Axially Chiral Allenyl Gold Complexes

Unprecedented allenyl gold complexes
have been achieved starting
from tri­phenyl­pro­pargyl­phos­pho­nium
bromide. Two different coordination modes of the allene isomer of
tri­phenyl­phos­pho­nium­pro­pargylide
to gold have been found depending on the gold oxidation state. Bromo-,
pentafluorophenyl-, and triphenylphosphine–gold­(I) allenyl
complexes were prepared in which the α carbon coordinates to
the gold­(I) center. A chiral pentafluorophenyl–gold­(III) allenyl
complex with the gold atoms coordinated to the γ carbon was
also prepared. All the complexes have been structurally characterized
by X-ray diffraction showing the characteristic distances for a CCC
unit.