Platinum blues constitute an intriguing and extensively studied family of c
omplexes generally containing a chain of four platinum atoms of mixed valen
ces and metal-metal bonds. There is no reason why they should constitute an
isolated type of complexes based exclusively on platinum, and we comment o
n a rational strategy for the preparation of a new family of rhodium and ir
idium blues. The most effective approach seems to be a redox condensation b
etween dinuclear complexes of a given metal in different oxidation states t
o yield the desired tetrametallic chain. Thus, by mixing equimolar amounts
of dinuclear rhodium or iridium pyrazolato (pz) complexes in oxidation stat
es I and II, [{M(mu-pz)(CNtBu)(2)}(2)] and d[{Mu-pz)(CNtBu(2))(NCME}(2)](PF
6)(2), novel Phodium and iridium pyrazolato blues of formula [{M(mu-pz)(CtN
rBu)(2)}(4)] (PF6)(2) are obtained by a redox condensation. Alternatively,
the oxidation of just one half of the dinuclear rhodium(I) or iridium(I) co
mplexes can be carried out with a conventional oxidant, such as [FeCp2]PF6,
in such a way that after the redox condensation the four metal atoms end u
p with a formal oxidation state of 1.5. In same cases, a direct partial oxi
dation of diiridium(I) complexes with diiodine can also be effective. Final
ly, a few comments of concern for the possible development of related linea
r polynuclear mixed-valence complexes are presented.