Effects of the addition of alcohols, cryoprotective agents, and salts on the photoionization yield of chlorophyll a in frozen vesicle solutions with and without electron acceptors

Journal Article · Thu Apr 20 00:00:00 EDT 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100345a068· OSTI ID:5110927

Hiff, T; Kevan, L ^[1]

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1. Univ. of Houston, TX (USA)

The photoionization yield of chlorophyll a (Chla) in rapidly frozen vesicles with and without potassium ferricyanide (FC) or tetrachloro-p-benzoquinone (TCBQ) has been studied versus several structural variations of phospholipid vesicles, including the addition of medium chain length alcohols, the effect of added salts (metal chlorides), the presence of a double bond in the alkyl tail of the surfactant, and the addition of dimethyl sulfoxide or glycerol which tend to enhance vesicular structure retention upon freezing. Variations in the photoionization yield versus these structural parameters are discussed in terms of distance variations between Chla and electron acceptors, loss of integrity of the vesicle structure, and differences in the degree of hydration of the headgroups of the surfactant molecules. Electron spin echo (ESE) deuterium modulation associated with a 5-doxylstearic acid spin probe interacting with deuterated water probes the degree of water interaction at the vesicle interface. The ESE data support a correlation between the degree of interface hydration and the photoionization yield for vesicles containing Chla and FC as an electron acceptor. Parallel ESE studies of 5-doxylstearic acid spin probes in anionic and cationic surfactant vesicles reveal changes in the interface hydration if the surfactant counterion is changed; this can be roughly correlated to the Chla photoionization yields.

• OSTI ID: 5110927
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 93:8; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALCOHOLS
PERFORMANCE
CHLOROPHYLL
PHOTOIONIZATION
FERRICYANIDES
POTASSIUM COMPOUNDS
QUINONES
BINDING ENERGY
CHEMICAL REACTION YIELD
ELECTRONS
EXPERIMENTAL DATA
MICELLAR SYSTEMS
PHOTOCHEMICAL REACTIONS
VALENCE
ALKALI METAL COMPOUNDS
AROMATICS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
COMPLEXES
DATA
ELEMENTARY PARTICLES
ENERGY
FERMIONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
IONIZATION
IRON COMPLEXES
LEPTONS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROTEINS
TRANSITION ELEMENT COMPLEXES
YIELDS
400500* - Photochemistry