DNA Mismatch Recognition by a Hexacoordinate Silicon Sandwich–Ruthenium Hybrid Complex

The diastereoselective synthesis
of two dinuclear Ru–Si
complexes is reported, in which silicon­(IV) is coordinated in an octahedral
fashion by two 1,10-phenanthrolines and one 4,5-pyrenediolato ligand
and additionally η6-coordinated to a (η5-pentamethylcyclopentadienyl)­ruthenium­(II) moiety through
one fused benzene ring of the pyrene ligand. One of these Ru–Si
hybrid complexes was found to selectively stabilize DNA duplexes that
contain cytosine–cytosine or cytosine–thymine mismatches,
and it is proposed that this occurs by a novel dual insertion/intercalation
binding mode in which the entire ruthenium sandwich unit is introduced
into the DNA π-stacking at the site of the DNA mismatch.