Curve-Structured Phenalenyl Chemistry: Synthesis, Electronic Structure, and Bowl-Inversion Barrier of a Phenalenyl-Fused Corannulene Anion

Nishida, Shinsuke; Ueda, Akira; Kobayashi, Tadahiro; Fukui, Kozo; Ogasawara, Kanako; Sato, Kazunobu; Takui, Takeji; Nakasuji, Kazuhiro

doi:10.1021/ja806708j

Cited by 55 publications

(29 citation statements)

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“…18 The majority of papers on this topic have been published in the 1990s; [19][20][21] however, also in very recent times, joint experimental-computational studies have been conducted. 22,23 More recently, the experimental and computational interest in inversion barriers has moved to bowl-shaped molecules, such as corannulene, [24][25][26][27][28][29] sumanene and its derivatives, [29][30][31][32] and other bowl-shaped hydrocarbons, including some derived from fullerene fragments. [33][34][35][36] Also, bowl-shaped and warped ("pringleshaped") boron nitride (BN) and aluminum nitride analogues of those hydrocarbons have been studied.…”

Section: Introductionmentioning

confidence: 99%

The INV24 test set: how well do quantum-chemical methods describe inversion and racemization barriers?

Goerigk

Sharma

2016

Can. J. Chem.

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For years, there has been ongoing interest in experimentally and theoretically understanding inversion and racemization processes. However, to the best of our knowledge, there has been no computational study that systematically investigated how well low-level quantum-chemical methods predict inversion barriers. Herein, we provide an answer to this question and we present the INV24 benchmark set of 24 high-level, ab initio inversion barriers. INV24 covers inversion in triatomics, in pyramidal molecules, in one cyclic system, and in various helical and bowl-shaped compounds. Our results indicate that previously applied DFT approximations combined with small basis sets are not reliable enough and that at least a triple-basis is needed for meaningful results. Moreover, we show that intramolecular London dispersion influences the barriers by 2 kcal/mol or more and that dispersion corrections should always be applied to DFT results. With our analysis of 34 DFT approximations, we can reproduce the well-known Jacob's Ladder scheme with (meta-)generalized-gradient-approximation methods underestimating barriers and global-hybrid DFT functionals performing better. Range-separated hybrids or Minnesota-type hybrids are not particularly superior to more conventional methods, such as B3LYP-D3. The by far best results are achieved with dispersioncorrected double hybrids, which give results below the chemical accuracy target of 1 kcal/mol. They also outperform wavefunction second-order perturbation theory approaches and we recommend using them whenever possible. Given that our systematic study of INV24 is the first of its kind, our findings have the potential to change common practice in this field and they will guide future investigations of inversion processes.Key words: barrier heights, chemical inversion, racemization barriers, benchmarking, density functional theory, wave-function theory.Résumé : Depuis des années, il y a un intérêt pour comprendre de manière expérimentale et théorique les processus d'inversion et de racémisation. Cependant, à notre connaissance, aucune étude computationnelle n'a évalué de manière systématique la précision des méthodes de chimie quantique de bas niveau pour prédire les barrières d'inversion. Dans le cadre des présents travaux, nous offrons une réponse à cette question et présentons la base de référence INV24 de 24 barrières d'inversion ab initio de haut niveau. L'application de la base INV24 couvre l'inversion des systèmes triatomiques dans les molécules pyramidales, dans un système cyclique et dans divers composés hélicoïdaux et de forme concave. Nos résultats indiquent que les approximations de DFT appliquées antérieurement, combinées avec des bases de petite taille, ne sont pas assez fiables et qu'une base tripleest minimalement requise pour que les résultats soient significatifs. De plus, nous montrons que la dispersion intramoléculaire de London a une incidence de 2 kcal/mol ou plus sur les barrières et que les résultats de DFT doivent toujours être corrigés pour tenir compte...

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Section: Introductionmentioning

confidence: 99%

The INV24 test set: how well do quantum-chemical methods describe inversion and racemization barriers?

Goerigk

Sharma

2016

Can. J. Chem.

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“…By taking advantage of the localized unpaired electronic spin on the NÀO moiety, chiral molecular magnets and paramagnetic organic chiral liquid crystals have extensively been implemented. [13,14] Cor-PLY is the first nonplanar phenalenyl derivative in the half-century-old phenalenyl chemistry.These studies have inspired us to design nonplanar pconjugated chiral phenalenyl radicals based on helicene. [11] As a consequence, phenalenyl derivatives exhibit unique physical properties and functionalities different from the those of spin-localized neutral radicals such as nitroxide derivatives.…”

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confidence: 99%

Chiral Stable Phenalenyl Radical: Synthesis, Electronic‐Spin Structure, and Optical Properties of [4]Helicene‐Structured Diazaphenalenyl

et al. 2012

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Helicenes are ortho-annelated polycyclic aromatic molecules with nonplanar helical conjugation of the p-electron system. [1] These aromatic molecules have attracted special attention not only because of the nonplanarity of the p-conjugated skeleton but also because of their inherent helical chirality. Recent developments in helicene chemistry have focused on the synthesis and optical resolution of new helicene derivatives [2] as well as on asymmetric catalysts, [3] molecular recognition, [4] and chiroptical functionalities. [5,6] However, almost all of the helicene derivatives investigated so far are intrinsically closed-shell electronic systems except for a few examples. [7] Thus, the chemistry of open-shell helicenes has been little explored in the past; to our knowledge there have been no experimental studies on helicene-based nonplanar chiral neutral p-radical systems. [8] As stable open-shell molecular systems possessing chirality, a number of nitroxide-based chiral neutral radical derivatives have been synthesized and characterized. [9] These systems were constructed by introducing a substituent having one or more asymmetric carbon atoms to an achiral nitroxide radical skeleton based on, for example, pyrrolidine-1-oxyl and a-nitronylnitroxide. By taking advantage of the localized unpaired electronic spin on the NÀO moiety, chiral molecular magnets and paramagnetic organic chiral liquid crystals have extensively been implemented. [9b, 10] In contrast to the nitroxide radicals, in phenalenyl (PLY in Figure 1), a planar neutral hydrocarbon p-radical, the electronic spin is extensively delocalized over the whole molec-ular skeleton. [11] As a consequence, phenalenyl derivatives exhibit unique physical properties and functionalities different from the those of spin-localized neutral radicals such as nitroxide derivatives. [11,12] Furthermore, our recent study revealed that the highly delocalized electronic structure inherent in phenalenyl also appears in a curved phenalenyl system with a corannulene substructure (Cor-PLY, Figure 1). [13,14] Cor-PLY is the first nonplanar phenalenyl derivative in the half-century-old phenalenyl chemistry.These studies have inspired us to design nonplanar pconjugated chiral phenalenyl radicals based on helicene. [11b] The chiral neutral p-radical is intriguing not only because of the spin delocalization in the three-dimensional (3D) helical p-conjugated network but also because of optical magnetic properties attributable to the combination of helicene chirality and delocalized electronic spin. Here we report the synthesis, electronic-spin structure, and optical properties of chiral diazaphenalenyl 1 (Figure 1), [15] in which a benzene ring is fused to a nitrogen-containing [4]helicene-type structure. Thanks to two terminal methoxy groups and three tert-butyl groups, radical 1 exhibits high configurational and chemical stability, enabling us to experimentally characterize both chiral and racemic species of 1 with the help of theoretical calculations. Solution-phase ESR and EN...

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“…These compounds provide suitable models for systematically studying the influences of substituents and ring size on the inversion dynamics (Table 5). Phenalene derivative 76 was synthesized from 1 in four steps (Scheme 21) [47]. Ketone 27, which was generated in 99% yield by Friedel-Crafts acylation of 1 as shown in Scheme 7, underwent the peri-formylation and the subsequent intramolecular aldol condensation to give phenalenone derivative 75.…”

Section: -74mentioning

confidence: 99%

“…Acylcorannulenes 27 can be obtained directly from corannulene by Friedel-Crafts acylation. Treatment of 1 with acid chlorides and AlCl 3 gave 27 in good to excellent yields [47,48]. Reports of diacylation indicate that a mixture of isomers is formed.…”

mentioning

confidence: 99%

“…Treatment of 28-Br with an excess of NaNH 2 and a catalytic amount of t-BuOK gave a buckybowl aryne (corannulyne), which was trapped by furan to yield a Diels-Alder product 31 in good yield [54]. Moreover, the reaction of o-trimethylsilylcorannulenyl triflate with cesium fluoride under mild conditions Scheme 7 Preparation of mono-substituted corannulene derivatives directly from corannulene [46][47][48] also generated corannulyne in situ. Corannulyne so generated can undergo Pd-catalyzed [2+2+2] cyclotrimerization [55], as well as oligomerization [56].…”

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confidence: 99%

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Synthesis, Structures, and Physical Properties of Aromatic Molecular-Bowl Hydrocarbons

Siegel

2014

Topics in Current Chemistry

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This chapter summarizes the synthesis, physical properties, structure, and crystal packing of buckybowls. Buckybowls exemplify an intermediate class of polynuclear aromatic compounds between the closed-shell fullerenes and the flat extended arrays of graphene. These warped sheets can be seen as fragments of fullerenes or the end cap of single-walled carbon nanotubes; and, their curvature endows them with physical properties distinct from flat polynuclear hydrocarbons, which opens up unique possibilities for molecular bowls in various organic materials applications.

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Curve-Structured Phenalenyl Chemistry: Synthesis, Electronic Structure, and Bowl-Inversion Barrier of a Phenalenyl-Fused Corannulene Anion

Cited by 55 publications

References 20 publications

The INV24 test set: how well do quantum-chemical methods describe inversion and racemization barriers?

The INV24 test set: how well do quantum-chemical methods describe inversion and racemization barriers?

Chiral Stable Phenalenyl Radical: Synthesis, Electronic‐Spin Structure, and Optical Properties of [4]Helicene‐Structured Diazaphenalenyl

Synthesis, Structures, and Physical Properties of Aromatic Molecular-Bowl Hydrocarbons

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