The properties of nonadiabatic trapping models of the reaction NH+H -N+H, are investigated in a collinear model as \veil as a non-collinear thermal reaction on the basis of theintrinsic reaction coordinate (IRC) intbr...The properties of nonadiabatic trapping models of the reaction NH+H -N+H, are investigated in a collinear model as \veil as a non-collinear thermal reaction on the basis of theintrinsic reaction coordinate (IRC) intbrmation obtained by ah initio calculations at QCISD/631 IG** ie\el. Using the unitied statistical theory fornonadiabatic trapping models. the thermal rateconstants over the temperature range of 2000-3000K are computed which are in excellent agreementwith the experiment results.展开更多
The photolysis of acetone has been studied at 6-311G basis set using unrestricted Hartree-Fock method. The results show that ground state acetone (S0) cannot easily dissociate. The electrons of acetone undergo n→Ⅱ t...The photolysis of acetone has been studied at 6-311G basis set using unrestricted Hartree-Fock method. The results show that ground state acetone (S0) cannot easily dissociate. The electrons of acetone undergo n→Ⅱ tran-sition in laser, and excited acetone (T1) can easily dissociate: CH3COCH3(T1)hv→CH3 + CHCO(R1) and acetyl canfurther undergo thermolytic dissociation: CH3CO→CH3 + CO(R2) . The dynamic information (ωK , Bkf , V0(S)) of reaction R2 is obtained and the vibrational state distributions of product CO are calculated. The calculated value consists with the experimental value.展开更多
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 ...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 orde展开更多
A new approach was employed to calculate the canonical (thermal) rate constant basedon unified statistical theory. All information for the calculation was obtained from ab initio meth-ods. The flux integral for any po...A new approach was employed to calculate the canonical (thermal) rate constant basedon unified statistical theory. All information for the calculation was obtained from ab initio meth-ods. The flux integral for any point of reaction coordinate was calculated by counting the numberof quantum states and applied to determine the dividing surfaces along the intrinsic reaction coor-dinate (IRC). The classical exchange reaction H2+H, as an example, was investigated. The IRC forthe reaction has been traced and detailed information of IRC was carried out at the QCISD/6-311 G** level .The calculated rate constants are well consistent with the experimental results.展开更多
MINDO/3 molecular orbital theory has been used to study the thermal rearrangements of HNCRCR'CO.The results obtained show that the activation energy of this rearrangement depends on the migrating group R and the g...MINDO/3 molecular orbital theory has been used to study the thermal rearrangements of HNCRCR'CO.The results obtained show that the activation energy of this rearrangement depends on the migrating group R and the group R'.展开更多
MINDO/3 MO method has been used to study the mechanism of the consecutive addition of HCN to propionitrile. The results obtained for the first five steps show that the reaction is exothermic, and step 1 is the rate d... MINDO/3 MO method has been used to study the mechanism of the consecutive addition of HCN to propionitrile. The results obtained for the first five steps show that the reaction is exothermic, and step 1 is the rate determining step.展开更多
质子化功能离子液体在许多重要领域具有潜在的应用价值,然而人们对其相互作用模式、质子转移行为等方面的认识尚不清晰.本文利用DFT/B3LYP和MP2方法,以脯氨酸阳离子[HPro]+、脯氨酸甲酯阳离子[HProC1]+和糖精阴离子[Sac]组成的质子化离...质子化功能离子液体在许多重要领域具有潜在的应用价值,然而人们对其相互作用模式、质子转移行为等方面的认识尚不清晰.本文利用DFT/B3LYP和MP2方法,以脯氨酸阳离子[HPro]+、脯氨酸甲酯阳离子[HProC1]+和糖精阴离子[Sac]组成的质子化离子液体(PILs)为研究对象,探讨气态离子对、分子对、双聚体团簇中的结构单元及其作用模式.利用过渡态和内禀反应坐标(IRC)理论研究气态[HPro]+[Sac]和[HProC1]+[Sac]中的质子转移反应,AIM(atoms in molecules)理论分析给出氢键相互作用本质等.计算结果表明,气态单聚体中氢转移能垒很小,体系中存在离子对和分子对的动态平衡.质子转移发生后,体系内部基本作用单元改变,作用强度下降,形成分子对的相互作用能量远远小于离子对的相互作用能量.双聚体团簇计算说明体系中没有质子转移反应发生,在[HPro]2+[Sac]2中相互作用的基本结构单元为离子、分子和两性离子,酯化后双聚体[HProC1]2+[Sac]2中全部为阴阳离子相互作用.质子转移反应、两性离子和酯化作用等的深入研究对于理解功能化PILs的性质、结构因素及其应用具有一定的实际意义.展开更多
文摘The properties of nonadiabatic trapping models of the reaction NH+H -N+H, are investigated in a collinear model as \veil as a non-collinear thermal reaction on the basis of theintrinsic reaction coordinate (IRC) intbrmation obtained by ah initio calculations at QCISD/631 IG** ie\el. Using the unitied statistical theory fornonadiabatic trapping models. the thermal rateconstants over the temperature range of 2000-3000K are computed which are in excellent agreementwith the experiment results.
基金Project supported by the National Natural Science Foundation of China (Grant No. 29773007).
文摘The photolysis of acetone has been studied at 6-311G basis set using unrestricted Hartree-Fock method. The results show that ground state acetone (S0) cannot easily dissociate. The electrons of acetone undergo n→Ⅱ tran-sition in laser, and excited acetone (T1) can easily dissociate: CH3COCH3(T1)hv→CH3 + CHCO(R1) and acetyl canfurther undergo thermolytic dissociation: CH3CO→CH3 + CO(R2) . The dynamic information (ωK , Bkf , V0(S)) of reaction R2 is obtained and the vibrational state distributions of product CO are calculated. The calculated value consists with the experimental value.
文摘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 orde
文摘A new approach was employed to calculate the canonical (thermal) rate constant basedon unified statistical theory. All information for the calculation was obtained from ab initio meth-ods. The flux integral for any point of reaction coordinate was calculated by counting the numberof quantum states and applied to determine the dividing surfaces along the intrinsic reaction coor-dinate (IRC). The classical exchange reaction H2+H, as an example, was investigated. The IRC forthe reaction has been traced and detailed information of IRC was carried out at the QCISD/6-311 G** level .The calculated rate constants are well consistent with the experimental results.
基金Project supported by the Natural Science Foundation of Jiangxi Province,China.
文摘MINDO/3 molecular orbital theory has been used to study the thermal rearrangements of HNCRCR'CO.The results obtained show that the activation energy of this rearrangement depends on the migrating group R and the group R'.
基金Project supported by the National Natural Science Foundation of Jiangxi Province.
文摘 MINDO/3 MO method has been used to study the mechanism of the consecutive addition of HCN to propionitrile. The results obtained for the first five steps show that the reaction is exothermic, and step 1 is the rate determining step.
文摘质子化功能离子液体在许多重要领域具有潜在的应用价值,然而人们对其相互作用模式、质子转移行为等方面的认识尚不清晰.本文利用DFT/B3LYP和MP2方法,以脯氨酸阳离子[HPro]+、脯氨酸甲酯阳离子[HProC1]+和糖精阴离子[Sac]组成的质子化离子液体(PILs)为研究对象,探讨气态离子对、分子对、双聚体团簇中的结构单元及其作用模式.利用过渡态和内禀反应坐标(IRC)理论研究气态[HPro]+[Sac]和[HProC1]+[Sac]中的质子转移反应,AIM(atoms in molecules)理论分析给出氢键相互作用本质等.计算结果表明,气态单聚体中氢转移能垒很小,体系中存在离子对和分子对的动态平衡.质子转移发生后,体系内部基本作用单元改变,作用强度下降,形成分子对的相互作用能量远远小于离子对的相互作用能量.双聚体团簇计算说明体系中没有质子转移反应发生,在[HPro]2+[Sac]2中相互作用的基本结构单元为离子、分子和两性离子,酯化后双聚体[HProC1]2+[Sac]2中全部为阴阳离子相互作用.质子转移反应、两性离子和酯化作用等的深入研究对于理解功能化PILs的性质、结构因素及其应用具有一定的实际意义.
