Chemical Science, Год журнала: 2024, Номер 15(28), С. 10803 - 10809
Опубликована: Янв. 1, 2024
The dimerization of nitrogen monoxide (NO) is highly relevant in biochemical and environmental redox processes. Here, it shown how structral constraint element-ligand cooperativity can steer this reaction.
Язык: Английский
Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(49)
Опубликована: Сен. 28, 2023
Organobismuth-catalyzed transfer hydrogenation has recently been disclosed as an example of low-valent Bi redox catalysis. However, its mechanistic details have remained speculative. Herein, we report experimental and computational studies that provide insights into a Bi-catalyzed azoarenes using p-trifluoromethylphenol (4) pinacolborane (5) hydrogen sources. A kinetic analysis elucidated the rate orders in all components catalytic reaction determined 1 (2,6-bis[N-(tert-butyl)iminomethyl]phenylbismuth) is resting state. In azobenzene 4, equilibrium between ⋅ [OAr]2 (Ar=p-CF3 -C6 H4 ) observed, thermodynamic parameters are established through variable-temperature NMR studies. Additionally, pKa -gated reactivity validating proton-coupled nature transformation. The ensuing crystallographically characterized, shown to be rapidly reduced presence 5. DFT calculations indicate rate-limiting transition state which initial N-H bond formed via concerted proton upon nucleophilic addition hydrogen-bonded adduct 4. These guided discovery second-generation catalyst, lower energy, leading at catalyst loadings cryogenic temperature.
Язык: Английский
Процитировано
11
Accounts of Chemical Research, Год журнала: 2024, Номер 57(8), С. 1087 - 1097
Опубликована: Апрель 6, 2024
ConspectusAluminum is the most abundant metal in earth's crust at 8%, and it also widely available domestically many countries worldwide, which ensures a stable supply chain. To further applications of aluminum (Al), such as catalysis electronic energy storage materials, there has been significant interest synthesis characterization new Al coordination compounds that can support electron transfer (ET) proton (PT) chemistry. This achieved using redox chemically noninnocent ligands (NILs) combined with highly M(III) oxidation state some cases heavier group 13 ions, Ga In.When participate chemistry or facilitate breaking making bonds, they are often termed noninnocent, respectively. Al(III) particular supports rich ligand-based because so inert will ligand across charge protonation states without entering into reaction lesser extent, we have reported on elements In, this be included Account, where available.This Account arranged two technical sections, (1) Structures Al–NIL complexes (2) Reactivity complexes. Highlights research work include reversible enabled by design to shut down radical coupling pathways prevent loss H2 from unsaturated sites. These properties turn Class III delocalization through when NIL bound different states. Characterization metalloaromatic character square planar achieved, delocalized structures provided model within understand predict ET PT compounds. The capacity perform employed reactions use reactivity only coupled ET/PT affords hydride As an example, initiate metal–ligand cooperative bond activation for catalysis: includes acceptorless dehydrogenation formic acid anilines hydrogenation In complementary approach, based used study dihydropyridinate (DHP–) was shown N-coordination ions lowers kinetic barriers DHP– formation. Taken together, discussion presented herein illustrates Al(III), Ga(III) In(III) holds promise developments storage.
Язык: Английский
Процитировано
3
The Journal of Physical Chemistry C, Год журнала: 2024, Номер 128(37), С. 15367 - 15379
Опубликована: Сен. 3, 2024
Lewis acid sites (LAS) at the CHA(001) and CHA(101) surfaces are investigated regarding their activity for MeOH-mediated hydrogen transfer reactions from MeOH to alkenes, yielding alkanes formaldehyde. Direct decomposition formaldehyde is also investigated. Furthermore, coupling of produced olefins with dienes H2O via Prins reaction studied. The reactivity LAS these compared that bulk Brønsted (BAS) surface BAS. Periodic density functional theory (DFT) used in connection DLPNO-CCSD(T) calculations on cluster models. Hydrogen found be often more favorable LAS, while both BAS have similar reactions.
Язык: Английский
Процитировано
2
Inorganic Chemistry, Год журнала: 2024, Номер unknown
Опубликована: Окт. 3, 2024
We report the synthesis of cationic 2,6-bisiminopyridine organoaluminum complexes, [(BIP)AlR
Язык: Английский
Процитировано
1
Inorganic Chemistry, Год журнала: 2023, Номер 63(1), С. 739 - 751
Опубликована: Дек. 21, 2023
Low-coordinate heteroleptic zinc hydrides are catalytically important but rare and synthetically challenging. We herein report three-coordinate monomeric hydride on a 2-anilidomethylpyridine framework (NNL). The synthetic success comes through systematically screening few different routes from precursors. During the process, ligand's anilide backbone interestingly appears to be more reactive than Zn's terminal site electrophilic Lewis Brønsted acids. proligand NNLH reacts with [Zn{N(SiMe3)2}2] ZnEt2 give [(NNL)ZnA] (A = N(SiMe3)2 (1), Et(2)). Both inert PhSiH3 H2 react HBpin only internal Zn–Nanilide bond borylated ligand NNLBpin (3). reactions of 1 2 Ph3EOH (E C, Si) afford series divergent compounds like [(NNLH)Zn(OSiPh3)2] (4), [Zn3(OSiPh3)4Et2] (5), [EtZn(OCPh3)] (6). But in all cases, it is invariably protonated by –OH equal or higher preference Zn–N Zn–C bonds. A DFT analysis rationalizes origin such reactivity pattern. Realizing that an acid-free route might key, reacting [(NNL)Li] ZnBr2 gives [(NNL)Zn(μ-Br)]2 (7), which successively treating KOSiPh3 desired [(NNL)ZnH] (8) as monomer Zn–H bond. Estimating steric 8 shows openness coordination sphere, criterion for efficient catalysis. This positive influence pyridyl sidearm reflected 8's superior activity hydroborating PhC(O)Me comparison Jones' two-coordinate anilido hydride.
Язык: Английский
Процитировано
3
Опубликована: Сен. 21, 2023
Herein we report the preparation and characterization of Group 13 metal complexes a tripodal tris(nitroxide) based ligand, designated (TriNOx3−)M (M = Al (1), Ga (2), In (3)). Complexes 1 2 both activate O–H bond range alcohols spanning ~13 pKa unit via an element-ligand cooperative pathway to afford zwitterionic (HTriNOx2–)M–OR. Structures these alcohol adduct products are discussed. We demonstrate that thermodynamic kinetic aspects reactions influenced by identity metal, with having higher reaction equilibrium constants proceeding at faster rate relative for any given alcohol. These parameters also alcohol, more acidic reacting completion than their less counterparts. Possible mechanistic pathways
Язык: Английский
Процитировано
1
Опубликована: Сен. 22, 2023
Herein we report the preparation and characterization of Group 13 metal complexes a tripodal tris(nitroxide) based ligand, designated (TriNOx3−)M (M = Al (1), Ga (2), In (3)). Complexes 1 2 both activate O–H bond range alcohols spanning ~13 pKa unit via an element-ligand cooperative pathway to afford zwitterionic (HTriNOx2–)M–OR. Structures these alcohol adduct products are discussed. We demonstrate that thermodynamic kinetic aspects reactions influenced by identity metal, with having higher reaction equilibrium constants proceeding at faster rate relative for any given alcohol. These parameters also alcohol, more acidic reacting completion than their less counterparts. Possible mechanistic pathways
Язык: Английский
Процитировано
1
Angewandte Chemie, Год журнала: 2023, Номер 135(49)
Опубликована: Сен. 28, 2023
Abstract Organobismuth‐catalyzed transfer hydrogenation has recently been disclosed as an example of low‐valent Bi redox catalysis. However, its mechanistic details have remained speculative. Herein, we report experimental and computational studies that provide insights into a Bi‐catalyzed azoarenes using p ‐trifluoromethylphenol ( 4 ) pinacolborane 5 hydrogen sources. A kinetic analysis elucidated the rate orders in all components catalytic reaction determined 1 (2,6‐bis[ N‐ tert ‐butyl)iminomethyl]phenylbismuth) is resting state. In azobenzene , equilibrium between ⋅ [OAr] 2 (Ar= ‐CF 3 −C 6 H observed, thermodynamic parameters are established through variable‐temperature NMR studies. Additionally, K ‐gated reactivity validating proton‐coupled nature transformation. The ensuing crystallographically characterized, shown to be rapidly reduced presence . DFT calculations indicate rate‐limiting transition state which initial N−H bond formed via concerted proton upon nucleophilic addition hydrogen‐bonded adduct These guided discovery second‐generation catalyst, lower energy, leading at catalyst loadings cryogenic temperature.
Язык: Английский
Процитировано
1
Inorganic Chemistry, Год журнала: 2024, Номер 63(9), С. 4028 - 4038
Опубликована: Фев. 22, 2024
Herein, we report the preparation and characterization of Group 13 metal complexes a tripodal tris(nitroxide)-based ligand, designated (TriNOx3–)M (M = Al (1), Ga (2), In (3)). Complexes 1 2 both activate O–H bond range alcohols spanning ∼10 pKa unit via an element-ligand cooperative pathway to afford zwitterionic (HTriNOx2–)M–OR. Structures these alcohol adduct products are discussed. We demonstrate that thermodynamic kinetic aspects reactions influenced by identity metal, with having higher reaction equilibrium constants proceeding at faster rate relative for any given alcohol. These parameters also alcohol, more acidic reacting completion than their less counterparts. Possible mechanistic pathways activation
Язык: Английский
Процитировано
0
Chemical Science, Год журнала: 2024, Номер 15(28), С. 10803 - 10809
Опубликована: Янв. 1, 2024
The dimerization of nitrogen monoxide (NO) is highly relevant in biochemical and environmental redox processes. Here, it shown how structral constraint element-ligand cooperativity can steer this reaction.
Язык: Английский
Процитировано
0