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Photophysical Properties of Perylenetetracarboxylic Diimide Dimers with Slipped “Face-to-Face” Stacked Structure and Different Bay Substitutions
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作者 Heyuan Liu Xiyou Li 《Journal of Materials Science and Chemical Engineering》 2016年第6期1-8,共8页
A series of perylenetetracarboxylic diimides (PDIs) dimers with slipped “face-to-face” stacked structure and different substituents at the bay positions have been synthesized and the molecular structures are charact... A series of perylenetetracarboxylic diimides (PDIs) dimers with slipped “face-to-face” stacked structure and different substituents at the bay positions have been synthesized and the molecular structures are characterized by 1H NMR, MALDI-TOF and elemental analysis. And different substituents at the bay positions of the PDI ring bring about various steric hindrances. These different steric hindrances have caused significant differences on the absorption and emission spectra. The correlation between the photophysical properties and the molecular structure is discussed. 展开更多
关键词 Slip-stacked dimers PDI Photophysical-Properties
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采用量子力学方法研究带正电氨基酸分子复合物间非键作用的强度
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作者 王一博 孙瑞鸿 +1 位作者 王长生 王磊 《化学研究》 CAS 2024年第1期61-67,共7页
非键作用是自然界中广泛存在的分子间作用,参与到生命体中最基本的蛋白质与核酸的相互作用等过程。该过程以氨基酸侧链与碱基的相互作用为主,因此准确预测氨基酸侧链与碱基等生物分子的相互作用具有十分重要的科学意义。选用量子力学方... 非键作用是自然界中广泛存在的分子间作用,参与到生命体中最基本的蛋白质与核酸的相互作用等过程。该过程以氨基酸侧链与碱基的相互作用为主,因此准确预测氨基酸侧链与碱基等生物分子的相互作用具有十分重要的科学意义。选用量子力学方法计算了15个含氨基酸侧链的带正电堆积复合物的相互作用能,并与CCSD(T)/CBS方法计算结果进行比较。计算结果表明,SCS-CCSD/CBS方法的均方根偏差为0.06 kcal/mol,线性相关系数为0.999 8;SCS-MI-CCSD/CBS方法的均方根偏差为0.11 kcal/mol,线性相关系数为0.999 9;MP2.5/CBS方法的均方根偏差为0.13 kcal/mol,线性相关系数为0.999 3,验证了上述方法的可靠性。而后进一步使用MP2.5/CBS方法计算精氨酸、组氨酸和赖氨酸侧链与中性分子形成堆积复合物在不同距离下的相互作用能,进而构建并完善了带正电氨基酸分子与中性分子间非键作用强度的标准数据。 展开更多
关键词 非键作用 量子力学方法 堆积复合物 氨基酸侧链
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π-Pimer,π-Dimer,π-Trimer,and 1Dπ-Stacks in a Series of Benzene Triimide Radical Anions:Substituent-Modulated π Interactions and Physical Properties in Crystalline State
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作者 De-Hui Tuo Shuxuan Tang +6 位作者 Pengfei Jin Jikun Li Xinping Wang Chuang Zhang Yu-Fei Ao Qi-Qiang Wang De-Xian Wang 《CCS Chemistry》 CSCD 2023年第6期1343-1352,共10页
We herein present the efficient syntheses,crystal structures,and physical properties of a series of novel benzene triimide(BTI)radical anions,emphasizing the relationship between molecular structure with spin–spin in... We herein present the efficient syntheses,crystal structures,and physical properties of a series of novel benzene triimide(BTI)radical anions,emphasizing the relationship between molecular structure with spin–spin intermolecular interactions and physical properties in the crystalline state.BTI radical crystals were preparedby reducingvarious substitutedBTIs(1)with cobaltocene(CoCp2),followed by sequential crystallization processes.Two isolable radical species,that is,neutral molecule-radical anion pair(2)and monoradical species(3),were obtained from BTIs bearing small substituents(ethyl and propyl),while for those bearing larger substituents(butyl,hexyl,and benzyl)sole monoradicals(3)were produced.The radical species showed diverse intermolecular stackings in the crystalline state referred to asπ-pimer,π-dimer,alternatingπ-trimer,and one-dimensional(1D)slippedπ-stacks depending on the length and size of the substituents.Different spin–spin interactions arising from the substituent-tuned radical packings were demonstrated by electron spin resonance(ESR)spectra.The structure–property relationshipwas studied in terms of magnetism and conductivity.The radicalπ-pimers andπ-stacks with effective charge transport exhibited paramagnetic property and conductivity feasibly at room temperature,whileπ-dimers andπ-trimers featuring thermally populated spin-triplet stateswere antiferromagnetic and nonconductive due to their strong radical–radical pairing effect. 展开更多
关键词 radical pimer radical dimer anion radical benzene triimide π-πstacking
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ZnSe/GaAs赝共格外延层中二聚体诱发的位错
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作者 冯国光 王宁 苏荫强 《电子显微学报》 CAS CSCD 1996年第2期191-199,共9页
在ZnSe/GaAs外延层中观察到完全的和不完全的层错四面棱锥体,层错梯形和层错管。本文提出一个模型:虽然这些层错的几何形状不同,但它们都起始于同一个源-界面处Se二聚体链构成的矩形环。此模型可以解释所有这些层错的组态。本文还指出... 在ZnSe/GaAs外延层中观察到完全的和不完全的层错四面棱锥体,层错梯形和层错管。本文提出一个模型:虽然这些层错的几何形状不同,但它们都起始于同一个源-界面处Se二聚体链构成的矩形环。此模型可以解释所有这些层错的组态。本文还指出这些抽出和插入型层错(尤其是层错管)的张应力和压应力对外延层退化过程中间隙原子或空位的扩散可能起着重要的作用。 展开更多
关键词 二聚体 层错 梯杆位错 外延层 外延生长 半导体
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Synthesis and Crystal Structure of N-Benzyl-N'-(2-pyridyl)urea and Its Mononuclear Cu(Ⅱ) Complex
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作者 何磊 罗晓兰 张文勤 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第11期1384-1388,共5页
A new ligand of N-benzyl-N'-(2-pyridyl)urea L and its self-assembly product with CuCl2, [Cu(Ⅱ)LCl2]∞ 1, have been synthesized and structurally characterized by IR, 1H NMR and single-crystal X-ray diffraction an... A new ligand of N-benzyl-N'-(2-pyridyl)urea L and its self-assembly product with CuCl2, [Cu(Ⅱ)LCl2]∞ 1, have been synthesized and structurally characterized by IR, 1H NMR and single-crystal X-ray diffraction analysis. In the structure of L, the urea groups adopt Z,E conformation to form dimers through intermolecular hydrogen bonds; while in complex 1, it assumes Z,Z conformation to fit for the coordination sphere of the Cu(Ⅱ) ions. The coordinated units are connected through intermolecular N-H...Cl hydrogen bonds to form an extended 2D framework. Finally, a 3D structure is obtained via π-π stacking interactions between pyridyl rings 展开更多
关键词 self-assembly dimerIZATION hydrogen bonds π-π stacking interactions
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核酸碱基的非谐性振动:Ⅲ,DNA叠加二聚体的一维和二维红外光谱
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作者 王桂秀 王建平 《化学学报》 SCIE CAS CSCD 北大核心 2012年第4期411-422,共12页
用量子化学计算方法研究了DNA碱基单体及其15个B型和2个G-四链体的叠加二聚体的非谐性振动光谱特征.研究发现,从碱基单体到二聚体,C=O伸缩模式之间的相互作用很强,表现在其非谐性振动频率和非谐性常数都发生了明显的改变,特别是在含碱基... 用量子化学计算方法研究了DNA碱基单体及其15个B型和2个G-四链体的叠加二聚体的非谐性振动光谱特征.研究发现,从碱基单体到二聚体,C=O伸缩模式之间的相互作用很强,表现在其非谐性振动频率和非谐性常数都发生了明显的改变,特别是在含碱基G的叠加体中.这些变化能在一维和二维红外光谱中很好地表现出来.利用振动模式的势能分布和非谐性常数的组成分析,讨论了叠加二聚体中C=O模式的离域化程度. 展开更多
关键词 量子化学计算 B型DNA叠加二聚体 G-四链体叠加二聚体 非谐性频率 非谐性常数
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