Isolation of an Annulated 1,4‐Distibabenzene Diradicaloid DOI Creative Commons
Henric Steffenfauseweh, Dennis Rottschäfer, Yury V. Vishnevskiy

и другие.

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(19)

Опубликована: Янв. 4, 2023

The first 1,4-distibabenzene-1,4-diide compound [(ADC)Sb]2 (5) based on an anionic dicarbene (ADC) (ADC=PhC{N(Dipp)C}2 , Dipp=2,6-iPr2 C6 H3 ) is reported as a bordeaux-red solid. Compound 5, featuring central six-membered C4 Sb2 ring with formally SbI atoms may be regarded base-stabilized cyclic bis-stibinidene in which each of the Sb bears two lone-pairs electrons. 5 undergoes 2 e-oxidation Ph3 C[B(C6 F5 )4 ] to afford [B(C6 ]2 (6) brick-red Each 6 has unpaired electron and lone-pair. broken-symmetry open-shell singlet diradical solution for (6)2+ calculated 2.13 kcal mol-1 more stable than closed-shell singlet. character according SS-CASSCF (state-specific complete active space self-consistent field) UHF (unrestricted Hartree-Fock) methods amounts 36 % 39 %, respectively. Treatments (PhE)2 yield [(ADC)Sb(EPh)]2 (7-E) (E=S or Se). Reaction (cod)Mo(CO)4 affords Mo(CO)4 (8).

Язык: Английский

Soot inception: Carbonaceous nanoparticle formation in flames DOI
Jacob W. Martin, Maurin Salamanca, Markus Kraft

и другие.

Progress in Energy and Combustion Science, Год журнала: 2021, Номер 88, С. 100956 - 100956

Опубликована: Сен. 17, 2021

Язык: Английский

Процитировано

192
Open-Shell Graphene Fragments DOI Creative Commons
Wangdong Zeng, Jishan Wu

Chem, Год журнала: 2020, Номер 7(2), С. 358 - 386

Опубликована: Ноя. 20, 2020

Язык: Английский

Процитировано

182
Unconventional singlet fission materials DOI
Tobias Ullrich, Dominik Munz, Dirk M. Guldi

и другие.

Chemical Society Reviews, Год журнала: 2021, Номер 50(5), С. 3485 - 3518

Опубликована: Янв. 1, 2021

Singlet fission (SF) is a photophysical downconversion pathway, in which singlet excitation transforms into two triplet excited states.

Язык: Английский

Процитировано

139
Recent advances in stable main group element radicals: preparation and characterization DOI
Zhongtao Feng, Shuxuan Tang, Yuanting Su

и другие.

Chemical Society Reviews, Год журнала: 2022, Номер 51(14), С. 5930 - 5973

Опубликована: Янв. 1, 2022

Radical species are significant in modern chemistry. Their unique chemical bonding and novel physicochemical properties play roles not only fundamental chemistry, but also materials science. Main group element radicals usually transient due to their high reactivity. Highly stable often stabilized by π-delocalization, sterically demanding ligands, carbenes weakly coordinating anions recent years. This review presents the advances synthesis, characterization, reactivity physical of isolable main radicals.

Язык: Английский

Процитировано

92
Aza-Triangulene: On-Surface Synthesis and Electronic and Magnetic Properties DOI Creative Commons
Tao Wang, Alejandro Berdonces‐Layunta, Niklas Friedrich

и другие.

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(10), С. 4522 - 4529

Опубликована: Март 7, 2022

Nitrogen heteroatom doping into a triangulene molecule allows tuning its magnetic state. However, the synthesis of nitrogen-doped (aza-triangulene) has been challenging. Herein, we report successful aza-triangulene on Au(111) and Ag(111) surfaces, along with their characterizations by scanning tunneling microscopy spectroscopy in combination density functional theory (DFT) calculations. Aza-triangulenes were obtained reducing ketone-substituted precursors. Exposure to atomic hydrogen followed thermal annealing and, when necessary, manipulations probe afforded target product. We demonstrate that Au(111), donates an electron substrate exhibits open-shell triplet ground This is derived from different Kondo resonances final product series intermediates Au(111). Experimentally mapped molecular orbitals match DFT-calculated counterparts for positively charged aza-triangulene. In contrast, receives extra displays closed-shell character. Our study reveals electronic properties metal surfaces offers approach fabrication new hydrocarbon structures, including reactive molecules.

Язык: Английский

Процитировано

90
Conceptual Density Functional Theory DOI
Frank De Proft, Paul Geerlings, Farnaz Heidar‐Zadeh

и другие.

Elsevier eBooks, Год журнала: 2022, Номер unknown, С. 306 - 321

Опубликована: Окт. 31, 2022

Язык: Английский

Процитировано

78
Oxygen hole formation controls stability in LiNiO2 cathodes DOI Creative Commons
Annalena R. Genreith‐Schriever, Hrishit Banerjee, Ashok S. Menon

и другие.

Joule, Год журнала: 2023, Номер 7(7), С. 1623 - 1640

Опубликована: Июль 1, 2023

Ni-rich lithium-ion cathode materials achieve both high voltages and capacities but are prone to structural instabilities oxygen loss. The origin of the instability lies in pronounced oxidation O during delithiation: for LiNiO2, NiO2, rock salt NiO, density functional theory dynamical mean-field calculations based on maximally localized Wannier functions yield a Ni charge state ca. +2, with varying between −2 (NiO), −1.5 (LiNiO2), −1 (NiO2). Calculated X-ray spectroscopy K K-edge spectra agree well experimental spectra. Using ab initio molecular dynamics simulations, we observe loss from (012) surface delithiated two O⋅− radicals combining form peroxide ion, ion being oxidized O2, leaving behind vacancies O2− ions. Preferential release 1O2 is dictated via singlet ground spin conservation.

Язык: Английский

Процитировано

72
From Stable Radicals to Thermally Robust High-Spin Diradicals and Triradicals DOI

Chan Shu,

Zhimin Yang⌈,

Andrzej Rajca

и другие.

Chemical Reviews, Год журнала: 2023, Номер 123(20), С. 11954 - 12003

Опубликована: Окт. 13, 2023

Stable radicals and thermally robust high-spin di- triradicals have emerged as important organic materials due to their promising applications in diverse fields. New fundamental properties, such SOMO/HOMO inversion of orbital energies, are explored for the design new stable radicals, including highly luminescent ones with good photostability. A relation singlet–triplet energy gap corresponding diradicals is proposed. Thermally triradicals, gaps that comparable or greater than a thermal at room temperature, more challenging synthesize but rewarding. We summarize number based on nitronyl nitroxides provide between experimental pairwise exchange coupling constant J/k species vs hyperfine constants monoradicals. This allows us identify outliers, which may correspond where not measured sufficient accuracy. Double helical diradicals, spin density delocalized over chiral π-system, been barely explored, sole example diradical possessing alternant π-system Kekulé resonance form. Finally, we discuss electrical conductivity derivatives triangulene diradicals.

Язык: Английский

Процитировано

70
Heteroatom-Based Diradical(oid)s DOI
Alexander Hinz, Jonas Bresien, Frank Breher

и другие.

Chemical Reviews, Год журнала: 2023, Номер 123(16), С. 10468 - 10526

Опубликована: Авг. 9, 2023

Heteroatom-centered diradical(oid)s have been in the focus of molecular main group chemistry for nearly 30 years. During this time, diradical concept has evolved and shifted to rational design specific applications. This review article begins with some important theoretical considerations tetraradical concept. Based on these considerations, terms ligand choice, steric, symmetry, electronic situation, element reactivity is highlighted examples. In particular, heteroatom-centered reactions are discussed compared closed-shell such as pericyclic additions. The comparison between reactivity, which proceeds a concerted manner, open-shell stepwise fashion, along diradical(oid) design, provides understanding interesting unusual class compounds. application diradical(oid)s, example small molecule activation or switches, also highlighted. final part application-related details spectroscopy followed by an update tetraradical(oid)s published last 10 years since 2013.

Язык: Английский

Процитировано

50
Endogenous Photosensitizers in Human Skin DOI
E. L. Bastos, Frank H. Quina, Maurı́cio S. Baptista

и другие.

Chemical Reviews, Год журнала: 2023, Номер 123(16), С. 9720 - 9785

Опубликована: Июль 17, 2023

Endogenous photosensitizers play a critical role in both beneficial and harmful light-induced transformations biological systems. Understanding their mode of action is essential for advancing fields such as photomedicine, photoredox catalysis, environmental science, the development sun care products. This review offers comprehensive analysis endogenous human skin, investigating connections between electronic excitation subsequent activation or damage organic biomolecules. We gather physicochemical photochemical properties key examine relationships chemical reactivity, location within primary biochemical events following solar radiation exposure, along with influence on skin physiology pathology. An important take-home message this that photosensitization allows visible light UV-A to have large effects skin. The presented here unveils potential causes continuous increase global cancer cases emphasizes limitations current protection approaches.

Язык: Английский

Процитировано

48