Ring Currents in Benzo‐ and Benzocyclobutadieno‐Annelated Biphenylene Derivatives

Radenković, Slavko; Tošović, Jelena; Havenith, Remco W. A.; Bultinck, Patrick

doi:10.1002/cphc.201402468

Cited by 17 publications

(23 citation statements)

References 48 publications

(74 reference statements)

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“…c). This picture is in agreement with ring current density analysis, which predicts a strong paratropic ring current in the central ring and weaker diatropic currents in terminal rings . The diatropic response of the benzenoid rings, depicted in the

B_{π z}^{ind}

maps (Fig.…”

Section: Resultssupporting

confidence: 89%

Canonical orbital contributions to the magnetic fields induced by global and local diatropic and paratropic ring currents

et al. 2017

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The induced magnetic field (IMF) of naphthalene, biphenyl, biphenylene, benzocyclobutadiene, and pentalene is dissected to contributions from the total π system, canonical π-molecular orbitals (CMO), and HOMO→π* excitations, to evaluate and interpret relative global and local diatropicity and paratropicity. Maps of the IMF of the total π system reveal its relative strength and topology that corresponds to global and local diatropic and paratropic ring currents. The total π magnetic response is determined by this of canonical HOMOs and particularly by paratropic contributions of rotational excitations from HOMOs to unoccupied π* orbitals. Low energy excitations and similar nodal structure of HOMO and π* induce strong paratropic fields that dominate on antiaromatic rings. High energy excitations and different nodal structures lead to weak paratropic contributions of canonical HOMOs, which are overwhelmed by diatropic response of lower energy canonical orbitals in aromatic rings. CMO-IMF analysis is found in agreement with ring current analysis. © 2017 Wiley Periodicals, Inc.

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B_{π z}^{ind}

maps (Fig.…”

Section: Resultssupporting

confidence: 89%

Canonical orbital contributions to the magnetic fields induced by global and local diatropic and paratropic ring currents

et al. 2017

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Section: Resultsmentioning

confidence: 99%

“…Of course, the dependency of the local aromaticity in polycyclic conjugated systems on the annelation manner -linear or angular -is not a new finding since the influence of annelation manner on the local aromaticity in benzenoid and nonbenzenoid polycyclic compounds have been studied in many recent papers. [92][93][94][95][96][97][98][99] Now, an interesting question is whether further annelation of the central benzene ring of 7 and 3 in the angular position by four-and six-membered ring, respectively, will increase the local aromaticity of the rings in these new compounds?…”

Section: Cyclobutadieno-annelated Benzenementioning

confidence: 99%

“…Depending on the size of annelating ring, the studied compounds have been presented in two figures, Figures 4 and 5. Before starting the analysis of the results, we should recall that fulvenes are generally regarded as nonaromatic compounds [99,100] and monocyclic annulene ions are aromatic or antiaromatic systems according to the Hü ckle rule. As is apparent from Figure 4, when going from 11 to 12, the numerical difference between the in-plane Hessian eigenvalues (red dotted line and blue dashed line) decreases in both rings, despite the occurrence of different geometrical deformations in the rings; from 11 to 12, the value of DR of the sixmembered ring (A) increases, while Da decreases and exactly the opposite trend is observed for five-membered ring (B).…”

Section: Tri-annelated Benzenementioning

confidence: 99%

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Characterization of Local Aromaticity in Polycyclic Conjugated Hydrocarbons Based on Anisotropy of π‐Electron Density

2017

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In recent contributions, it was demonstrated that the anisotropy of π‐electron density could be considered as a reliable descriptor to probe the aromaticity in a wide range of annulene and hetero‐monocyclic compounds. The electron density anisotropy on a plane can be simply measured by the ratio of two in‐plane Hessian eigenvalues associated with the eigenvectors lying in the plane. This descriptor is undirected and has a circular symmetry for aromatic rings, whereas it is directed and has an elliptical shape in antiaromatic cycles. This research takes a step forward towards the extension of this approach to polycyclic conjugated hydrocarbons. The obtained results show that the anisotropy of the π‐electron density works nicely for the assessment of local aromaticity in polycyclic compounds. This finding provides clear evidence to have a universally successful aromaticity descriptor based on the topological properties of one‐electron density distribution.

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“…Theoretical studies are valuable approaches to explore the mechanism of reactions in the molecules and their electronic structures levels in addition to electronic parameters that acquired by means of theoretical calculations employ the computational methods of quantum chemistry 1,2 . The improvement in theoretical studies and applications have accomplish a point where predicted features of logical accuracy can be obtained from DFT (density functional theory) studies 3,4 .…”

Section: Introductionmentioning

confidence: 99%

Theoretical Studies on Electrophilic Aromatic Substitution Reaction for 8-Hydroxyquinoline

Obayes¹,

Al.Azawi²,

Khazaal³

et al. 2016

Orient. J. Chem

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Theoretical investigations of organic molecules for the objective of their structural stability are the most important techniques in this regards. Recently calculations and simulation reactions utilizing theoretical studies become attractive conventional method for the researchers. Density function theory (DFT) method was used to study the reaction of 8-hydroxyquinoline with 4-ethoxycarbonyl-benzene diazonium chloride as electrophilic aromatic substitution reaction. To study any reaction there are two explanations: first explanation depends on the reactant molecules and second explanation depends on the stability of the product molecules. Determine the stability of the molecule by comparing the energies (total energy, energy level of (HOMO), and energy gap), we have three stable molecules, are: HQ-7-YBAEE (II) for the total energy, HQ-6-YBAEE (II) for the energy level of (HOMO) and HQ-2-YBAEE (II) for the energy gap. The molecule HQ-4-YBAEE (II) is always at least stability in all data.

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Ring Currents in Benzo‐ and Benzocyclobutadieno‐Annelated Biphenylene Derivatives

Cited by 17 publications

References 48 publications

Canonical orbital contributions to the magnetic fields induced by global and local diatropic and paratropic ring currents

Canonical orbital contributions to the magnetic fields induced by global and local diatropic and paratropic ring currents

Characterization of Local Aromaticity in Polycyclic Conjugated Hydrocarbons Based on Anisotropy of π‐Electron Density

Theoretical Studies on Electrophilic Aromatic Substitution Reaction for 8-Hydroxyquinoline

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