An experimental and computational study of intramolecular charge transfer: Diarylamino derivatives of 7H-benzimidazo(2,1-a)benz(d,e)isoquinolin-7-ones

A novel intramolecular donor–acceptor system of four isomers consisting of 7H-benzimidazo(2,1-a)benz(d,e)isoquinolin-7-ones and diarylamine units was synthesized and characterized; the absorption and fluorescence spectra of the system in a variety of solvents were investigated. Intramolecular charge transfer was confirmed within the system by virtue of shifts in emission maximum with increasing solvent polarity; a high dipole moment for the intramolecular excited state was calculated using the Lippert equation. Shorter lifetimes were observed in polar solvents compared with those in non-polar solvents, indicating strong dipole–dipole interactions occurred. The ground-state geometry, lowest energy transition and the UV–vis spectrum of the system were studied using density functional theory and time-dependent density functional theory at B3LYP/6-31G^* level, which showed that the calculated outcomes were in good agreement with experimental data.     

碳的线型同素异形体-卡宾(Carbyne)研究进展

介绍了卡宾（Ｃａｒｂｙｎｅ）的发现及研究史，评述了其合成、结构的研究进展。     

Hardness, isomer shifts and chemical bond properties of rare earth orthoferrites

The chemical bond parameters of the rare earth iron orthoferrites were calculated using the chemical bond dielectric theory of complex structural crystals. The environment factor defined by electron polarizabilities and covalency was employed to calculate Mossbauer isomer shift of REFeO₃. The calculated isomer shift of YFeO₃ was in agreement with its measurement value. The hardness of YFeO₃ was predicted, which is also in agreement with the experimental value.     

Isomer separation of Cu and Cu with a resonance ionization laser ion source

Radioactive copper isotopes were ionized with the resonance ionization laser ion source (RILIS) at the on-line isotope separator ISOLDE (CERN). Using the different hyperfine structure in the 3d¹⁰ 4s  ²S_1/2 – 3d¹⁰ 4p  ²P⁰_1/2 transition the low- and high-spin isomers of ⁷⁰Cu were selectively enhanced by tuning the laser wavelength. The light was provided by a narrow-bandwidth dye laser pumped by copper vapor lasers (CVL) and frequency doubled in a BBO crystal. The ground state to isomeric state intensity ratio could be varied by a factor of 30, allowing to assign gamma transitions unambiguously to the decay of the individual isomers. It is shown that the method can also be used to determine magnetic moments. In a first experiment for the 1⁺ ground state of ⁷⁰Cu a magnetic moment of (+)1.8(3) μ_N and for the high-spin isomer of ⁷⁰Cu a magnetic moment of (±)1.2(3) μ_N could be deduced.     

塔西南坳陷下奥陶统风化壳中地开石的发现及其意义

地开石发育状况直接反映了地开石形成时储集层溶蚀孔隙发育、连通程度和上覆地层的温度条件,因而研究地开石对油气勘探有着重要的意义.我国仅在陕甘宁盆地、塔里木盆地下奥陶统风化壳白云岩溶蚀孔中发现地开石,塔里木盆地地开石的发现表明,塔里木盆地西部,尤其是巴楚—麦盖提地区的下奥陶统风化壳是寻找天然气聚集的最有利地区.     

A zirconium-containing sandwich-type dimer based on trivacant α- and β-[GeW9O34] units, [Zr3O(OH)2(α-GeW9O34)(β-GeW9O34)]

A new zirconium-containing sandwich-type dimer based on trivacant α- and β-[GeW₉O₃₄]¹⁰⁻ units, [Zr₃O(OH)₂(α-GeW₉O₃₄)(β-GeW₉O₃₄)]¹²⁻, was synthesized and characterized by IR spectroscopy, UV electronic spectroscopy and single crystal X-ray diffraction. The central bent of the polyanion contains three oxygen atoms alternating with the three zirconium atoms. The polyanion represents a rare example of the sandwich POMs containing two different isomer subunits.     

硝酸—硫酸—磷酸体系中氯苯的选择性硝化

研究了在硝酸—硫酸—磷酸体系中氯苯的选择性硝化反应,实验表明,80℃时,在适当比例的硝酸—硫酸—磷酸体系中,氯苯—硝化产物中邻对比可达0.87,产物得率达97％以上。     

甲醇同系列异构体数目的计算机求法

本文使用查询计算的方法,给出了甲醇同系列异构体数目的计算机求法。计算了碳原子数目为85以下的甲醇同系列同分异构体的数目。计算精度为36 bits。     

高压液相色谱分析并纯化[6,7-~3H]雌酚酮

[6,7-~H]雌酚酮与其原料[6,7]脱氢雌酚酮结构相近,分离困难。在YWG-NH_2柱上,流动相为无水乙醇/已烧,紫外波长280 nm,液闪剂为PPO时,对[6,7-~H]雌酚酮进行了色谱分析和放化纯分析。分析时间不超过10 min,测量精度约0.7%,最小检出量为10~(-7)和10~(-10)Ci。当流动相为异丙酵/环已烧时,对氚标记后未经层析纯化的样品进行了分离纯化,分离纯化时间不到35 min,纯化的[6,7-~3H]雌酚酮的放化纯为99%,测量精度为0.1%。     

胆甾型冠醚液晶固定相分离丁醇碳链异构体的GC研究

以４‘－胆甾烯氧羰基苯并－１５－冠－５（ＣＨ－Ｂ－１５－Ｃ－５）涂渍于硅烷化１０２白色担体上作为一种新型的ＧＣ固定相，对几种丁醇碳链异构体的气固色谱，普通气流色谱和冠醚液晶气液色谱的分离效果进行了比较研究，并探讨了分离机理。