88-15-3Relevant academic research and scientific papers
Effects of oligothiophene π-bridge length on physical and photovoltaic properties of star-shaped molecules for bulk heterojunction solar cells
Min, Jie,Luponosov, Yuriy N.,Baran, Derya,Chvalun, Sergei N.,Shcherbina, Maxim A.,Bakirov, Artem V.,Dmitryakov, Petr V.,Peregudova, Svetlana M.,Kausch-Busies, Nina,Ponomarenko, Sergei A.,Ameri, Tayebeh,Brabec, Christoph J.
, p. 16135 - 16147 (2014)
The preparation of four different star-shaped donor (D)-π-acceptor (A) small molecules (N(Ph-1T-DCN-Me)3, N(Ph-2T-DCN-Me)3, N(Ph-2T-DCN-Hex)3and N(Ph-3T-DCN-Hex)3) possessing various oligothiophene π-bridge lengths and their use in solution-processed bulk heterojunction small molecule solar cells is reported. Optical and electrochemical data show that increasing oligothiophene π-bridge length leads to a decrease of the optical band gap due to a parallel increase of the highest occupied molecular orbital (HOMO) level. Furthermore, subtle modifications of a molecular π-bridge length strongly affect the thermal behavior, solubility, crystallization, film morphology and charge carrier mobility, which in turn significantly change the device performance. Although the moderately increasing oligothiophene π-bridge length uplifts the HOMO level, it nevertheless induces an increase of the efficiency of the resulting solar cells due to a simultaneous improvement of the short circuit current (Jsc) and fill factor (FF). The study demonstrates that such an approach can represent an interesting tool for the effective modulation of the photovoltaic properties of the organic solar cells (OSCs) at a moderate cost.
Effects of acid-modified HBEA zeolites on thiophene acylation and the origin of deactivation of zeolites
Chen, Zhihua,Feng, Yuefei,Tong, Tianxia,Zeng, Aiwu
, p. 92 - 98 (2014)
The liquid phase Friedel-Crafts acylation of thiophene with acetic anhydride over HBEA zeolites modified by hydrochloric, nitric, and acetic acid was investigated in a trickle bed reactor. The catalytic stability of the HBEA zeolite was doubled after treatment with the hydrochloric and nitric acids due to the increase of the ratio of Broensted to Lewis acid sites, the surface area, and the average pore diameter. The deactivated zeolites can be regenerated by calcination in a muffle furnace and the superior reusability of the zeolite HBEA was demonstrated after nine cycles. Moreover, the carbon deposit was proved to be one of the main reasons for the deactivation by using 13C NMR MAS, 27Al NMR MAS, and TGA.
High luminescence quantum yields and long luminescence lifetime from Eu(III) complex containing two crystal water based on a new β-diketonate ligand
Sun, Youyi,Gao, Jiangang,Zheng, Zhi,Su, Wei,Zhang, Qijin
, p. 977 - 980 (2006)
New members of family of Eu(III) complex based on the thenoylacetophenone have been synthesized and characterized. The compounds were found for high metal luminescence quantum yields and long luminescence lifetime, especially for compound with two crystal water, corresponding with other compounds containing two crystal water. The result is attributed to high molar absorption coefficients of the Eu(III) complex according to UV-vis and emission spectra. The high molar absorption coefficients balance quenching effect from O{single bond}H oscillators of water contained in compound.
Rapid, chemoselective and mild oxidation protocol for alcohols and ethers with recyclable N-chloro-N-(phenylsulfonyl)benzenesulfonamide
Badani, Purav,Chaturbhuj, Ganesh,Ganwir, Prerna,Misal, Balu,Palav, Amey
supporting information, (2021/06/03)
Chlorine is the 20th most abundant element on the earth compared to bromine, iodine, and fluorine, a sulfonimide reagent, N-chloro-N-(phenylsulfonyl)benzenesulfonamide (NCBSI) was identified as a mild and selective oxidant. Without activation, the reagent was proved to oxidize primary and secondary alcohols as well as their symmetrical and mixed ethers to corresponding aldehydes and ketones. With recoverable PS-TEMPO catalyst, selective oxidation over chlorination of primary and secondary alcohols and their ethers with electron-donating substituents was achieved. The reagent precursor of NCBSI was recovered quantitatively and can be reused for synthesizing NCBSI.
Visible light mediated selective oxidation of alcohols and oxidative dehydrogenation of N-heterocycles using scalable and reusable La-doped NiWO4nanoparticles
Abinaya, R.,Balasubramaniam, K. K.,Baskar, B.,Divya, P.,Mani Rahulan, K.,Rahman, Abdul,Sridhar, R.,Srinath, S.
, p. 5990 - 6007 (2021/08/24)
Visible light-mediated selective and efficient oxidation of various primary/secondary benzyl alcohols to aldehydes/ketones and oxidative dehydrogenation (ODH) of partially saturated heterocycles using a scalable and reusable heterogeneous photoredox catalyst in aqueous medium are described. A systematic study led to a selective synthesis of aldehydes under an argon atmosphere while the ODH of partially saturated heterocycles under an oxygen atmosphere resulted in very good to excellent yields. The methodology is atom economical and exhibits excellent tolerance towards various functional groups, and broad substrate scope. Furthermore, a one-pot procedure was developed for the sequential oxidation of benzyl alcohols and heteroaryl carbinols followed by the Pictet-Spengler cyclization and then aromatization to obtain the β-carbolines in high isolated yields. This methodology was found to be suitable for scale up and reusability. To the best of our knowledge, this is the first report on the oxidation of structurally diverse aryl carbinols and ODH of partially saturated N-heterocycles using a recyclable and heterogeneous photoredox catalyst under environmentally friendly conditions.
The dehydrogenative oxidation of aryl methanols using an oxygen bridged [Cu-O-Se] bimetallic catalyst
Choudhury, Prabhupada,Behera, Pradyota Kumar,Bisoyi, Tanmayee,Sahu, Santosh Kumar,Sahu, Rashmi Ranjan,Prusty, Smruti Ranjita,Stitgen, Abigail,Scanlon, Joseph,Kar, Manoranjan,Rout, Laxmidhar
supporting information, p. 5775 - 5779 (2021/04/12)
Herein, we report a new protocol for the dehydrogenative oxidation of aryl methanols using the cheap and commercially available catalyst CuSeO3·2H2O. Oxygen-bridged [Cu-O-Se] bimetallic catalysts are not only less expensive than other catalysts used for the dehydrogenative oxidation of aryl alcohols, but they are also effective under mild conditions and at low concentrations. The title reaction proceeds with a variety of aromatic and heteroaromatic methanol examples, obtaining the corresponding carbonyls in high yields. This is the first example using an oxygen-bridged copper-based bimetallic catalyst [Cu-O-Se] for dehydrogenative benzylic oxidation. Computational DFT studies reveal simultaneous H-transfer and Cu-O bond breaking, with a transition-state barrier height of 29.3 kcal mol?1
Phase Separation-Promoted Redox Deracemization of Secondary Alcohols over a Supported Dual Catalysts System
Zhao, Zhitong,Wang, Chengyi,Chen, Qipeng,Wang, Yu,Xiao, Rui,Tan, Chunxia,Liu, Guohua
, p. 4055 - 4063 (2021/08/12)
Unification of oxidation and reduction in a one-pot deracemization process has great significance in the preparation of enantioenriched organic molecules. However, the intrinsic mutual deactivation of oxidative and reductive catalysts and the extrinsic incompatible reaction conditions are unavoidable challenges in a single operation. To address these two issues, we develop a supported dual catalysts system to overcome these conflicts from incompatibility to compatibility, resulting in an efficient one-pot redox deracemization of secondary alcohols. During this transformation, the TEMPO species onto the outer surface of silica nanoparticles catalyze the oxidation of racemic alcohols to ketones, and the chiral Rh/diamine species in the nanochannels of the thermoresponsive polymer-coated hollow-shell mesoporous silica enable the asymmetric transfer hydrogenation (ATH) of ketones to chiral alcohols. To demonstrate the general feasibility, a series of orthogonal oxidation/ATH cascade reactions are compared to prove the compatible benefits in the elimination of their deactivations and the balance of the cascade directionality. As presented in this study, this redox deracemization process provides various chiral alcohols with enhanced yields and enantioselectivities relative to those from unsupported dual catalysts systems. Furthermore, the dual catalysts can be recycled continuously, making them an attractive feature in the application.
PhIO-Mediated oxidative dethioacetalization/dethioketalization under water-free conditions
Du, Yunfei,Ouyang, Yaxin,Wang, Xi,Wang, Xiaofan,Yu, Zhenyang,Zhao, Bingyue,Zhao, Kang
, p. 48 - 65 (2021/06/16)
Treatment of thioacetals and thioketals with iodosobenzene in anhydrous DCM conveniently afforded the corresponding carbonyl compounds in high yields under water-free conditions. The mechanistic studies indicate that this dethioacetalization/dethioketalization process does not need water and the oxygen of the carbonyl products comes from the hypervalent iodine reagent.
Development of Trifluoromethanesulfonic Acid-Immobilized Nitrogen-Doped Carbon-Incarcerated Niobia Nanoparticle Catalysts for Friedel-Crafts Acylation
Yang, Xi,Yasukawa, Tomohiro,Yamashita, Yasuhiro,Kobayashi, Shū
, p. 15800 - 15806 (2021/10/25)
Heterogeneous trifluoromethanesulfonic acid-immobilized nitrogen-doped carbon-incarcerated niobia nanoparticle catalysts (NCI-Nb-TfOH) that show excellent catalytic performance with low niobium loading (1 mol %) in Friedel-Crafts acylation have been developed. These catalysts exhibit higher activity and higher tolerance to catalytic poisons compared with the previously reported TfOH-treated NCI-Ti catalysts, leading to a broader substrate scope. The catalysts were characterized via spectroscopic and microscopic studies.
Photoinduced Cross-Coupling of Aryl Iodides with Alkenes
Liu, Yuliang,Li, Haoyu,Chiba, Shunsuke
supporting information, p. 427 - 432 (2021/01/26)
A protocol for photoinduced cross-coupling of aryl iodides having polar π-functional groups or elongated π-conjugation with alkenes has been developed. The radical cascade mechanism involving generation of aryl radicals via C-I bond homolysis of photoexcited aryl iodides and their subsequent addition to alkenes is proposed. The method enables iodide-selective cross-coupling over other halogen leaving groups with functional group compatibility on both arene and alkene motifs.
