Results 71 to 80 of about 43,860 (248)

Post‐Modification of Tripyrenylenes to Enantiopure π‐Extended D3‐Symmetric Propellers

Chemistry – A European Journal, EarlyView.
The post‐modification of tripyrenylenes to π‐extended enantiopure propellers with tris‐phenanthrophenazines is presented and the chiroptical properties as well as the solid‐state packings investigated in comparison to the corresponding racemic mixtures.
Dennis Popp, Melanie Bruttel, Sebastian Möbert, Anusha Sounder Rajan, Christoph Keck, Darius Boehm, Frank Rominger, Sven M. Elbert, Michael Mastalerz   +8 more
wiley   +1 more source

Synthesis and Structure of an S‐Shaped Double Expanded Helicene With Seven Fused Anthracene Units

Chemistry – A European Journal, EarlyView.
The anthracene‐fused aromatic compound was synthesized by four‐fold cycloisomerization of the corresponding alkyne precursor. X‐ray crystallographic analysis revealed that this compound had a double helical structure of Ci symmetry, in which the terminal and central anthracene units were triply stacked.
Shinji Toyota, Kaito Hohno, Takehiro Kihara, Yu Watanabe, Yuki Shigihara, Eiji Tsurumaki, Masahiro Yamashina   +6 more
wiley   +1 more source

Catalyst‐Free Selective Reduction of Nitrogen Dioxide to Nitric Oxide

Chemistry – A European Journal, EarlyView.
Common main group reductants selectively convert nitrogen dioxide to nitric oxide in a catalyst‐free manner. Computational studies suggest divergent reaction pathways depending on the reductant employed. Where boranes and silanes proceed via a two‐electron process, and hydrogen surrogates undergo stepwise one‐electron processes.
Awais W. Seyyad, Agamemnon E. Crumpton, Reece Lister‐Roberts, Meera Mehta   +3 more
wiley   +1 more source

Nitrooxylation in Organic Synthesis: From Classical Nitrate Ester Formation to Modern Catalytic Strategies

Chemistry – A European Journal, EarlyView.
Nitrooxylation—the installation of nitrate esters (–ONO2) has evolved from classical mixed‐acid protocols to catalytic and mechano‐, flow‐, photo‐, and electrochemical strategies. This review delineates ionic and radical manifolds for C–ONO2 bond formation, emphasizing mechanistic control, selected substrate scope, and selectivity.
Jayanta Dey, Dmitry Katayev
wiley   +1 more source

Charge Resonance Interaction in Aromatic Trimer Radical Cations Revealed by IR Spectroscopy: The Case of Pyrrole Homo‐ and Heterotrimers

Chemistry – A European Journal, EarlyView.
We demonstrate the power of high‐resolution infrared spectroscopy and complementary quantum chemical calculations to unravel the evolution of the aromatic charge resonance interaction (CR) in cold trimer radical cations for the prototypical pyrrole clusters.
Dashjargal Arildii, Otto Dopfer
wiley   +1 more source

Mechanistic Insights Into Sustainable Catalytic Pyrolysis of Biomass‐Derived Ferulic Acid: The Role of Alumina Regeneration

Chemistry – A European Journal, EarlyView.
Surface‐bound ferulate phenolate complexes undergo styrene‐like polymerization on alumina, yielding a polymeric carbonaceous layer that progressively transforms into polyaromatic carbon domains with concomitant release of aromatic products, while parallel surface‐assisted decarboxylation produces 4‐vinylguaiacol. ABSTRACT A fundamental understanding of
Tetiana V. Kulik, Borys B. Palianytsia, Mykola M. Ilchenko, Nataliia S. Nastasiienko, David J. Morgan, Liudmila P. Storozhuk, David J. Willock, Greg Shaw, Duncan F. Wass, Rafael Luque, Philip R. Davies, Mykola T. Kartel   +11 more
wiley   +1 more source

Cyclization of a 1,8‐Diphenylanthracene by Scholl Reactions to Form Five‐ and Seven‐Membered Ring Embedded Polycyclic Aromatic Hydrocarbons

Chemistry – A European Journal, EarlyView.
Reactions of 10‐mesityl‐1,8‐diphenylanthracene with DDQ/TfOH produced three products via sequential formation of a five‐ or seven‐membered ring. Unexpectedly, the triply cyclized product with a rubicene substructure was formed through cyclization involving 1,2‐methyl shift.
Tatsuhiro Sasaki, Eiji Tsurumaki, Shinji Toyota   +2 more
wiley   +1 more source

β‐Ketonitrile‐Modified Prodan Derivatives as Large‐Stokes‐Shift Solvatochromic Fluorophores With Enhanced Brightness and Ratiometric Thermometric Response

Chemistry – A European Journal, EarlyView.
We report a systematic study of β‐ketonitrile–modified Prodan‐type solvatochromic fluorophores. The β‐ketonitrile substitution induces marked bathochromic shifts in absorption and emission and significantly enhances fluorescence quantum yields in nonpolar solvents.
Hiroaki Asakawa, Takuya Tanaka, Kensei Konishi, Gen‐ichi Konishi   +3 more
wiley   +1 more source

Impacts of refining Canadian partially upgraded bitumen: Fluid catalytic cracking

The Canadian Journal of Chemical Engineering, EarlyView.
Abstract In this study, we examine the fluid catalytic cracking (FCC) performance of vacuum gas oil (VGO) from partially upgraded bitumen (PUB), a novel refinery feedstock from Canadian bitumen. FCC experiments were conducted in a lab‐scale FCC unit with VGOs from two different PUBs prepared using thermal cracking and solvent deasphalting, along with ...
Yi Zhang, Anton Alvarez‐Majmutov, Rafal Gieleciak, Jinwen Chen   +3 more
wiley   +1 more source

Aliphatic and polycyclic aromatic hydrocarbons profiles of photomodified natural bitumen of Agbabu, Southwestern Nigeria

Bulletin of the Chemical Society of Ethiopia, 2010
The impact of sunlight on aliphatic and polycyclic aromatic hydrocarbons profiles of Agbabu natural bitumen in Nigeria was investigated. The raw flow type of the bitumen was purified and exposed to sunlight for six consecutive months.
O.M. Olabemiwo, G.O. Adediran, F.A. Adekola, A.A. Olajire   +3 more
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