From Neutral Diarsenes to Diarsene Radical Ions and Diarsene Dications DOI Creative Commons
Hanns M. Weinert,

Christoph Wölper,

Aleksa Radović

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(25)

Published: Feb. 23, 2024

Abstract Diarsene [L(MeO)GaAs] 2 (L=HC[C(Me)N(Ar)] , Ar=2,6‐ i Pr C 6 H 3 4 ) reacts with MeOTf and Me NHC ( NHC=1,3,4,5‐tetra‐methylimidazol‐2‐ylidene) to the diarsene [L(TfO)GaAs] 5 carbene‐coordinated [L(MeO)GaAsAs( NHC)Ga(OMe)L] ). The NHC‐coordination results in an inversion of redox properties which shows only a reversible reduction event at E 1/2 =−2.06 V vs Fc 0/+1 whereas oxidation =−1.31 . Single electron transfer reactions yielded [K[2.2.2.]cryp][L(MeO)GaAs] 8 NHC)‐Ga(OMe)L][B(C F ] 9 containing radical anion ⋅ − NHC‐coordinated cation NHC)Ga(OMe)L]⋅ + ), respectively, while salt‐elimination reaction triflate‐coordinated Na[B(C gave [LGaAs] [B(C 11 dication 2+ Compounds 1 – were characterized by 13 NMR, EPR IR, UV‐Vis spectroscopy single crystal X‐ray diffraction (sc‐XRD). DFT calculations provided detailed understanding electronic nature diarsenes ions respectively.

Language: Английский

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

et al.

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(16), P. 10468 - 10526

Published: Aug. 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.

Language: Английский

Citations

53
Unveiling Three Interconvertible Redox States of Boraphenalene DOI
Chun‐Lin Deng, Kimberly K. Hollister, Andrew Molino

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(9), P. 6145 - 6156

Published: Feb. 21, 2024

Neutral 1-boraphenalene displays the isoelectronic structure of phenalenyl carbocation and is expected to behave as an attractive organoboron multi-redox system. However, isolation new redox states have remained elusive even though preparation neutral boron(III)-containing phenalene compounds been extensively studied. Herein, we adopted N-heterocyclic carbene ligand stabilization approach achieve first stable ambipolar 1-boraphenalenyl radical 1•. The cation 1+ anion 1– also electrochemically observed chemically isolated, representing forms boraphenalene for study non-Kekulé polynuclear benzenoid molecules. Experimental theoretical investigations suggest that interconvertible three-redox-state species undergo reversible electronic modifications, which primarily take place on polycyclic framework molecules, exhibiting atypical behavior compared known donor-stabilized compounds. Initial reactivity studies, aromaticity evaluations, photophysical studies show redox-state-dependent trends. While luminescent in both solution solid states, 1• exhibits boron-centered undergoes substitution chemistry boraphenalenyl skeleton serves a single-electron transfer reductant.

Language: Английский

Citations

10
Advances and recent trends in dipnictenes chemistry DOI
Lothar Weber, Falk Ebeler, Rajendra S. Ghadwal

et al.

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 461, P. 214499 - 214499

Published: March 16, 2022

Language: Английский

Citations

32
Recent advances of mesoionic N-heterocyclic olefins DOI

Qiuming Liang,

Datong Song

Dalton Transactions, Journal Year: 2022, Volume and Issue: 51(24), P. 9191 - 9198

Published: Jan. 1, 2022

This Perspective article highlights the recent development of mesoionic N-heterocyclic olefins (mNHOs), where exo-cyclic olefinic carbon is not bonded to strongly electron-withdrawing groups. The unquenched basicity and nucleophilicity make mNHOs strong σ-donors enable unique reactivity patterns.

Language: Английский

Citations

32
Diazoalkenes: From an Elusive Intermediate to a Stable Substance Class in Organic Chemistry DOI Creative Commons
Max M. Hansmann

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(35)

Published: April 25, 2023

Over decades diazoalkenes (R2 C=C=N2 ) were postulated as reactive intermediates in organic chemistry even though their direct spectroscopic detection proved very challenging. In the 1970/80ies several groups probed existence mainly indirectly by trapping experiments or directly matrix-isolation studies. 2021, our group and Severin reported independently synthesis characterization of first room-temperature stable diazoalkenes, which initiated a rapidly expanding research field. Up to now four different classes N-heterocyclic substituted have been reported. Their properties unique reactivity, such N2 /CO exchange utilization vinylidene precursors transition metal are presented. This review summarizes early discoveries from initial postulation transient, elusive species up recent findings derivatives.

Language: Английский

Citations

22
Room‐Temperature‐Stable Diazoalkenes by Diazo Transfer from Azides: Pyridine‐Derived Diazoalkenes DOI Creative Commons

Justus Reitz,

Patrick W. Antoni,

Julian J. Holstein

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(19)

Published: March 3, 2023

Recently, stable diazoalkenes have received significant attention as a new substance class in organic chemistry. While their previous synthetic access was exclusively limited to the activation of nitrous oxide, we here establish much more general approach utilizing Regitz-type diazo transfer with azides. Importantly, this is also applicable weakly polarized olefins such 2-pyridine olefins. The pyridine are not accessible by allowing for considerable extension scope only recently accessed functional group. diazoalkene has properties distinct from previously reported classes, photochemically triggered loss dinitrogen affording cumulenes and C-H insertion products. Pyridine-derived represent so far least reported.

Language: Английский

Citations

18
Combining Distibene, Diazoolefins, and Visible Light: Synthesis and Reactivity of Inorganic Rings DOI
Prasenjit Palui,

Sangita Ghosh,

Rosa M. Gomila

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 7, 2025

The chemistry of heterocycles containing "diaza" units has been extensively studied due to their applications ranging from pharmaceuticals advanced materials. In contrast, incorporating heavier elements, such as Sb and Bi, remain exceedingly rare lack straightforward synthetic methodologies. Herein, we present a comprehensive experimental theoretical investigation the first diazadistiboylidenes (1a, 1b), synthesized via [3 + 2]-cycloaddition between distibene diazoolefins. These stiboylidenes are key intermediates promote selective nucleophilic substitution, leading example diantimonyl anion. Furthermore, upon visible-light irradiation, could isolate methylenedistibiranes, analogs methylenediaziridine (C2H4N2). findings offer novel platform for heavy dipnictogen chemistry, showcasing that diazoolefins, in combination with visible light, can facilitate formation unprecedented serve CO2 activation.

Language: Английский

Citations

1
Vanadium complexes with N-heterocyclic vinylidene ligands DOI
Bastiaan Kooij, Zhaowen Dong, Paul Varava

et al.

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(26), P. 4204 - 4207

Published: Jan. 1, 2022

The preparation and the structural characterization of vanadium complexes with terminal bridging N-heterocyclic vinylidene ligands is reported. synthesis was enabled by utilization diazoolefins as ligand precursors. Structural data theoretical results show that vinylidenes can act 6e- donor ligands, leading to strong metal-carbon interactions.

Language: Английский

Citations

19
Novel hydroquinazoline derivatives from Schiff base and study their biological activity DOI

Mohammed Khalaf Auaed,

Ayad Suleiman Hamad

Materials Today Proceedings, Journal Year: 2023, Volume and Issue: unknown

Published: May 1, 2023

Language: Английский

Citations

10
Quantification of the Donor‐Acceptor Character of Ligands by the Effective Fragment Orbitals DOI Creative Commons
Gerard Comas‐Vilà, Pedro Salvador

ChemPhysChem, Journal Year: 2024, Volume and Issue: 25(18)

Published: June 4, 2024

Abstract Metal‐ligand interactions are at the heart of transition metal complexes. The Dewar‐Chat‐Duncanson model is often invoked, whereby metal‐ligand bonding decomposed into simultaneous ligand→metal electron donation and metal→ligand back‐donation. separate quantification both effects not a trivial task, neither from experimental nor computational exercises. In this work we present effective fragment orbitals (EFOs) their occupations as general procedure beyond Kohn‐Sham density functional theory (KS‐DFT) framework for identification donor‐acceptor interactions, using solely wavefunction complex. Using common Fe(II) octahedral complex framework, quantify σ‐donor, π‐donor, π‐acceptor character large chemically diverse set ligands, by introducing respective descriptors σ d , π . We also explore effect size, coordination number, spin state on donor/acceptor features. spin‐state shown to be most critical effect, inducing systematic decrease sigma π‐backdonation going low high spin. Finally, illustrate ability EFOs rationalize Tolman electronic parameter trans influence in planar square complexes terms these new descriptors.

Language: Английский

Citations

4