Processi fotoindotti in complessi di pigmenti (bilirubine) e proteine (HSA) Giovanni Agati 1,3, Marina Mazzoni 1,3, Riccardo Pratesi 2,3 1, Istituto di Fisica Applicata Nello Carrara, via Madonna del Piano, Sesto (Fi) 2, Dipartimento di Fisica, Polo

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Processi fotoindotti in complessi di pigmenti
(bilirubine) e proteine (HSA) Giovanni Agati
1,3, Marina Mazzoni 1,3, Riccardo Pratesi 2,3 1,
Istituto di Fisica Applicata Nello Carrara, via
Madonna del Piano, Sesto (Fi)2, Dipartimento di
Fisica, Polo Scientifico, Sesto (Fi)3, INFM,
sez. A, Polo Scientifico, Sesto
(Fi)mazzoni_at_ifac.cnr.it
An application
Photoisomerization quantum yields fitting by
excitons deduced from the structural
spectroscopic (CD) analysis and the exciton
coupling model
Circular dichroism jumps at ? 458nm in the
reversible photoisomerization of (Z,Z) and (Z,E)
isomers of BR-IX induced by bichromatic
irradiation (? 450nm and ? 514nm) at
photoequilibrium 70 (Z,Z)-30 (Z,E) (down
state) 95 (Z,Z)- 5 (Z,E) green line (up
state). The insert refer to CD of pure isomers.
Absorption and circular dichroism spectra
analysis for the determination of the excitation
energy bands of the interacting chromophores
(excitons). The excitons C? and C? are fitting
gaussians of the CD spectra, C? is the difference
between absorption and the sum of C? and C?
normalised to absorption.
c2, s2 chromophore occupation probability of the
exciton states
Typical chromophore conversion efficiency for
BR-IX h-1 15