Theoretical Study of Doubly Resonant Sum-Frequency Vibrational Spectroscopy for 1,1′-Bi-2-naphthol Molecules on Water Surface

Abstract

By combining molecular dynamics (MD) simulation and density functional theory (DFT) calculations, we investigate the surface doubly resonant sum-frequency vibrational spectroscopy (SFVS) for a monolayer of R-1,1′-bi-2naphthol (R-BN) molecules on water surface. MD simulations indicate that the R-BN molecules stand perpendicularly on the water surface due to hydrogen bonding with the water molecules. DFT and time-dependent density functional theory (TDDFT) methods are employed to obtain potential energy shifts, transition dipoles, and their derivatives, which are then used to calculate both the Franck− Condon and Herzberg−Teller terms to the surface hyperpolarizabilities. The theoretical SFVS agrees well with the experimental result. The origin of the SFVS peaks and symmetry properties of the hyperpolarizabilities tensor are also analyzed, which indicates that theoretical computations can obtain the most important components that are helpful for experimental SFVS analysis. The current work shows that theoretical calculations can provide useful detailed molecular information, such as molecular structure, orientation, and excited structure at interfaces, in studies of surface doubly resonant SFVS.

Doubly resonant SFG and DFG spectroscopies: An analytic model for data analysis including distorted and rotated vibronic levels. I. Theory

“…However, after the promising first experimental results, [19][20][21][22][23] literature has recently shown a renewed interest to exploit the specificities of DR-SFG. [24][25][26][27][28][29][30][31][32][33][34] Theory for doubly resonant FG processes follows the formalism developed for resonant Raman scattering (RRS). The basic models rely on standard (Born-Oppenheimer, harmonic vibrations, Condon and/or Herzberg-Teller) approximations, and the level of accuracy of the vibronic structure description governs the complexity of the model.…”

“…20,22,23 To a lesser extent than for RRS, extensions have been introduced in DR-FG beyond the conventional approximations. The main approaches focus on the inclusion of non-Condon 28,70 and non-adiabatic 71,72 terms, in particular to account for the specific properties of DR-SFG from chiral liquids. As for quadratic coupling, one formulation of the DR-SFG response including mode distortion and mode mixing in the TT frame has been published.…”

A theoretical study of sum-frequency generation for chiral solutions near electronic resonance

“…[20] The second excited state is of A symmetry and its excited energy is 3.8520 eV with an oscillator strength of 0.0001 [20] , which is very weak. Thus in order to obtain the electric dipole transition moments between the excited electronic states, we use the "excited wavefunctions" for an approximation.…”

All-experimental analysis of doubly resonant sum-frequency generation spectra: Application to aggregated rhodamine films

“…47,48 For all these reasons, DR-SFG appears suitable to complement the panel of optical spectroscopic techniques applied to study charge transfer processes in situ, from static absorption and resonance Raman to ultrafast pump-probe and two-dimensional electronic 40 and infrared spectroscopies. Historically, DR-SFG with tunable visible lasers has been applied to investigate the model chiral response of coupled oscillators 49 like binapthol in the liquid phase [50][51][52] or in monolayers [53][54][55] both theroretically and experimentally; the vibrational and electronic structures of chromophores [56][57][58][59][60] and conjugated polymers; 61,62 and the charge transfer states induced by molecular adsorption on metals. [63][64][65][66][67][68][69] When the visible wavelength is tuned, most of these works also confront the delicate problem of data analysis, and coupling between electronic and vibrational resonances.…”