Effects of Temperature and Host Concentration on the Supramolecular Enantiodifferentiating [4 + 4] Photodimerization of 2-Anthracenecarboxylate through Triplet-Triplet Annihilation Catalyzed by Pt-Modified Cyclodextrins

Rao, Ming; Wu, Wanhua; Yang, Cheng

doi:10.3390/molecules24081502

Cited by 18 publications

(13 citation statements)

References 52 publications

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“…In addition, as can be seen from Table 2, lowering the temperature can significantly enhance the enantioselectivity of the photoreaction, especially at the higher salt concentration. This suggests that the lower temperature can force closer packing of the AC pair included in the CD cavity to energetically and entropically better differentiate the diastereomeric precursor complexes [4i,21] …”

Section: Resultsmentioning

confidence: 99%

Supramolecular Enantiodifferentiating Photocyclodimerization of 2‐Anthracenecarboxylic Acid Mediated by Bridged β‐Cyclodextrins: Critical Effects of the Host Structure, pH and Co‐Solvents

Wang

Rao

et al. 2021

Chemistry An Asian Journal

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Several sulfoxide‐ and sulfone‐bridged β‐cyclodextrin (CD) dimers were synthesized for mediating the enantiodifferentiating [4+4] photocyclodimerization of 2‐anthracenecarboxylic acid (AC). The complexation behavior of these chiral hosts with AC was investigated by UV‐vis, circular dichroism, fluorescence, and NMR spectroscopies and certified the formation of 1 : 1 and 1 : 2 host‐guest complexes. The product distribution and enantioselectivity of the photoreaction turned out to be a critical function of the chemical structure of bridged CDs. Comparing to the sulfur‐bridged 2AX−3GX β‐CD dimer 7, the conversion of the photolyzes with sulfoxide‐bridged was significantly improved, and the ee of cyclodimer 2 was remarkably increased from −82.8% with 7 to −96.7% with the sulfoxide‐bridged 2AX−3GX β‐CD dimer 8. The relative yields and ee values of the slipped cyclodimers 5 and 6 were greatly enhanced in the presence of 6 M CsCl. The reaction selectivity is susceptible to the pH variation of the aqueous buffer solution, demonstrating that the supramolecular photochirogenesis is controlled by multidimensional factors, including the chemical structure of the chiral host, solvent, and pH conditions.

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Section: Resultsmentioning

confidence: 99%

Supramolecular Enantiodifferentiating Photocyclodimerization of 2‐Anthracenecarboxylic Acid Mediated by Bridged β‐Cyclodextrins: Critical Effects of the Host Structure, pH and Co‐Solvents

Wang

Rao

et al. 2021

Chemistry An Asian Journal

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“…Subsequently, they used complex 142 b-βCD in a similar study but inconsistent results with low enantioselectivites were found, caused by low water solubility resulting in aggregation. [237] Consequently, complex 142 a-γCD was tested using both laser (523 nm) and LED irradiation (365 nm) including a temperature dependence study (Table 37). Photodimerization induced by 142 a-γCD under LED irradiation did not result in any significant change in product distribution (entries 1-4).…”

Section: Additional Transformationsmentioning

confidence: 99%

Synthetic Application of Cyclodextrins in Combination with Metal Ions, Complexes, and Metal Particles

Molnár

2020

ChemCatChem

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Cyclodextrins are green, environmentally benign products available through the enzymatic degradation of starch for a multitude of varied applications. This review attempts to collect useful information with respect to catalytic studies performed with the use of cyclodextrin and modified cyclodextrin preparations applied in combination of or loaded with varied catalytically active species including metal ions, complexes, and metal particles. Major sections are about their use in hydrogenation, reduction, oxidation, hydroformylation and coupling reactions. Additional sections include their utilization in ring formation and ring opening as well as degradation of pollutants. In the last part, examples about ester hydrolysis, hydroboration and hydrosilylation, as well as hydrogen production are treated. Data collected and analyzed indicate the importance and high potential of cyclodextrin-based catalysts in sustainable chemistry.

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“…Furthermore, different isomers of the dimer can be formed [9,22,23]. Therefore, the regio-and enantioselectivity of anthracene photodimerization has been investigated comprehensively, both via experiment and quantum chemistry calculations [24][25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Photoreactivity of an Exemplary Anthracene Mixture Revealed by NMR Studies, including a Kinetic Approach

et al. 2021

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Anthracenes are an important class of acenes. They are being utilized more and more often in chemistry and materials sciences, due to their unique rigid molecular structure and photoreactivity. In particular, photodimerization can be harnessed for the fabrication of novel photoresponsive materials. Photodimerization between the same anthracenes have been investigated and utilized in various fields, while reactions between varying anthracenes have barely been investigated. Here, Nuclear Magnetic Resonance (NMR) spectroscopy is employed for the investigation of the photodimerization of two exemplary anthracenes: anthracene (A) and 9-bromoanthracene (B), in the solutions with only A or B, and in the mixture of A and B. Estimated k values, derived from the presented kinetic model, showed that the dimerization of A was 10 times faster in comparison with B when compounds were investigated in separate samples, and 2 times faster when compounds were prepared in the mixture. Notably, the photoreaction in the mixture, apart from AA and BB, additionally yielded a large amount of the AB mixdimer. Another important advantage of investigating a mixture with different anthracenes is the ability to estimate the relative reactivity for all the reactions under the same experimental conditions. This results in a better understanding of the photodimerization processes. Thus, the rational photofabrication of mix-anthracene-based materials can be facilitated, which is of crucial importance in the field of polymer and material sciences.

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Effects of Temperature and Host Concentration on the Supramolecular Enantiodifferentiating [4 + 4] Photodimerization of 2-Anthracenecarboxylate through Triplet-Triplet Annihilation Catalyzed by Pt-Modified Cyclodextrins

Cited by 18 publications

References 52 publications

Supramolecular Enantiodifferentiating Photocyclodimerization of 2‐Anthracenecarboxylic Acid Mediated by Bridged β‐Cyclodextrins: Critical Effects of the Host Structure, pH and Co‐Solvents

Supramolecular Enantiodifferentiating Photocyclodimerization of 2‐Anthracenecarboxylic Acid Mediated by Bridged β‐Cyclodextrins: Critical Effects of the Host Structure, pH and Co‐Solvents

Synthetic Application of Cyclodextrins in Combination with Metal Ions, Complexes, and Metal Particles

Photoreactivity of an Exemplary Anthracene Mixture Revealed by NMR Studies, including a Kinetic Approach

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