Anionic derivatives of <i>altan</i>‐corannulene

Monaco, Guglielmo; Zanasi, Riccardo

doi:10.1002/poc.3117

Cited by 18 publications

(88 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…18,19 For reviews, please see refs 21−24. In a previous paper in this journal, 5 we studied altancorannulene (structure 1 in Figure 1) and altan-coronene (structure 2, in Figure 1). In this study, we examine the doubly altanized altan−altan-corannulene (structure 3 of Figure 2), which was introduced by Monaco and Zanasi in ref 4, as well as altan−altan-coronene (structure 4, in Figure 2)these days preferably called 10,25 (altan) 2 -coronenewhich has not, so far, been considered. To compare our results with those of ref 4, we also examine the dianions of structures 1−4.…”

Section: ■ Introductionmentioning

confidence: 99%

Topological Ring Currents and Bond Currents in Some Neutral and Anionic Altans and Iterated Altans of Corannulene and Coronene

Dickens¹,

Mallion²

2018

J. Phys. Chem. A

View full text Add to dashboard Cite

The novel series of conjugated systems called altans, defined nearly a decade ago, was subsequently extended to multiple ("iterated") altans, and their magnetic properties were calculated by Monaco and Zanasi using the ab initio ipso-centric formalism. Such properties of the single ("mono") altans of corannulene and coronene, calculated by this sophisticated ab initio approach, had earlier been compared with those calculated via the rudimentary Hückel-London-Pople-McWeeny (HLPM) method-a parameter-free topological, quasi graph-theoretical approach requiring knowledge only of the conjugated system's molecular graph and the areas of its constituent rings. These investigations are here extended to double and triple altans. HLPM bond currents in several neutral mono altans are found to differ from those in the corresponding dianion only in those bonds that lie on the structures' perimeters, while the HLPM bond currents in all bonds in the neutral double and triple altans of corannulene and coronene are precisely the same as in the respective dianions. Some rationalization of these unexpected phenomena is offered in terms of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) nature of the role played by the lone nonbonding orbital in each of the neutral species and its respective dianion.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Topological Ring Currents and Bond Currents in Some Neutral and Anionic Altans and Iterated Altans of Corannulene and Coronene

Dickens¹,

Mallion²

2018

J. Phys. Chem. A

View full text Add to dashboard Cite

show abstract

“…The problem also arose in some recent calculations (not yet published) in which, following the ab initio calculations of Monaco and Zanasi, [28,29] we attempted to extend our earlier studies of the neutral altans and multiple ('iterated') altans of corannulene and coronene, [30] and their dianions, [31] to the tetra-anions and hexa-anions of the same parent species.…”

Section: Introductionmentioning

confidence: 99%

Some Observations on Triplet Ground-States in the Context of ‘Topological’ (HLPM) Ring-Currents in Conjugated Systems

Dickens¹,

Mallion²

2019

Croat. chem. acta (Online)

View full text Add to dashboard Cite

When the quasi graph-theoretical Hückel–London–Pople–McWeeny (HLPM) approach is used to calculate ‘topological’ π-electron ring-currents and bond-currents in conjugated hydrocarbons, a problem is identified that occurs whenever application of the Aufbau process gives rise to a π-electronic ground-state configuration that is a triplet. This circumstance seems to occur only occasionally and, even when it does, the generally somewhat outré molecular graphs in question appear unlikely to represent extant or viable conjugated systems. The molecular graphs of four examples are used to illustrate this ‘triplet ground-state problem’, only one of which represents a hydrocarbon that has actually been synthesised. It is pointed out that the ‘triplet ground-state problem’ does constitute an intrinsic limitation of the HLPM approach. It is, though, a limitation that is also necessarily inherent in other equivalent (though ostensibly different) methods of calculating magnetic properties due to π-electron ring-currents — methods that are likewise founded on the Hückel molecular-orbital conventions. When a triplet ground-state arises, topological ring-currents and bond-currents cannot be calculated by the HLPM method and its equivalents. Infinite paramagnetism is formally to be predicted in such situations.

show abstract

“…Quantitative measures of electron flow around rings and bonds have been proposed and applied in numerical assessments of the (anti)aromatic character of (poly)cyclic systems . As the following is not limited to “bonds” in their traditional, though fuzzy, chemical meaning, we will adopt the expression pair current strength , rather than bond current susceptibility or bond current strength.…”

Section: Theoretical and Computational Methodsmentioning

confidence: 99%

Hydrogen–hydrogen bonding: The current density perspective

2015

Self Cite

View full text Add to dashboard Cite

Current density plots of closed-shell intermolecular H-H interactions characterized by a bond critical point (BCP) show two vortices separated by a saddle, a pattern which allows for a clear definition of a pair current strength. This H-H current strength turns out to be roughly related to the potential energy density at the BCP and then to the dissociation energy. The same pattern is also recognizable, at least for an azimuthal orientation of a field perpendicular to the H-H line, for the intramolecular interactions previously investigated to propose the H-H bonding. In the case of the H atoms of the bay region of polycyclic aromatic hydrocarbons, the current of the H-H delocalized diatropic vortex gives a quantitative indication of stabilization; however, on rotation of the field and the subsequent onset of a bay-delocalized paratropic vortex (a typical signature of antiaromaticity), the diatropic vortex can be reshaped or it can even disappear, consistently with its smallness, and thus showing the effect of other more relevant interactions.

show abstract

Anionic derivatives of altan‐corannulene

Cited by 18 publications

References 54 publications

Topological Ring Currents and Bond Currents in Some Neutral and Anionic Altans and Iterated Altans of Corannulene and Coronene

Topological Ring Currents and Bond Currents in Some Neutral and Anionic Altans and Iterated Altans of Corannulene and Coronene

Some Observations on Triplet Ground-States in the Context of ‘Topological’ (HLPM) Ring-Currents in Conjugated Systems

Hydrogen–hydrogen bonding: The current density perspective

Contact Info

Product

Resources

About