Catechol oxidation: considerations in the design of wet adhesive materials.

Catechols are found as functional groups in Nature as the 3,4-dihydroxy isomer, generally with electron donating substituents and as the 2,3-dihydroxy isomer, with an electron withdrawing substituent. Adhesive properties of catechol materials rely on the vicinal diol configuration, yet conversely, cohesive properties of catechol materials depend on catechol oxidation that promote subsequent crosslinking reactions. While the pH-dependent oxidation of catechol by dioxygen is well recognized, a better understanding of substituent effects on catechol redox chemistry is important in the design of new catechol-containing functional materials.

Photocatalytic carbon disulfide production via charge transfer quenching of quantum dots.

Carbon disulfide, a potentially therapeutic small molecule, is generated via oxidative cleavage of 1,1-dithiooxalate (DTO) photosensitized by CdSe quantum dots (QDs). Irradiation of DTO-QD conjugates leads to λ(irr) independent photooxidation with a quantum yield of ~4% in aerated pH 9 buffer solution that drops sharply in deaerated solution. Excess DTO is similarly decomposed, indicating labile exchange at the QD surfaces and a photocatalytic cycle.