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Kinetic Study and NBO Analysis of the Dehydrogenation Mechanism of Five-membered Ring Heterocyclic 2,5-Dihydro-[furan, thiophene, selenophene]

Kinetic Study and NBO Analysis of the Dehydrogenation Mechanism of Five-membered Ring Heterocyclic 2,5-Dihydro-[furan, thiophene, selenophene]
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摘要 The theoretical study of the dehydrogenation of 2,5-dihydro-[furan （1）, thiophene （2）, and selenophene （3）] was carried out using ab initio molecular orbital （MO） and density functional theory （DFT） methods at the B3LYP/6-311G＊＊//B3LYP/6-311G＊＊ and MP2/6-311G＊＊//B3LYP/6-311G＊＊ levels of theory. Among the used methods in this study, the obtained results show that B3LYP/6-311G＊＊ method is in good agreement with the available experimental values. Based on the optimized ground state geometries using B3LYP/6-311G＊＊ method, the natural bond orbital （NBO） analysis of donor-acceptor （bond-antibond） interactions revealed that the stabilization energies associated with the electronic delocalization from non-bonding lone-pair orbitals [LP（e）x3] to C＊C（1）- H（2） antibonding orbital, decrease from compounds 1 to 3. The LP（e）x3→σ＊c（1）-H（2） resonance energies for compounds 1--3 are 23.37, 16.05 and 12.46 kJ/mol, respectively. Also, the LP（e）xa→σ＊c（1）-H（2） delocalizations could fairly explain the decrease of occupancies of LP（e）x3 non-bonding orbitals in ring of compounds 1-3 （3 〉2 〉 1）. The electronic delocalization from LP（e）x3 non-bonding orbitals to σ＊c（1）-G（2） antibonding orbital increases the ground state structure stability, Therefore, the decrease of LP（e）x3→σ＊c（1）-H（2） delocalizations could fairly explain the kinetic of the dehydrogenation reactions of compounds 1-3 （kl〉k2〉k3）. Also, the donor-acceptor interactions, as obtained from NBO analysis, revealed that the πc（4）=c（7）→σ＊c（1）-H（2） resonance energies decrease from compounds 1 to 3. Further, the results showed that the energy gaps between πC（4）-C（7） bonding and σ＊c（1）-H（2） antibonding orbitals decrease from compounds 1 to 3. The results suggest also that in compounds 1--3, the hydrogen elimi- nations are controlled by LP（e）→σ＊ resonance energies. Analysis of bond order, natural bond orbital charges, bond indexes, synchronicity parameters, and IRC calculations indicate that these reactions are occurring through a con- certed and synchronous six-membered cyclic transition state type of mechanism. The theoretical study of the dehydrogenation of 2,5-dihydro-[furan （1）, thiophene （2）, and selenophene （3）] was carried out using ab initio molecular orbital （MO） and density functional theory （DFT） methods at the B3LYP/6-311G＊＊//B3LYP/6-311G＊＊ and MP2/6-311G＊＊//B3LYP/6-311G＊＊ levels of theory. Among the used methods in this study, the obtained results show that B3LYP/6-311G＊＊ method is in good agreement with the available experimental values. Based on the optimized ground state geometries using B3LYP/6-311G＊＊ method, the natural bond orbital （NBO） analysis of donor-acceptor （bond-antibond） interactions revealed that the stabilization energies associated with the electronic delocalization from non-bonding lone-pair orbitals [LP（e）x3] to C＊C（1）- H（2） antibonding orbital, decrease from compounds 1 to 3. The LP（e）x3→σ＊c（1）-H（2） resonance energies for compounds 1--3 are 23.37, 16.05 and 12.46 kJ/mol, respectively. Also, the LP（e）xa→σ＊c（1）-H（2） delocalizations could fairly explain the decrease of occupancies of LP（e）x3 non-bonding orbitals in ring of compounds 1-3 （3 〉2 〉 1）. The electronic delocalization from LP（e）x3 non-bonding orbitals to σ＊c（1）-G（2） antibonding orbital increases the ground state structure stability, Therefore, the decrease of LP（e）x3→σ＊c（1）-H（2） delocalizations could fairly explain the kinetic of the dehydrogenation reactions of compounds 1-3 （kl〉k2〉k3）. Also, the donor-acceptor interactions, as obtained from NBO analysis, revealed that the πc（4）=c（7）→σ＊c（1）-H（2） resonance energies decrease from compounds 1 to 3. Further, the results showed that the energy gaps between πC（4）-C（7） bonding and σ＊c（1）-H（2） antibonding orbitals decrease from compounds 1 to 3. The results suggest also that in compounds 1--3, the hydrogen elimi- nations are controlled by LP（e）→σ＊ resonance energies. Analysis of bond order, natural bond orbital charges, bond indexes, synchronicity parameters, and IRC calculations indicate that these reactions are occurring through a con- certed and synchronous six-membered cyclic transition state type of mechanism.
作者 Shiroudi, Abolfazl Zahedi, Ehsan
机构地区 Chemistry Department
出处 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2011年第11期2249-2256,共8页 中国化学（英文版）
关键词 unimolecular reaction ab initio DEHYDROGENATION density functional theory （DFT） intrinsic reaction coordinate （IRC） natural bond orbital （NBO） unimolecular reaction, ab initio, dehydrogenation, density functional theory （DFT）, intrinsic reaction coordinate （IRC）, natural bond orbital （NBO）
分类号 O643.1 [理学—物理化学] O626.11 [理学—有机化学]
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参考文献30

  • 1Wellington, C. A.;Walters, W. D.J. Am. Chem. Soc. 1961, 83,4888.
  • 2Thomas, A. L.; Wellington, C. A. J Chem. Soc., A 1969, 2895.
  • 3Wellington, C. A.; James, T. L.; Thomas, A. C. J Chem. Soc.,A 1969,2897.
  • 4James, T. L.; Wellington, C. A. J Chem. Soc., A 1968, 2398.
  • 5Nori-Shargh, D.; Shiroudi, A.; Naeem-Abyaneh, R.; Nozari, M. Phosphorus, Sulfur, Silicon 2005, 180, 435.
  • 6Baldwin, J. F. Tetrahedron Lett. 1966, 2953.
  • 7Benson, S. W.; Shaw, R. Trans. Faraday Soc. 1967, 63, 985.
  • 8Shiroudi, A.; Zahedi, E.; Zabihi, R. Reaction Kinetics, Mechanisms and Catalysis 2011, 102, 21.
  • 9Dewar, M. J. S.; Healy, E. F.; Stewart, J. J. P. J. Chem. Soc., Faraday Trans. 2 1984, 80, 227.
  • 10Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Zakrazewski, V. G.; Montgomery, J. A.; Startmann, Jr. R. E.; Burant, J. C.; Dapprich, S.; Millam, J. M.; Daniels, A. D.; Kudin, K. N.; Strain M. C.; Farkas, O.; Tomasi, J.; Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Adamo, C.; Clifford, S.; Ochter- ski, J.; Petersson, G. A.; Ayala, P. Y.; Cui, Q.; Morokuma, K.; Malik, D. K.; Rabuck, A. D.; Raghavachar, K.; Fores- man, J. B.; Cioslowski, J.; Ortiz, J. V.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, 1.; Gomperts, R.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanyakkara, A.; Gonzalez, C.; Challacombe, M.; Gill P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Andres, J. L.; Head-Gordon, M.; Replogle, E. S., Pople, J. A. Gaussian 98, Revision A.3, Gaussian Inc., Pittsburgh, PA, USA, 1998.
Chinese Journal of Chemistry
2011年 第11期

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