Acetone solutions of [Au(OClO
3)(
PCy
3)] react with com
plexes [M{S
2C=(
t-Bu-fy)}
2]
2- [
t-Bu-fy = 2,7-di-
tert-butylfluoren-9-ylidene; M = Pd (
2a), Pt (
2b)] or [M{S
2C=(
t-Bu-fy)}(dbb
py)] [dbb
py = 4,4'-di-
tert-butyl-2,2'-bi
pyridyl; M = Pd(
3a), Pt (
3b)] to give the heteronuclear com
plexes [M{S
2C=(
t-Bu-fy)}
2{Au(PCy
3)}
2] [2:1 molar ratio; M = Pd (
4a),Pt (
4b)], [M{S
2C=(
t-Bu-fy)}(dbb
py){Au(PCy
3)}]ClO
4 [1:1 molar ratio; M = Pd (
5a), Pt (
5b)], or [M{S
2C=(
t-Bu-fy)}(dbb
py){Au(PCy
3)}
2](ClO
4)
2 [2:1 molar ratio; M = Pd (
6a), Pt (
6b)]. The crystal structures of
3a,
4a,
4b,
5b,and
6a have been solved by single-crystal X-ray studies and, in the cases of the heteronuclear derivatives, revealthe formation of short Pd···Au or Pt···Au metallo
philic contacts in the range of 3.048-3.311 Å. Com
pounds
4aand
b and
5a and
b undergo a dynamic
process in solution that involves the migration of the [Au(PCy
3)]
+ unitsbetween the sulfur atoms of the dithiolato ligands. The coordination of
2a and
b and
3a and
b to [Au(PCy
3)]
+ unitsresults in im
portant modifications of their
photo
physical
pro
perties. The dominant effect in the absor
ption s
pectrais an increase in the energy of the MLCT (
4a and
b) or charge transfer to diimine (
5a,
b,
6a,
b) transitions becauseof a decrease in the energies of the mixed metal/dithiolate HOMOs. The Pd com
plexes
2a and
4a are luminescentat 77 K, and the features of their emissions are consistent with an essentially metal-centered
3d-d state. The Pt/Aucom
plexes are also luminescent at 77 K, and their emissions can be assigned as originating from a MLCT tri
pletstate (
4b) or a mixture of charge transfer to diimine and diimine intraligand
pi.gif" BORDER=0 >-
pi.gif" BORDER=0 >* tri
plet states (
5b and
6b).