Electron transfer articles within Nature Chemistry

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  • Article
    | Open Access

    The spontaneous recombination of photogenerated radicals surrounded by solvent molecules is an important energy-wasting elementary step in photoredox reactions. Now the decisive role that cage escape plays in these reactions is shown in three benchmark photocatalytic reactions, with quantitative correlations observed between photoredox product formation rates and cage escape quantum yields.

    • Cui Wang
    • , Han Li
    •  & Oliver S. Wenger
  • Article
    | Open Access

    Although surface-bound molecular catalysts offer well-defined active sites on heterogeneous supports, it is challenging to identify key radical intermediates in the reaction mechanism. Now, a characterization method has been developed that combines film electrochemistry and EPR spectroscopy to track radical intermediates in real time, exemplified by alcohol oxidation with a surface-immobilized nitroxide.

    • Maryam Seif-Eddine
    • , Samuel J. Cobb
    •  & Maxie M. Roessler
  • Article |

    Although interfacial proton-coupled electron transfers are critical reaction steps in chemical and biological processes, studies investigating these reactions are complicated by surface heterogeneity. Now, interfacial proton-coupled electron transfer kinetics are studied and modelled at isolated, well-defined active sites to provide a foundation for understanding complex reactions involved in energy conversion and catalysis.

    • Noah B. Lewis
    • , Ryan P. Bisbey
    •  & Yogesh Surendranath
  • Article
    | Open Access

    Radiation damage in biology is largely mediated by radicals and low-energy electrons formed by water ionization and extensive, localized water ionization can be caused by ultrafast processes following the core-level ionization of hydrated metal ions. Now it has been shown that, for Al3+ ions, relaxation occurs via sequential solute–solvent electron transfer-mediated decay.

    • G. Gopakumar
    • , I. Unger
    •  & O. Björneholm
  • Article
    | Open Access

    Although noble metal coordination complexes typically show promising photophysical properties that enable applications in lighting, photocatalysis and solar energy conversion, first-row transition metal complexes rarely display properties as attractive. Now, two Cr(0) complexes are shown to afford excited-state lifetimes of ~50 ns and photophysical properties analogous to noble metal complexes, enabling efficient photoredox catalysis.

    • Narayan Sinha
    • , Christina Wegeberg
    •  & Oliver S. Wenger
  • Article |

    Quantum state-to-state understanding of collisional charge transfer is a long-time goal of chemical dynamics. Now, using high-resolution molecular-beam experiments with spin–orbit state-selected ions and surface-hopping calculations, a vibrational-state-specific mechanism has been observed for the reaction Ar+(2P3/2) + N2 → Ar + N2+(v′, J′). Besides the well-known long-range harpooning mechanism, a hard-collision glory scattering mechanism was also identified.

    • Guodong Zhang
    • , Dandan Lu
    •  & Hong Gao
  • Article |

    H3+ and D3+ serve as initiators of many chemical reactions in interstellar clouds. Now the ultrafast formation dynamics of D3+ from a light-driven bimolecular reaction starting from D2–D2 dimers have been measured. It has also been shown that the emission direction of D3+ can be controlled by driving the reaction with a more complex two-colour laser pulse.

    • Lianrong Zhou
    • , Hongcheng Ni
    •  & Jian Wu
  • Article |

    Molecular π-stacked chromophores are promising photonic materials, but much of our understanding is limited to covalent dimers. Now it has been shown that, in a slip-stacked perylenediimide trimer, coherent vibronic coupling to high-frequency modes facilitates ultrafast state mixing between the Frenkel exciton and charge-transfer states, which then collapses by solvent fluctuations and low-frequency vibronic coupling, resulting in ultrafast symmetry-breaking charge separation.

    • Chenjian Lin
    • , Taeyeon Kim
    •  & Michael R. Wasielewski
  • Article |

    Controlling the crystallographic registry of layered materials through interlayer twist angles has introduced a distinctive degree of freedom for tuning their electronic behaviour. Now, the interfacial electrochemical kinetics of solution-phase redox complexes at twisted bilayer graphene electrodes have been modulated by the angle-dependent tuning of moiré-derived flat bands.

    • Yun Yu
    • , Kaidi Zhang
    •  & D. Kwabena Bediako
  • Article |

    Molecular catalysts for artificial photosynthesis can break down during operation and stop working, whereas biological photosynthesis uses an enzymatic repair strategy to maintain function. Now, the degradation pathway of a hydrogen-evolving RuPt photocatalyst has been identified, enabling the development of an active repair strategy involving the use of 1O2 to reoxidize the deactivated bridging ligand.

    • Michael G. Pfeffer
    • , Carolin Müller
    •  & Sven Rau
  • Article |

    Self-propelled artificial chemical swimmers have previously been developed for chemical sensing. Now, hybrid bioelectrochemical swimmers, capable of translating chiral molecular information into macroscopic motion, have been developed. Diastereomeric interactions between enantiopure oligomers immobilized on the swimmer and a chiral molecule present in solution control the trajectory of the device.

    • Serena Arnaboldi
    • , Gerardo Salinas
    •  & Alexander Kuhn
  • Article |

    The use of anionic redox chemistry in high-capacity Li-rich cathodes is being hampered by voltage hysteresis, the origin of which remains obscure. Now it has been shown that sluggish ligand-to-metal charge transfer kinetically traps an intermediate Fe4+ species and is responsible for voltage hysteresis in the prototypical Li-rich cation-disordered rock-salt Li1.17Ti0.33Fe0.5O2.

    • Biao Li
    • , Moulay Tahar Sougrati
    •  & Jean-Marie Tarascon
  • News & Views |

    Transition metal complexes with metal-to-ligand charge transfer (MLCT) luminescence and photoactivity typically rely on precious metals such as ruthenium or iridium. Now, two complexes of the Earth-abundant 3d manganese have displayed room-temperature MLCT luminescence in solution and a unique excited-state reactivity.

    • Katja Heinze
  • Article |

    Manganese(i) is isoelectronic to iron(ii) but has typically been overlooked as a cheap Earth-abundant metal for the development of 3d6 metal-to-ligand charge transfer (MLCT) emitters and photosensitizers. Now, using chelating isocyanide ligands, air-stable manganese(i) complexes have been obtained that exhibit MLCT luminescence, as well as energy- and electron-transfer photoreactivity.

    • Patrick Herr
    • , Christoph Kerzig
    •  & Oliver S. Wenger
  • News & Views |

    Excited anion states provide doorways for molecular electron capture. Now, two-dimensional photoelectron spectroscopy of cluster anions has been shown to be a powerful tool for revealing the role of the local environment in facilitating the process.

    • C. Annie Hart
    •  & Richard Mabbs
  • Article |

    Although electron-driven chemistry is ubiquitous, how molecular electron capture is altered by solvent remains poorly understood. Now, using anion two-dimensional photoelectron spectroscopy, it is shown that the presence of water molecules can enhance electron capture and that considering the mechanism from the perspective of the anion offers further understanding.

    • Aude Lietard
    • , Golda Mensa-Bonsu
    •  & Jan R. R. Verlet
  • Article |

    Solvent plays a critical role in electron-transfer reactions, but short-range solvation dynamics are challenging to observe. Now, femtosecond X-ray solution scattering has been used to directly monitor the reorganization of water upon ultrafast intramolecular electron transfer in a bimetallic complex. Coherent motions of the first-shell water molecules are observed, arising from changes in solute–solvent hydrogen bonding.

    • Elisa Biasin
    • , Zachary W. Fox
    •  & Munira Khalil
  • Article |

    134Ce and 134La have great potential as companion diagnostic isotopes for radiotherapeutics labelled with α-emitting 225Ac and 227Th. Now, by controlling the CeIII/CeIV redox couple, the large-scale production, purification and characterization of 134Ce- and 134La-based radiolabels has been achieved and their use for in vivo positron emission tomography is demonstrated.

    • Tyler A. Bailey
    • , Veronika Mocko
    •  & Rebecca J. Abergel
  • Article |

    Electronic–vibrational interplay can enable electron and energy transfer processes to be regulated. Now, coherence spectroscopy has been used to disentangle two vibrational pathways that control an electron transfer reaction. It has been shown that a fast, effectively ballistic, electron transfer along one vibrational path acts like a pulse to generate a coherent wavepacket along another vibrational pathway.

    • Shahnawaz R. Rather
    • , Bo Fu
    •  & Gregory D. Scholes
  • Article |

    Metal–organic frameworks (MOFs) can combine porosity and magnetic order within their lattice, which makes them attractive for the development of stimuli-responsive magnets. Now, a MOF has been prepared that converts from a ferrimagnet to a paramagnet with CO2 uptake, and returns to the ferrimagnetic state on releasing CO2.

    • Jun Zhang
    • , Wataru Kosaka
    •  & Hitoshi Miyasaka
  • Article |

    Singlet fission produces two low-energy triplet excitons that are difficult to dissociate into free charges. Now, separate optima in charge yield have been observed as a function of driving force for singlet and triplet excitons in pentacene. At optimal driving forces, the triplet-exciton dissociation rate is at least five orders of magnitude smaller than the singlet-exciton dissociation rate.

    • Natalie A. Pace
    • , Nadezhda V. Korovina
    •  & Obadiah G. Reid
  • News & Views |

    Although transporting a starship crewmember onto the surface of an alien planet is clearly science fiction, quantum state teleportation is not, and has been observed in various systems over the last few decades. Now, electron-spin teleportation has been observed in a carefully designed molecular system, paving the way for such behaviour to be tailored through molecular engineering.

    • Malcolm D. E. Forbes
  • Article |

    Quantum teleportation moves the quantum state of a system between physical locations without losing its coherence, an essential criterion for emerging quantum information applications. Now, electron-spin-state teleportation in covalent organic electron donor–acceptor–stable radical molecules is demonstrated using entangled electron spins produced by photo-induced electron transfer.

    • Brandon K. Rugg
    • , Matthew D. Krzyaniak
    •  & Michael R. Wasielewski
  • Article |

    A series of tungsten hydride complexes have been synthesized to mimic a proton-coupled electron transfer (PCET) step undergone by metal–hydride intermediates during solar fuel catalysis. It is shown that, by incorporating proton-accepting bases into the second coordination sphere, their PCET oxidation mechanism changes and its rate increases by several orders of magnitude.

    • Tianfei Liu
    • , Meiyuan Guo
    •  & Leif Hammarström
  • Article |

    The capture of an electron by a molecule represents one of the most fundamental chemical transformations, but its mechanism at very low energies remains unclear. Now, it is shown that low-energy electron attachment to hexafluorobenzene is mediated by a non-valence correlation-bound state of the anion.

    • Joshua P. Rogers
    • , Cate S. Anstöter
    •  & Jan R. R. Verlet
  • Article |

    Mononuclear gold(II) complexes are very labile (and thus very rare) species. Now, a gold(II) porphyrin complex has been isolated and characterized, and its reactivity towards dioxygen, nitrosobenzene and acids investigated. Owing to a second-order Jahn–Teller distortion, the gold atoms were found to adopt a 2+2 coordination mode in a planar N4 environment.

    • Sebastian Preiß
    • , Christoph Förster
    •  & Katja Heinze
  • Article |

    With recent and improved understanding of how nuclear and electronic degrees of freedom can interact with each other comes the opportunity to directly control electronic processes. Now it has been shown that ultrafast vibrational excitation can direct light-induced intramolecular electron transfer along a specific path.

    • Milan Delor
    • , Stuart A. Archer
    •  & Julia A. Weinstein
  • News & Views |

    Helium, the 'most noble' of the noble gases, had only been coaxed into forming molecular ions or van der Waals compounds. It has now been seen in a stable solid compound, Na2He, under high pressure.

    • Maosheng Miao
  • Article |

    Electron-transfer-mediated decay (ETMD) is a recently discovered type of electronic relaxation that involves the refilling of a core hole by an electron from a neighbouring species. It has now been observed in LiCl solution, when previously it had only been seen in rare-gas clusters. Spectra generated during ETMD are observed to be sensitive to the immediate environment of the initially ionized ion.

    • Isaak Unger
    • , Robert Seidel
    •  & Nikolai V. Kryzhevoi
  • Article |

    Helium is generally recognized as being chemically inert. A thermodynamically stable compound of helium and sodium, Na2He, has been predicted computationally and then synthesized at high pressure. It exists as an electride, where strongly localized electrons serve as anions located at the centre of Na8 cubes.

    • Xiao Dong
    • , Artem R. Oganov
    •  & Hui-Tian Wang
  • News & Views |

    Charge transfer through DNA has been well studied over recent decades from both a biological and electronics perspective. It has now been shown that charge transfer can be accelerated one hundredfold by using highly energetic 'hot holes', revealing a new mechanism that could help to create useful electronic biomaterials.

    • D. N. Beratan
    •  & D. H. Waldeck
  • Article |

    A protein-only redox film inspired by the architecture of bacterial electroactive biofilms has been developed. The film is formed using a rubredoxin–prion domain chimeric protein. The prion domains self-assemble into fibres that are decorated with rubredoxin. This results in highly organized films, able to transport electrons over several microns, and wire enzymes to electrodes.

    • Lucie Altamura
    • , Christophe Horvath
    •  & Vincent Forge
  • Article |

    Single-molecule junctions provide a unique platform to understand how molecular structure affects electronic transport. Now it has been shown that electronic transport through a π-stacked dimer can be precisely controlled when pulling it apart. This behaviour is caused by quantum interference effects that are turned ON or OFF depending on dimer conformation.

    • Riccardo Frisenda
    • , Vera A. E. C. Janssen
    •  & Nicolas Renaud
  • Article |

    Charge transfer in DNA is of fundamental interest in chemistry and biochemistry and has possible applications in nano-electronics. Now it has been shown, through a combined experimental and theoretical study, that the migration of positive charges through low-lying orbitals of nucleobases (deep-hole transfer) leads to charge transfer that is faster than previously considered transport regimes.

    • Nicolas Renaud
    • , Michelle A. Harris
    •  & Ferdinand C. Grozema
  • Article |

    The existence (or not) of electronic coherence in homopolymers is dependent on a balance between monomer–monomer interactions and environmental heterogeneity. Now, by understanding how even–odd orbital symmetry influences coherence and produces resistance oscillations as a function of distance—it is shown that DNA sequences can be designed to support coherent charge transport.

    • Chaoren Liu
    • , Limin Xiang
    •  & Nongjian Tao
  • Article |

    While important for solar energy conversion, it is unclear whether electron transfer at molecular–semiconductor interfaces is influenced only by the distance over which the injected electron tunnels and whether specific through-bond pathways are active. Now, a pathway for electron transfer has been identified through comparative analysis of compounds with phenyl- or xylyl-thiophene bridges.

    • Ke Hu
    • , Amber D. Blair
    •  & Curtis P. Berlinguette
  • Article |

    The influence of the thermodynamic driving force for photoinduced electron-transfer between single-walled carbon nanotubes and fullerene derivatives has been investigated. The Marcus inverted region and small reorganization energies were observed for this model organic heterojunction. Small reorganization energies aid in minimizing energy losses for solar conversion to electricity or fuels.

    • Rachelle Ihly
    • , Kevin S. Mistry
    •  & Jeffrey L. Blackburn
  • Article |

    Proposed as the source of the light-dependent magnetic compass in migratory birds, the radical pair mechanism is thought to operate in flavoproteins in the retina. Now, it has been demonstrated that the primary magnetic field effect on flavin photoreactions can be chemically amplified by slow radical termination reactions under conditions of continuous photoexcitation.

    • Daniel R. Kattnig
    • , Emrys W. Evans
    •  & P. J. Hore
  • Article |

    Metal centres play an important role in the damage to biomolecules caused by radiation, but the respective microscopic mechanisms are unknown. Now it is shown that the absorption of X-rays by a metal ion leads to an intricate chain of ultrafast relaxation steps that results in the complete degradation of the metal's local environment.

    • V. Stumpf
    • , K. Gokhberg
    •  & L. S. Cederbaum
  • Article |

    Uncertainty associated with solution-based electron-transfer studies of DNA–metal-complex systems has now been overcome by combining X-ray and time-resolved infrared data obtained for ruthenium polypyridyl–DNA crystals. Using these methods both the geometry of the reaction site and the kinetics of the reversible photo-induced one-electron oxidation of guanine have been determined.

    • James P. Hall
    • , Fergus E. Poynton
    •  & Susan J. Quinn
  • Article |

    The rotational state of a molecule is not generally considered to play a role in how fast it reacts; however, when the temperature is low quantum effects become more important. Now, it is shown that at low temperatures rotationally excited H2 molecules react with He faster than non-rotating ground-state molecules — a process mediated by stronger long-range attraction.

    • Yuval Shagam
    • , Ayelet Klein
    •  & Edvardas Narevicius
  • News & Views |

    Electron transfer is ubiquitous across both life and modern technologies, and thus being able to control it is an attractive goal. Now, targeted infrared excitation has been used to modulate the efficiency of electron transfer in a series of donor–bridge–acceptor molecules.

    • Igor V. Rubtsov
  • News & Views |

    Molecules can transfer charge between electron donors and acceptors, and can also transport charge when connected between metallic electrodes. These processes are assumed to show generally similar trends, however, a significant departure from this has now been observed in a series of biphenyl bridges.

    • Gemma C. Solomon
  • Article |

    Charge transport in molecular systems is typically through coherent tunnelling over a short distance or incoherent hopping over a long distance. An intermediate regime between those two transport mechanisms has now been found for DNA systems with stacked guanine–cytosine sequences.

    • Limin Xiang
    • , Julio L. Palma
    •  & Nongjian Tao
  • News & Views |

    The synchronous movement of protons and electrons orchestrated by enzymes gives rise to highly efficient catalytic processes in nature, such as photosynthesis. Now, researchers have choreographed similar reactivity for a metal hydride complex, setting the stage for efficient solar fuel production in artificial systems.

    • Jillian L. Dempsey
  • Article |

    Proton-coupled electron transfer (PCET) of metal hydrides, in which electrons and protons go to or from different molecular sites, are key steps in catalytic reactions involving solar fuels. Using [(Cp)W(CO)3H] as a model compound, it is now shown that this PCET reaction can occur in a concerted fashion, suggesting a possible low-barrier pathway to catalysis.

    • Marc Bourrez
    • , Romain Steinmetz
    •  & Leif Hammarström
  • News & Views |

    A better understanding of electron transfer through molecules could provide the basis for many technological breakthroughs. Now, the rate of electron transfer has been enhanced in a family of molecules by making them more rigid, and this phenomenon may be explained by the loss of electronic energy to vibrations.

    • John R. Miller