Lewis acidic stiborafluorenes for the fluorescence turn-on sensing of fluoride in drinking water at ppm concentrations

Lewis acidic organoantimony(v) derivatives have been developed for the fluorescence turn-on sensing of fluoride in biphasic water–CH2Cl2mixtures at sub-ppm concentrations.</p

Phosphino-Stibine Ligands for the Synthesis of Heterometallic Complexes

The phosphino‐stibine ligands (o‐PPh2C6H4)2SbR [R = o‐PPh2C6H4 (L1), Ph (L2), Cl (L3)] were incorporated into tungsten and molybdenum carbonyl complexes leading to the formation of cis‐[W(CO)4{(o‐PPh2C6H4)2SbR}] [R = o‐PPh2C6H4 (1), Ph (2), Cl (3)], fac‐[W(CO)3{(o‐PPh2C6H4)3Sb}] (4), fac‐[W(CO)3{(o‐PPh2C6H4)2SbCl}] (5), fac‐[(W(CO)3{(o‐PPh2C6H4)2Sb})2] (6), fac‐[Mo(CO)3{(o‐PPh2C6H4)2SbR}] [R = o‐PPh2C6H4 (7), Ph (8), Cl (9)]. Compounds 1 and 4 were allowed to react with MX salts with M = Cu, Ag, Au and X = Cl–, [PF6]–, respectively. These reactions yielded cis‐[W(CO)4{(o‐PPh2C6H4)3Sb}{MCl}] [M = Cu (10), Ag (11)], cis‐[W(CO)4{(o‐PPh2C6H4)2Sb}{AuCl(o‐PPh2C6H4)}{AuCl}] (12) cis‐[(W(CO)4{(o‐PPh2C6H4)2Sb})2AuCl] (13), cis‐[W(CO)3(μ‐CO){(o‐PPh2C6H4)3Sb}{Cu}][PF6] (14), cis‐[W(CO)4{(o‐PPh2C6H4)3Sb}{AgMeCN}][PF6] (15), cis‐[W(CO)4{(o‐PPh2C6H4)3Sb}{Au}][PF6] (16) cis‐[W(CO)2(μ‐CO){(o‐PPh2C6H4)3Sb}{Cu2(μ‐Cl)2}] (17), fac‐[W(CO)3{(o‐PPh2C6H4)3Sb}{AuCl}] (18), and fac‐[W(CO)2(μ‐CO){(o‐PPh2C6H4)3Sb}{ML}][PF6] [M = Cu, L = MeCN (19), M = Ag, L = MeCN (20), M = Au (21)]. Complexes 10–21 all show metal‐metal distances below the sum of the corresponding van der Waals radii. The proximity of the two metal centers is especially significant in 19–21, indicating the presence of metal‐metal bonding

[ 18 F]–NHC–BF 3 adducts as water stable radio-prosthetic groups for PET imaging

The radiofluorination of N-heterocyclic carbene (NHC) boron trifluoride adducts affords novel [ 18 F]-positron emission tomography probes which resist hydrolytic fluoride release

Preparation of [ 18 F]-NHC-BF 3 conjugates and their applications in PET imaging

[ 18 F]-NHC-BF 3 functionalized bioactive molecules can be successfully synthesized by 18 F– 19 F isotopic exchange in one labelling step affording highly stable PET probes which can visualize targeted tumours in mice

Fluorinated antimony(v) derivatives: strong Lewis acidic properties and application to the complexation of formaldehyde in aqueous solutions

As part of our ongoing studies of water tolerant Lewis acids, we have synthesized and investigated the properties of Sb(C(6)F(5))(3)(O(2)C(6)Cl(4)), a fluorinated stiborane whose Lewis acidity approaches that of B(C(6)F(5))(3). While chloroform solutions of this Lewis acid can be kept open to air or exposed to water for extended periods of time, this new Lewis acid reacts with P(t)Bu(3) and paraformaldehyde to form the corresponding formaldehyde adduct (t)Bu(3)P–CH(2)–O–Sb(C(6)F(5))(3)(O(2)C(6)Cl(4)). To test if this reactivity can also be observed with systems that combine the phosphine and the stiborane within the same molecule, we have also prepared o-C(6)H(4)(PPh(2))(SbAr(2)(O(2)C(6)Cl(4))) (Ar = Ph, C(6)F(5)). These yellow compounds, which possess an intramolecular P→Sb interaction, are remarkably inert to water but do, nonetheless, react with and accomodate formaldehyde into the P/Sb pocket. In the case of the fluorinated derivative o-C(6)H(4)(PPh(2))(Sb(C(6)F(5))(2)(O(2)C(6)Cl(4))), formaldehyde complexation, which occurs in water/dichloromethane biphasic mixtures, is accompanied by a colourimetric turn-off response thus highlighting the potential that this chemistry holds in the domain of molecular sensing

Structural Evidence for Pnictogen-Centered Lewis Acidity in Cationic Platinum-Stibine Complexes Featuring Pendent Amino or Ammonium Groups

As part of our continuing interest in the chemistry of cationic antimony Lewis acids as ligands for late transition metals, we have now investigated the synthesis of platinum complexes featuring a triarylstibine ligand substituted by an o-[(dimethylamino)methyl]phenyl group referred to as ArN. More specifically, we describe the synthesis of the amino stibine ligand Ph2SbArN (L) and its platinum dichloride complex [LPtCl]Cl which exists as a chloride salt and which shows weak coordination of the amino group to the antimony center. We also report the conversion of [LPtCl]Cl into a tricationic complex [LHPt(SMe2)]3+ which has been isolated as a tris-triflate salt after reaction of [LPtCl]Cl with SMe2, HOTf and AgOTf. Finally, we show that [LHPt(SMe2)][OTf]3 acts as a catalyst for the cyclization of 2-allyl-2-(2-propynyl)malonate