts in the solid-state a conformation that is adequate to interact simultaneously through hydrogen-bonding (sulfonamide NH) and anion-jt interaction with an halide located on top of the pentafluorophenyl ring...

Fig. 31 X-ray crystal structtue of the complex formed between the pentafluorophenyl receptor B and tetra-n-butylammonium bromide. The sulfonamide receptor and the organic cation are shown in stick representation while the bromide is represented with van der Waals surface...

Ravikumar I, Lakshminarayanan PS, Arunachalam M et al (2009) Anion complexation of a pentafluorophenyl-substituted tripodal urea receptor in solution and the solid state selectivity toward phosphate. Dalton Trans 4160 -168... 

X. Sun, H. S. Lee, S. Lee, X. Q. Yang, J. McBreen, Electrochem. Solid-State Lett. 1998, 1, 239-240. A novel lithium battery electrolyte based on Uthium fluoride and a tris(pentafluorophenyl) borane anion receptor in DME. 

Lee YM, Seo JE, Choi N-S, Park J-K (2005) Influence of tris(pentafluorophenyl) borane as an anion receptor on ionic conductivity of LiClQ4-based electrol3rie for lithium batteries. Electrochim Acta 50 2843-2848. doi 10.1016/j.electacta.2004.11.058... 

Xie B, Lee HS, Li H, Yang XQ, McBreen J, Chen LQ (2008) New electrolytes using Li20 or Li202 oxides and tris(pentafluorophenyl)borane as boron based anion receptor for lithium batteries. Electrochem Commun 10 1195-1197. doi 10.1016/j.elecom.2008.05.043... 

Another concept for anion receptors comprises bases on boron. It is possible to obtain highly conducting liF solutions in nonaqueous solvents hy means of boron additives, such as tris(pentafluorophenyl)borane (TPFPB) (see Figure 17.15) [423, 424], Solubihty of LiF can be increased by 6 orders of magnitude up to 1 mol- solutions. This observation can be exclusively attributed to Equation 17.27 Moreover, 1 molL solutions of LiF and boron-based anion receptors show good electrochemical stabiHty up to 5 V vs Li. Therefore, full battery systems... 

Figure 17.15 Structure of the anion receptor and Lewis acid tris(pentafluorophenyl)borane (TPFPB).

X 10 S cm". This approach is seemingly espedally useful for battery electrolytes, because the transference number of the lithium ion is increased recently, Weng et al. [519] reported an improved synthesis of tetrafluoro-catechol [105] that is a starting material for the fluorinated boronate ester, 2-(pentafluorophenyl)-tetrafluoro-l,3,2-benzodioxaborole (PFPTFBB). PEPTEBB acts as an anion receptor. In addition, it is an effective redox shuttle for overcharge protection of lithium-ion batteries. Conceptually, this approach is similar to the use of lithium salts with large anions or the immobilization of anions at polymer backbones. 

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