Salts with the Triborate Anion [B3O3F2(OH)2]–: A Combined Experimental and Theoretical Study

Reactions of [3-NC-B11F10]2–with aqueous bases resulted in a cluster degradation. From the reaction mixtures, salts of the [B3O3F2(OH)2]–anion (1) with [Ph4P]+or [Ph3MeP]+as countercations were isolated. Both salts were investitgated by single-crystal X-ray diffraction. In the solid state the triborate anions form infinite hydrogen-bonded chains. In the [Ph4P]+salt the anions and the chains are coplanar, whereas in the [Ph3MeP]+salt the planes of the anions are twisted against each other. The bonding parameters of the anion are compared to values of the related [B3O3(OH)4]–anion (2) and to values derived from density functional calculations. In addition, the triborate anion 1was characterized by 11B and 19F NMR spectroscopy as well as by MALDI mass spectrometry. The experimental chemical shifts are compared to calculated values (DFT-GIAO).(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)