CO releasing molecules (CORMs) of transition metal carbonyl complexes are emerging as a new interdisciplinary advance of inorganic chemistry, biological medicine and materials chemistry. In this paper, new ionic Fischer carbene carbonyl complexes were devised, in which Cr, Mo and W metals as metallic center carried five CO whilst the quaternary ammonium finely tuned the water solubility of Fc-CORMs. The myoglobin assays showed that one Fc-CORM released at least two molecules of carbon monoxide in well-controlled fashion under physiological conditions. The structure-releasing correlation revealed that the central metal was the key factor governing their carbon monoxide release behavior. The CO release rate of Fc-CORM-Mo (2a～2e) is quicker than Fc-CORM-Cr (1a～1e), much faster than Fc-CORM-W (3a～3e). The antibacterial activity test found that Fc-CORM (1b) with medium CO release rate effectively inhibited the growth and survival of Escherichia coli, with an minimal inhibitory concentration (MIC) value of 30 μmol/L. As for drug-resistant bacteria, Fc-CORM (2a～2e) and Fc-CORM (3a～3e) showed bactericidal activity. Mechanism study indicated that the antibacterial activity relied on the CO release rate of Fc-CORMs.

A variety of chromone-containing polycyclic compounds are efficiently generated via Pd-catalyzed decarboxylation [2 + 2 + 2] annulation of 3-iodochromones, bridged olefins and o-bromobenzoic acids, in which o-bromobenzoic acids were employed as the electrophilic aryl units.

The crystal structure of [Cu 2 (cit)(phen) 2 ]•6H 2 O (1) (cit＝citrate anion, phen＝1,10-phenanthroline) reveals an unusual hydrogen-bonded water dodecamer. The centrosymmetric dodecamer contains a decameric core with two pensile monomers, which is described as a chair with two handles. The structure, being predicted to be relative stable to other dodecameric structures, is stabilized by hydrogen bonding with the carboxylate groups of citrate ligands. The variable-temperature magnetic study of 1 shows weak antiferromagnetic interaction.

No abstract