Far-infrared vibrational spectra of all-trans, 9-cis and 13-cis retinal measured by THz time-domain spectroscopy
نویسندگان
چکیده
Low-frequency torsional vibration modes of the conjugated polyene chain of the biologically important chromophore retinal are of major relevance when studying its photoisomerization dynamics. We present absorptivity and dispersion spectra of three dierent retinal isomers in the far-infrared region between 10 and 100 cmÿ1 (0.3±3.0 THz) measured by terahertz time-domain spectroscopy at 298 and 10 K. At low temperatures the observed broad absorption bands resolve into narrow peaks correlating to torsional modes of the molecule. Comparison of the absorption spectra of dierent retinal isomers enables the approximate localization of the modes within the molecule. Experimental linewidths and transition strengths are reported. Ó 2000 Elsevier Science B.V. All rights reserved.
منابع مشابه
Towards T-ray spectroscopy of retinal isomers: A review of methods and modelling
The terahertz gap lies between the infrared and millimeter regions of the electromagnetic spectrum. Terahertz (THz) waves, or T-rays, bridge the gap between electronics and photonics, have novel properties and interact uniquely with many materials. Various rotational, vibrational and translational modes of molecules are within the THz range (0.1–10 THz). Since these modes are unique to a partic...
متن کاملSubmillimeter Spectrum of Formic Acid
We have measured new submillimeter-wave data around 600 GHz and around 1.1 THz for the C isotopologue of formic acid and for the two deuterium isotopomers; in each case for both the trans and cis rotamer. For cis-DCOOH and cis-HCOOD in particular only data up to 50 GHz was previously available. For all species the quality and quantity of molecular parameters has been increased providing new mea...
متن کاملTerahertz spectroscopy of naphthalene, a-naphthol, b-naphthol, biphenyl and anthracene
The far-infrared THz spectra of naphthalene, a-naphthol, b-naphthol, biphenyl and anthracene have been measured using THz time-domain spectroscopy. The low-energy vibrational modes of measured molecules are discussed based on their characteristic and common features. The complex dielectric functions are obtained. Meanwhile, it is shown that the experimental results can be well fitted by a stand...
متن کاملAngle-dependent terahertz time-domain spectroscopy of amino acid single crystals.
The measurement of absorption spectra using angle-dependent terahertz (THz) time-domain spectroscopy for amino acid single crystals of l-cysteine and l-histidine is reported for the first time. Linearly polarized THz radiation enables us to observe angle-dependent far-infrared absorption spectra of amino acid single crystals and determine the direction of the oscillating dipole of the molecules...
متن کاملStudy of Photoisomerization in Cis-Retinal as a Natural Photo Switch in Vision Using Density Functional Theory
In the present study, theoretical chemical reactivates Photo isomerization in Cis-Retinal as a Natural Photo switch in Vision. DFT hybrid functional, B3LYP and, post-HF method, were the theoretical methods applied utilizing G09 software. 6-31G+ (d,p) basis set employed for structural optimizations, and single point computations performed using B3LYP/6-31G+(d,p). The isomers cis molecule retinal...
متن کامل