Tris[(triphenylphosphine)gold(I)]oxonium dihydrogentrifluoride as the product of an attempted preparation of [(triphenylphosphine)gold(I)] fluoride

摘要

The reaction of equivalent quantities of (triphenylphosphine)gold chloride and silver fluoride in CH2Cl2/MeOH gives tris[(triphenylphosphine)gold(I)]oxonium dihydrogentrifluoride in good yield. This product is formed through the action of water in the reaction medium. Crystals of {[(Ph3P)Au](3)O}(-)[H2F3](-) 1.5 CH2Cl2 (monoclinic, space group P2(1)/c, Z = 4) contain the cations as hexanuclear dimers with short intra- and intermolecular Au-Au contacts. The structural details are similar to those of related salts with different anions. The [H2F3](-) anion is V-shaped with one symmetrical and one unsymmetrical F-H-F hydrogen bond and is best described as an addition compound of an HF molecule and a [F-H-F](-) anion. The results indicate a high affinity of H2O/OH- for (phosphine)gold fluorides and - by the same token prove that tri(gold)oxonium cations are stable to anhydrous HF and F- anions. By contrast, hydrochloric acid is known to degrade {[(R3P)Au](3)O}(+) affording (R3P)AuCl and water. [References: 34]