The molecular structure of(1S,2R)-2-amino-1-phenylpropan^(-1)-ol(abbreviated as 2APPO)conformers have been studied in the gas phase.Natural Bond Orbital Analysis and Non Linear Optical properties of 2APPO have been pe...The molecular structure of(1S,2R)-2-amino-1-phenylpropan^(-1)-ol(abbreviated as 2APPO)conformers have been studied in the gas phase.Natural Bond Orbital Analysis and Non Linear Optical properties of 2APPO have been performed by DFT level of theory using B3LYP/6-311++G(d,p)basis set.The atomic charges,electronic exchange interaction and charge delocalization of the molecule have been performed by Natural Bond Orbital(NBO)analysis,Natural Population Analysis(NPA) and Non Linear Optical(NLO)properties have been constructed at B3LYP/6-311++G(d,p)level to underst and the optical properties.展开更多
The molecular structure, the Natural Bond orbital (NBO) and the Time Dependent-DFT of both isomers cis or γ-Cl and trans or δ-Cl of RuCl2(L)2, where L stands respectively for 2-phenylazopyridine (Azpy), 2,4-dimethyl...The molecular structure, the Natural Bond orbital (NBO) and the Time Dependent-DFT of both isomers cis or γ-Cl and trans or δ-Cl of RuCl2(L)2, where L stands respectively for 2-phenylazopyridine (Azpy), 2,4-dimethyl-6-[phenylazo]pyridine (Dazpy), 2-[(3,5-dimethylphenyl)azopyridine] (Mazpy) and 2-pyridylazonaphtol (Nazpy) were calculated with DFT method at B3LYP/LANL2DZ level. The prediction of the frontier orbitals (Highest Occupied Molecular Orbital or HOMO and Lowest Unoccupied Molecular Orbital or LUMO) shows that the most active complexes suitable for electronic reactions are admitted to be the trans isomers. Moreover, δ-RuCl2 (Azpy)2 is discovered to react more actively as photo-sensitizer since its energy gap is the minimum. Besides, electronic structures of all complexes through NBO calculation indicate that Ru-N bonds are made of delocalization of occupancies from lone pair orbital of N atoms to the ruthenium. Moreover, Ru was assumed to have almost the same charge regardless the structure of the azopyridine ligands in the complex indicating that the ligands provide only a steric effect that is responsible for the ruthenium’s selectivity. Concerning the transition state, NBO analysis also highlights that the transition LP(Ru) π*(N1-N2) does correspond to t2g?π*(L). This transition is assumed to correspond to Metal to Ligand Charge Transfer (MLCT) that is responsible for the photo-sensitiveness of the metallic complex. Besides, TDDFT calculation of complexes showed that δ-RuCl2(Nazpy)2 displays the largest band during the absorption. For that reason, it is admitted to be the best photosensitizer due to a large system of conjugation provided by Nazpy ligand.展开更多
A theoretical study of the thermal decomposition kinetics of ethane halides（C2H6-nXn（n = 1～3）;X = F,Cl,Br） has been carried out at the B3LYP/6-31＋＋G＊＊ and B3PW91/631＋＋G＊＊ levels of theory.Among these meth...A theoretical study of the thermal decomposition kinetics of ethane halides（C2H6-nXn（n = 1～3）;X = F,Cl,Br） has been carried out at the B3LYP/6-31＋＋G＊＊ and B3PW91/631＋＋G＊＊ levels of theory.Among these methods and comparison of activation parameters with available experimental values,the B3PW91/6-31＋＋G＊＊ method is in good agreement with the experimental data.The analysis of bond order and natural bond orbital（NBO） charges,bond indexes,and synchronicity parameters suggest the elimination of HX in reactions 1～9（HF：compounds 1～3,HCl：compounds 4～6,and HBr：compounds 7～9） occur through a concerted and slightly asynchronous four-membered cyclic transition state type of mechanism.展开更多
Ab initio molecular orbital calculations have been used to investigate the thermal decomposition kinetics of 2-chloroethylethyldichlorosilane at the B3LYP/6-311＋G^＊＊,B3PW91/6-311＋G^＊＊,and MPW1PW91/6-311＋G^＊＊ ...Ab initio molecular orbital calculations have been used to investigate the thermal decomposition kinetics of 2-chloroethylethyldichlorosilane at the B3LYP/6-311＋G^＊＊,B3PW91/6-311＋G^＊＊,and MPW1PW91/6-311＋G^＊＊ levels of theory.Among these methods,the results（activation parameters） obtained using the B3LYP/6-311＋G＊＊ level are in good agreement with the available experimental data.The calculated data imply that in the unimolecular β-elimination reactions of the studied compound in the gas phase,the polarization of C（1）-Cl（3） and C（1）-H（4） bonds in the sense of C（1）^δ＋-Cl（3）^δ-and C（1）^δ＋-H（4）^δ-,respectively,is a determining factor in the gas phase elimination reactions 1,2 and 3.Analysis of bond order,natural bond orbital charges,bond indexes,synchro-nicity parameters,and IRC calculations suggest the elimination of 2-chloroethylethyldichlorosilane via reactions 1～3 can be described as concerted and slightly asynchronous.The transition state structures of these reactions are a four-membered cyclic structure.展开更多
酸性固色粉NBO是粉末型的高效酸性固色剂,可用冷水配制成30%~40%的溶液使用。酸性染料染色锦纶/氨纶混纺织物,经过酸性固色粉NBO固色,其耐皂洗色牢度、耐汗渍色牢度均能提高0.5~2.0级。用酸性荧光玫红Rhodamine B 400%测试酸性固色粉NB...酸性固色粉NBO是粉末型的高效酸性固色剂,可用冷水配制成30%~40%的溶液使用。酸性染料染色锦纶/氨纶混纺织物,经过酸性固色粉NBO固色,其耐皂洗色牢度、耐汗渍色牢度均能提高0.5~2.0级。用酸性荧光玫红Rhodamine B 400%测试酸性固色粉NBO对染色织物颜色的影响,结果显示:荧光玫红锦纶几乎没有色变;荧光玫红锦纶/氨纶混纺织物有轻微色变,但在可接受范围内。展开更多
The spectroscopic properties of the FT-IR and FT-Raman spectra of the 2-[(2,3-dimethylphenyl)amino]benzoic acid(DMPABA)compound have been recorded in the region 4 000~400cm^(-1).The molecular structure,vibrational wav...The spectroscopic properties of the FT-IR and FT-Raman spectra of the 2-[(2,3-dimethylphenyl)amino]benzoic acid(DMPABA)compound have been recorded in the region 4 000~400cm^(-1).The molecular structure,vibrational wavenumbers were calculated using DFT(B3LYP)method with 6-31G(d,p)and 6-311++G(d,p)basis sets.The Geometrical structure,vibrational frequencies,corresponding vibrational assignments of 2-[(2,3-dimethylphenyl)amino]benzoic acid(DMPABA)have been investigated experimentally and theoretically using Gaussian03 software package.The detailed Molecular orbital calculation such as Natural Bond Orbitals(NBO),Natural Population Analysis(NPA)and Mulliken analysis of atomic charges is also calculated.展开更多
The Fourier Transform Infrared and Raman spectra of the L-Alaninium oxalate(LAO)have been recorded and analyzed.The fundamental vibrational wave numbers intensities of vibrational bands and optirmized geometrical para...The Fourier Transform Infrared and Raman spectra of the L-Alaninium oxalate(LAO)have been recorded and analyzed.The fundamental vibrational wave numbers intensities of vibrational bands and optirmized geometrical parameters of the compound were evaluated using DFT(B3LYP)method with 6-31+-G(d,p)basis set.Natural Bond Orbital(NBO)and Natural Population Analysis(NPA)analysis for the LAO compound was carried out.Mulliken population analyses on atomic charges were also calculated.展开更多
The Molecular Structure of 4-Amino-3-phenylbutanoic acid conformers have been studied in the gas phase. Natural Bond Orbital Analysis(NBO) and Mulliken analysis of atomic charges of 4-Amino-3-phenylbutanoic acid have ...The Molecular Structure of 4-Amino-3-phenylbutanoic acid conformers have been studied in the gas phase. Natural Bond Orbital Analysis(NBO) and Mulliken analysis of atomic charges of 4-Amino-3-phenylbutanoic acid have been performed by DFT level of theory using B3 LYP/6-311++G(d,p) basis set. The atomic charges, electronic exchange interaction and charge delocalization of the molecule have been performed by Natural Bond Orbital(NBO) analysis and Natural Population Analysis(NPA) have been constructed at B3 LYP/6-311++G(d,p) level.展开更多
By using loading test and high temperature test, the electric-property stability of NbO anode and metal Nb anode werestudied in comparison. The reason for higher stability of NbO anode was analyzed by thermodynamics a...By using loading test and high temperature test, the electric-property stability of NbO anode and metal Nb anode werestudied in comparison. The reason for higher stability of NbO anode was analyzed by thermodynamics and kinetics. The loading teswas performed in 38% H2SO4 at 85 ℃ and 12 V for 10 d. The high temperature test was carried out at 250 ℃ in air atmosphere fo30 h. It is found that the NbO anode possesses higher ability to restrain crystallization film as compared with metal Nb anode. It isconsidered that, oxygen in NbO anode matrix restrains the migration of oxygen in Nb2O5 anodic oxidation film to matrix, and resultsin that the anodic oxidation film has higher stability.展开更多
In order to investigate the non-bonded interaction between picene and B12 N12 nano ring(BNNR) in different orientations and distances, we focused on a single-wall boronnitride B12 N12 nano-ring. The geometry of molecu...In order to investigate the non-bonded interaction between picene and B12 N12 nano ring(BNNR) in different orientations and distances, we focused on a single-wall boronnitride B12 N12 nano-ring. The geometry of molecules was optimized using the B3 LYP method with 6-31 g* basis set. The reactivity and stability of picene as an aromatic compound alone and upon exposure to BNNR were checked. Then NBO, FREQ, NICS and adsorption energy of picene alone and in the presence of BNNR Field were derived to estimate the picene structural stability.The results of any order were found to reduce the reactivity and increase the stability for picene in the presence BNNR field.展开更多
The structural,electronic and optical properties of KNbO 3 （KN）,NaNbO3（NN）and K05 Na0.5NbO3（KNN） in paraelectric cubic phase were calculated employing the plane-wave pseudopotential method based on density funct...The structural,electronic and optical properties of KNbO 3 （KN）,NaNbO3（NN）and K05 Na0.5NbO3（KNN） in paraelectric cubic phase were calculated employing the plane-wave pseudopotential method based on density functional theory （DFT）.The calculated electronic structures of the three crystals show similar features in the valence bands and the lower conduction bands.However,the structures in higher conduction bands differ markedly due to the effect of Na and K atoms.The calculated optical properties reveal that the features of optical spectrum at low energy are dominated by the transitions from O2p valence bands to Nb 4d conduction bands and those at high energy are related to the transitions to K 4s4p and/or Na 3s3p states.Moreover,the optical constants of KNN are approximately the average of KN and NN at high energy.Therefore,the optical properties of KNN in high energy region can probably be altered by changing the ratio of Na/K.展开更多
A theoretical study of the thermal decomposition kinetics of oxetane （1）, 2-methyloxetane （2）, and 2,2-dimethyloxetane （3） has been carried out at the B3LYP/6-311＋G＊＊, B3PW91/6-311＋G＊＊, and MPW1PW91/6-311...A theoretical study of the thermal decomposition kinetics of oxetane （1）, 2-methyloxetane （2）, and 2,2-dimethyloxetane （3） has been carried out at the B3LYP/6-311＋G＊＊, B3PW91/6-311＋G＊＊, and MPW1PW91/6-311＋G＊＊ levels of theory. The MPW1PW91/6-311＋G＊＊ method was found to give a reasonable good agreement with the experimental kinetics and thermodynamic parameters. The decomposition reaction of compounds 1～3 yields formaldehyde and the corresponding substituted olefin. Based on the optimized ground state geometries using MPW1PW91/6-311＋G＊＊ method, the natural bond orbital （NBO） analysis of donor-acceptor （bond-antibond） interactions revealed that the stabilization energies associated with the electronic delocalization from σC3-C4 bonding to σ＊O1-C2 antibonding orbitals decrease from compounds 1 to 3. The σC3-C4→σO1-C2 resonance energies for compounds 1～3 are 2.63, 2.59 and 2.45 kcal mol-1, respectively. Further, the results showed that the energy gaps between σC3-C4 bonding and σ＊O1-C2 antibonding orbitals decrease from compounds 1 to 3. Also, the decomposition process in these compounds are controlled by σ→σ＊ resonance energies. Moreover, the obtained order of energy barriers could be explained by the number of electron-releasing methyl groups substituted to the Csp3 atom （which is attached to oxygen atom）. NBO analysis shows that the occupancies of σCsp3-O bonds decrease for compounds 1～3 as 3〈2〈1, and those of σCsp3-O bonds increase in the opposite order （3 〉 2 〉 1）. This fact illustrates a comparatively easier thermal decomposition of the sCsp3-O bond in compound 3 compared to compound 2, and in compound 2 compared to compound 1. NBO results indicate that these reactions are occurring through a concerted and asynchronous four-membered cyclic transition state type of mechanism.展开更多
文摘The molecular structure of(1S,2R)-2-amino-1-phenylpropan^(-1)-ol(abbreviated as 2APPO)conformers have been studied in the gas phase.Natural Bond Orbital Analysis and Non Linear Optical properties of 2APPO have been performed by DFT level of theory using B3LYP/6-311++G(d,p)basis set.The atomic charges,electronic exchange interaction and charge delocalization of the molecule have been performed by Natural Bond Orbital(NBO)analysis,Natural Population Analysis(NPA) and Non Linear Optical(NLO)properties have been constructed at B3LYP/6-311++G(d,p)level to underst and the optical properties.
文摘The molecular structure, the Natural Bond orbital (NBO) and the Time Dependent-DFT of both isomers cis or γ-Cl and trans or δ-Cl of RuCl2(L)2, where L stands respectively for 2-phenylazopyridine (Azpy), 2,4-dimethyl-6-[phenylazo]pyridine (Dazpy), 2-[(3,5-dimethylphenyl)azopyridine] (Mazpy) and 2-pyridylazonaphtol (Nazpy) were calculated with DFT method at B3LYP/LANL2DZ level. The prediction of the frontier orbitals (Highest Occupied Molecular Orbital or HOMO and Lowest Unoccupied Molecular Orbital or LUMO) shows that the most active complexes suitable for electronic reactions are admitted to be the trans isomers. Moreover, δ-RuCl2 (Azpy)2 is discovered to react more actively as photo-sensitizer since its energy gap is the minimum. Besides, electronic structures of all complexes through NBO calculation indicate that Ru-N bonds are made of delocalization of occupancies from lone pair orbital of N atoms to the ruthenium. Moreover, Ru was assumed to have almost the same charge regardless the structure of the azopyridine ligands in the complex indicating that the ligands provide only a steric effect that is responsible for the ruthenium’s selectivity. Concerning the transition state, NBO analysis also highlights that the transition LP(Ru) π*(N1-N2) does correspond to t2g?π*(L). This transition is assumed to correspond to Metal to Ligand Charge Transfer (MLCT) that is responsible for the photo-sensitiveness of the metallic complex. Besides, TDDFT calculation of complexes showed that δ-RuCl2(Nazpy)2 displays the largest band during the absorption. For that reason, it is admitted to be the best photosensitizer due to a large system of conjugation provided by Nazpy ligand.
文摘A theoretical study of the thermal decomposition kinetics of ethane halides（C2H6-nXn（n = 1～3）;X = F,Cl,Br） has been carried out at the B3LYP/6-31＋＋G＊＊ and B3PW91/631＋＋G＊＊ levels of theory.Among these methods and comparison of activation parameters with available experimental values,the B3PW91/6-31＋＋G＊＊ method is in good agreement with the experimental data.The analysis of bond order and natural bond orbital（NBO） charges,bond indexes,and synchronicity parameters suggest the elimination of HX in reactions 1～9（HF：compounds 1～3,HCl：compounds 4～6,and HBr：compounds 7～9） occur through a concerted and slightly asynchronous four-membered cyclic transition state type of mechanism.
文摘Ab initio molecular orbital calculations have been used to investigate the thermal decomposition kinetics of 2-chloroethylethyldichlorosilane at the B3LYP/6-311＋G^＊＊,B3PW91/6-311＋G^＊＊,and MPW1PW91/6-311＋G^＊＊ levels of theory.Among these methods,the results（activation parameters） obtained using the B3LYP/6-311＋G＊＊ level are in good agreement with the available experimental data.The calculated data imply that in the unimolecular β-elimination reactions of the studied compound in the gas phase,the polarization of C（1）-Cl（3） and C（1）-H（4） bonds in the sense of C（1）^δ＋-Cl（3）^δ-and C（1）^δ＋-H（4）^δ-,respectively,is a determining factor in the gas phase elimination reactions 1,2 and 3.Analysis of bond order,natural bond orbital charges,bond indexes,synchro-nicity parameters,and IRC calculations suggest the elimination of 2-chloroethylethyldichlorosilane via reactions 1～3 can be described as concerted and slightly asynchronous.The transition state structures of these reactions are a four-membered cyclic structure.
文摘酸性固色粉NBO是粉末型的高效酸性固色剂,可用冷水配制成30%~40%的溶液使用。酸性染料染色锦纶/氨纶混纺织物,经过酸性固色粉NBO固色,其耐皂洗色牢度、耐汗渍色牢度均能提高0.5~2.0级。用酸性荧光玫红Rhodamine B 400%测试酸性固色粉NBO对染色织物颜色的影响,结果显示:荧光玫红锦纶几乎没有色变;荧光玫红锦纶/氨纶混纺织物有轻微色变,但在可接受范围内。
文摘The spectroscopic properties of the FT-IR and FT-Raman spectra of the 2-[(2,3-dimethylphenyl)amino]benzoic acid(DMPABA)compound have been recorded in the region 4 000~400cm^(-1).The molecular structure,vibrational wavenumbers were calculated using DFT(B3LYP)method with 6-31G(d,p)and 6-311++G(d,p)basis sets.The Geometrical structure,vibrational frequencies,corresponding vibrational assignments of 2-[(2,3-dimethylphenyl)amino]benzoic acid(DMPABA)have been investigated experimentally and theoretically using Gaussian03 software package.The detailed Molecular orbital calculation such as Natural Bond Orbitals(NBO),Natural Population Analysis(NPA)and Mulliken analysis of atomic charges is also calculated.
文摘The Fourier Transform Infrared and Raman spectra of the L-Alaninium oxalate(LAO)have been recorded and analyzed.The fundamental vibrational wave numbers intensities of vibrational bands and optirmized geometrical parameters of the compound were evaluated using DFT(B3LYP)method with 6-31+-G(d,p)basis set.Natural Bond Orbital(NBO)and Natural Population Analysis(NPA)analysis for the LAO compound was carried out.Mulliken population analyses on atomic charges were also calculated.
文摘The Molecular Structure of 4-Amino-3-phenylbutanoic acid conformers have been studied in the gas phase. Natural Bond Orbital Analysis(NBO) and Mulliken analysis of atomic charges of 4-Amino-3-phenylbutanoic acid have been performed by DFT level of theory using B3 LYP/6-311++G(d,p) basis set. The atomic charges, electronic exchange interaction and charge delocalization of the molecule have been performed by Natural Bond Orbital(NBO) analysis and Natural Population Analysis(NPA) have been constructed at B3 LYP/6-311++G(d,p) level.
文摘By using loading test and high temperature test, the electric-property stability of NbO anode and metal Nb anode werestudied in comparison. The reason for higher stability of NbO anode was analyzed by thermodynamics and kinetics. The loading teswas performed in 38% H2SO4 at 85 ℃ and 12 V for 10 d. The high temperature test was carried out at 250 ℃ in air atmosphere fo30 h. It is found that the NbO anode possesses higher ability to restrain crystallization film as compared with metal Nb anode. It isconsidered that, oxygen in NbO anode matrix restrains the migration of oxygen in Nb2O5 anodic oxidation film to matrix, and resultsin that the anodic oxidation film has higher stability.
基金supported by the Islamic Azad University of Islamshahr
文摘In order to investigate the non-bonded interaction between picene and B12 N12 nano ring(BNNR) in different orientations and distances, we focused on a single-wall boronnitride B12 N12 nano-ring. The geometry of molecules was optimized using the B3 LYP method with 6-31 g* basis set. The reactivity and stability of picene as an aromatic compound alone and upon exposure to BNNR were checked. Then NBO, FREQ, NICS and adsorption energy of picene alone and in the presence of BNNR Field were derived to estimate the picene structural stability.The results of any order were found to reduce the reactivity and increase the stability for picene in the presence BNNR field.
基金Supported by the National Natural Science Foundation of China (Nos. 50862005,51062005,91022034 and 91022027)the Jiangxi Natural Science Foundation and Cooperative Project (Nos. 2008GZC000,2009JX02060,2010GQW0038 and [2008]212)+1 种基金Foundation of Jiangxi Educational Committee (GJJ11204)the Jiangxi Colleges and Universities "Advanced Ceramics" scientific and technological innovation team
文摘The structural,electronic and optical properties of KNbO 3 （KN）,NaNbO3（NN）and K05 Na0.5NbO3（KNN） in paraelectric cubic phase were calculated employing the plane-wave pseudopotential method based on density functional theory （DFT）.The calculated electronic structures of the three crystals show similar features in the valence bands and the lower conduction bands.However,the structures in higher conduction bands differ markedly due to the effect of Na and K atoms.The calculated optical properties reveal that the features of optical spectrum at low energy are dominated by the transitions from O2p valence bands to Nb 4d conduction bands and those at high energy are related to the transitions to K 4s4p and/or Na 3s3p states.Moreover,the optical constants of KNN are approximately the average of KN and NN at high energy.Therefore,the optical properties of KNN in high energy region can probably be altered by changing the ratio of Na/K.
文摘A theoretical study of the thermal decomposition kinetics of oxetane （1）, 2-methyloxetane （2）, and 2,2-dimethyloxetane （3） has been carried out at the B3LYP/6-311＋G＊＊, B3PW91/6-311＋G＊＊, and MPW1PW91/6-311＋G＊＊ levels of theory. The MPW1PW91/6-311＋G＊＊ method was found to give a reasonable good agreement with the experimental kinetics and thermodynamic parameters. The decomposition reaction of compounds 1～3 yields formaldehyde and the corresponding substituted olefin. Based on the optimized ground state geometries using MPW1PW91/6-311＋G＊＊ method, the natural bond orbital （NBO） analysis of donor-acceptor （bond-antibond） interactions revealed that the stabilization energies associated with the electronic delocalization from σC3-C4 bonding to σ＊O1-C2 antibonding orbitals decrease from compounds 1 to 3. The σC3-C4→σO1-C2 resonance energies for compounds 1～3 are 2.63, 2.59 and 2.45 kcal mol-1, respectively. Further, the results showed that the energy gaps between σC3-C4 bonding and σ＊O1-C2 antibonding orbitals decrease from compounds 1 to 3. Also, the decomposition process in these compounds are controlled by σ→σ＊ resonance energies. Moreover, the obtained order of energy barriers could be explained by the number of electron-releasing methyl groups substituted to the Csp3 atom （which is attached to oxygen atom）. NBO analysis shows that the occupancies of σCsp3-O bonds decrease for compounds 1～3 as 3〈2〈1, and those of σCsp3-O bonds increase in the opposite order （3 〉 2 〉 1）. This fact illustrates a comparatively easier thermal decomposition of the sCsp3-O bond in compound 3 compared to compound 2, and in compound 2 compared to compound 1. NBO results indicate that these reactions are occurring through a concerted and asynchronous four-membered cyclic transition state type of mechanism.
