Investigation of crystal structure, vibrational characteristics and molecular conductivity of 2,3-dichloro-5,6-dicyno-p-benzoquinone

Rani, Poonam; Rajput, Gunjan; Yadav, R.A.

doi:10.1016/j.saa.2014.08.044

Cited by 5 publications

(2 citation statements)

References 32 publications

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“…Several parameters in the DFT calculation cannot fully correspond to the antioxidant trends of DPPH and ABTS, such as ΔE (LUMO −HOMO) , because DFT mainly calculates the electronic structure of the molecule (Rani et al, 2015). In contrast, other factors, such as electron transfer ability and electron cloud distribution, in addition to the electronic structure, may affect antioxidant capacity (Lee, Sharma, et al, 2020).…”

Section: Resultsmentioning

confidence: 99%

Different processing methods on anthocyanin composition and antioxidant capacity in blueberry juice: Based on metabolomics and DFT analysis

Liu,

Ma,

Zhang

et al. 2024

eFood

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Blueberry juice is one of deep‐processed products of blueberries, anthocyanins are main bioactive substance in blueberry juice. However, anthocyanins have poor stability. Thermal, high pressure, electric field, magnetic field and cobalt source irradiation were used to treat blueberry juice, and then the treated blueberry juice composition and antioxidant capacity were determined to explore ways to better protect anthocyanins. Metabolomics was used to qualitatively and quantitatively analyze the anthocyanins in blueberry juice, a total of 54 anthocyanins were identified. Different processing methods of treatment did not significantly change the types of anthocyanins in blueberry juice. Their effects were mainly focused on the changes in content. By determining the antioxidant capacity of blueberry juice, it was found that there is more than a simple linear relationship between the total anthocyanin content of blueberry juice and its antioxidant capacity. Therefore, the structural parameters of the four main anthocyanin monomers of blueberry juice were calculated using density functional theory to predict the antioxidant capacity and the antioxidant capacity of the monomers was determined for validation. The effect of different treatments on the change of antioxidant activity of blueberry juice due to anthocyanin occupancy was explained using equivalent antioxidant. The results showed that the 1 kGy irradiation treatment had a better protective effect on the anthocyanins, whereas the change in the percentage of anthocyanins due to this treatment was the key factor for the change in their antioxidant capacity.

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Section: Resultsmentioning

confidence: 99%

Different processing methods on anthocyanin composition and antioxidant capacity in blueberry juice: Based on metabolomics and DFT analysis

Liu,

Ma,

Zhang

et al. 2024

eFood

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“…Single‐crystal X‐ray diffraction analysis unequivocally established the formation of a 1 : 1 adduct, Mes 3 P−DDQ (Scheme 2). [13] Electron donor−acceptor adduct 1 , with its P−O bond length of 1.6030(10) Å and typical metrics for a reduced DDQ moiety, [14] is structurally similar to Stephan's compound J (P−O 1.606(3) Å, δ 31 P{ 1 H}=70.8 ppm), [3c] yet due to the increased electron accepting capability of DDQ no Lewis acid activation is required (cf. EA(TCQ)=−4.55 eV, EA(TCQ−B(C 6 F 5 ) 3 )=−5.61 eV).…”

Section: Methodsmentioning

confidence: 99%

Homolytic C−H Bond Activation by Phosphine−Quinone‐Based Radical Ion Pairs

Helling,

van der Zee,

Hofman

et al. 2023

Angew Chem Int Ed

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Herein, we present the formation of transient radical ion pairs (RIPs) by single‐electron transfer (SET) in phosphine–quinone systems and explore their potential for the activation of C–H bonds. PMes3 (Mes = 2,4,6‐Me3C6H2) reacts with DDQ (2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone) with formation of the P–O bonded zwitterionic adduct Mes3P–DDQ (1), while the reaction with the sterically more crowded PTip3 (Tip = 2,4,6‐iPr3C6H2) afforded C–H bond activation product Tip2P(H)(2‐[CMe2(DDQ)]‐4,6‐iPr2‐C6H2) (2). UV‐Vis and EPR spectroscopic studies showed that the latter reaction proceeds via initial SET, forming RIP [PTip3]•+[DDQ]•–, and subsequent homolytic C–H bond activation, which was supported by DFT calculations. The isolation of analogous products, Tip2P(H)(2‐[CMe2{TCQ–B(C6F5)3}]‐4,6‐iPr2‐C6H2) (4, TCQ = tetrachloro‐1,4‐benzoquinone) and Tip2P(H)(2‐[CMe2{oQtBu–B(C6F5)3}]‐4,6‐iPr2‐C6H2) (8, oQtBu = 3,5‐di‐tert‐butyl‐1,2‐benzoquinone), from reactions of PTip3 with Lewis‐acid activated quinones, TCQ–B(C6F5)3 and oQtBu–B(C6F5)3, respectively, further supports the proposed radical mechanism. As such, this study presents key mechanistic insights into the homolytic C–H bond activation by the synergistic action of radical ion pairs.

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Homolytic C−H Bond Activation by Phosphine−Quinone‐Based Radical Ion Pairs

Helling,

van der Zee,

Hofman

et al. 2023

Angewandte Chemie

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Herein, we present the formation of transient radical ion pairs (RIPs) by single‐electron transfer (SET) in phosphine−quinone systems and explore their potential for the activation of C−H bonds. PMes3 (Mes=2,4,6‐Me3C6H2) reacts with DDQ (2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone) with formation of the P−O bonded zwitterionic adduct Mes3P−DDQ (1), while the reaction with the sterically more crowded PTip3 (Tip=2,4,6‐iPr3C6H2) afforded C−H bond activation product Tip2P(H)(2‐[CMe2(DDQ)]‐4,6‐iPr2‐C6H2) (2). UV/Vis and EPR spectroscopic studies showed that the latter reaction proceeds via initial SET, forming RIP [PTip3]⋅+[DDQ]⋅−, and subsequent homolytic C−H bond activation, which was supported by DFT calculations. The isolation of analogous products, Tip2P(H)(2‐[CMe2{TCQ−B(C6F5)3}]‐4,6‐iPr2‐C6H2) (4, TCQ=tetrachloro‐1,4‐benzoquinone) and Tip2P(H)(2‐[CMe2{oQtBu−B(C6F5)3}]‐4,6‐iPr2‐C6H2) (8, oQtBu=3,5‐di‐tert‐butyl‐1,2‐benzoquinone), from reactions of PTip3 with Lewis‐acid activated quinones, TCQ−B(C6F5)3 and oQtBu−B(C6F5)3, respectively, further supports the proposed radical mechanism. As such, this study presents key mechanistic insights into the homolytic C−H bond activation by the synergistic action of radical ion pairs.

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Investigation of crystal structure, vibrational characteristics and molecular conductivity of 2,3-dichloro-5,6-dicyno-p-benzoquinone

Cited by 5 publications

References 32 publications

Different processing methods on anthocyanin composition and antioxidant capacity in blueberry juice: Based on metabolomics and DFT analysis

Different processing methods on anthocyanin composition and antioxidant capacity in blueberry juice: Based on metabolomics and DFT analysis

Homolytic C−H Bond Activation by Phosphine−Quinone‐Based Radical Ion Pairs

Homolytic C−H Bond Activation by Phosphine−Quinone‐Based Radical Ion Pairs

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