The second-order nonlinear optical (NLO) properties of light-harvesting complexes (LHs) from the purple photosynthetic bacteria Thermochromatium (Tch.) tepidum were investigated for the first time by means of hyper-Rayleigh scattering (HRS). The carotenoid (Car) molecules bound to the isolated LH1 and LH2 proteins gave rise to second-harmonic scattering; however, they showed an opposite effect of the collective contribution from Car, that is, the first hyperpolarizability (β) reduced substantially from (10 510 ± 370) × 10(-30) esu for LH1 to (360 ± 120) × 10(-30) esu for LH2. Chromatophores of Tch. tepidum also showed a giant hyperpolarizability of (11 640 ± 630) × 10(-30) esu. On the basis of the structural information on bacterial LHs, it is found that the effective β of an LH is governed by the microenvironment and orientational correlation among the Car chromophores, which is concluded to be coherently enhanced for LH1. For LH2, however, additional destructive effects between different Car molecules may account for the small β value. This work demonstrates that LH1 and native membranes of purple bacteria can be potent NLO materials and that HRS is a promising spectroscopic means for investigating structural information of pigment-protein supramolecules.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpcb.6b07461 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Synthesis and Optical and Nonlinear Optical Properties of Linear and Two-Dimensional Charge Transfer Chromophores Based on Polyoxometalates.
Inorg Chem
December 2024
Department of Chemistry, Lancaster University, Lancaster LA1 4YB, United Kingdom.
Article Synopsis
- This study focuses on the first nonlinear optical (NLO) chromophores made of arylimido-polyoxometalates featuring two-dimensional (2D) structures, comparing their properties with one-dimensional counterparts through synthesized arylimido-hexamolybdate derivatives.* -
- Findings reveal that the 2D chromophores exhibit notable red-shifts in their electronic absorption spectra due to larger conjugated systems, along with mixed valence behavior in electrochemical measurements depending on the positioning of the acceptors.* -
- The highest hyperpolarizability values were observed in one compound, emphasizing a strong 2D response, with contributions from phenyl bridges and polyoxometalates evident in the computed electronic
Elucidating the Photophysics and Nonlinear Optical Properties of a Novel Azo Prototype for Possible Photonic Applications: A Quantum Chemical Analysis.
ACS Omega
October 2024
Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, São Paulo, São Paulo 05588-090, Brazil.
The photophysics and nonlinear optical responses of a novel nitrothiazol-methoxyphenol molecule were investigated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods with the polarizable continuum model to take the solvent effect into account. Special attention is paid to the description of the lowest absorption band, characterized as a strong π → π* state in the visible region of the spectrum. The TD-DFT emission spectrum analysis reveals a significant Stokes shift of more than 120 nm for the π → π* state in gas phase condition.
View Article and Find Full Text PDFElectronic structure, global reactivity descriptors and nonlinear optical properties of glycine interacted with ZnO, MgO and CaO for bacterial detection.
Sci Rep
October 2024
Spectroscopy Department, National Research Centre, 33 El-Bohouth St., 12622, Dokki, Giza, Egypt.
Modern laboratory medicine relies on analytical instruments for bacterial detection, focusing on biosensors and optical sensors for early disease diagnosis and treatment. Thus, Density Functional Theory (DFT) was utilized to study the reactivity of glycine interacted with metal oxides (ZnO, MgO, and CaO) for bacterial detection. Total dipole moment (TDM), frontier molecular orbitals (FMOs), FTIR spectroscopic data, electronic transition states, chemical reactivity descriptors, nonlinear optical (NLO) characteristics, and molecular electrostatic potential (MESP) were all investigated at the B3LYP/6-31G(d, p) level using DFT and Time-Dependent DFT (TD-DFT).
View Article and Find Full Text PDFThe effect of complex formation on the static and frequency-dependent nonlinear optical properties: A combined experimental and theoretical investigation.
Spectrochim Acta A Mol Biomol Spectrosc
January 2025
Sakarya University, Faculty of Science, Department of Physics, Sakarya 54147, Türkiye.
A novel mixed ligand Mn(II) complex of 6-Bromopyridine-2-carboxylic acid (6Brpca) and 4,4'-dimethyl-2,2'-dipyridyl has been prepared and structurally characterized using single-crystal X-ray diffraction. The spectroscopic properties were also analyzed by using FT-IR and UV-Vis spectral techniques. The coordination complexes having transition metal ions are known to have promising optical nonlinearity behavior.
View Article and Find Full Text PDFSynthesis, crystal structure analysis, computational modelling and evaluation of anti-cervical cancer activity of novel 1,5-dicyclooctyl thiocarbohydrazone.
Phys Chem Chem Phys
September 2024
Department of Chemistry, University of Lucknow, Lucknow - 226007, Uttar Pradesh, India.
Thiocarbazones are widely used as bioactive and pharmaceutical intermediates in medicinal chemistry and have been shown to exhibit diverse biological and pharmacological activities such as antimicrobial, anticancer, anti-viral, anti-convulsant and anti-inflammatory In continuation of our interest in biologically active heterocycles and in an attempt to synthesize a spiro derivative, 1,2,4,5-tetraazaspiro[5.7]tridecane-3-thione, herein, the synthesis of 1,5-dicyclooctyl thiocarbohydrazone (3) has been reported reaction of the cyclooctanone and thiocarbohydrazide. The structure was assigned on the basis of detailed spectral analysis and also confirmed by X-ray crystal studies.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!