Several configurations of colloidal wires are obtained by infiltration of charge‐stabilized polystyrene spheres into cylindrical pores of a silicon membrane (see figure). As channel dimensions are comparable to those of particles, wirelike arrangements are governed by the ratio between the pore diameter and the particle diameter. Also, Coulomb repulsion between particles plays a very important role in the particle ordering.

We use photoelectron spectroscopy, low energy electron diffraction, scanning tunneling microscopy, and density functional theory to investigate coverage dependent iodine structures on Pd(110). At 0.5 ML (monolayer), a c(2 × 2) structure is formed with iodine occupying the four-fold hollow site. At increasing coverage, the iodine layer compresses into a quasi-hexagonal structure at 2/3 ML, with iodine occupying both hollow and long bridge positions. There is a substantial difference in electronic structure between these two iodine sites, with a higher electron density on the bridge bonded iodine. In addition, numerous positively charged iodine near vacancies are found along the domain walls. These different electronic structures will have an impact on the chemical properties of these iodine atoms within the layer.

The inside cover shows strands of colloidal crystal wires made from latex spheres. The processing method, reported by Francisco Meseguer and co‐workers , concerns the infiltration of particles into microporous silicon with channels that are a few times larger than latex particles. The important parameter is the ratio between the pore diameter and the particle size: the confinement ratio D. In the reported experiments, D varies between 1 and 3.