212619-93-7Relevant articles and documents
Aqua, alcohol, and acetonitrile adducts of tris(perfluorophenyl)borane: Evaluation of bronsted acidity and ligand lability with experimental and computational methods
Bergquist, Catherine,Bridgewater, Brian M.,Harlan, C. Jeff,Norton, Jack R.,Friesner, Richard A.,Parkin, Gerard
, p. 10581 - 10590 (2000)
Equilibrium studies have been performed to determine the Bronsted acidity of [(C6F5)3B (OH2)]· H2O, the aqua species that exists in acetonitrile solutions of B(C6F5)3 in the presence of water. NMR spectroscopic analysis of the deprotonation of [(C6F5)3B(OH2)]·H 2O with 2,6-But2C5H3N in acetonitrile allows a pK value of 8.6 to be determined for the equilibrium [(C6F5)3B(OH2)]·H 2O ? [(C6F5)3B(OH)]- + [H3O]+. On the basis of a calculated value for the hydrogen bond interaction in [(C6F5)3B(OH2)]·H 2O, the pKa for (C6F5)3B(OH2) is estimated to be 8.4 in acetonitrile. Such a value indicates that (C6F5)3B(OH2) must be regarded as a strong acid, with a strength comparable to that of HCl in acetonitrile. Dynamic NMR spectroscopic studies indicate that the aqua and acetonitrile ligands in (C6F5)3B(OH2) and (C6F5)3B(NCMe) are labile, with dissociation of H2O being substantially more facile than that of MeCN, by a factor of ca. 200 in rate constant at 300 K. Ab initio calculations were performed in the gas phase and with a dielectric solvent model to determine the strength of B-L bonds (L = H2O, ROH, MeCN) and hydrogen bonds involving B-OH2 and B-O(H)R derivatives.
Photo Lewis acid generators: Photorelease of B(C6F5)3 and applications to catalysis
Khalimon, Andrey Y.,Shaw, Bryan K.,Marwitz, Adam J. V.,Piers, Warren E.,Blackwell, James M.,Parvez, Masood
, p. 18196 - 18206 (2015/10/28)
A series of molecules capable of releasing of the strong organometallic Lewis acid B(C6F5)3 upon exposure to 254 nm light have been developed. These photo Lewis acid generators (PhLAGs) can now serve as photoinitiators for several important B(C6F5)3-catalyzed reactions. Herein is described the synthesis of the triphenylsulfonium and diphenyliodonium salts of carbamato- and hydridoborates, their establishment as PhLAGs, and studies aimed at defining the mechanism of borane release. Factors affecting these photolytic reactions and the application of this concept to photoinduced hydrosilylation reactions and construction of siloxane scaffolds are also discussed.
A photo Lewis acid generator (PhLAG): Controlled photorelease of B(C 6F5)3
Khalimon, Andrey Y.,Piers, Warren E.,Blackwell, James M.,Michalak, David J.,Parvez, Masood
, p. 9601 - 9604 (2012/07/14)
A molecule that releases the strong organometallic Lewis acid B(C 6F5)3 upon irradiation with 254 nm light has been developed. This photo Lewis acid generator (PhLAG) now enables the photocontrolled initiation of several reactions catalyzed by this important Lewis acid. Herein is described the synthesis of the triphenylsulfonium salt of a carbamato borate based on a carbazole function, its establishment as a PhLAG, and the application of the photorelease of B(C6F5) 3 to the fabrication of thin films of a polysiloxane material.