Title of Paper:The Study for Formation Mechanism of Spectral Red Edge of Green Vegetation

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Affiliation of Author(s):材料科学与技术学院

Journal:SPECTROSCOPY AND SPECTRAL ANALYSIS

Key Words:Red edge Chlorophyll Porphyrins Q band

Abstract:Red edge of green vegetation is caused by strong chlorophyll absorption, and its position shifts to long-wavelength with the increase of chlorophyll. Chlorophyll, including chlorophyll a and b, belongs to porphyrin derivative in molecular structure. Therefore, it is found that the other synthesized porphyrin may also is of red edge property. In order to study the formation mechanism of red edge, a serious of porphyrins and metalloporphyrins including Tetraphenylporphyrin (TPP), Tetrakis-(4-methoxyphenyl) porphyrin (TMPP), Tetrakis-(4-sulfophenyl) porphyrin (Na-4 TPPS), Tetrapyridylporphin (TPyP), Tetramethylporphyrin (TMP), Tetrakis-(4-methoxyphenyl)porphyrin zinc (ZnTMPP) and Tetrakis-(4-methoxyphenyl) porphyrin copper (CuTMPP) were synthesized and characterized by UV-Vis-NIR, FT-ER and H-1 NMR. With systematically analysis of their UV-Vis spectrum (absorption, transmittance and solid reflectance), we found that porphyrins or metalloporphyrins can also cause the red edge similar to chlorophyll. The red edge is caused by strong Q band absorption of porphyrins, and red edge is right slope of absorptionvalley in their UV-Vis transmittance spectrum. The red edge position is related to the concentration of porphyrin, the substituents on the porphyrin ring, and the center metal of metalloporphyrins. Red edge position will shift to short-wavelength when phenylic H is substituted by electron-withdrawing group, and shift to long-wavelength when substituted by electron-donating group as well as increasing concentration of porphyrins. The change of substituent group in porphyrins ring is influence more obviously than the change of substituent groups in benzene ring of TPP. The number of Q bands will decrease when metal ions insert to porphyrin ring. Therefore, red edge position will be strongly influenced by metalloporphyrins.

ISSN No.:1000-0593

Translation or Not:no

Date of Publication:2017-12-01

Co-author:王晶,Liu Lang,Xiang Teng-fei,Zheng Shun-li,Ding Shi-bing,Liu Pan-jin

Correspondence Author:lc