Impact of choice of alkane deposition solvent on 4-fluorobenzoic acid layers adsorbed on silver nanostructures

Surface-enhanced infrared absorption (SEIRA) experiments revealed that the chain length and evaporation rate of alkane deposition solvents altered 4-fluorobenzoic acid (4FBA) adsorption. 4FBA did not dissociate in the multilayer with the fast-evaporating n-pentane deposition solvent. However, with n-hexane and heavier solvents, the evaporation rate was slow enough to allow significant formation of 4-fluorobenzoate ions (4FBI) in the multilayer. Strong intermolecular attractions were present with heavier deposition solvents as evidenced by the incorporation of n-heptane into the 4FBI multilayer. This work will apply to many synthetic, biological, and environmental areas involving the interaction of metal nanostructures with oxygenated or halogenated hydrocarbons.