Association of chlorophyll with amides on plasticized polyethylene particles. I. N,N-dimethylmyristamide
Model systems have been prepared in which chlorophyll a and N,N-dimethylmyristamide (DMMA) are adsorbed together in various ratios to particles of polyethylene swollen with undecane. The adsorption is performed by equilibrating the particles with methanol-water solutions of increasing water content. Absorption spectra of the coated particles in viscous suspensions show sharp well-marked bands over much of the composition range examined. With the aid of second derivative spectra, the red absorption band has been resolved into three components, at 661.5, 674 and 689 nm. Fluorescence spectra have also been resolved into their principal components with some assistance from comparison with spectra of chlorophyll in undecane solution containing DMMA. At room temperature (295 K) the resolvable components are of monomeric chlorophyll at 670 nm, and of associated species at 681 and 725 nm. Fluorescence at 77 K is of similar intensity but is distributed differently, in favor of longer-wave components. Corresponding to the 295 K components are emission bands at 675, 683-5 and 735 nm. Other components appear under certain conditions: at 695 to 700 nm when the chlorophyll and DMMA concentrations are both high, and at 705 nm when the ratio of DMMA to chlorophyll is low. If DMMA is absent or at low concentration, much of the chlorophyll exists as an aggregated form absorbing near 741 nm and fluorescing weakly near 760 nm at 77 K. Adsorption isotherms indicate some degree of cooperativity in the binding of chlorophyll and DMMA to the particles. The photoreduction of p-dinitrobenzene by hydrazobenzene, sensitized by these particles, has been demonstrated.
- Research Organization:
- Charles F. Kettering Research Lab., Yellow Springs, OH (USA)
- DOE Contract Number:
- AC02-82ER12039
- OSTI ID:
- 6739124
- Report Number(s):
- DOE/ER/12039-T2-Pt.1; ON: DE83000349
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
14 SOLAR ENERGY
AMIDES
ADSORPTION
CHLOROPHYLL
ABSORPTION SPECTRA
FLUORESCENCE
PARTICLES
PHOTOSYNTHESIS
POLYETHYLENES
REDUCTION
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
LUMINESCENCE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC POLYMERS
PHOTOCHEMICAL REACTIONS
PHYTOCHROMES
PIGMENTS
POLYMERS
POLYOLEFINS
PORPHYRINS
SORPTION
SPECTRA
SYNTHESIS
400500* - Photochemistry
140505 - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)