Hyperpolarisability of (donor)2-acceptor‐type molecules determined by EFISHG

Abstract

Molecular first‐order hyperpolarisabilities β of (donor)2‐acceptor type molecules have been determined by electric field induced second‐harmonic generation (EFISHG) experiments at 1.06 μm. The hyperpolarisability values are enhanced in these two dimensional charge transfer molecules, compared with a reference linear model molecule. One of these molecules absorbs part of the second‐harmonic beam. We propose a determination method for β that takes into account this phenomenon. Crystals of the title molecules exhibit second harmonic generation by the powder test.

Synthesis and quadratic molecular hyperpolarizabilities of two new chiral boronates: Computational and experimental study

“…The b measurements were carried out by the electric field induced second harmonic (EFISH) technique [17,18]. The data were recorded using a picosecond Nd:YAG pulsed (10 Hz) laser operating at 1.064 lm.…”

Design, Synthesis, Structural and Nonlinear Optical Properties of Photochromic Crystals: Toward Reversible Molecular Switches

“…Molecular and Bulk NLO Properties: Experiments and Theoretical Calculations. By electric field induced second harmonics (EFISH) experiments, we obtained values of β·μ, the scalar product of the quadratic hyperpolarizability, and the dipole moment (eq 1). The experiments were performed in dioxane, and the fundamental wavelength was 1907 nm (see Experimental Section for details).…”

“…The SHG intensity was detected by a photomultiplier (Hamamatsu) and the signal was read on an oscilloscope (Tektronic TDS 620). For electric field induced second harmonics (EFISH) technique, the centrosymmetry of the solution was broken by applying a pulsed electric field of 5 kV for 5 μs (Lasermetrics). Solutions of MNA (2-methyl-4-nitroaniline, μ.β = 71 × 10 -48 esu at 1907 nm) served as reference.…”

Synthesis, Crystal Structure, and Second-Order Nonlinear Optical Properties of a New Bis(salicylaldiminato)nickel(II) Metal Complex

“…Before discussing the properties of the metal complex (NiL) I , it coud be interesting to study the related ligand (H 2 L), which would provide an example of Λ-shaped chromophore. Such structures made of two “push−pull” subunits have been reported to exhibit enhanced hyperpolarizabilities, by the sole virtue of their two charge-transfer axis and hence large additional β tensor components. , Moreover, the investigation of the role devoted to the metal center in I may benefit from the comparison betweeen the metal complex (NiL) and the ligand (H 2 L), especially at the theoretical levels. Attempts to prepare the Schiff-base ligand were made by reacting 4-(diethylamino)salicylaldehyde and 1,2-diamino-4,5-dinitrobenzene, with a catalytic amount of H 2 SO 4 .…”