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via metathesis polymerization: Concepts and applications
Published in Y. Yagci, M.K. Mishra, O. Nuyken, K. Ito, G. Wnek, Tailored Polymers & Applications, 2020
Michael R. Buchmeiser, Frank Sinner, M. Mupa
Using precipitation polymerization techniques, ROMP may be used for the preparation of new heterogeneous catalysts. Thus, ROMP of norborn-2-ene-5-(N,N-di(pyrid-2-yl)carbamide followed by cross-linking with 1,4,4a,5,8,8a-hexahydro-1,4,5,8-exo-endo-dimethanonaphtalene [23] and subsequent loading of the resulting resin with palladium(II) chloride results in the formation of a heterogeneous Pd (II) catalyst [39]. The synthesis of the support and loading of the resin is summarized in Scheme 2. The resulting material represents a typical small particle catalyst [31]. The carrier particles have a mean diameter of 20–40 μm, possess only macropores (> 1000 Å) and are therefore characterized by a low specific surface area (4–6 m2/g) both in the dry as well as in the wetted state. Consequently, swelling is a minor problem. As the palladium-loaded chelating groups are located at the surface of the particle [22, 23], they are easily accessible and diffusion plays a minor role. As a consequence of the high selectivity of the ligand for palladium, no substitution by other metal ions which might be present in technical grade chemicals occurs. The high affinity of the ligand for palladium also leads to a high temperature stability of up to 150°C and to an extraordinary pH-stability of the resulting complex. Thus, palladium may not be removed from the ligand within a pH range of 0–12. Preparation of heterogeneous Pd-catalyst via ROMP.
Chemicals from Olefin Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
The Wacker process uses an aqueous solution of palladium(II) chloride, copper(II) chloride catalyst system. In the course of the reaction, the ethylene is oxidized to acetaldehyde and the palladium (Pd2+) ions are reduced to palladium metal: CH2=CH2+H2O+PdCl2→CH3CHO+2HCl+Pdo
Examples from the Chemical Industry
Published in John Andraos, Synthesis Green Metrics, 2018
Step 1: kg ethylenecu m oxygen at STP (0°C and 1 atm)mol% copper(II)chloridemol% palladium(II)chloridecu m cooling waterkg steam at p=1.4 MPakg steam at p=460 kPakg acetaldehydeT (rxn)=100°CP (rxn)=700 kPa
Synthesis and properties of isothiocyanate liquid crystals containing cyclohexene unit
Published in Liquid Crystals, 2021
Danyang Wan, Xin Gu, Juanli Li, Minggang Hu, Zhaoyi Che, Qiang Guo, Lingchao Mo, Jian Li, Zhongwei An
1,4-Dibromobenzene and n-butyllithium (2.5 mol/L in hexane) were purchased from Sun Chemical (Shanghai, China) Technology Co. LTD and used as received. Bis(triphenylphosphine)palladium(II) chloride (Pd(PPh3)2Cl2) was purchased from Ruike New Material Co. Ltd (Shaanxi, China). 4-Propylcyclohexanone, 4-pentylcyclohexanone, 4-bromo-2,6-difluoroaniline, 3,5-difluoro-4-isothiocyanato-4ʹ-(4-propylcyclohexyl)-1,1ʹ-biphenyl (3CPUNCS), 3,5-difluoro-4-isothiocyanato-4ʹ-(4-pentylcyclohexyl)-1,1ʹ-biphenyl (5CPUNCS), 3,5-difluoro-4-isothiocyanato-4ʹ’-propyl-1,1ʹ:4ʹ,1ʹ’-terphenyl (3PPUNCS) and 3,5-difluoro-4-isothiocyanato-4ʹ’-pentyl-1,1ʹ:4ʹ,1ʹ’-terphenyl (5PPUNCS) were purchased from Xi’an Caijing Opto-Electrical Science Technology Co. Ltd (Shaanxi, China) and used as received. Tetrahydrofuran, p-tolylsulfonic acid, toluene, triisopropyl borate, ethanol, tetrabutylammonium bromide (TBAB), potassium carbonate, ethyl acetate and heptane were all purchased from Sinopharm Chemical Reagent Co. (Shanghai, China). THF was distilled from sodium under nitrogen atmosphere prior to use.
Carbon nanotube-zeolite composite catalyst - characterization and application
Published in Journal of Dispersion Science and Technology, 2021
Ádám Prekob, Viktória Hajdu, Béla Fiser, Ferenc Kristály, Béla Viskolcz, László Vanyorek
The core of the composite structure was zeolite (diam. 2 mm, 5 A molecule sieve, Roth). Nitrogen-doped bamboo-like carbon nanotubes (N-BCNTs) were synthetized on the zeolite beads to achieve the SoS system. During the CCVD synthesis of N-BCNTs n-butylamine (Scharlau Chem., reagent grade) was used as carbon source and nickel(II) nitrate hexahydrate (Ni(NO3)2·6 H2O, Merck Chem., purity 99,9999) as catalyst. The SoS system was decorated with three different catalytically active metals, Pd (reduced from palladium(II) chloride, PdCl2, Chinoin Ltd., 99%), Rh (reduced from rhodium-acetate dimer, [(CH3CO2)2Rh]2, Sigma-Aldrich, purity 99,99), and Pt (reduced from hexachloroplatinic acid hexahydrate, H2PtCl6·6H2O, Sigma-Aldrich, ACS reagent, ≥37.50% Pt basis). For the solvation of the PdCl2, Patosolv (alcohol mixture, Molar Chem.) was used. The activity of the three final catalysts (Pd-, Rh-, and Pt-SoS) was compared in 1-butene (Messer) hydrogenation (hydrogen, purity 4.0, Messer; nitrogen, purity 4.0, Messer).
Synthesis and properties of novel 6,7-dihydrocyclopenta[5,6-b]benzofuran-based liquid crystal compounds
Published in Liquid Crystals, 2021
Danyang Wan, Jian Li, Lingchao Mo Mo, Xiaozhe Yang, Zhaoyi Che, Minggang Hu, Juanli Li, Zhongwei An
Anisole, butyryl chloride, aluminium chloride, hexamethylenetetramine (HMTA), acetic anhydride, concentrated sulphuric acid (98%), sodium borohydride, tetrahydrofuran (THF), p-toluenesulfonic acid, toluene, palladium on activated carbon (5% Pd/C), acetonitrile, N-bromosuccinimide (NBS), boron tribromide, dichloromethane, triethylamine, copper(I) iodide, n-heptane and ethyl acetate were purchased from Sinopharm Chemical Reagent Co. (Shanghai, China) and used without any further purification. Bis(triphenylphosphine)palladium(II) chloride (Pd(PPh3)2Cl2) was purchased from Ruike New Material Co. Ltd (Shaanxi, China). 5-Ethynyl-1,2,3-trifluorobenzene, 1-butyl-4-ethynylbenzene, 1-ethoxy-4-ethynyl-2,3-difluorobenzene, 4ʹ-(4-ethylcyclohexyl)-3,4,5-trifluoro-1,1ʹ-biphenyl (2CPUF), 4ʹ-ethyl-3,4,5-trifluoro-1,1ʹ-biphenyl (2PUF), 4-butyl-4ʹ-(4-ethylcyclohexyl)-1,1ʹ-biphenyl (2CPP4), 4-butyl-4ʹ-ethyl-1,1ʹ-biphenyl (2PP4), 4-ethoxy-4ʹ-(4-ethylcyclohexyl)-2,3-difluoro-1,1ʹ-biphenyl (2CPYO2) and 4-ethoxy-4ʹ-ethyl-2,3-difluoro-1,1ʹ-biphenyl (2PYO2) were purchased from Xi’an Caijing Opto-Electrical Science Technology Co. Ltd (Shaanxi, China) and used as received.