The influence of nanoparticles on the excitation energies of the photochromic dihydroazulene/vinylheptafulvene system

Abstract

This paper studies how nanoparticles affect photochromic systems, focusing on the influence of gold nanoparticles on the optical properties of the dihydroazulene/vinylheptafulvene (DHA/VHF) system.

The effects of solvation on the back reaction and storage capabilities of solar thermal energy storage systems

“…Earlier, it was investigated how solvation affects the storage energies and thermal back reaction barriers, 18 and we have also studied the effects of nanoparticles on the storage properties and kinetics of the DHA/VHF couple. 19,20 Consequently, we wish to expand upon the knowledge available on the thermal back reaction of MOST systems, since it is crucial to their applicability. We have chosen to study three different NBD/QC derivatives, the parent-DHA/VHF system, and a 3-amino-substituted-DHA/VHF system for which the structures and relevant reaction schemes are depicted in Fig.…”

Optimization of the thermochemical properties of the norbornadiene/quadricyclane photochromic couple for solar energy storage using nanoparticles

“…18 Furthermore, we found that the NPs can enhance both one and two photon absorption of these systems while also providing significant redshifts in the absorption and clear alterations in the electric properties. [19][20][21] Hence, the coupling of such NPs to the NBD/QC system could be used as catalyst for the thermal back reaction while also possible tuning optical properties for solar energy storage.…”

Hybrid theoretical models for molecular nanoplasmonics

“…19,20 The theoretical modeling of systems of such an intrinsic complexity requires a multiscale description, which is able to capture the individual and collective behavior of the composite system. Focusing on the molecular nanoplasmonics, 8,[21][22][23][24][25][26][27][28] the requirement of a multiscale hybrid approach arises naturally: the small subsystem, i.e., the single molecule or the molecular aggregate, and the larger component, i.e., the nanostructure, need to be described by means of different approaches. The level of description is adapted according to the different size and level of accuracy required/affordable.…”

“…Hybrid methods for molecular plasmonics can be categorized based on the level of theory for the molecular target and on the description of the plasmonic nanostructure. Considering the molecular target, we can distinguish three main categories, ordered in terms of increasing complexity: (i) classical polarizable point dipole models ("dip" in the rest of this work), 22,[29][30][31][32][33][34] where the molecule is characterized only by using a frequency-dependent polarizability tensor (often isotropic); (ii) two-level quantum mechanical models ("2lev" from now on), a model derived from quantum optics where the molecule is described as a quantum system with two states (ground and excited), 7 separated by a certain excitation energy and coupled through a transition dipole, possibly obtained from empirical data; (iii) fully atomistic models based on a quantum-chemistry description ("QM," to comply with the standard acronyms of hybrid quantumchemistry models), 2,6,11,12,[24][25][26][27][28][35][36][37][38][39][40][41][42][43][44][45][46] providing chemical details and predictive power. The present classification is somewhat rough, and, in particular, for polaritonic chemistry, the 2lev model has been extended to include the dependence on one or a few nuclear coordinates to model photochemistry.…”

“…QM/classical approaches can be further classified by following the modeling of the NP: 6 QM/continuum, in which the NP is defined as a continuum characterized by a dielectric function, 11,12,27,36,[38][39][40][41][42]45,46 and QM/discrete, in which a discrete, atomistic but classical description of the NP is adopted. [24][25][26]28,37,43,44 QM/continuum models can be seen as an extension of continuum solvation models, which were proposed in the literature over the years, such as the polarizable continuum model (PCM). 51,52 The NP is, in fact, treated as a finite dielectric medium, with a given size, shape, and nature, and it is characterized by a frequency-dependent permittivity function ϵ(ω).…”