Results 41 to 50 of about 2,992 (134)
A simple formula for calculating resonance energy of benzenoid hydrocarbons
Macedonian Journal of Chemistry and Chemical Engineering, 2006 The topological resonance energy (TRE) of a catacondensed benzenoid hydrocarbon with h six-membered rings and K Kekulé structures can be calculated by the (approximate) formula TRE = Ah + B + CK e–Dh, where A = 0.136, B = –0.223, C = 0.281, and D = 0.454.
Ivan Gutman, Slavko Slavko Radenković
doaj
A Failed Encounter in Mathematics and Chemistry: The Folded Models of van ‘t Hoff and Sachse [PDF]
, 2016 Three-dimensional material models of molecules were used throughout the 19th century, either functioning as a mere representation or opening new epistemic horizons. In this paper, two case studies are examined: the 1875 models of van ‘t Hoff and the 1890
Friedman, Michael
core
Multifunctional sequence-defined macromolecules for chemical data storage [PDF]
, 2018 Sequence-defined macromolecules consist of a defined chain length (single mass), end-groups, composition and topology and prove promising in application fields such as anti-counterfeiting, biological mimicking and data storage. Here we show the potential
Dawyndt, Peter +5 more
core +2 more sources
Supramolecular Host‐Guest Complexation Dynamics by Cost‐Efficient Electronic Structure Methods
Chemistry – A European Journal, EarlyView.We present a cost‐effective multilevel workflow for the kinetic profiling of host–guest systems, illustrated with cucurbit[6]uril and alkylammonium cations. The method combines rapid docking and reaction path searches at the semi‐empirical level, with refinement of the results using modern density functional theory, accurately reproducing experiment ...
Thomas Gasevic +6 more
wiley +1 more source
Twisted 1‐ and 2‐Azaperopyrenes: Synthesis, Structure, and Properties
Chemistry – A European Journal, EarlyView.ABSTRACT A synthesis of hitherto unknown 1‐ and 2‐azaperopyrenes, twisted nitrogen‐doped peropyrenes, is reported. The synthesis is based on a Brønsted acid‐mediated benzannulation of alkynes. Key alkyne intermediates are synthesized via two complementary routes, including a Pd/C‐catalyzed, copper‐ and amine‐free Sonogashira‐type coupling of (hetero ...
Ricardo Molenda +4 more
wiley +1 more source
COMPUTING THE ANTI-KEKULÉ NUMBER OF CERTAIN NANOTUBES AND NANOCONES
Studia Universitatis Babes-Bolyai Chemia, 2015 Let G(V,E) be a connected graph. A set M subset of E is called a matching if no two edges in M have a common end-vertex. A matching M in G is perfect if every vertex of G is incident with an edge in M.
Mehar Ali MALIK, Muhammad IMRAN
doaj
Understanding the mechanism stabilizing intermediate spin states in Fe(II)-Porphyrin
, 2017 Spin fluctuations in Fe(II)-porphyrins are at the heart of heme-proteins functionality. Despite significant progress in porphyrin chemistry, the mechanisms that rule spin state stabilisation remain elusive.
Alavi, Ali, Manni, Giovanni Li
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Performance of 3D-space-based atoms-in-molecules methods for electronic delocalization aromaticity indices [PDF]
, 2010 Several definitions of an atom in a molecule (AIM) in three-dimensional (3D) space, including both fuzzy and disjoint domains, are used to calculate electron sharing indices (ESI) and related electronic aromaticity measures, namely, Iringand multicenter ...
Bultinck, Patrick +4 more
core +1 more source
Chemistry – A European Journal, EarlyView.The mechanism of pacifigorgiadiene synthase from Burkholderia gladioli was investigated through isotopic labeling experiments and DFT calculations. The results revealed an unexpected labeling pattern which appeared to be different in the main and the side products, requiring unprecedented mechanistic explanations, including a “break‐flip‐cyclise ...
Zhiyong Yin +6 more
wiley +1 more source
ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.Graphitic carbon doped with an edge‐predominant pyridinic structure is synthesized using a sustainable, rapid microwave process. The material enhances vanadium redox reactions, improving energy efficiency and durability in VRFB electrodes, with a 94.12% discharge capacity retention over 1000 cycles.
Heeyeon An, Sieun Jeon, Yongjin Chung
wiley +1 more source