Spectroscopic Studies of Chlorophyll a Complexes with Trinitro-Substituted Flourene Derivatives

• Main Author: Smalley, Stephanie
• Format: Others
• Published: TopSCHOLAR® 2004
• Subjects: Chemistry
• Online Access: http://digitalcommons.wku.edu/theses/517; http://digitalcommons.wku.edu/cgi/viewcontent.cgi?article=1520&context=theses

Absorption, fluorescence, and excited-state lifetime studies of chlorophyll a (Chl a) with fluorene, 2-(2,4,7-Trinitro-fluoren-9-ylideneaminooxy)-propionic acid (TFPR), 2- (2,4,7-Trinitro-fluoren-9-ylidenemethyl)-phenol, (TFPH), and 9-Isopropylidene-2,4,7- trinitro-9H-fluorene (ITNF) have been investigated. These systems were studied in acetonitrile and dichloromethane at room temperature. Absorption data were analyzed with the Nash plot. Linearity of the Nash plots proved that a 1:1 complex was formed between the donor and acceptor. Ground state binding constants (Ka) of each system were also determined from the y-intercept of these plots. Fluorescence data were analyzed with a Stern-Volmer plot. The quenching constants (Ksv) were obtained from the slope of these plots. These results show that the quenching occurs dynamically, statically, or by electron transfer mechanisms. Molecular modeling was also performed on these systems, which provided thermodynamic parameters, dipole moments and electron affinities.