Oxidation of [M(η-C5H5)2], M 4;= 4;Cr, Fe or Co, by the new Brønsted acid H2O·B(C6F5)3 yielding the salts [M(η-C5H5)2]+A–, where A– 4;= 4;[(C6F5)3B(µ-OH)B(C6F5)3]– or [(C6F5)3BOH  · 4;· 4;·  H2OB(C6F5)3]– †

Autor: H. Doerrer, Linda, L. H. Green, Malcolm
Zdroj: Journal of the Chemical Society, Dalton Transactions; December 21, 1999, Vol. 1999 Issue: 24 p4325-4329, 5p
Abstrakt: The Brønsted acids H2O·B(C6F5)3 and D2O·B(C6F5)3 have been synthesized. Reaction of neutral divalent metallocenes [M(η-C5H5)2], M 4;= 4;Cr, Fe or Co, with two equivalents of H2O·B(C6F5)3 2a resulted in metallocene oxidation and formation of salts containing [M(η-C5H5)2]+ cations together with the hydroxoborate anion [HOB(C6F5)3]– which is hydrogen bonded to the second acid equivalent, namely [M(η-C5H5)2][(F5C6)3BOH  · 4;· 4;·  H2OB(C6F5)3], M 4;= 4;Cr 3a, Fe 4a or Co 5a. Treatment of one equivalent of 2a and one equivalent of B(C6F5)3 1 with [M(η-C5H5)2] yielded salts containing the same metallocene cations but now with µ-OH bridged anions, as in [M(η-C5H5)2][(F5C6)3B(µ-OH)B(C6F5)3], where M 4;= 4;Cr 3b or Co 5b. All products have been characterised by NMR spectroscopy, elemental analysis, and the single-crystal structures of 2a, 3a, 4a, and 5a have been determined.
Databáze: Supplemental Index