Studying the spectral diffusion dynamics of chlorophyll a and chlorophyll b using two-dimensional electronic spectroscopy

Relaxation Dynamics of Chlorophyll b in the Sub-ps Ultrafast Timescale Measured by 2D Electronic Spectroscopy

“…The attention was firstly focused on the non-oscillating population decay contributions. Based on the results of previous measurements [18], we were not expecting a particularly rich evolution of the non-oscillating decay signal in the first ps after photoexcitation. Indeed, the population decay can be described with a bi-exponential function both at RT and 77 K. We summarize the results of the fitting procedure in Figure 3, which reports the 2D-DAS (2D-decay associated spectra) associated with each time constant resulting from the bi-exponential fitting of both sets of measurements.…”

“…Higher energy vibronic transitions appear instead as separated sidebands, usually identified as Qy(0,1) and Qx(0,1), Fewer are the investigations on the properties of the isolated chlb molecule in solution and even more scarce are the works devoted to the characterisation of its relaxation dynamics. Time-resolved techniques [16,17], and in particular also multidimensional spectroscopy [18,19], have so far been exploited to unveil the ultrafast relaxation dynamics of chlb and identify possible variations with respect to chla. These works, however, targeted the dynamics beyond the first hundreds of femtoseconds (fs), studying, for example, the spectral diffusion [18] and internal conversion dynamics [17].…”

“…Time-resolved techniques [16,17], and in particular also multidimensional spectroscopy [18,19], have so far been exploited to unveil the ultrafast relaxation dynamics of chlb and identify possible variations with respect to chla. These works, however, targeted the dynamics beyond the first hundreds of femtoseconds (fs), studying, for example, the spectral diffusion [18] and internal conversion dynamics [17]. Nonetheless, the very early steps of the relaxation dynamics immediately after photoexcitation are crucial to initiating all the ensuing processes, including energy transfer when the chlb molecule is part of a light-harvesting chromophore network.…”

Measuring Ultrafast Spectral Diffusion and Correlation Dynamics by Two‐Dimensional Electronic Spectroscopy

“…More recent 2DES experiments using the CLSω t technique on Chl b show that the FFCF trend for Chl a described above also applies to Chl b . The experiments show significant difference of both Chl b and Chl a CLS values between the protic methanol and the aprotic solvents (THF and diethyl ether) …”

“…The experiments show significant differenceo fboth Chl b and Chl a CLS values between the protic methanol and the aprotic solvents (THF and diethylether). [53] Apart from measuring the FFCF of the Q y transition in Chl a molecules, 2DES was also performed to measure the correlation dynamics between Chl a's Q y and Q x transitions. The Q x !…”