Laser pulse trains for controlling excited state dynamics of adenine in water

Abstract

We investigate theoretically the control of the ultrafast excited state dynamics of adenine in water by laser pulse trains, with the aim to extend the excited state lifetime and to suppress nonradiative relaxation processes. For this purpose, we introduce the combination of our field-induced surface hopping method (FISH) with the quantum mechanical-molecular mechanical (QM/MM) technique for simulating the laser-driven dynamics in the condensed phase under explicit inclusion of the solvent environment. Moreover, we employ parametric pulse shaping in the frequency domain in order to design simplified laser pulse trains allowing to establish a direct link between the pulse parameters and the controlled dynamics. We construct pulse trains which achieve a high excitation efficiency and at the same time keep a high excited state population for a significantly extended time period compared to the uncontrolled dynamics. The control mechanism involves a sequential cycling of the population between the lowest and higher excited states, thereby utilizing the properties of the corresponding potential energy surfaces to avoid conical intersections and thus to suppress the nonradiative decay to the ground state. Our findings provide a means to increase the fluorescence yield of molecules with an intrinsically very short excited state lifetime, which can lead to novel applications of shaped laser fields in the context of biosensing.

Pulse‐Train Photoelectron Spectroscopy of Electronic and Nuclear Dynamics in Molecules

“…Thus, a pulse sequence of a given separation, or a pulse train is seen as a potentially good optical source to control the excited-state dynamics. [44] In the present paper, on the other hand, we show how the regularized pulse train can be utilized to track the electronic state (not only excitation but deexcitation as in the Rabi oscillation) and nuclear dynamics before ionization and illustrate numerically that the photoelectron spectroscopy is a practical means of obtaining a record of the electron nucleus simultaneous dynamics traveling among several excited states.…”

Adenine‐Based Coordination Polymers: Synthesis, Structure, and Properties

“…The UV/Vis spectra of compounds I – III and the adenine molecule were recorded in the solid state at room temperature. The UV/Vis spectrum of adenine has two distinct bands at 252 nm and 292 nm, which could be due to π → π* and n → π* transitions, respectively . The UV/Vis spectra of I – III also exhibited similar features, which could be due to the π → π* and n → π* transitions of the adenine molecule (Figure S43) .…”

“…The UV/Vis spectrum of adenine has two distinct bands at 252 nm and 292 nm, which could be due to π → π* and n → π* transitions, respectively . The UV/Vis spectra of I – III also exhibited similar features, which could be due to the π → π* and n → π* transitions of the adenine molecule (Figure S43) . The photoluminescence spectra were also recorded for the powdered samples of I – III along with adenine by using excitation wavelengths of 288 nm ( I and III ) and 284 nm ( II ).…”

Coherent phase control of internal conversion in pyrazine

“…In a theoretical study that included the explicit shape of the laser pulse, Mitrić and coworkers [41] used a closed loop strategy to suppress IC of adenine in water. They used a library of three-parameter sine phase functions to shape the laser pulse, along with on-thefly classical dynamics and Tully's surface-hopping procedure.…”