Further Evidence for 'Extended' Cumulene Complexes: Derivatives from Reactions with Halide Anions and Water.

Reactions of [Ru{C=C(H)-1,4-C H C≡CH}(PPh ) Cp]BF ([1 a]BF ) with hydrohalic acids, HX, results in the formation of [Ru{C≡C-1,4-C H -C(X)=CH }(PPh ) Cp] [X=Cl (2 a-Cl), Br (2 a-Br)], arising from facile Markovnikov addition of halide anions to the putative quinoidal cumulene cation [Ru(=C=C=C H =C=CH )(PPh ) Cp] . Similarly, [M{C=C(H)-1,4-C H -C≡CH}(LL)Cp ]BF [M(LL)Cp'=Ru(PPh ) Cp ([1 a]BF ); Ru(dppe)Cp* ([1 b]BF ); Fe(dppe)Cp ([1 c]BF ); Fe(dppe)Cp* ([1 d]BF )] react with H /H O to give the acyl-functionalised phenylacetylide complexes [M{C≡C-1,4-C H -C(=O)CH }(LL)Cp'] (3 a-d) after workup. The Markovnikov addition of the nucleophile to the remote alkyne in the cations [1 a-d] is difficult to rationalise from the vinylidene form of the precursor and is much more satisfactorily explained from initial isomerisation to the quinoidal cumulene complexes [M(=C=C=C H =C=CH )(LL)Cp'] prior to attack at the more exposed, remote quaternary carbon.

The Antimicrobial Activity of a Carbon Monoxide Releasing Molecule (EBOR-CORM-1) Is Shaped by Intraspecific Variation within Populations.

Carbon monoxide releasing molecules (CORMs) have been suggested as a new synthetic class of antimicrobials to treat bacterial infections. Here we utilized a novel EBOR-CORM-1 ([NEt][MnBr(CO)]) capable of water-triggered CO-release, and tested its efficacy against a collection of clinical strains that differ in infection-related virulence traits. We found that while EBOR-CORM-1 was effective in clearing planktonic and biofilm cells of strain PAO1 in a concentration dependent manner, this effect was less clear and varied considerably between different cystic fibrosis (CF) lung isolates.