Structure and excitonic coupling in self-assembling monolayers of azobenzene-functionalized alkanethiols

Optical properties and the geometric structure of self-assembled monolayers of azobenzene-functionalized alkanethiols are examined by UV/visible and near edge X-ray absorption fine structure spectroscopy and density functional theory. The analysis of the energetic shifts has substantiated sizable excitonic coupling among the azobenzene chromophores as a vital mechanism that hinders trans to cis isomerization in densely packed self-assembled monolayers.