We describe the synthesis of [ o -Ph 2 P(O)(C 6 H 4 )SbPh 3 ] + ([2] + ), an intramolecularly base-stabilized stibonium Lewis acid which was obtained by reaction of [ o -Ph 2 P(C 6 H 4 )SbPh 3 ] + with NOBF 4 . This cation reacts with fluoride anions to afford the corresponding fluorostiborane o -Ph 2 P(O)(C 6 H 4 )SbFPh 3 , the structure of which indicates a strengthening of the PO → Sb interaction. When deployed in fluoride-containing POPC unilamellar vesicles, [2] + behaves as a potent fluoride anion transporter whose activity greatly exceeds that of [Ph 4 Sb] + . 
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                            Redox-controlled chalcogen and pnictogen bonding: the case of a sulfonium/stibonium dication as a preanionophore for chloride anion transport
                        
                    
    
            Our interest in the chemistry of tunable chalcogen and pnictogen bond donors as Lewis acidic platforms for the complexation and transport of anions has led us to investigate examples of such compounds that can be activated by redox events. Here, we describe the synthesis of [ o -MePhS(C 6 H 4 )SbPh 3 ] 2+ ([ 3 ] 2+ ) and [ o -MePhS(C 6 H 4 )Sb( p -Tol) 3 ] 2+ ([ 4 ] 2+ ), two dicationic stibonium/sulfonium bifunctional Lewis acids which were obtained by methylation of the phenylthioether derivatives [ o -PhS(C 6 H 4 )SbPh 3 ] + ([ 1 ] + ) and [ o -PhS(C 6 H 4 )Sb( p -Tol) 3 ] + ([ 2 ] + ), respectively. An evaluation of the chloride anion transport properties of these derivatives using chloride-loaded POPC unilamellar vesicles shows that the activity of the monocations [ 1 ] + and [ 2 ] + greatly exceeds that of the dications [ 3 ] 2+ and [ 4 ] 2+ , a phenomenon that we assign to the higher lipophilicity of the monocationic compounds. Harnessing this large transport activity differential, we show that [ 4 ] 2+ can be used as a prechloridophore that is readily activated by reduction of the sulfonium moiety. Indeed, [ 4 ] 2+ reacts with GSH to afford [ 2 ] + as an active transporter. This activation, which has been monitored in aqueous solution, can also be carried out in situ , in the presence of the chloride-loaded POPC unilamellar vesicles. 
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                            - Award ID(s):
- 1856453
- PAR ID:
- 10248492
- Date Published:
- Journal Name:
- Chemical Science
- Volume:
- 11
- Issue:
- 37
- ISSN:
- 2041-6520
- Page Range / eLocation ID:
- 10107 to 10112
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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