Results 31 to 40 of about 5,976 (269)
Molecules, 2020 Density functional calculations and up to five different basis sets have been applied to the exploration of the structural, enthalpy and free energy changes upon conversion of the azepine to the corresponding N-oxide.
René Fournier +5 more
doaj +1 more source
Molecules, 2023 We utilized a cycloaromatization reaction driven by relief of excited state antiaromaticity to photouncage aldehydes and ketones. We developed several synthetic routes towards the synthesis of photocaged carbonyls as allylically substituted 3-(2 ...
Adam Campbell +2 more
doaj +1 more source
Why 1,2‑quinone derivatives are more stable than their 2,3‑analogues? [PDF]
, 2015 In this work, we have studied the relative stability of 1,2- and 2,3-quinones. While 1,2-quinones have a closed-shell singlet ground state, the ground state for the studied 2,3-isomers is open-shell singlet, except for 2,3-naphthaquinone that has a ...
Dominikowska, Justyna +6 more
core +2 more sources
The Silacyclobutene Ring: An Indicator of Triplet State Baird-Aromaticity
Inorganics, 2017 Baird’s rule tells that the electron counts for aromaticity and antiaromaticity in the first ππ* triplet and singlet excited states (T1 and S1) are opposite to those in the ground state (S0). Our hypothesis is that a silacyclobutene (SCB) ring fused with
Rabia Ayub +2 more
doaj +1 more source
Edge modification of PAHs: the effect of embedded heterocycles on the aromaticity pattern [PDF]
, 2015 International audienceAromaticity studies carried out on the condensed model system 2 with different heteroatoms showed that the NICS(1) aromaticity in the five-membered ring correlates with that in the parent five-membered ring having the same ...
Bouit, Pierre-Antoine +3 more
core +3 more sources
Cyclobutadiene: The Antiaromatic Paradigm? [PDF]
ChemInform, 2006 AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
openaire +2 more sources
Magnetic Shielding, Aromaticity, Antiaromaticity and Bonding in the Low-Lying Electronic States of Benzene and Cyclobutadiene [PDF]
, 2016 Aromaticity, antiaromaticity, and their effects on chemical bonding in the ground states (S 0), lowest triplet states (T 1), and the first and second singlet excited states (S 1 and S 2) of benzene (C 6H 6) and square cyclobutadiene (C 4H 4) are ...
Hearnshaw, Peter +2 more
core +1 more source
Synthesis, Electronic Properties and WOLED Devices of Planar Phosphorus-Containing Polycyclic Aromatic Hydrocarbons [PDF]
, 2015 International audienceWe describe the synthesis and the physical properties of polyaromatic hydrocarbons (PAHs) containing a phosphorus atom at the edge.
Aparicio, Fátima +10 more
core +3 more sources
Dominant Role of the pi Framework in Cyclobutadiene [PDF]
, 2004 The extrinsic antiaromaticity of archetypal cyclobutadiene (CBD) is addressed with particular emphasis on the sigma-pi separability problem. The destabilization energy E(d)(CBD) of CBD is obtained by appropriate homodesmotic reactions involving the open ...
Baric, D. +3 more
core +1 more source
Donor–Acceptor Pentacene Analogues With Near‐Infrared Emission and Tunable Aromaticity
Angewandte Chemie, EarlyView.Air‐ and photostable heterocyclic pentacene analogues with donor and acceptor groups flanking a para‐quinodimethane core exhibit large dipole moments, narrow bandgaps, reversible redox behavior, and NIR‐I to NIR‐II absorption and emission with pronounced solvatochromism.
Krzysztof Nowak +6 more
wiley +2 more sources