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https://repositorio.ufba.br/handle/ri/7530
metadata.dc.type: | Artigo de Periódico |
Title: | Vibrational spectroscopic study of brazilin and brazilein, the main constituents of brazilwood from Brazil |
Other Titles: | Vibrational Spectroscopy |
Authors: | Oliveira, Luiz F. C. de Edwards, Howell G. M. Velozo, Eudes da Silva Nesbitt, M. |
metadata.dc.creator: | Oliveira, Luiz F. C. de Edwards, Howell G. M. Velozo, Eudes da Silva Nesbitt, M. |
Abstract: | In this work, the vibrational spectra (FT-Raman and infrared spectra) of brazilin, the major component of brazilwood Caesalpinia echinata (from Bahia, Brazil), and brazilein, the oxidised pigment, are investigated. The FT-Raman spectra of the compounds show different patterns in the carbonyl stretching region, where brazilein presents a Raman feature at 1697 cm−1 that is tentatively assigned to a coupled vibrational mode described by CO and aromatic CC stretching. Infrared measurements are used to support this assignment. The spectral region between 1700 and 1500 cm−1 is also proposed as a fingerprint for brazilin and brazilein. Comparisons with some quinones and polyalcohols as parent molecules and other deep red resin pigments such as “dragon’s blood” are undertaken to assist the vibrational assignment. As a test of the spectroscopic protocol for the identification of these pigments in natural brazilwoods, an 80-year-old archival specimen of Caesalpinia echinata was analysed non-destructively and the feature of brazilein shown from the Raman spectrum. |
Keywords: | Brazilin Brazilein Brazilwood FT-Raman spectroscopy |
URI: | http://www.repositorio.ufba.br/ri/handle/ri/7530 |
Issue Date: | 26-Apr-2002 |
Appears in Collections: | Artigo Publicado em Periódico (Química) |
Files in This Item:
File | Description | Size | Format | |
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1-s2.0-S0924203101001382-main.pdf Restricted Access | 118,86 kB | Adobe PDF | View/Open Request a copy |
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