Molecular-Chain Formation Induced by Infrared-Laser Light Observed in l-Cysteine and Potassium Dihydrogenphosphate

Each of amino acids and phosphate group is capable of forming a chain through repeating dehydration condensation reaction. We have observed Raman scattering spectra of l-cysteine (HSCH 2 CH(NH 2 )COOH) and potassium dihydrogenphosphate (KH 2 PO 4 or KDP) before and after irradiation of one pulse of...

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Bibliographic Details
Published inJapanese Journal of Applied Physics Vol. 50; no. 10; pp. 101601 - 101601-4
Main Authors Tsujibayashi, Toru, Ichimiya, Masayoshi, Toyoda, Koichi, Ohno, Nobuhito
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.10.2011
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Summary:Each of amino acids and phosphate group is capable of forming a chain through repeating dehydration condensation reaction. We have observed Raman scattering spectra of l-cysteine (HSCH 2 CH(NH 2 )COOH) and potassium dihydrogenphosphate (KH 2 PO 4 or KDP) before and after irradiation of one pulse of an erbium-doped yttrium aluminum garnet (Er:YAG) laser with its wavelength of 2.94 μm, duration of 0.2 ms, and peak power density of 0.4 MW/cm 2 . Extra peaks are observed in the spectra after the irradiation, which are not seen in the spectra before the laser irradiation. Comparison of the experimentally obtained spectra with the calculated ones of the chain compounds suggests that the laser light does induce such reactions.
Bibliography:Experimentally obtained Raman scattering spectra of KDP powders, (a) before and (b) after the irradiation of one pulse of the Er:YAG laser light. Calculated Raman scattering spectra of linear chains of phosphate groups; the numbers of groups in the chain are (a) 1, (b) 2, (c) 3, and (d) 4. Ball and stick diagrams of the targeted molecules are shown as insets. Experimentally obtained Raman scattering spectrum of l-cysteine powders in a wide range of the Raman shift. Experimentally obtained Raman scattering spectra of l-cysteine powders around 3,000 cm -1 , (a) before and (b) after the irradiation of one pulse of the Er:YAG laser light. Calculated Raman scattering spectra of linear chains of l-cysteine around 3,000 cm -1 ; the numbers of molecules in a chain are (a) 1, (b) 2, and (c) 3. Ball and stick diagrams of the targeted molecules are shown as insets. Experimentally obtained Raman scattering spectra of l-cysteine powders around 1,000 cm -1 , (a) before and (b) after the irradiation of one pulse of the Er:YAG laser light. Calculated Raman scattering spectra of linear chains of l-cysteine around 1,000 cm -1 ; the numbers of molecules in the chain are (a) 1, (b) 2, and (c) 3. Scanning electron microscope images of l-cysteine powders; (a) the image of the spot where one pulse of the Er:YAG laser light was irradiated and (b) that without irradiation. The scale is indicated by the bar at the right bottom for each image.
ISSN:0021-4922
1347-4065
DOI:10.1143/JJAP.50.101601