Triruthenium and Triosmium Carbonyl Cluster Complexes Containing Bridging Ligands Derived from 2-Amino-7,8-benzoquinoline

The ruthenium cluster complexes [Ru3(μ3-η3-abq-C,N,N)(CO)9] (1) and [Ru3(μ-H)2(μ3-η3-abq-C,N,N)2(CO)6] (2) (H2abq = 2-amino-7,8-benzoquinoline) have been stepwise prepared
from [Ru3(CO)10(MeCN)2]. Both compounds contain cyclometalated abq ligands which span
a Ru−Ru edge through the N atom of an amido fragment and chelate the remaining Ru
atom through both the quinolinic N atom and the C atom of the cyclometalated ring. For
steric reasons, the cyclometalation is responsible for the observation of short
Ru−Namido bond lengths. The reaction of the osmium cluster [Os3(CO)10(MeCN)2] with H2abq gives the amido-bridged decacarbonyl derivative [Os3(μ-Η)(μ-η1-Habq-N)(CO)10] (3).
Curiously, while complex 3 is stable in refluxing toluene, the ruthenium analogue of 3 has
not been detected. Compounds 1−3 represent the first trinuclear carbonyl clusters containing
ligands derived from 2-amino-7,8-benzoquinoline.