%0 Journal Article %T How Dimerization Through a Spiro Junction Modifies the Nonlinear Optical Properties of a Push-Pull Organic Dye: Insights from Theory and Hyper-Rayleigh Scattering %+ Institut des Sciences Moléculaires (ISM) %+ MOLTECH-Anjou %+ Laboratoire de Chimie Théorique appliquée %A Castet, Frédéric %A Lerychard, Timothée %A Pielak, Kornelia %A Szalóki, György %A Dalinot, Clément %A Leriche, Philippe %A Sanguinet, Lionel %A Champagne, Benoît %A Rodriguez, Vincent %< avec comité de lecture %J ChemPhotoChem %I Wiley %V 1 %N 3 %P 93-101 %8 2017 %D 2017 %R 10.1002/cptc.201600039 %Z Chemical SciencesJournal articles %X The second-order nonlinear optical (NLO) properties of a push–pull monomer, as well as of its dimer composed of two monomeric units connected through a non-conjugated spiro junction, are investigated by means of hyper-Rayleigh scattering (HRS) and quantum chemical calculations. It is shown that dimerization to form a molecule with an orthogonal geometry enhances the first hyperpolarizability by circa 20 % and induces a decrease of the dipolar character of the HRS response. Theoretical calculations correlate well with experimental measurements and allow an in-depth rationalization of the impact of the spiro linkage on the NLO properties through a detailed analysis of the relevant electronic excited states. %G English %L hal-02564478 %U https://univ-angers.hal.science/hal-02564478 %~ CNRS %~ UNIV-ANGERS %~ UNIV-BORDEAUX %~ INC-CNRS %~ MOLTECH-ANJOU %~ TEST-HALCNRS %~ TEST2-HALCNRS