We offer here evidence for halogen bonding induced by silver nanoparticles (SNPs) in a multilayer containing 4-iodobenzoate ion (4IBI) and CCl(4). SERS experiments show in the monolayer that CCl(4) does not adsorb and 4-iodobenzoic acid (4IBA) adsorbs as 4IBI. SEIRA experiments reveal that 4IBI forms in the multilayer during deposition from CCl(4) on SNPs. Further infrared experiments on clean BaF(2) prove that 4IBI formation caused by underlying SNPs was necessary for CCl(4) inclusion in a 4IBI multilayer. Several potential scenarios involving intermolecular attraction between CCl(4) and 4IBI are proposed to explain the results. Although halogen bonding involving solvents has been theoretically and experimentally demonstrated in solution phase chemistry, in bulk crystals, and at the monolayer level, here it is shown that halogen bonding interactions can also be significant in multilayer films. Results from this work will likely impact a range of applications across diverse fields where halogen bonding in thin films and nucleation chemistry are important.
Copyright © 2012 Elsevier Inc. All rights reserved.