The rate of direct fluorination of B12H122− to high-purity B12F122− in cold CH3CN increased by adding a large excess of KF to the reaction mixture (this removed the HF byproduct as it was formed).1 In contrast, direct fluorination of B12H11(NH3)− in cold CH3CN with added KF produced B12H11 −nFn(NH3)− species that decomposed faster than they were formed as n → 11. In addition, the direct fluorination in cold CH3CN with added anhydrous HF was slower in the case of B12H122− but faster in the case of B12H11(NH3)−, resulting in a good yield of high-purity KB12F11(NH3) in only 4 h. Possible reasons for these unexpected differences will be presented. The direct fluorination of B12H10(NH3)2 isomers and the structures of 1,2-, 1,7-, and 1,12-B10F10(NH3)2 will also be presented, as will a comparison of the cation−anion interactions and hydrogen bonding in the crystalline salt hydrates Na(H2O)4(B12F11(NH3)) and Na2(H2O)4(B12F12).2,3 1. Peryshkov, D. V.; Popov, A. A.; Strauss, S. H. "Direct Perfluorination of K2B12H12 in Acetonitrile Occurs at the Gas Bubble–Solution Interface and is Inhibited by HF. Experimental and DFT Study of Inhibition by Protic Acids and Soft, Polarizable Anions," J. Am. Chem. Soc. 2009, 131, 18393. 2. Current affiliations: EVB, Peach State Labs, LLC, Rome GA 30162; AMP, Bend Research, Bend, OR 97701; DVP, Assistant Professor of Chemistry, University of South Carolina, Columbia, SC 29208. 3. SHS is the recipient of the 2016 ACS Award for Creative Work in Fluorine Chemistry (sponsored by the Juhua Group Technology Center (China)).

Direct fluorination of B12H122−, B12H11(NH3)−, and isomers of B12H10(NH3)2 in CH3CN: The effects of added KF, HF, or H2O

251st National Meeting (2016)

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