Structural evolution of dicarbon-silver cluster anions: from flat to 3-dimensional and from attached to core–shell

Abstract

Coinage-metal based nanocomposites and interfaces attract much attention due to a variety of technological applications in the areas of materials, catalysis, molecular electronics, etc. In particular, carbon-silver systems exhibit significant prospects for multiple practical uses. The reported study at a DFT level concentrates on such cluster anions with a diatomic carbon component and presents a variety of isomers evolving with size from planar to nonplanar geometries. Structures, stabilities, charge distributions, vertical electron-detachment energies and simulated IR spectra for C2Agn – (n = 4–17) are discussed, with dicarbon attached outside or inserted inside the silver entity. In particular, the spectra show two main bands associated with the relative motions of the carbon and silver parts as a whole and stretching vibration in C2. Their relative intensities are correlated with the structural features of the systems. A sequential mechanism is proposed for formation of the metastable core–shell C2Ag17 – species (found to release the carbon core upon electron detachment). The results are believed to be accessible for experimental verification.