Syntheses of lipophilic tetraarylborate ions substituted with many perfluoroalkyl groups and their stability under acid conditions

Syntheses are investigated on several new kinds of perfluoroalkyl-substituted tetraarylborate ions such as tetrakis(3,5-bis(nonafluorobutyl)phenyl)borate, tetrakis(3,5-bis(heptafluoro-2-propyl)phenyl)borate (PFPB), tetrakis(3-(heptafluoro-2-propyl)-1-(trifluoromethyl)phenyl)borate, and tetrakis(3-(heptafluoro-2-propyl)phenyl)borate. Solubilities of tetramethylammonium tetraarylborates in some hydrophobic halocarbon solvents and rate constants of acid-catalyzed decomposition of the tetraarylborate ions in methanolic sulfuric acid solutions and in dichloromethane/aqueous sulfuric acid two-phase system are determined. Trifluoromethyl- and perfluoroalkyl-substituent effects on the lipophilicity and chemical stability of the tetraarylborate ions are discussed in comparisons with a range of those described previously.