Trempe Alexandra, Levenberg Alexander, Ortega Angel David Gonzalez, Lujan Maria A, Picorel Rafael, Zazubovich Valter
Department of Physics, Concordia University, 7141 Sherbrooke Str. West, Montreal, Quebec H4B 1R6, Canada.
Estacion Experimental de Aula Dei (CSIC), Avda. Montañana 1005, Zaragoza 50059, Spain.
J Phys Chem B. 2021 Apr 8;125(13):3278-3285. doi: 10.1021/acs.jpcb.0c09042. Epub 2021 Mar 25.
Spectral hole burning has been employed for decades to study various amorphous solids and proteins. Triplet states and respective transient holes were incorporated into theoretical models and software simulating nonphotochemical spectral hole burning (NPHB) and including all relevant distributions, in particular the distribution of the angle between the electric field of light and transient dipole moment of the chromophore . The presence of a chlorophyll triplet state with a lifetime of several milliseconds explains the slowdown of NPHB (on the depth vs illumination dose scale) with the increase of the light intensity, as well as larger hole depths observed in weak probe beam experiments, compared to those deduced from the hole growth kinetics (HGK) measurements (signal collected at a fixed wavelength while a stronger burning beam is on) in cytochrome bf and chemically modified LH2. We also considered the solvent deuteration effects on triplet lifetime and concluded that both triplet states and local heating likely play a role in slowing down the HGK with increasing burn intensity.
光谱烧孔技术已被应用数十年，用于研究各种非晶态固体和蛋白质。三重态和相应的瞬态孔已被纳入理论模型和软件中，用于模拟非光化学光谱烧孔（NPHB），并包括所有相关分布，特别是光电场与发色团瞬态偶极矩之间夹角的分布。叶绿素三重态寿命为几毫秒，这解释了随着光强增加，NPHB（在深度与光照剂量尺度上）减缓的现象，以及在弱探测光束实验中观察到的比细胞色素bf和化学修饰的LH2中从孔生长动力学（HGK）测量（在较强的烧孔光束开启时在固定波长处收集信号）推断出的孔深度更大的现象。我们还考虑了溶剂氘代对三重态寿命的影响，并得出结论，随着烧孔强度增加，三重态和局部加热可能都在减缓HGK方面发挥作用。
