scholarly journals One-Step Simultaneous Synthesis of Circularly Polarized Luminescent Multiple Helicenes Using a Chrysene Framework

2020 ◽  
Author(s):  
Tomoyuki Ikai ◽  
Shoya Yamakawa ◽  
Nozomu Suzuki ◽  
Eiji Yashima
Keyword(s):  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Circularly Polarized ◽  
X Ray Crystallography ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
One Step ◽  
Acidic Conditions ◽  
Simultaneous Synthesis

<p>A series of multiple helicenes was simultaneously synthesized in one step by intramolecular cyclization of a single chrysene derivative containing two 2-[(4-alkoxyphenyl)ethynyl]phenyl units accompanied by rearrangements of the aryl pendants. The electrophile-induced double cyclization with or without aryl migrations proceeded efficiently under acidic conditions to afford annulative p-extension of the chrysene units and produced quadruple (QH-<b>2</b>), triple (TH-<b>2</b>), and double (DH-<b>2</b>) helicenes containing [4]- and/or [5]helicene frameworks with dynamic and/or static helicene chirality in one step. Three multiple helicenes’ structures were determined by X-ray crystallography and/or density functional theory calculations. The multiple TH-<b>2</b> and DH-<b>2</b> helicenes were separated into enantiomers because of the stable one and two [5]helicene moieties, respectively, and showed intense circular dichroism and circularly polarized luminescence. Although QH-<b>2</b>, which comprises four [4]helicene subunits, was not resolved into enantiomers, the TH-<b>2</b> enantiomers were further separated into a pair of diastereomers at low temperature resulting from their substituted [4]helicene chirality.</p>

scholarly journals One-Step Simultaneous Synthesis of Circularly Polarized Luminescent Multiple Helicenes Using a Chrysene Framework

2020 ◽  
Author(s):  
Tomoyuki Ikai ◽  
Shoya Yamakawa ◽  
Nozomu Suzuki ◽  
Eiji Yashima
Keyword(s):  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Circularly Polarized ◽  
X Ray Crystallography ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
One Step ◽  
Acidic Conditions ◽  
Simultaneous Synthesis

<p>A series of multiple helicenes was simultaneously synthesized in one step by intramolecular cyclization of a single chrysene derivative containing two 2-[(4-alkoxyphenyl)ethynyl]phenyl units accompanied by rearrangements of the aryl pendants. The electrophile-induced double cyclization with or without aryl migrations proceeded efficiently under acidic conditions to afford annulative p-extension of the chrysene units and produced quadruple (QH-<b>2</b>), triple (TH-<b>2</b>), and double (DH-<b>2</b>) helicenes containing [4]- and/or [5]helicene frameworks with dynamic and/or static helicene chirality in one step. Three multiple helicenes’ structures were determined by X-ray crystallography and/or density functional theory calculations. The multiple TH-<b>2</b> and DH-<b>2</b> helicenes were separated into enantiomers because of the stable one and two [5]helicene moieties, respectively, and showed intense circular dichroism and circularly polarized luminescence. Although QH-<b>2</b>, which comprises four [4]helicene subunits, was not resolved into enantiomers, the TH-<b>2</b> enantiomers were further separated into a pair of diastereomers at low temperature resulting from their substituted [4]helicene chirality.</p>

scholarly journals N-Heterocyclic carbene-catalyzed enantioselective hetero-[10 + 2] annulation

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Qiupeng Peng ◽  
Shi-Jun Li ◽  
Bei Zhang ◽  
Donghui Guo ◽  
Yu Lan ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Higher Order ◽  
Heterocyclic Carbenes ◽  
Wide Scope ◽  
Functional Theory ◽  
One Step ◽  
High Yields ◽  
Powerful Strategy

AbstractHigher-order cycloadditions are a powerful strategy for the construction of polycycles in one step. However, an efficient and concise version for the induction of asymmetry is lacking. N-heterocyclic carbenes are widely used organocatalysts for asymmetric synthesis and could be an ideal choice for enantioselective higher-order cycloadditions. Here, we report an enantioselective [10 + 2] annulation between catalytically formed aza-benzofulvene intermediates and trifluoromethyl ketone derivatives. This protocol exhibits a wide scope, high yields, and good ee values, reflecting a robust and efficient higher-order cycloaddition. Density functional theory calculations provide an accurate prediction of the reaction enantioselectivity, and in-depth insight to the origins of stereocontrol.

scholarly journals Synthesis of Chromium(II) Complexes with Chelating Bis(alkoxide) Ligand and Their Reactions with Organoazides and Diazoalkanes

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 273 ◽  
Author(s):  
Sudheer S. Kurup ◽  
Richard J. Staples ◽  
Richard L. Lord ◽  
Stanislav Groysman
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Aryl Azides ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography ◽  
Chromium Vi ◽  
Imido Complexes ◽  
Structure And Bonding

Synthesis of new chromium(II) complexes with chelating bis(alkoxide) ligand [OO]Ph (H2[OO]Ph = [1,1′:4′,1′’-terphenyl]-2,2′’-diylbis(diphenylmethanol)) and their subsequent reactivity in the context of catalytic production of carbodiimides from azides and isocyanides are described. Two different Cr(II) complexes are obtained, as a function of the crystallization solvent: mononuclear Cr[OO]Ph(THF)2 (in toluene/THF, THF = tetrahydrofuran) and dinuclear Cr2([OO]Ph)2 (in CH2Cl2/THF). The electronic structure and bonding in Cr[OO]Ph(THF)2 were probed by density functional theory calculations. Isolated Cr2([OO]Ph)2 undergoes facile reaction with 4-MeC6H4N3, 4-MeOC6H4N3, or 3,5-Me2C6H3N3 to yield diamagnetic Cr(VI) bis(imido) complexes; a structure of Cr[OO]Ph(N(4-MeC6H4))2 was confirmed by X-ray crystallography. The reaction of Cr2([OO]Ph)2 with bulkier azides N3R (MesN3, AdN3) forms paramagnetic products, formulated as Cr[OO]Ph(NR). The attempted formation of a Cr–alkylidene complex (using N2CPh2) instead forms chromium(VI) bis(diphenylmethylenehydrazido) complex Cr[OO]Ph(NNCPh2)2. Catalytic formation of carbodiimides was investigated for the azide/isocyanide mixtures containing various aryl azides and isocyanides. The formation of carbodiimides was found to depend on the nature of organoazide: whereas bulky mesitylazide led to the formation of carbodiimides with all isocyanides, no carbodiimide formation was observed for 3,5-dimethylphenylazide or 4-methylphenylazide. Treatment of Cr2([OO]Ph)2 or H2[OO]Ph with NO+ leads to the formation of [1,2-b]-dihydroindenofluorene, likely obtained via carbocation-mediated cyclization of the ligand.

scholarly journals Six-fold C–H borylation of hexa-peri-hexabenzocoronene

2020 ◽  
Vol 16 ◽  
pp. 391-397 ◽  
Author(s):  
Mai Nagase ◽  
Kenta Kato ◽  
Akiko Yagi ◽  
Yasutomo Segawa ◽  
Kenichiro Itami
Keyword(s):  
Density Functional ◽  
Bathochromic Shift ◽  
Density Functional Theory Calculations ◽  
Absorption Bands ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography ◽  
Polycyclic Aromatic ◽  
Direct Functionalization ◽  
Poorly Soluble

Hexa-peri-hexabenzocoronene (HBC) is known to be a poorly soluble polycyclic aromatic hydrocarbon for which direct functionalization methods have been very limited. Herein, the synthesis of hexaborylated HBC from unsubstituted HBC is described. Iridium-catalyzed six-fold C–H borylation of HBC was successfully achieved by screening solvents. The crystal structure of hexaborylated HBC was confirmed via X-ray crystallography. Optoelectronic properties of the thus-obtained hexaborylated HBC were analyzed with the support of density functional theory calculations. The spectra revealed a bathochromic shift of absorption bands compared with unsubstituted HBC under the effect of the σ-donation of boryl groups.

scholarly journals Structural Effects of meso-Halogenation on Porphyrins: meso-Xn-ABCD Macrocycles

2021 ◽  
Author(s):  
Keith J Flanagan ◽  
Maximilian Paradiz Dominguez ◽  
Zoi Melissari ◽  
Hans-Georg Eckhardt ◽  
René M Williams ◽  
...  
Keyword(s):  
Conformational Analysis ◽  
Crystal Engineering ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Normal Coordinate ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Past ◽  
Meso Position

The use of halogens in the crystal engineering of porphyrin scaffolds has been a topic of strong interest over the past decades. Previously, this was focused on the introduction of a variety of halogens on the meso-phenyl groups of the porphyrin. However, investigations into the effects of direct halogenation of porphyrins at the meso-position on their crystalline architectures have not been conducted to date. Herein we have characterized a series of direct meso-halogenated porphyrins using single crystal X-ray crystallography. This is accompanied by a detailed conformational analysis of all deposited meso-halogenated porphyrins in the CCDC. In this study we have used the Hirshfeld fingerprint plots together with normal-coordinate structural decomposition and determined crystal structures to elucidate the conformation, present intermolecular interactions, and compare respective contacts within the crystalline architectures. Additionally, we have used density functional theory calculations to determine the structure of several halogenated porphyrins. This contrasts conformational analysis with existing X-ray structures and gives a method to characterize samples that are difficult to crystallize.

Sign inversions of circularly polarized luminescence for helical compounds by chemically fine-tuning operations

2020 ◽  
Vol 56 (12) ◽  
pp. 1863-1866 ◽  
Author(s):  
Wei-Bin Lin ◽  
Dong-Qiang He ◽  
Hai-Yan Lu ◽  
Zhi-Qiang Hu ◽  
Chuan-Feng Chen
Keyword(s):  
Fine Tuning ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
One Step

Sign inversions of CPL by fine-tuning operations on structures of helical compounds were realized by one step-oxidation or TPA-modification.

scholarly journals Ab-Initio Study of Circular Dichroism and Circularly Polarized Luminescence of Spin-allowed and Spin-forbidden Transitions: From Organic Ketones to Lanthanide Complexes

2019 ◽  
Author(s):  
Frédéric GENDRON ◽  
Barry Moore II ◽  
Olivier Cador ◽  
Fabrice Pointillart ◽  
Jochen Autschbach ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Ab Initio ◽  
Density Functional ◽  
Lanthanide Complex ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Forbidden Transitions ◽  
Polarized Luminescence ◽  
Self Consistent Field ◽  
Circular Dichroïsm

<div><div><div><p>Complete and restricted active space self-consistent field (CAS-/RAS-SCF) wavefunction methods are applied for the calculation of circular dichroism (CD) and circularly polarized luminescence (CPL) of a series of molecules comprising four organic ketones, the chiral Cobalt(III) complex Λ-[Co(en)3]3+ and the Europium(III) complex [Eu(DPA)3]3–. The ab-initio results are in good agreement with the experimental data and previous results obtained with Kohn-Sham density functional theory in the case of the spin-allowed transitions. CD and CPL properties are calculated ab-initio for the first time for the spin-forbidden transitions of both a transition metal and a lanthanide complex.</p></div></div></div>

scholarly journals Deep-red circularly polarized luminescent C70 derivatives

2020 ◽  
Author(s):  
Haruka Kano ◽  
Hironobu Hayashi ◽  
Kyohei Matsuo ◽  
Michiya Fujiki ◽  
Hiroko Yamada ◽  
...  
Keyword(s):  
Chiral Recognition ◽  
Addition Reaction ◽  
Optical Resolution ◽  
Mirror Image ◽  
Chiral Hplc ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Nanocarbon Materials ◽  
One Step

Abstract Optically active fullerenes (C76, C82, C84), including C60 and C70 derivatives carrying organic substituents, possess various potent applications because of unique spectroscopic, catalytic, and chiral recognition properties. However, their inherent photoexcited chirality has not yet been elucidated because of a very poor quantum yield of fluorescence (FL). With this background in mind, we synthesized new chiral C70 derivatives, X70A, solely by reacting bis-borylated xanthene with C70 in a one-step double addition reaction with 20% yield, followed by a successful optical resolution using a recyclable chiral-HPLC technique. The isolated X70A enantiomers were confirmed by their mirror-image circular dichroism spectra in the range of 300 nm and 700 nm. The enantiomeric pair of X70A in toluene revealed clearly mirror-image circularly polarized luminescence (CPL) spectra with a high |glum| value of 7.0 × 10–3 at 690 nm associated with FL lifetime of 0.99 ns. The deep-red CPL of X70A should provide new photofunctionality as chiral nanocarbon materials.

Phenanthro[9,10-a]corannulene by one-step annulative π-extension of corannulene

2017 ◽  
Vol 95 (3) ◽  
pp. 329-333 ◽  
Author(s):  
Kenta Kato ◽  
Yasutomo Segawa ◽  
Kenichiro Itami
Keyword(s):  
Crystal Structure ◽  
Density Functional ◽  
Photophysical Properties ◽  
Coupling Reaction ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
X Ray ◽  
Palladium Catalyzed ◽  
One Step ◽  
The One

The one-step π-extension of corannulene was achieved using a palladium-catalyzed C–H coupling reaction. The X-ray crystal structure and photophysical properties of the thus formed phenanthro[9,10-a]corannulene (1) were investigated, and the structural properties of 1 were examined by density functional theory calculations. In contrast to dibenzo[g,p]chrysene, the most stable structure of 1 was a butterfly-shaped structure, resulting from the bowl-shaped distortion of the corannulene moiety.

scholarly journals Conformational and structural diversity of iridium dimethyl sulfoxide complexes

2017 ◽  
Vol 73 (6) ◽  
pp. 1032-1042 ◽  
Author(s):  
Benjamin M. Ridgway ◽  
Ana Foi ◽  
Rodrigo S. Corrêa ◽  
Damian E. Bikiel ◽  
Javier Ellena ◽  
...  
Keyword(s):  
Dimethyl Sulfoxide ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Structural Diversity ◽  
Stable Form ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography ◽  
Conformational Preferences ◽  
Clinically Significant

Transition metal complexes containing dimethyl sulfoxide (DMSO) are important precursors in catalysis and metallodrugs. Understanding the solid-state supramolecular structure is crucial for predicting the properties and biological activity of the material. Several crystalline phases of DMSO-coordinated iridium anions with different cations, potassium (1a) and n-butylammonium (1b), were obtained and their structures determined by X-ray crystallography. Compound (1a) is present in two solvatomorphic forms: α and β; the β form contains disordered solvent water. In addition, the structures exhibit different rotamers of the trans-[IrCl4(DMSO)2]− anion with the trans-DMSO ligands being oriented in anti and gauche conformations. In consideration of these various conformers, the effects of the crystallized solvent and intermolecular interactions on the conformational preferences of the anion are discussed. In addition, density functional theory calculations were used to investigate the energies of the anions in the different conformations. It was found that hydrogen bonds between water and the DMSO complex stabilize the gauche conformation which is the least stable form of the trans-DMSO complex. Consequently, by controlling the number of hydrogen-bond donors and acceptors and the amount of water, it may be possible to obtain different solvatomorphs of clinically significant metallodrugs.

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