𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Chlorophyll and pheophytin derivatives in geochemical transformation pathways: A surface-enhanced resonance Raman spectroscopic study

✍ Scribed by Paul S. Woolley; Brendan J. Keely; Ronald E. Hester


Book ID
101292626
Publisher
John Wiley and Sons
Year
1998
Tongue
English
Weight
299 KB
Volume
4
Category
Article
ISSN
1075-4261

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✦ Synopsis


Protected surface-enhanced resonance Raman spectroscopy (PSERRS) has been used to study a number of chlorophyll transformation products that have been suggested as intermediates in the so-called Treibs hypothesis which describes the transformation of ancient chlorophyll a (chl a) in the biosphere into desoxophylloerythroetio-porphyrin (DPEP) found in sedimentary environments. Both Soret- and Qy-resonant PSERR spectra have been recorded, providing two-dimensional structural fingerprints containing a number of bands which enable the presence of specific peripheral substituents to be identified. Some of these marker bands can be assigned directly to vibrational modes of the particular substituents. This has allowed further characterization of the vibrational spectrum of chl a; in particular, a vinyl mode has been identified which previously was thought to be Raman silent.