• Title/Summary/Keyword: CPD (Cyclopentadiene)

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Thermal Formation of Polycyclic Aromatic Hydrocarbons from Cyclopentadiene (CPD)

  • Kim, Do-Hyong;Kim, Jeong-Kwon;Jang, Seong-Ho;Mulholland, James A.;Ryu, Jae-Yong
    • Environmental Engineering Research
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    • v.12 no.5
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    • pp.211-217
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    • 2007
  • Polycyclic aromatic hydrocarbon growth from cyclopentadiene (CPD) pyrolysis was investigated using a laminar flow reactor operating in a temperature range of 600 to $950^{\circ}c$. Major products from CPD pyrolysis are benzene, indene and naphthalene. Formation of observed products from CPD is explained as follows. Addition of the cyclopentadienyl radical to a CPD $\pi$-bond produces a resonance-stabilized radical, which further reacts by one of three unimolecular channels: intramolecular addition, C-H bond $\beta$-scission, or C-C bond $\beta$-scission. The intramolecular addition pathway produces a 7-norbornenyl radical, which then decomposes to indene. Decomposition by C-H bond $\beta$-scission produces a biaryl intermediate, which then undergoes a ring fusion sequence that has been proposed for dihydrofulvalene-to-naphthalene conversion. In this study, we propose C-C bond $\beta$-scission pathway as an alternative reaction channel to naphthalene from CPD. As preliminary computational analysis, Parametric Method 3 (PM3) molecular calculation suggests that intramolecular addition to form indene is favored at low temperatures and C-C bond $\beta$-scission leading to naphthalene is predominant at high temperatures.

Canonical Sampling Method for Initial Conditions for Reactive Flux Calculations Using Nose-Hoover Chains

  • Lee, Song-Hi;Pak, Young-Shang
    • Bulletin of the Korean Chemical Society
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    • v.25 no.4
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    • pp.533-538
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    • 2004
  • Canonical sampling method has been presented to generate the initial conditions for reactive flux studies of organic reactions in water. Velocity Verlet version of Nose-Hoover chain dynamics algorithm has been employed to sample the initial conditions according to canonical distribution. The unstable normal mode of a transition state has been introduced to define a dividing plane separating reactant and product regions in reaction processes. This method has been implemented and tested for the case iels-Alder reaction of methyl vinyl ketone (MVK) and cyclopentadiene (CPD) in water, providing a reliable tool for further reactive flux molecular dynamics studies in condensed media.

Isomerization of Endo-tetrahydrodicyclopentadiene over Y Zeolite Catalysts (Y 제올라이트 촉매 상에서 Endo-Tetrahydrodicyclopentadiene의 이성화 반응)

  • Kim, Jinhan;Kim, Ji-Yun;Park, Eunseo;Han, Jeongsik;Kwon, Tae Soo;Park, Young-Kwon;Jeon, Jong-Ki
    • Applied Chemistry for Engineering
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    • v.25 no.1
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    • pp.66-71
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    • 2014
  • Synthesis of exo-tetrahydrodicyclopentadiene (exo-THDCPD) through the isomerization of endo-tetrahydrodicyclopentadiene (endo-THDCPD) was investigated over HY zeolite catalysts. Conversion of endo-THDCPD increased with the increase of $Si/Al_2$ ratio of HY zeolite catalysts, which can be attributed to increase of acid strength with increase of $Si/Al_2$ ratio. Yield of exo-THDCPD, however, was the highest over HY with $Si/Al_2$ ratio of 30, because the production of cyclopentadiene and oligomers was minimized. The optimal reaction temperature was $180^{\circ}C$ because the higher reaction temperature increased the production of by-products. The yield of exo-THDCPD also increased with the amount of the catalyst in feed. In the isomerization reaction of endo-THDCPD using the HY zeolite catalysts, it was confirmed that the internal diffusion resistance in the pore of catalysts would have more significant effects on the reaction activity than that of the external diffusion resistance of catalysts.