TY - JOUR

T1 - Photo-excited charge transfer from adamantane to electronic bound states in water

AU - Wang, Xiangfei

AU - Krause, Pascal

AU - Kirschbaum, Thorren

AU - Palczynski, Karol

AU - Dzubiella, Joachim

AU - Bande, Annika

N1 - Funding Information: X. W.'s work receives support from the Chinese Scholar Council (CSC). T. K. acknowledges the support from the Helmholtz Einstein International Berlin Research School in Data Science (HEIBRiDS). The computing resources come from the Freie Universität Berlin (HPC cluster Curta87) and the Dirac HPC of the Helmholtz-Zentrum Berlin.

PY - 2024

Y1 - 2024

N2 - Aqueous nanodiamonds illuminated by UV light produce free solvated electrons, which may drive high-energy reduction reactions in water. However, the influence of water conformations on the excited-state electron-transfer mechanism are still under debate. In this work, we offer a theoretical study of charge-transfer states in adamantane-water structures obtained by linear-response time-dependent density-functional theory. Small water clusters with broken hydrogen bonds are found to efficiently bind the electron from adamantane. A distinction is made with respect to the nature of the water clusters: some bind the electron in a water cavity, others along a strong permanent total dipole. These two types of bound states are more strongly binding, the higher their electron affinity and their positive electrostatic potential, the latter being dominated by the energy of the lowest unoccupied molecular orbital of the isolated water clusters. Structural sampling in a thermal equilibrium at room temperature via molecular dynamics snapshots confirms under which conditions the underlying waters clusters can occur and verifies that broken hydrogen bonds in the water network close to adamantane can create traps for the solvated electron.

AB - Aqueous nanodiamonds illuminated by UV light produce free solvated electrons, which may drive high-energy reduction reactions in water. However, the influence of water conformations on the excited-state electron-transfer mechanism are still under debate. In this work, we offer a theoretical study of charge-transfer states in adamantane-water structures obtained by linear-response time-dependent density-functional theory. Small water clusters with broken hydrogen bonds are found to efficiently bind the electron from adamantane. A distinction is made with respect to the nature of the water clusters: some bind the electron in a water cavity, others along a strong permanent total dipole. These two types of bound states are more strongly binding, the higher their electron affinity and their positive electrostatic potential, the latter being dominated by the energy of the lowest unoccupied molecular orbital of the isolated water clusters. Structural sampling in a thermal equilibrium at room temperature via molecular dynamics snapshots confirms under which conditions the underlying waters clusters can occur and verifies that broken hydrogen bonds in the water network close to adamantane can create traps for the solvated electron.

UR - http://www.scopus.com/inward/record.url?scp=85186214418&partnerID=8YFLogxK

U2 - 10.1039/d3cp04602h

DO - 10.1039/d3cp04602h

M3 - Article

AN - SCOPUS:85186214418

VL - 26

SP - 8158

EP - 8176

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 10

ER -