Switchable molecular conductivity.

We demonstrate the switchability of the molecular conductivity of a citrate. This was made possible through mechanical stretching of two conformers of such citrate capped on and linked between gold nanoparticles (AuNPs) self-assembled as a film. On the basis of experimental results, theoretical analysis was conducted using the density function theory and Green's function to study the electron flux in the backbone.

Protonation of O2 adsorbed on a Pt3 island supported on transition metal surfaces.

The reduction in oxygen on bimetallic tips X(S)Pt(3) (X(S) = Co(3), Ni(3), Pt(6), Co(3)Pt(3)) in aqueous acid medium is studied. It is found that a locally neutral neighborhood of an active site in the bimetallic tip as well as adduct hydration assist in the protonation. It is concluded that metallic tips of Pt, Co(3)Pt, and Co are comparable in performance for the oxygen reduction reaction.

Mechanism of carbon nanotubes unzipping into graphene ribbons.

The fabrication of graphene nanoribbons from carbon nanotubes (CNTs) treated with potassium permanganate in a concentrated sulfuric acid solution has been reported by Kosynkin et al. [Nature (London) 458, 872 (2009)]. Here we report ab initio density functional theory calculations of such unzipping process.

Local reactivity of O2 with Pt3 on Co3Pt and related backgrounds.

We study the local reactivity of molecular oxygen with bimetallic substrates of a platinum trimer island supported on nanotips of CoPt, Pt, Co, Ni, and Fe. Because of the reduced interatomic distances and varying interaction strengths with the substrates, the supported island interaction with oxygen can be tuned from stronger to weaker relative to the interaction of a freestanding island with oxygen despite that there is no well-behaved trend with the binding energy of the island to the substrates.

Biatomic substrates for bulk-molecule interfaces: the PtCo-oxygen interface.

We develop an ab initio procedure for materials participating in electron transfer reactions, to consider biatomic backgrounds (e.g., substrates, catalysts, electrodes), thus the precise effects of the continuum and long-range interactions as well as the effects of the discrete and local nature of the chemistry can be combined to study molecules under such biatomic backgrounds.