Journal of Molecular Structure-theochem最新文献_第10页

The role of tautomerization in acetylacetone as a complexing agent: Theoretical perspectives 在络合剂乙酰丙酮中互变异构化的作用:理论观点

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.07.013

Aned de Leon , M.C. Acosta-Enríquez , Abraham F. Jalbout , A. Apolinar-Iribe , S.J. Castillo

引用次数: 2

Theoretical study on the nonlinear optical properties of donor/acceptor-functionalized trigonal dehydrobenzoannulenes 供体/受体功能化三角区脱氢苯环烯非线性光学性质的理论研究

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.07.001

Ming-Xue Li , Kui Han , Hai-Peng Li , Yang Ge , Qiong-Hua Wu , Gang Tang , Yu-xi Wu

引用次数: 9

Density functional theory for N–O bond dissociation enthalpies of quinoxaline-1,4-dioxide derivatives: Theoretical method assessment and prediction 喹诺啉-1,4-二氧化物衍生物N-O键解离焓的密度泛函理论:理论方法评估和预测

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.07.002

Jiaheng Zhang , Wenfeng Zhou , Bing Peng , Suxia Zhang , Haixiang Gao , Zhiqiang Zhou

引用次数: 3

Structural, electronic, and magnetic properties of FenOm+ (n + m = 5) clusters FenOm+ (n + m = 5)簇的结构、电子和磁性能

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.06.032

Ben-Fu Xu, Chuan-Lu Yang, Mei-Shan Wang, Xiao-Guang Ma

引用次数: 7

Theoretical studies on the spectral and DNA-photocleavage properties of Co(III) and Ru(II) polypyridyl complexes Co(III)和Ru(II)多吡啶配合物的光谱和dna光裂解性质的理论研究

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.07.017

Ti-Fang Miao , Jun Li , Si-Yan Liao , Juan Mei , Kang-Cheng Zheng

{"title":"Theoretical studies on the spectral and DNA-photocleavage properties of Co(III) and Ru(II) polypyridyl complexes","authors":"Ti-Fang Miao , Jun Li , Si-Yan Liao , Juan Mei , Kang-Cheng Zheng","doi":"10.1016/j.theochem.2010.07.017","DOIUrl":"10.1016/j.theochem.2010.07.017","url":null,"abstract":"<div>Theoretical studies on the spectral and DNA-photocleavage properties of Co(III) and Ru(II) polypyridyl complexes [M(phen)2(pyip)]n+ (M=Co(III) and Ru(II), n  <!-->3 and 2, respectively) have been carried out, using DFT, HF and CIS methods. The electronic absorption spectra of the two complexes were calculated and simulated using TDDFT and CPCM model. The calculated results show that both the geometric structure and spectra of the Co(III) complex are greatly affected by the solvent effect, whereas those of the Ru(II) complex are affected only slightly by the solvent effect. The calculated and simulated spectra of these complexes in solution are in satisfying agreement with experimental ones, and the characters of the interested spectral bands are deeply discussed. In addition, the photo-induced oxidation–reduction mechanisms on the DNA-photocleavage by Co(Ш) and Ru(II) polypyridyl complexes are also preliminarily explained in theory.</div>","PeriodicalId":16419,"journal":{"name":"Journal of Molecular Structure-theochem","volume":"957 1","pages":"Pages 108-113"},"PeriodicalIF":0.0,"publicationDate":"2010-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.theochem.2010.07.017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75315624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

van der Waals interactions in sterically crowded disilenes 空间拥挤二原子中的范德华相互作用

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.07.006

Wolfgang W. Schoeller

{"title":"van der Waals interactions in sterically crowded disilenes","authors":"Wolfgang W. Schoeller","doi":"10.1016/j.theochem.2010.07.006","DOIUrl":"10.1016/j.theochem.2010.07.006","url":null,"abstract":"<div>Since double bonded systems constituted by higher main group elements are necessarily substituted by bulky substituents, in order to protect these structures kinetically, van der Waals interactions are dominant on the resulting bonding energies. This aspect, studied in detail with different density functional methods for a variety of selected disilenes, is compared with the results of MP2 calculations. Throughout a triple-ζ basis set was used, in order to allow flexible bonding. The bonding energies in the disilenes were characterized by dissociation into singlet silylenes. For the parent disilene the equilibrium was studied in addition with CCSD calculations utilizing Dunning type basis sets. The corrections for dispersion energies on the functionals BP86, PBE, and B3LYP were at times evaluated according to the Grimme approach, and the results compared with the refit double-hybrid functional BP97-D and MP2. They are sizable for the bulky systems. The only known case of reversible silylene–disilene in equilibrium is studied too. This silylene is known in a cis or trans conformation, with a stronger steric stronger congestion in the cis geometry. The dispersion corrections on stability favor to more extent the more encumbered geometries. Overall the calculations indicate that the traditional density functionals, like B3LYP or BP86 are not capable to describe properly the bulky molecular structures.</div>","PeriodicalId":16419,"journal":{"name":"Journal of Molecular Structure-theochem","volume":"957 1","pages":"Pages 66-71"},"PeriodicalIF":0.0,"publicationDate":"2010-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.theochem.2010.07.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88072726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

The spectroscopic, NMR analysis of 1-(2,6-Dichloro-4-nitrophenyl)-5-amino-4-cyanopyrazole by ab initio HF and density functional methods 用从头算HF和密度泛函方法对1-(2,6-二氯-4-硝基苯基)-5-氨基-4-氰吡唑进行了光谱、核磁共振分析

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.06.025

Li Xiao-Hong , Zhang Xian-Zhou

引用次数: 1

Computational optimum conditions for FOX-7 synthesis – A comparative synthesis route FOX-7合成的计算最优条件-比较合成路线

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.06.026

Ken-Fa Cheng, Min-Hsien Liu, Cheng Chen, Yaw-Sun Hong

{"title":"Computational optimum conditions for FOX-7 synthesis – A comparative synthesis route","authors":"Ken-Fa Cheng, Min-Hsien Liu, Cheng Chen, Yaw-Sun Hong","doi":"10.1016/j.theochem.2010.06.026","DOIUrl":"10.1016/j.theochem.2010.06.026","url":null,"abstract":"<div>1,1-Diamino-2,2-dinitroethene (FOX-7) was theoretically synthesized in both aqueous and gaseous environment in this study, based on experience of experimental methods, from 2-methylimidazole via oxidation followed by nitration and aminolysis. Reaction routes closely related to experimental processes were successfully constructed, and the corresponding kinetic rate constants and energy barriers were estimated for each elementary reaction. Furthermore, other reaction conditions that are distinct from those reported in the literature (including the use of a solvated oxidative reaction system, the replacement of nitrating agent HNO3 by N2O5, and the adoption of cupric oxide or ferrous oxide catalysts for aminolysis) were employed in the corresponding reaction systems. The modeling results suggest that water is a good medium for the oxidation reaction, N2O5 is the better agent for nitration, and ferrous oxide is a suitable catalyst for aminolysis in hydrated systems. In contrast with the computed activation energies of the experimental routes, the comparable data estimates throughout the reaction stages were considered to imply more feasible pathways for FOX-7 synthesis.</div>","PeriodicalId":16419,"journal":{"name":"Journal of Molecular Structure-theochem","volume":"957 1","pages":"Pages 6-14"},"PeriodicalIF":0.0,"publicationDate":"2010-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.theochem.2010.06.026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88858286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Natural bond orbital (NBO) population analysis of some benzyl nitrites 几种亚苄基亚硝酸盐的天然键轨道(NBO)居群分析

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.07.005

Li Xiao-Hong , Yin Geng-Xin , Zhang Xian-Zhou

{"title":"Natural bond orbital (NBO) population analysis of some benzyl nitrites","authors":"Li Xiao-Hong , Yin Geng-Xin , Zhang Xian-Zhou","doi":"10.1016/j.theochem.2010.07.005","DOIUrl":"10.1016/j.theochem.2010.07.005","url":null,"abstract":"<div>Theoretical study of several benzyl nitrites have been performed using quantum computational ab initio RHF and density functional B3LYP and B3PW91 methods with 6-31G∗∗ basis set. Geometries obtained from DFT calculations were used to perform NBO analysis. It is noted that weakness in the O3–N2 sigma bond is due to <math><mrow><msub><mrow><mi>n</mi></mrow><mrow><mtext>O</mtext><mn>1</mn></mrow></msub><mo>→</mo><msubsup><mrow><mi>σ</mi></mrow><mrow><mtext>O</mtext><mn>3</mn><ms>–</ms><mtext>N</mtext><mn>2</mn></mrow><mrow><mo>∗</mo></mrow></msubsup></mrow></math> delocalisation and is responsible for the longer O3–N2 bond lengths in the selected benzyl nitrites. It is also noted that decreased occupancy of the localized <math><mrow><msub><mrow><mi>σ</mi></mrow><mrow><mtext>O</mtext><mn>3</mn><ms>–</ms><mtext>N</mtext><mn>2</mn></mrow></msub></mrow></math> orbital in the idealized Lewis structure, or increased occupancy of <math><mrow><msubsup><mrow><mi>σ</mi></mrow><mrow><mtext>O</mtext><mn>3</mn><ms>–</ms><mtext>N</mtext><mn>2</mn></mrow><mrow><mo>∗</mo></mrow></msubsup></mrow></math> of the non-Lewis orbital, and their subsequent impact on molecular stability and geometry (bond lengths) are related with the resulting p character of the corresponding sulfur natural hybrid orbital (NHO) of <math><mrow><msub><mrow><mi>σ</mi></mrow><mrow><mtext>O</mtext><mn>3</mn><ms>–</ms><mtext>N</mtext><mn>2</mn></mrow></msub></mrow></math> bond orbital. In addition, the charge transfer energy decreases with the increasing of the Hammett constants of substituent groups.</div>","PeriodicalId":16419,"journal":{"name":"Journal of Molecular Structure-theochem","volume":"957 1","pages":"Pages 61-65"},"PeriodicalIF":0.0,"publicationDate":"2010-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.theochem.2010.07.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75470924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Structure and vibrational spectra of sulfur hexafluoride encapsulated α-cyclodextrin 六氟化硫包封α-环糊精的结构与振动谱

Journal of Molecular Structure-theochem Pub Date : 2010-10-15 DOI: 10.1016/j.theochem.2010.07.010

Rahul V. Pinjari, Vivekanand V. Gobre, Shridhar P. Gejji

{"title":"Structure and vibrational spectra of sulfur hexafluoride encapsulated α-cyclodextrin","authors":"Rahul V. Pinjari, Vivekanand V. Gobre, Shridhar P. Gejji","doi":"10.1016/j.theochem.2010.07.010","DOIUrl":"10.1016/j.theochem.2010.07.010","url":null,"abstract":"<div>Density functional calculations have been utilized to understand the interactions of sulfur hexafluoride (SF6) with α-cyclodextrin (α-CD) host. An encapsulation of SF6 (guest) within the host cavity and its binding to primary as well as secondary hydroxyl rims of α-CD exhibiting different hydrogen bonding patterns have been analyzed. The present calculations have shown that interactions between the guest and protons within the host cavity yield the minimum energy complex wherein guest penetrates from secondary hydroxyl end of the host. Calculated vibrational spectra reveal frequency downshift of S–F stretching in the guest molecule on complexation. Frequency shift in opposite direction has been noticed for O–H vibrations of secondary hydroxyls of the host those facilitate relatively strong hydrogen bonded interactions. These inferences have been supported by mapping difference molecular electron density on the bond critical points in molecular electron density topography. The electronic structure and vibrational spectra derived from the density functional calculations based on the B3LYP and the X3LYP functional are similar. Use of X3LYP functional however, predicts shortening of O6H⋯O6′ as well as CH⋯F hydrogen bonds and thus points to the strengthened host–guest interactions and in turn binding energies of SF6 within these complexes employing the X3LYP functional turn out to be nearly ∼35–40% higher compared to those obtained within the framework of B3LYP theory.</div>","PeriodicalId":16419,"journal":{"name":"Journal of Molecular Structure-theochem","volume":"957 1","pages":"Pages 77-83"},"PeriodicalIF":0.0,"publicationDate":"2010-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.theochem.2010.07.010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73322830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2