Themed collection Ultrafast photoinduced energy and charge transfer

This article summarizes the papers presented and discussed at the 2019 Faraday discussion meeting on Ultrafast Photoinduced Charge and Energy Transfer. It also reflects on the remarkable progress in time-resolved studies since a related and pioneering discussion meeting that took place in 1959.

We explore Dexter coupling pathway interferences in non-covalent assemblies, employing a method that enables the assessment of Dexter coupling pathway strengths, interferences, and their physical origins in the context of one-particle and two-particle (i.e., coulombic) operators.

2-Dimensional electronic vibrational spectroscopy presents a novel experimental and theoretical approach to study energy transfer.

After presenting the basic theoretical models of excitation energy transfer and charge transfer, I describe some of the novel experimental methods used to probe them. Finally, I discuss recent results concerning ultrafast energy and charge transfer in biological systems, in chemical systems and in photovoltaics based on sensitized transition metal oxides.

Strong coupling between plasmon modes and chlorins in synthetic light-harvesting maquette proteins yields hybrid light-matter states (plexcitons) whose energies are controlled by design of protein structure, enabling the creation of new states not seen under weak coupling.

A combination of ultrafast spectroscopy and DFT/TD-DFT calculations of a recently synthesised iron carbene complex elucidates the ultrafast excited state evolution processes in these systems.

In this work, we use absorbance, circular dichroism (CD), and two-dimensional fluorescence spectroscopy (2DFS) to study the local conformations and conformational disorder within chromophore-labeled DNA constructs.

Coarse-grained model for dimeric PSII core complex reveals robust light harvesting through inter-monomer energy transfer and pooling in CP47s.

In this paper, we discuss our recent efforts to correlate the role of density of states, entropy, and configurational and energetic disorder to the open-circuit voltage, V_OC, of model type-II organic polymer photovoltaics.

Direct MCTDH quantum dynamics simulations, with automatic active coordinate generation, applied to potential molecular sunscreens.

We consider energy transfer in a vibronic dimer and show that the synchronisation dynamics of local mode displacements exhibit a rich behaviour which arises directly from the distinct time-evolutions of different vibronic quantum coherences.

Two-photon excitation (TPE) profiles of LHCII samples containing different xanthophyll complements were measured in the presumed 1¹A_g⁻ → 2¹A_g⁻ (S₀ → S₁) transition region of xanthophylls. Additionally, TPE profiles of Chls a and b in solution and of WSCP, which does not contain carotenoids, were measured. The results indicate that direct two-photon absorption by Chls in the presumed S₀ → S₁ transition spectral region of carotenoids is dominant over that of carotenoids, with negligible contributions of the latter. These results suggest the re-evaluation of previously published TPE data obtained with photosynthetic pigment–protein complexes containing (B)Chls and carotenoids.

Laser-induced energy deposition and heat transport in CuO is studied by picosecond time-resolved X-ray absorption spectroscopy.

We present numerical simulations on bacterial reaction centre (bRC) inspired model systems that utilize the recently developed MACGIC-iQUAPI method.

Herein we explore the symmetry breaking charge transfer process in two dipyrrin-based bichromophoric systems.

Here, we investigate the photochemistry of a catechol : o-quinone heterodimer as a model system for uncovering the photoprotective roots of eumelanin.

Ultrafast electron transfer occurs with greater-than-statistical rate enhancement at cryogenic temperatures owing to quantum coherence.

Photoinduced proton-coupled electron transfer (PCET) plays a key role in a wide range of energy conversion processes, and understanding how to design systems to control the PCET rate constant is a significant challenge.

Perturbation of molecular packing and dielectric environment at a quantum dot surface can promote singlet fission in diphenylpentacene aggregates.

It is generally presumed that the vast majority of carriers created by chemical doping of semiconducting polymer films are coulombically trapped by the counteranion, with only a small fraction that are free and responsible for the increased conductivity essential for organic electronic applications.

Excited state energy transfer in disordered systems has attracted significant attention owing to the importance of this phenomenon in both artificial and natural systems that operate in electronically excited states.

We present the synthesis and photophysical characterization of a water stable PCN-223(freebase) metal organic framework (MOF) constructed from meso-tetrakis(4-carboxyphenyl)porphyrin (TCPP).

Photobases convert light energy to proton removal power. What limits their applicability? Hydrogen bonding, solvation, and photon energy cost.

Sequence affects the energetics and role of charge transfer in oligonucleotides.

A fucoxanthin derivative has negligible charge-transfer character of the S₁/ICT state resulting in slowing down of the carotenoid–chlorophyll energy transfer.