6196-95-8Relevant articles and documents
Green synthesis of 1-phenyl-1-ortho-xylene ethane in IL and reaction mechanism
Sun, Xuejun,Zhou, Xinming,Cao, Bobo,Cao, Ziping,Fu, Hui
, p. 14998 - 15004 (2017)
1-Phenyl-1-ortho-xylene ethane (PXE) in IL was synthesized, and the catalysts used were AlCl3 in 1-butyl-3-methylimidazolium bromide ([BMIM][Br]) or 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), and H2SO4. When the concentrations of AlCl3 in IL, ortho-xylene and styrene were 0.35, 0.03 and 0.005?mol, respectively, it could be discovered that ([BMIM][Br]) was the best catalyst. When the mole fraction concentration of AlCl3/[BMIM][Br] was more than 0.40%, the reaction was able to achieve 100% conversion. When the reaction time was longer than 60 minutes, the percentage conversion of ortho-xylene attained was 100%. The mechanisms of the reaction were investigated by the DFT method at the B3LYP/6-311++G(d, p) level. The potential energy surface (PES) profile indicated that the energy of transition state was 22.59 kcal mol?1. This indicated that the activation energy of reaction was 28.24 kcal mol?1, which illustrated that the reaction occurred easily. Vibrational frequencies were observed in FT-IR spectra, the corresponding vibrational modes νs(H4-C3Al-H5) and νas(H4-C3Al-H5) indicated that an Al3+ ion was combined with a C3 atom. In addition, the repeated use of the catalysts was studied; the ionic liquids could still catalyze the reaction and the percentage yield of PXE was larger than 91% after 6 runs.
Alkylation of O-xylene and styrene catalyzed by cross-linked poly acidic ionic liquids catalyst with novel mesoporous-macroporous structure
Gao, Huaying,Zhou, Yuming,Sheng, Xiaoli,Zhao, Shuo,Zhang, Chao,Fang, Jiasheng,Wang, Beibei
, p. 138 - 146 (2018)
Cross-linked poly acidic ionic liquids (MPM-C6V-SO3CF3-IL) with mesoporous and macroporous network structure have been synthesized in different solvents. The novel solid acid catalyst with special network structure has a large surface area (103.83 m2/g), large pore volume (0.72 cm3/g) and abundant mesopores and macropores, which help to improve the contact between active site and reactants. Catalytic performance of catalyst was investigated through alkylation of o-xylene and styrene. Different reaction parameters specifically solvent on obtained catalyst and production of PXE were systematically investigated. Under optimal reaction conditions (reaction time was 3 h, reaction temperature was 120 °C, catalyst amount was 0.17 g (0.5 wt%), and o-xylene/styrene mass ratio was 7.5:1), a high conversion of styrene (100%) and 1,2-diphenylethane (PXE) yield of 99.67% was obtained, which is superior to commercial acid in liquid and even previous acids synthesized by our own group. Moreover, catalyst could keep relatively high thermostability under reaction and are easy to be separated and recycled from the solution, which are critical for heterogeneous solid catalysts. Thus, this novel catalyst can be potentially applied in other acidic reactions.
Highly active and green aminopropyl-immobilized phosphotungstic acid on mesoporous LaSBA-15 for alkylation of o-xylene with styrene
Sheng, Xiaoli,Zhou, Yuming,Zhang, Yiwei,Duan, Yongzheng,Xue, Mengwei
, p. 360 - 367 (2012)
The Keggin phosphotungstic acid, H3PW12O40 (HPW), was successfully immobilized on the surface of mesostructured LaSBA-15 by means of chemical bonding to aminosilane groups. The catalysts were characterized by elemental analysis, N2 adsoption, TEM, DRS-UV, and FTIR spectroscopy. Characterization results suggest that the surface area decreased after grafting amino groups to silica and the structures of heteropolyanions on amine-modified LaSBA-15 was maintained. Their catalytic behaviors were investigated in the alkylation of o-xylene with styrene. Among the functionalized catalysts, when the content of amino-groups was suitable, it had the best catalytic performances in terms of yield and stability. It is worth mentioning that the catalysts could be used repeatedly without loss of the activity and selectivity during several catalytic cycles. The good stability can be attributed to the strong interaction between the amino groups on the surface of LaSBA-15 and HPW anions.
One-step synthesis of hierarchical aluminosilicates using alkoxy-functionalized ionic liquid as a novel template
Fu, Xiaoqin,Sheng, Xiaoli,Zhou, Yuming,Fu, Zhiwei,Zhao, Shuo,Zhang, Zewu,Zhang, Yiwei
, p. 6036 - 6045 (2016)
Hierarchical zeolites have bridged the gap between conventional zeolite and mesoporous materials, which not only maintain the excellent advantages of microporous sieves, but also effectively resolve the diffusion limitations. Herein, a novel alkoxy-functionalized ionic liquid was employed as a mesoporous structure-directing agent to synthesize hierarchical aluminosilicates with dual micro-mesoporous channels. X-ray diffraction (XRD), N2 adsorption-desorption isotherms (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature-programmed desorption (TPD), thermogravimetric analysis (TGA) and 27Al magic-angle spinning nuclear magnetic resonance (27Al MAS NMR) were used to characterize the structural and textural features of the hierarchical aluminosilicates. The results showed that the ionic liquid (MTPI) employed played the role of a mesoporous structure-directing agent which was trapped within the pores of a faujasite structure through -Si-O-Al- and -Si-O-Si- linkages. The mesoporous diameters and structures of the final hierarchical materials could be uniformly tailored by tuning the added amount of template. Hierarchical aluminosilicates with the combined advantages of both mesoporous properties and the microporous crystalline structure of zeolites exhibited high catalytic activity and resistance to deactivation in the alkylation of o-xylene with styrene, as compared to the conventional zeolite with the sole presence of micropores. The distinct catalytic performance of hierarchical aluminosilicates could be attributed to the short diffusion routes and abundant exposed acidic sites on the external surface.
Deep compositional understanding of TBA: AlCl3 ionic liquid for its applications
Bhakthavatsalam, Vishnupriya,Chandra, Sudeshna,Choudhury, Rudra Prosad,Lande, Sharad V.,Pradhan, Jeevan,Sakhalkar, Mangesh
, (2020/07/31)
Chloroaluminate ionic liquids (ILs) have been immensely used as homogeneous catalyst in Friedel-Crafts reaction. We have recently synthesized chloroaluminate ILs by reacting aluminium chloride with a hydrophobic neutral ligand i.e. tributylamine (TBA:AlCl3). The current study elaborates on the investigations of the composition of the ionic liquids at various stages of their formation. The ionic liquids were synthesized using various mole ratios of tributyl amine and aluminium chloride in range of 1:1 to 1:2.3, in presence of an aromatic solvent in a one pot reaction. Various characterization techniques like Mass spectrometry, 27Al Nuclear Magnetic Resonance, 31P Nuclear Magnetic Resonance and Fourier Transform Infrared spectroscopy were used to elucidate the formation of various moieties of the TBA:AlCl3 Ionic Liquid. This study also elaborates on the investigations of the cationic and anionic moieties and their structure-property relationship for various applications. Various Friedel-Crafts reaction of industrial importance were performed using the ionic liquid having (Al2Cl7)?moiety to assess its performance and compared with conventional processes. The synthesized products were characterised by sophisticated analytical techniques like 1H NMR, 13C NMR, FTIR, GC–MS, GC-FID, to name a few. This class of ionic liquids also have importance in various electrochemical applications like aluminium deposition and aluminium batteries.