نتایج جستجو برای: aromaticity

تعداد نتایج: 1178  

2016
Jun Yuan Tingting Sun Xin He Ke An Jun Zhu Liang Zhao

Polymetalated aromatic compounds are particularly challenging synthetic goals because of the limited thermodynamic stability of polyanionic species arising from strong electrostatic repulsion between adjacent carbanionic sites. Here we describe a facile synthesis of two polyaurated complexes including a tetra-aurated indole and an octa-aurated benzodipyrrole. The imido trinuclear gold(I) moiety...

Journal: :Science 2001
X L Li A E Kuznetsov H F Zhang A I Boldyrev L S Wang

Aromaticity is a concept invented to account for the unusual stability of an important class of organic molecules: the aromatic compounds. Here we report experimental and theoretical evidence of aromaticity in all-metal systems. A series of bimetallic clusters with chemical composition MAl4- (M = Li, Na, or Cu), was created and studied with photoelectron spectroscopy and ab initio calculations....

Journal: :Journal of computational chemistry 2016
Xiaohu You Artem R. Oganov Ivan A. Popov Alexander I. Boldyrev

After the first introduction of π aromaticity in chemistry to explain the bonding, structure, and reactivity of benzene and its derivatives, this concept was further applied to many other compounds featuring other types of aromaticity (i.e., σ, δ). Thus far, there have been no reports on d-AO-based spherical σ aromaticity. Here, we predict a highly stable bare Ce6O8 cluster of a spherical shape...

Journal: :The journal of physical chemistry. A 2011
Slavko Radenković Patrick Bultinck

In the recent work by Khatua et al. (Khatua, S.; Roy, D. R.; Bultinck, P.; Bhattacharjee, M.; Chattaraj, P. K. Phys. Chem. Chem. Phys.2008, 10, 2461-2474) the synthesis and structure of a fac-trioxo molybdenum metalloligand and its sodium complex containing 1D hexagonal chains of sodium ions was reported. In the same paper, the aromaticity of hexagonal Na clusters was quantified by means of the...

The quantum chemical calculations were performed to investigate the interplay between the anion˗π and intramolecular hydrogen bond (IMHB) interactions in the various complexes of 1,3,5-triamino-2,4,6-trinitrobenzene (ANB) with Hˉ, Fˉ, Clˉ and Brˉ anions. For better understanding the cooperative effects, the parent molecules (ANB) and the corresponding complexes of 1,3,5˗trinitrobenzene with the...

2017
M Garcia-Borràs S Osuna J M Luis M Solà

The synthesis of endohedral metallofullerenes (EMFs) from a carbon soot sample of an arc discharge leads to a variety of EMFs that are obtained in different relative abundances. In the present work, we show that these abundances can be predicted from aromaticity calculations. In particular, we use the normalized Additive Local Aromaticity (ALAN) index. Our results show that the most abundant Sc...

Journal: :The Journal of organic chemistry 2006
Marcin Palusiak Sílvia Simon Miquel Solà

In this work, we analyze a series of o-hydroxyaryl aldehydes to discuss the interrelation between the resonance-assisted hydrogen bond (RAHB) formation and the aromaticity of the adjacent aromatic rings. As compared to the nonaromatic reference species (malonaldehyde), the studied compounds can be separated into two groups: first, the set of systems that have a stronger RAHB than that of the re...

Journal: :Organic & biomolecular chemistry 2014
Alexander S Ivanov Alexander I Boldyrev

The adaptive natural density partitioning (AdNDP) method has been applied for the first time to porphyrinoids in order to describe their aromaticity. The analysis of π-electron system reveals that aromaticity of annulene originates from 6-π-electron delocalization, while aromaticity of porphyrin can be better described in terms of local aromaticities of the appended 6-π-electron pyrrolic hetero...

2012
Agata Martyniak Pawel Lipkowski Noel Boens Aleksander Filarowski

The ketoenamine-enolimine tautometic equilibrium has been studied by the analysis of aromaticity and electron-topological parameters. The influence of substituents on the energy of the transition state and of the tautomeric forms has been investigated for different positions of chelate chain. The quantum theory of atoms in molecules method (QTAIM) has been applied to study changes in the electr...

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