Charge Transfer Effect on Relaxation Mechanism in Hydrated Pyrrole‐Water Systems Following N‐2s Ionization

This study investigates the relaxation mechanisms of pyrrole and pyrrole-water clusters (C₄H₅N-(H₂O)_n, where <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics><mml:mrow><mml:mi>n</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0</mml:mn> <mml:mo>-</mml:mo> <mml:mn>3</mml:mn></mml:mrow> <mml:annotation>${n = 0 - 3}$</mml:annotation> </mml:semantics> </mml:math> ) following N-2s ionization of pyrrole. Using various theoretical methods, we focus on the influence of water molecules and charge transfer on these non-radiative relaxation pathways. Our simulations included pyrrole solvated in 494 explicit water molecules equilibrated at 300 K and also employed a polarizable continuum model (PCM) to make the system more realistic and gain additional insights. In hydrated environments, the hydrogen bonding network between pyrrole and surrounding water molecules facilitates enhanced non-radiative relaxation pathways following inner valence ionization. Since these are hydrogen bonding systems, we have explored the possibility of proton transfer, which could occur in conjunction with other electronic decay processes.