Femtosecond transient grating studies of electron transfer in porphyrin and chlorophyll donor-acceptor molecules

Conference · Fri Apr 01 04:00:00 EST 1994

OSTI ID:10141888

Wiederrecht, G P; Svec, W A; Wasielewski, M R

Transient grating studies of electron transfer in artificial photosynthetic systems are described. These systems include simple donor-acceptor molecules where the donor, a chlorophyll or porphyrin, is rigidly attached to an easily reduced species such as napthoquinone or benzoquinone. We have previously synthesized acceptor molecules which have well defined absorption bands upon reduction and are well removed from the excited and cationic states of porphyrins and chlorophylls. They also possess large molar extinction coefficients that dominate the spectra and have well defined polarization characteristics. These traits are ideal for polarization sensitive transient grating experiments which enable accurate determination of the angle of the transition dipole between the initial excitation and the acceptor probe, dynamic solvation effects on the charge separated species, and any time dependent rotation of the chromophores relative to each other. An example of the type of molecule utilized for these experiments is a free base porphyrin (HP) donor and a pyromellitic diimide (PI) acceptor directly bonded to the porphyrin ring.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 10141888
• Report Number(s): ANL/CHM/CP--81875; CONF-940593--8; ON: DE94009694
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505
550200
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMISTRY
BIOMIMETIC PROCESSES
CHLOROPHYLL
ELECTRON TRANSFER
NITRILES
PHOTOCHEMICAL, PHOTOBIOLOGICAL, AND THERMOCHEMICAL CONVERSION
PORPHYRINS
STRUCTURE-ACTIVITY RELATIONSHIPS