464-17-5Relevant academic research and scientific papers
Synthesis, Characterization, and Catalytic Activity of NAPO-5 and NAPO-11
Elangovan, Shanmugam P.,Krishnasamy, Vengaimuthu,Murugesan, Velayutham
, p. 3659 - 3664 (1995)
Nickel-substituted aluminophosphate molecular sieves (NAPO-5 and NAPO-11) were synthesized hydrothermally using triethylamine and dipropylamine as templates.Structures were confirmed by X-ray powder pattern, and unit cell parameters calculated by a standard least square refinement technique.The isomorphous substitution of nickel in the aluminophosphate framework is evidenced by the considerable increase in unit cell volume compared to unsubstituted AlPO4-5 and AlPO4-11.In addition, electron spin resonance and diffuse reflectance spectra were carried out to produce supporting evidence for the isomorphous substitution of nickel.Acidity was determined by TPD-TGA method which shows two types of acid sites.Symmetry and asymmetry vibrations were obtained from infrared spectra.Chemical analysis by ICP and BET surface area are also reportedd.The physicochemical properties of the catalysts were correlated towards isomerization of camphene at various (WHSV)-1 values and temperatures.The products formed are tricyclene and 2-bornene and the selective formation of tricyclene was achieved over, these catalysts.
Methoxylation of α-pinene over heteropolyacids immobilized in silica
Pito,Matos,Fonseca,Ramos,Vital,Castanheiro
body text, p. 140 - 146 (2010/10/01)
The methoxylation of α-pinene was studied using heteropolyacids immobilized on silica as catalysts, at 60 °C, being the α-terpinyl methyl ether the main product. Tungstophosphoric acid (PW), molybdophosphoric acid (PMo), tungstosilicic acid (SiW) and molybdosilicic acid (SiMo) were immobilized on silica by sol-gel method. It was observed that the catalytic activity of the silica-supported heteropolyacids decreases in the series: PW2_S > SiW_S > PMo_S > SiMo_S. A series of PW immobilized on silica with different PW loading were prepared. It was observed that the catalytic activity increases with the amount of PW immobilized on silica. However, at high amount of PW on silica, a decrease of the catalytic activity was observed. Good values of selectivity to α-terpinyl methyl ether (about 60% near complete conversion) were obtained with all catalysts. Catalytic stability of the PW2_S was evaluated by performing consecutive batch runs with the same catalyst sample. After the third batch it was observed a stabilisation of the initial activity. A kinetic model was developed assuming that the α-pinene is consumed according to the parallel reaction network. It was observed that the kinetic model fits the experimental concentration data quite well.
Catalytic Transformation of camphene over Aluminophosphate-based Molecular Sieves
Elangovan, S. P.,Arabindoo, Banumathi,Krishnasamy, V.,Murugesan, V.
, p. 4471 - 4476 (2007/10/03)
The catalytic transformation of camphene over AlPO4-11, SAPO-5, SAPO-11, VAPO-5, VAPO-11, CoAPO-5, CoAPO-11, NAPO-5, NAPO-11, ZAPO-5 and ZAPO-11 in the vapour phase has been studied.The products formed are tricyclene, bornylene and monocyclic terpenes.The
Catalytic transformation of camphene over alumina, silica-alumina and zeolite catalysts
Elangovan, S. P.,Krishnasamy, V.
, p. 1041 - 1045 (2007/10/02)
Isomerisation of camphene in the vapour phase over alumina prepared from aluminium foil, aluminium isopropoxide, aluminium sulphate and aluminium nitrate, silica-alumina in different ratios (0.88, 1.86, 3.16) and zeolites such as H-5A, H-ZSM-5, H-Y has been studied.The products formed are tricyclene, bornylene and monocyclic terpenes.The product distribution is influenced by the acidic strength of the catalysts.Maximum amount of tricyclene is formed over lower acidic strength while maximum amounts of monocyclics like dipentene, terpinolene, α-and τ-terpinenes, p-menthene and p-cymene are formed over higher acidic strength.The concentration of bornylene in the product increases with acidity.The effects of temperature, contact time and partial pressure of pyridine on the conversion and product distribution have also been investigated.
Electronic Effects of Polar Substituents in the Gas Phase Unimolecular Elimination of 4-Substituted Isobornyl Acetates
Chuchani, Gabriel,Hernandez A, Jose A.,Morris, David G.,Shepherd, Alistair G.
, p. 917 - 922 (2007/10/02)
The rates of gas-phase elimination of a series of 4-substituted isobornyl acetates have been measured in the presence of propene between 209-370 deg C and within a pressure range 37-153 Torr; a static system with seasoned vessels was used.The reaction are unimolecular, homogeneous, and obey a first-order rate law; electron-withdrawing substituents at C(4) cause a diminution in the elimination rate, such that ρ1 -0.69 in a Hammett treatment.The temperature dependence of the rate coefficients is illustrated for the Arrhenius equation for isobornyl acetate: logk/s-1=(12.82+/-0.13)-(189.2+/-1.5)kJmol-1/2.303RT.The results are consistent with a cyclic transition state in which C(2)-O cleavage is more advanced than that of C(3)-H.The major primary product of elimination of isobornyl acetate is bornylene, which partially isomerises to camphene and tricyclene under the reaction conditions.Bornylene also undergoes a retro-Diels-Alder reaction to yield the trimethylcyclopentadiene and ethylene.
