Reactions of boron compounds with difluorophosphoric acid; characterisation of the tetrakis(difluorophosphato)borate anion by multinuclear (11B, 19F, and 31P) nuclear magnetic resonance spectroscopy
Abstract
The tetrakis(difluorophosphato)borate anion, [B(PO2F2)4]–(1), has been identified and characterised in solution by means of 11B, 19F, and 31P n.m.r. spectroscopy. (1) is formed from H3BO3 and P2O3F4 in HPO2F2. It is also the initial product of the reaction of BBr3 or BCl3 with excess HPO2F2; however, it is gradually converted to (2), which is believed to be [BF(PO2F2)3]–. (2) is also generated directly from either BF3 or BF4– in P2O3F4–HPO2F2 mixtures, in which it is gradually converted to (1).