A general route to t
he complexes [CpTi(
3-S)
3M
3(diolefin)
3] (M = Rh, diolefin = cod, nbd,tfbb; M = Ir, diolefin = cod) consists of t
he reactions of t
he anion [Cp
2Ti
2(
-S)
2(S)
2]
2-, obtainedby mono-deprotonation of Cp
2Ti(SH)
2 with butyllithium in THF, with t
he appropriatecomplexes [{M(
-Cl)(diolefin)}
2]. Replacement of t
he diolefin by carbon monoxide in [CpTi(
3-S)
3M
3(diolefin)
3] gives t
he carbonyl derivatives [CpTi(
3-S)
3M
3(CO)
6]. Furt
her reactionsof t
he carbonyliridium complex with tertiary phosphine and phosphite ligands produce t
he62-e valence clusters [CpTi(
3-S)
3Ir
3(
-CO)(CO)
3(PR
3)
3] (PR
3 = PPh
3, PMe
3, P(OMe)
3,PMePh
2). Remarkable features in t
he structure of t
hese compounds, as found for [CpTi(
3-S)
3Ir
3(
-CO)(CO)
3{P(OMe)
3}] by X-ray diffraction studies, are a distorted tetra
hedral metalframework with short Ir-Ir distances and a tetra
hedral coordination of t
he iridium atomclosest to t
he titanium. A delocalized bonding sc
heme can be proposed for t
he iridium triangleand, at least, an interaction between t
he tetra
hedral iridium and t
he titanium atom. T
hecomplexes [CpTi(
3-S)
3Ir
3(
-CO)(CO)
3(PR
3)
3] quickly exchange all t
heir carbonyl ligands with
13CO under normal conditions to give t
he labeled complexes. Indeed, an equilibrium betweent
he compounds [CpTi(
3-S)
3Ir
3(
-
13CO)(
13CO)
3(PR
3)
3] and [CpTi(
3-S)
3Ir
3(
-
13CO)(
13CO)
4(PR
3)
2]and free phosphine exists under an atmosp
here of
13CO. In addition, t
hese compounds arefluxional, since t
hey exhibit a single carbonyl resonance in t
he low-temperature
13C{
1H}NMR spectrum, probably due to very fast carbonyl scrambling. Furt
hermore, t
he reactionof [CpTi(
3-S)
3Ir
3(
-CO)(CO)
3(PPh
3)
3] with HBF
4 gives t
he unsymmetric and nonfluxionalhydride of formula [CpTi(
3-S)
3Ir
3(
-CO)(H)(CO)
3(PPh
3)
3]BF
4.
