UCL logo

UCL Discovery

UCL home » Library Services » Electronic resources » UCL Discovery

MIMICKING PRIMARY PROCESSES IN PHOTOSYNTHESIS - PHOTOCHEMISTRY OF COVALENTLY-LINKED PORPHYRIN QUINONES STUDIED BY EPR SPECTROSCOPY

KURRECK, H; AGUIRRE, S; BATCHELOR, SN; DIEKS, H; VONGERSDORFF, J; KAY, CWM; MOSSLER, H; ... MOBIUS, K; + view all (1995) MIMICKING PRIMARY PROCESSES IN PHOTOSYNTHESIS - PHOTOCHEMISTRY OF COVALENTLY-LINKED PORPHYRIN QUINONES STUDIED BY EPR SPECTROSCOPY. SOLAR ENERGY MATERIALS AND SOLAR CELLS , 38 (1-4) 91 - 110.

Full text not available from this repository.

Abstract

Porphyrin quinones (P-Q's), covalently linked via different aliphatic bridges, have been synthesized and studied in their (porphyrin) cationic and (semiquinone) anionic radical states by EPR, ENDOR and TRIPLE resonance techniques. Time-resolved and steady-state photoexcitation experiments showed that intra- and intermolecular electron transfer (ET) processes occur in these systems, both in isotropic and reversed micellar solution. Analysis of the experimental data showed the occurrence of photochemical redox processes which result in the formation of hydroquinoid and chlorin type derivatives. Strong polarisation effects were observed for the doublet species - generated by intermolecular ET - under steady-state illumination. It is demonstrated that the polarisation pattern can be explained by the encounter of a triplet and a doublet species allowing the radical triplet pair mechanism to occur. Using a porphyrin linked to a redox active crown ether quinone, complexation of sodium cations in the crown gave rise to well resolved sodium ENDOR lines with an unusual high spin density at the alkali metal ion. Moreover, interesting photochemically induced conformational changes, such as folding and unfolding of donor and acceptor with respect to one another in the case of a flexible butylene bridge, could be detected.

Type: Article
Title: MIMICKING PRIMARY PROCESSES IN PHOTOSYNTHESIS - PHOTOCHEMISTRY OF COVALENTLY-LINKED PORPHYRIN QUINONES STUDIED BY EPR SPECTROSCOPY
Location: INTERLAKEN, SWITZERLAND
Keywords: ELECTRON-PARAMAGNETIC RESONANCE, RHODOBACTER-SPHAEROIDES R-26, TRIPLET PAIR MECHANISM, TIME-RESOLVED EPR, RHODOPSEUDOMONAS-VIRIDIS, CHARGE SEPARATION, MODEL COMPOUNDS, RADICALS, FLUORESCENCE, POLARIZATION
UCL classification: UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > London Centre for Nanotechnology
URI: http://discovery.ucl.ac.uk/id/eprint/71633
Downloads since deposit
0Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item