The following gold(I) and silver(I) complexes of the tritertiary phosphine 1,1,1-
tris(diphenylphosphinomethyl)ethane, tripod , have been synthesised: Au3(tripod)X3
[X = Cl(1), Br(2), I(3)];
[Au3 (tripod)2Cl2 ]Cl
(4); Au(tripod)X [X = Br(5), I(6)]; Ag3(tripod)(NO3)3
(7), Ag(tripod)NO3
(8). They were
characterized by X-ray diffraction (complexes 2, 3 and 4), P31
NMR spectroscopy, electrospray and FAB mass
spectrometry and infrared spectroscopy. Complexes 2 and 3 show a linear coordination geometry for Au(I),
with relatively short Au-P bond distances. Complex 3 has a Au•••Au
intramolecular distance of 3.326 A°
,
while complex 2 had a short Au•••Au intermolecular interaction of 3.048 A°
. Complexes 4-6 were found by
P31
NMR spectroscopy studies to contain a mixture of species in solution, one of which crystallised as
[Au3(tripod|)2Cl2]Cl which was shown by X-ray diffraction to contain both tetrahedral and linear Au(I), the
first example of a Au(I) complex containing such a mixture of geometries. The reaction of [Au3(tripod)Cl3] (1)
with tripod led successfully to the formation of [Au3(tripod)Cl3][Au3(tripod|)2Cl2]+ and [Au3(tripod|)3Cl]2+
. The silver(I)
complexes, 7 and 8 appear to contain linear and tetrahedral Ag(I), respectively.
Different Coordination Modes of a Tripod Phosphine in Gold(I) and
Silver(I) Complexes