1774-34-1Relevant academic research and scientific papers
Redox Properties of Diaryl Chalcogenides and Their Oxides
Engman, Lars,Lind, Johan,Merenyi, Gabor
, p. 3174 - 3182 (1994)
The redox proeprties of diaryl chalcogenides and their corresponding oxides were studied by means of pulse radiolysis.Diaryl sulfides, selenides, and tellurides were found to be readily (k = 109 - 1010 M-1 s-1) oxidized to the corresponding radical cations by a variety of one-electron oxidants (Tl2+, OH., Br.-, N3.).None of the radical cations appeared to form three-elecron-bonded dimers with their corresponding chalcogenides.The radical cations of diaryl chalcogenides were also formed by one-electron reduction of their respective oxides.Among one-electron reductants tested, only the solvated electron was able to rapidly (k = (0.9 - 2) x 1010 M-1 s-1) reduce diphenyl sulfoxide and diphenyl selenoxide between pH 3 and 13.Diphenyl telluroxide is present predominantly as a hydrate, (C6H5)2Te(OH)2, which undergoes protonation/dehydration below pH 5.3 to yield (C6H5)2TeOH+.Both of these species react rapidly with the solvated electron to yield the radical cation, but only (C6H5)2TeOH+ reacts with CO2.- with measurably fast rate (k = 6 x 109 M-1 s-1).Upon one-electron oxidation, bis(4-hydroxymethyl) sulfide (pH > 0.5) and bis(4-hydroxyphenyl) telluride (pH > 2.5) were found to readily deprotonate to form phenoxyl radicals.Below pH 2.5, it was also possible to observe the radical cation spectrum of the organotellurium compound.One-electron reduction potentials of a variety of diaryl chalcogenide observing their redox equilibria by pulse radiolysis.The following E0 values versus NHE were determined E0 ((C6H5)2S.+/(C6H5)2S) = 1.54 V; E0 ((C6H5)2Se.+/(C6H5)2Se) = 1.37 V; E0 ((C6H5)2Te.+/(C6H)2Te) = 1.14 V; E0 ((4-HO-C6H4)2Te.+/(4-OH-C6H4)2Te) = 0.95 V; E0 ((4-H2N-C6H4)2Te.+/(4-H2N-C6H4)2Te) = 0.80 V; E0 ((4-OOCCH2O-C6H4)2S.+/(4-OOCCH2O-C6H4)2S) = 1.21 V.The two-electron redox potentials of the telluroxide/telluride redox couple were determined by means of EMF titration as a function of the pH.A value of 0.65 V was obtained for both the ((4-HO-C6H4)2Te(OH)2,2H+)/(4-HO-C6H4)2Te,2H2O) and the ((4-H2N-C6H4)2Te(OH)2,2H+)/((4-H2N-C6H4)2Te,2H2O) couples.The chalcogen-oxygen single-bond strengths in the OH adducts to diaryl chalcogenides were found to increase as one traverses the chalcogens from sulfur to tellurium.This is in contrast to the trend for the corresponding chalcogen-oxygen double bond strengths.A dissociation enthalpy of 84 kcal/mol was estimated for the Te=O bond in diaryl telluroxides.Calculated one-electron reduction potentials for diphenyl sulfoxide and dimethyl sulfoxide did not provide a thermodynamic rationale for the low reactivity of dialkyl sulfoxides toward the hydrated electron.Finally, the (C6H5)2S.+ radical cation was produced by reduction of (C6H5)2SO in a 50/50 v/v water/tert-butyl alcohol mixture.We thus propose (C6H5)2S.+ as a useful one-electron oxidant in mixed solvents.
Robust and fast oxidation of sulfides by immobilized Mo(VI) complex on magnetic nanoparticles in solvent-free condition
Babaei, Behnam,Basharnavaz, Hadi,Bezaatpour, Abolfazl
, (2020)
In this research, a heterogeneous catalyst by modifying the magnetically reusable manganese ferrite nanomaterials with oxo-peroxomolybdenum (VI) Schiff base complex was prepared. The prepared catalyst was characterized completely using different physicochemical methods. The recoverable heterogeneous catalyst was tested with different sulfides for the sulfoxidation process under solvent-free situation. The significant and superior turnover frequency (TOF) of the nanocatalyst was acquired to oxidize C7H8S compound (9408 h?1). The offered nanocatalyst has been shown catalytic selectivity, activity, and reusability in a short time. Furthermore, the heterogeneous catalyst has good recoverability at least five consecutive cycles without losing its selectivity towards products in the oxidation reaction.
Green, inexpensive, and fast conversion of sulfides to sulfoxides by multiusable Mo(VI) macrocyclic Schiff base complex supported on Fe3O4 nanoparticles in solvent-free conditions
Bezaatpour, Abolfazl,Payami, Fatemeh,Eskandari, Habibollah
, p. 910 - 920 (2017)
In the present study, the macrocyclic-based Mo(VI) Schiff base complex was harbored on Fe3O4 nanoparticles and characterized by X-ray powder diffraction, scanning electron microscope, energy-dispersive X-ray spectroscopy, infrared spectroscopy, transmission electron microscopy, vibrating sample magnetometry, diffuse reflectance spectra, and atomic absorption spectroscopy. Separable nanocatalyst was tested under solvent-free conditions for the oxidation of methyl phenyl sulfide, diphenyl sulfide, benzyl phenyl sulfide, dipropyl sulfide, dibutyl sulfide, dimethyl sulfide, bis (4-hydroxyphenyl) sulfide, diallyl sulfide, and benzothiophene using H2O2 (30% in water) as green oxidant. This catalyst is very efficient for thioanisole oxidation with 100% conversion in 3 min. We were able to separate the nanocatalyst magnetically using external magnetic field and to apply the catalyst at least six consecutive times without a significant decrease in conversion. Remarkable and excellent turnover frequency of the catalyst was obtained to oxidize the thioanisole (526,000 h?1), dimethyl sulfide (526,000 h?1), diallyl sulfide (526,000 h?1), dibutyl sulfide (521,000 h?1), and dipropyl sulfide (500,000 h?1). The prepared nanocatalyst has been beneficial in catalytic activity, selectivity, reaction time, and reusability with easy separation.
Fe(III)-salen complex supported on dendrimer functionalized magnetite nanoparticles as a highly active and selective catalyst for the green oxidation of sulfides
Asadi, Zahra,Masteri-Farahani, Majid,Niakan, Mahsa
, (2020)
In this study, we reported the preparation of polyamidoamine-modified magnetite nanoparticles and their use for the immobilization of Fe(III)-salen complex to form a novel magnetic catalyst. The prepared catalyst was characterized by some modern techniques i.e. Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), N2 adsorption-desorption analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM), and inductively couple plasma atomic emission spectroscopy (ICP-AES). The catalyst showed excellent activity and selectivity for the oxidation of sulfides to sulfoxides (conversion 87–100percent, selectivity 82–100percent) using H2O2 (30percent w/w) as oxidant in aqueous medium at 50 °C. Furthermore, the catalyst could be recovered in a facile manner from the reaction mixture by using a magnet and reused for five cycles with high catalytic stability.
Deep eutectic solvent-assisted synthesis of highly efficient nanocatalyst (n-TiO2@TDI@DES (ZnCl2:urea)) for chemoselective oxidation of sulfides to sulfoxides
Taghavi, Shaghayegh,Amoozadeh, Ali,Nemati, Firouzeh
, (2020/12/21)
This study proposed a straightforward process to synthesize 2,4-toluene diisocyanate (TDI)-functionalized TiO2 nanoparticles in which a cost-effective linker (TDI) with high reactivity was employed to couple nano-TiO2 through covalent bonding to a deep eutectic solvent (DES). By this method, DES was successfully immobilized on the TiO2@TDI surface as an adsorbent and stabilizer. The structural, morphological, and physicochemical characteristics of the synthesized nanocatalysts were evaluated using various analytical methods including Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM–EDX), and elemental analysis. The heterogeneity of the catalyst was also examined by a hot filtration test. The obtained TiO2@TDI@DES nanoparticles offered superior catalytic behavior and excellent yield as well as recyclability for the chemoselective oxidation of sulfide into sulfoxide using a green oxidant (hydrogen peroxide). This catalyst exhibited excellent reusability as it can be recovered for six successive cycles with no significant leach or reduction of catalytic efficiency.
Selective synthesis of sulfoxides and sulfonesviacontrollable oxidation of sulfides withN-fluorobenzenesulfonimide
Cao, Zhong-Yan,Li, Xiaolong,Lu, Hao,Wang, Panpan,Wang, Shengqiang,Xu, Xiaobo,Yan, Leyu,Yang, A-Xiu
supporting information, p. 8691 - 8695 (2021/10/22)
A practical and mild method for the switchable synthesis of sulfoxides or sulfonesviaselective oxidation of sulfides using cheapN-fluorobenzenesulfonimide (NFSI) as the oxidant has been developed. These highly chemoselective transformations were simply achieved by varying the NFSI loading with H2O as the green solvent and oxygen source without any additives. The good functional group tolerance makes the strategy valuable.
Modification of MnFe2O4 surface by Mo (VI) pyridylimine complex as an efficient nanocatalyst for (ep)oxidation of alkenes and sulfides
Bouzari, Narges,Bezaatpour, Abolfazl,Babaei, Behnam,Amiri, Mandana,Boukherroub, Rabah,Szunerits, Sabine
, (2021/03/04)
In this current paper, we report a new type of heterogeneous molybdenum (+6) complex, prepared by covalent grafting of cis-dioxo?molybdenum (VI) pyridylimine complex on the surface of MnFe2O4 nanoparticles (NP) and characterized using various physicochemical techniques. The recyclable prepared nanocatalyst was tested for sulfoxidation of sulfides and epoxidation of alkenes under solvent-free condition. The catalyst exhibited high turnover frequency for the oxidization of cyclooctene and cyclohexene (10,850 h?1) and thioanisole and dimethyl sulfide (41,250 h?1). The synthesized catalyst was found highly efficient, retrievable and eco-friendly catalyst for the (ep)oxidation of alkenes and sulfides in excellent yields in a short time. Furthermore, the synthesized nanocatalyst can be reused for four runs without apparent loss of its catalytic activity in the oxidation reaction.
Sulfoxidation inside a hypercrosslinked microporous network nanotube catalyst
Shi, Zhaocheng,Ying, Zhong,Yang, Liusai,Meng, Xiaoyan,Wu, Lidan,Yu, Leshu,Huang, Sen,Xiong, Linfeng
supporting information, p. 1542 - 1547 (2020/02/06)
In the present work, a kind of efficient heterogeneous catalyst was synthesized from amine-functionalized hypercrosslinked bottlebrush copolymers of microporous network nanotubes (amine-MNNs) and Na2WO4. The synthesized tungstate-supported microporous network nanotubes (TMNNs) catalyst was shown to be highly active in the selective H2O2 oxidation of sulfides to sulfoxides or sulfones under mild conditions due to the high specific surface area (800 m2 g-1) and firm structure of the nanotubes. The catalyst was found to be very stable and could be recycled at least 8 times without any significant loss of activity. These results present a new opportunity for the development of efficient green organic catalytic materials with high activity.
Synthesis and nano-Pd catalyzed chemoselective oxidation of symmetrical and unsymmetrical sulfides
Li, Xing,Du, Jia,Zhang, Yongli,Chang, Honghong,Gao, Wenchao,Wei, Wenlong
, p. 3048 - 3055 (2019/03/21)
A highly chemoselective, efficient and nano-Pd catalyzed protocol for the rapid construction of sulfoxides and sulfones via the oxidation of symmetrical and unsymmetrical sulfides using H2O2 as an oxidant has been developed, respectively. The ready availability of starting materials, easy recovery and reutilization of the catalyst, wide substrate scope, and high yields make this protocol an attractive alternative. The process also involves the metal-free and microwave-promoted synthesis of symmetrical diarylsulfides, and FeCl3-mediated preparation of symmetrical diaryldisulfides through the reaction of arenediazonium tetrafluoroborates with Na2S·9H2O as a sulfur source. In addition, unsymmetrical sulfides were generated via the K2CO3-mediated reaction of arenediazonium tetrafluoroborates with symmetrical disulfides.
Synthesis and characterization of indium and thallium immobilized on isonicotinamide-functionalized mesoporous MCM-41: Two novel and highly active heterogeneous catalysts for selective oxidation of sulfides and thiols to their corresponding sulfoxides and disulfides
Molaei, Somayeh,Ghadermazi, Mohammad
, (2019/05/29)
Two highly ordered isonicotinamide (INA)-functionalized mesoporous MCM-41 materials supporting indium and thallium (MCM-41-INA-In and MCM-41-INA-Tl) have been developed using a covalent grafting method. A surface functionalization method has been applied to prepare Cl-modified mesoporous MCM-41 material. Condensation of this Cl-functionalized MCM-41 with INA leads to the formation of MCM-41-INA. The reaction of MCM-41-INA with In(NO3)3 or Tl(NO3)3 leads to the formation of MCM-41-INA-In and MCM-41-INA-Tl catalysts. The resulting materials were characterized using various techniques. These MCM-41-INA-In and MCM-41-INA-Tl catalysts show excellent catalytic performance in the selective oxidation of sulfides and thiols to their corresponding sulfoxides and disulfides. Finally, it is found that the anchored indium and thallium do not leach out from the surface of the mesoporous catalysts during reaction and the catalysts can be reused for seven repeat reaction runs without considerable loss of catalytic performance.
