Infrared spectra of one-monolayer Langmuir-Blodgett (LB) films of chlorophyll-<i>a</i> (Chl-<i>a</i>) can be obtained with a high signal-to-noise ratio by using the attenuated total reflection (ATR) technique. The observed spectra indicate that Chl-<i>a</i> assumes a five-coordinated monomer in the LB films; it seems that both the ester and keto C=O groups are free from any interactions, and a water molecule coordinates to the Mg atom. Comparison of the spectra of the one-monolayer LB films with those of the cast films shows that the structure of Chl-<i>a</i> is quite different between the two kinds of films; in contrast to the LB films the cast films are liable to have the dimer or oligomer of Chl-<i>a</i>. The fact that the five-coordinated monomer is predominant in the LB films suggests that Chl-<i>a</i> molecules are highly oriented in the one-monolayer LB films.
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.
Contact your librarian or system administrator
Login to access OSA Member Subscription