Results 81 to 90 of about 60,540 (292)

Machine Learning Accelerated Computational Design of Bio‐Inspired Catalysts in the Nitrogen Reduction Reaction

open access: yesAdvanced Materials, EarlyView.
We introduce a computational workflow that combines quantum chemical calculations and machine learning techniques to predict the catalytic performance of a wide range of catalysts in the nitrogen reduction reaction (NRR). The analysis of the trained models provides insights into the complex structure–activity relationship in experimental catalytic ...
Leonardo Di Ciano   +5 more
wiley   +1 more source

Step‐Edge Functionalization by N‐Heterocyclic Carbenes Enhances Catalytic Activity in Electrochemical CO2 Reduction

open access: yesAdvanced Materials, EarlyView.
Atomically precise functionalization by N‐heterocyclic carbenes enhances the catalytic efficiency of macroscopically defined step edges toward electrochemical CO2${\rm CO}_2$ reduction. Sub‐molecular imaging reveals conformational differences between specific NHCs, which can be correlated with their catalytic performance. Photoelectron spectroscopy and
Philipp Wiesener   +9 more
wiley   +1 more source

New description of the substituent effect on electronic spectra by means of substituent constants

open access: yesJournal of Molecular Structure: THEOCHEM, 1991
著者らは近年,電子スペクトルに対する置換基効果を置換基定数で記述する新しい方法を研究してきた。電子スペクトルで測定される一重項あるいは三重項遷移エネルギー(1.3Euv)は, Swain らの FR 置換基定数あるいは湯川らの置換基定数 (σi ,σπ+,σπ-)を用いて, 1.3EUV=aF+bR+C, 1,3EUV=ασi+βσπ++γσπ-+Cと記述された。そして,これらは共役系の n-π* 吸収帯を初め,共役系および脂肪族系の n-π* 吸収帯,分子内電荷移動吸収帯,分子化合物の分子間電荷移動吸収帯およびそれら錯体形成による成分化合物自身の吸収帯などに対する置換基効果に適用できる一般式であることを明らかにした。さらに,ベンゼン置換体の吸収帯を用いて,これらの式の適用限界を議論した ...
Bunji UNO, Tanekazu KUBOTA
openaire   +2 more sources

Steric Coordination Modulated Iodine Chemistry With Four‐Electron Conversion for Zinc‐Iodine Batteries

open access: yesAdvanced Materials, EarlyView.
A dual‐additive electrolyte strategy is developed to address the hydrolysis of I+ in the aqueous electrolytes. The steric‐hindrance effect of TES− effectively shields I+ from nucleophilic attacks by hydroxyl groups, facilitating the reversible I−/I0/I+ conversion with four‐electron transfer.
Shuai Wang   +8 more
wiley   +1 more source

Trimethylsilyl Substituent Effects on the Triazolium-catalysed Benzoin Condensation [PDF]

open access: yes, 2021
In the benzoin condensation catalysed by N-heterocyclic carbenes (NHCs) there exists a unique 2-substituent effect. 2-Substituted aldehydes with 2-Lewis basic substituents will preferentially take part in the first addition step of NHC to aldehyde ...
MACRAE, HECTOR,IAN
core  

Light Switchable Ionic Conductivity of Arylazopyrazole Modified Polysiloxanes

open access: yesAdvanced Materials Technologies, EarlyView.
We present a polysiloxane functionalized with a novel arylazopyrazole dye that undergoes reversible photoisomerization. Upon lithium bis(trifluoromethanesulfonyl)imide addition and UV irradiation, the polymer exhibits a shift in tan(d) toward higher frequencies and enhanced ionic conductivity.
Malte S. Beccard   +7 more
wiley   +1 more source

NMR characterization of substituent effects in cation–π interactions

open access: yes, 2012
Substituent effects in C6H5X…M+ (M+ = Li+, Na+, K+, and ) systems have been characterized using isotropic nuclear magnetic shielding constants (σ). Good linear relationship between σ and the Hammett substituent constant σp is established which suggests ...
Suresh, Cherumuttathu H.   +3 more
core   +1 more source

Naphthyridine‐Based Donor–Acceptor Boron Difluoride Complexes Targeting Red Emission in Organic Light‐Emitting Diodes

open access: yesAdvanced Optical Materials, EarlyView.
Four donor–acceptor boron difluoride complexes based on triphenylamine donor and a naphthyridine acceptor units were synthesized, studied, and applied as OLED emitters. They exhibit pronounced intramolecular charge transfer character, balanced charge transport properties, and tunable emission. Near‐unity PLQYs are achieved for selected compounds, while
Omar Lahna   +8 more
wiley   +1 more source

Dissociative Electron Transfer to N‐(Arylthio)phthalimides: Factors Affecting the Formation and Dissociation of Radical Anions

open access: yesChemElectroChem
A series of chemically and biologically relevant N‐(arylthio)phthalimides is synthesized and its electrochemical reduction investigated. The results of the electrochemical study are analysed through application of Savéant's dissociative electron transfer
Michael A. Saley   +2 more
doaj   +1 more source

Iron Porphyrin-Based Composites for Electrocatalytic Oxygen Reduction Reactions

open access: yesMolecules
The oxygen reduction reaction (ORR) is one of the most critical reactions in energy conversion systems, and it facilitates the efficient conversion of chemical energy into electrical energy, which is necessary for modern technology.
Stennard Leetroy George   +4 more
doaj   +1 more source

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