Computation of ECD and CPL vibronic spectra: adiabatic and nonadiabatic approaches

Computation of ECD and CPL vibronic spectra: adiabatic and nonadiabatic approaches Fabrizio Santoro,1 1 Consiglio Nazionale delle Ricerche-CNR, Istituto di Chimica dei Composti Organometallici, Area della Ricerca del CNR, Via Moruzzi 1, I-56124-Pisa. fabrizio.santoro@iccom.cnr.it In recent years we developed time-independent (TI) and time-dependent (TD) approaches to simulate the lineshapes of electronic spectra of large molecules, computing the associated vibronic structures[1] . Here we illustrate their application to chiroptical spectroscopies and in particular to electronic circular dichroism (ECD) and circularly polarized luminescence (CPL). We show how these computations can help to determine the dominant conformers of large chiral pyridocyclophanes [2], to explain the difference in the lineshapes of absorption and ECD and in emission and CPL of a series of substituted helicenes [3], and to understand the origin of the change of sign in the ECD spectra of chirally substituted benzenes [4]. Furthermore we present some recent applications of a nonadiabatic quantum dynamical approach we recently proposed to compute the ECD vibronic shapes of exciton coupled dimers and multimers [5]. References [1] Santoro F.; Barone V. Computational approach to the study of the lineshape of absorption and electronic circular dichroism spectra Int. J. Quantum. Chem 2010, 110, 624-636 [2] Padula D.; Lahoz I. R.; Díaz C.; Hernández F. E.; Di Bari L.; Rizzo A.; Santoro F.; Magdalena Cid.; M A combined experimental-computational investigation to uncover the puzzling behaviour of chiral pyridocyclophanes: chiroptical response and one- and two-photon absorption, Chem. Eur J. 2015 DOI:10.1002/chem.20150055 [3] Liu Y.; Lin N.; Santoro F.; Longhi G.; Abbate S. Vibronic calculations of the electronic circular Dichroism and circularly polarized luminescence of substituted helicenes, in preparation [4] Pescitelli G.; Barone V.; Di Bari L.; Rizzo A.; Santoro F. Vibronic coupling dominates the electronic circular dichroism of the benzene chromophore 1Lb band J. Org. Chem. 2013, 78, 7398-7405. [5] Padula D.; Picconi D.; Lami A.; Pescitelli G.; Santoro F. Electronic circular dichroism in exciton-coupled dimers: vibronic spectra from a general all-coordinates quantum-dynamical approach J. Phys. Chem. A 2013 117, 3355-3368