The Q-Band Energetics and Relaxation of Chlorophylls a and b as Revealed by Visible-to-Near Infrared Time-Resolved
Rong-Yao Gao1, Jian-Wei Zou2, Yan-Ping Shi1
1Key Laboratory of Advanced Light Conversion Materials and Biophotonics, School of Chemistry and Life Resources, Renmin University of China, Beijing 100872, P. R. China.
Abstract:
Chlorophyll (Chl) is the most abundant light-harvesting pigment of oxygenic photosynthetic organisms; however, the Q-band energetics and relaxation dynamics remain unclear. In this work, we have applied femtosecond time-resolved (fs-TA) absorption spectroscopy in 430-1,700 nm to Chls a and b in diluted pyridine solutions under selective optical excitation within their Q-bands. The results revealed distinct near-infrared absorption features of the Bx,y ← Q and Bx,y ← Q transitions in 930-1,700 nm, which together with the steady-state absorption in 400-700 nm unveiled the Qx(0,0)-state energy that lies 1,000 ± 400 and 600 ± 400 cm-1 above the Qy(0,0)-state for Chls a and b, respectively. In addition, the Q-to-Q internal conversion time constants are estimated to be less than 80 fs for Chls a and b. These findings may shed light on understanding the roles of the Chls in the primary excitation energy transfer reactions of photosynthesis.
More Related Videos
10:08High-Throughput Analysis of Non-Photochemical Quenching in Crops Using Pulse Amplitude Modulated Chlorophyll Fluorometry
Published on: July 6, 2022
10:20Evaluation of Photosynthetic Behaviors by Simultaneous Measurements of Leaf Reflectance and Chlorophyll Fluorescence Analyses
Published on: August 9, 2019
Related Concept Videos
Molecular Spectroscopy: Absorption and Emission
UV–Vis Spectroscopy: Molecular Electronic Transitions
Light as Energy
Photons
A photon is a discrete electromagnetic particle or bundle of energy. Photons are characterized by their frequency, wavelength, and amplitude, similar to the properties of a wave. Waves with higher frequencies transmit more energy and have shorter wavelengths than longer wavelengths that transmit...
The Antenna Complex
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent...
Deactivation Processes: Jablonski Diagram
