title: UV-Vis Reflection-Absorption Spectroscopy at air-liquid interfaces.
abstract: UV-Visible Reflection-Absorption Spectroscopy (UVRAS) technique is reviewed with a general perspective on fundamental and applications. UVRAS is formally identical to IR Reflection-Absorption Spectroscopy (IRRAS), and therefore, the methodology developed for this IR technique can be applied in the UV-visible region. UVRAS can be applied to air-solid, air-liquid or liquid-liquid interfaces. This review focuses on the use of UVRAS for studying Langmuir monolayers. We introduce the theoretical framework for a successful understanding of the UVRAS data, and we illustrate the usage of this data treatment to a previous study from our group comprising an amphiphilic porphyrin. For ultrathin films with a thickness of few nm, UVRAS produces positive or negative bands when p-polarized radiation is used, depending on the incidence angle and the orientation of dipole absorption. UVRAS technique provides highly valuable information on tilt of chromophores at the air-liquid interface, and moreover allows the determination of optical parameters. We propose UVRAS as a powerful technique to investigate the in situ optical properties of Langmuir monolayers.
authors.affiliation: Institute of Fine Chemistry and Nanochemistry, Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie, Córdoba, E-14014, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Rubia-Payá
authors.affiliation: Institute of Fine Chemistry and Nanochemistry, Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie, Córdoba, E-14014, Spain.
authors.forename: Gustavo
authors.initials: G
authors.lastname: de Miguel
authors.affiliation: Institute of Fine Chemistry and Nanochemistry, Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie, Córdoba, E-14014, Spain.
authors.forename: María T
authors.initials: MT
authors.lastname: Martín-Romero
authors.affiliation: Institute of Fine Chemistry and Nanochemistry, Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie, Córdoba, E-14014, Spain. Electronic address: jjginer@uco.es.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Giner-Casares
authors.affiliation: Institute of Fine Chemistry and Nanochemistry, Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie, Córdoba, E-14014, Spain. Electronic address: lcamacho@uco.es.
authors.forename: Luis
authors.initials: L
authors.lastname: Camacho
keywords: Aggregation; Chromophores; Interfaces; Langmuir monolayers; Reflection spectroscopy; Self-assembly