Structural evaluation of azobenzene-functionalized self-assembled monolayers on gold by reflectance FTIR spectroscopy

The end-group-dominated molecular orientation in azobenzene self-assembled monolayers (SAMs), CnAzoC2SH (n = 1–4), on gold was evaluated by grazing incidence reflection absorption FTIR spectroscopy. All these azobenzene SAMs form highly organized and closely packed structures, with the molecule tilting gradually away from the surface normal direction with increasing end group alkyl length.