Reactivity patterns for the activation of CO and CS with alumoxane and aluminum hydrides.

Carbon dioxide is readily fixed when reacting with either alumoxane dihydride [{MeLAl(H)}2(μ-O)] (1) or aluminum dihydride [MeLAlH2] (2) (MeL = HC[(CMe)N(2,4,6-Me3C6H2)]2-) to produce bimetallic aluminum formates [(MeLAl)2(μ-OCHO)2(μ-O)] (3) and [(MeLAl)2(μ-OCHO)2(μ-H)2] (5), respectively. Furthermore, [(MeLAl)2(μ-OCHO)2(μ-OH)2] (4) is easily obtained upon the reaction of 3 or 5 with H2O. The stability of the unusual dialuminum diformate dihydride core observed in 5 stems from the proximity of the Al centers allowing the formation of two Al-HAl bridges and precluding further hydride transfer to the HCO2 moieties.

The Role of the DNA Backbone in Minor-Groove Ligand Binding.

Molecular recognition between ligands and nucleic acids plays a key role in therapeutic activity. Some molecules interact with DNA in a nonbonded manner through intercalation or through the DNA grooves. The recognition of minor-groove binders is attributed to a set of hydrogen-bonding interactions between the binders and the hydrogen-bond-acceptor groups on the groove floor and walls.