对硝基甲苯的同步辐射光电离研究

光电离对硝基甲苯（PNT）可获得其电离势及碎片离子的出现势，并由此推断出离子产生的可能通道．目前尚未见到有关PNT光电离研究的报道，仅George等［‘j使用电子轰击电离质谱测得过它的电离势．我们使用同步辐射光电离质谱测得了PNT的电离势和8种碎片离子的出现势，给出了飞行时间（TOF）质谱图，归属了质谱中的主要离子峰，初步分析了光解离电离通道．1实验部分实验装置由阈值光电子一光离子符合（TPEPICO）装置改造而成［’，’］，光电离室上方的四极质谱计由TOF质谱计代替，下方的四极质谱计由盛固体样品的小炉取代．样品蒸…     

Some remarks on the periodical change of the stability constants of the lanthanide complexes

The correlations between the values of the lgK (K = stability constant of the lanthanide complex) and the reciprocal of the ionic radius 1/r or the sum of the ionization potentials ₁ ³ I for the lanthanide ions were reviewed for different ligands. A straight-line relationship (lgK – lgK)/lgK vs. (1/r – 1/r)/(1/r) or vs. ( ₁ ³ I – ₁ ³ I)/ ₁ ³ I was found within the tetrads La-Nd, Gd-Ho, and Er-Lu.

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Bemerkungen zum periodischen Wechsel der Stabilitätskonstanten von Lanthaniden-Komplexen

Zusammenfassung Es wurde eine Übersicht der Korrelationen zwischen den Werten von logK (K = Stabilitätskonstante der Lanthanidenkomplexe) und den reziproken Ionenradien 1/r oder der Summe der Ionisierungspotentiale ₁ ³ I für die Lanthanidenionen für verschiedene Liganden gegeben. Dabei wurde eine lineare Korrelation für (lgK – lgK)/lgK gegen (1/r – 1/r)/(1/r) oder gegen ( ₁ ³ I – ₁ ³ I)/_1/3 I innerhalb der Tetraden La-Nd, Gd-Ho und Er-Lu aufgefunden.

     

线性簇合物SC2nS2－(n =1～12)电子吸收光谱

应用密度泛函理论,在B3LYP/6-31G*水平上优化了线性簇合物SC2nS2－(n =1～12)的基态平衡几何结构,并计算了它们的谐振动频率.在基态平衡构型下,通过TD-B3LYP/cc-pvTZ和TD-B3LYP/cc-pvDZ计算,确定了簇合物SC2nS2－(n =1～10) 电子跃迁的垂直激发能和对应的振子强度.基于计算结果,导出了电子跃迁吸收波长与体系大小n的解析关系式,以及SC2nS2－体系第一电离能与体系大小n的解析表达式,并讨论了不同端位原子对碳链体系激发态性质的影响.     

High resolution recycle gas chromatography with off-line flame ionization detection

Preliminary results of a recycle system employing fused silica capillary columns are discussed. The unit, which can be operated with a pre-column for multidimensional GC, utilizes continuous stream splitting for off-line flame ionization detection. Commercially available rotary valves were used for recirculation of the chromatographic zone between column loops. Adsorptive activity, which is shown to be additive, is a serious limitation in the analysis of polar compounds. The successful application of recycle chromatography to increase resolution on non-polar mixtures is demonstrated.     

聚芴类发光材料合成中间体的质谱分析

利用电喷雾电离（ESI）质谱－质谱（MS－MS）技术，分析了新化合物2，7－双（4，4，5，5－四甲基－1，3，2－二氧杂硼烷－2－基）－9，9－二辛基芴的EI和ESI的质谱，确认了该谱图中母离子和子离子的关系，讨论了其碎裂途径，为其结构鉴定提供了依据。     

CFCl3的理论和紫外光电子能谱研究

采用紫外光电子能谱(PES)和量子化学方法,研究了以CFCl3化合物为代表的系列化合物(CFCl3、CF2Cl2、CF3Cl、CCl4)不同离子态的电子结构和性质。结果表明,四种化合物CF3Cl、CF2Cl2、CFCl3、CCl4的第一电离能依次下降。结合从头算自洽场分子轨道(abinitioSCFMO)和外壳层格林函数法(OVGF)计算对化合物的PES进行了分析和指认,表明化合物的外层轨道中Cl的孤对电子成分对电离能存在明显的影响;外层格林函数法计算得到电离能与实验吻合很好;同时发现在外壳层格林函数法计算结果中由于考虑相关能,得到的分子轨道存在能级顺序的交错。     

Theoretical investigation on the GaH molecule and its positive ion

The gallium monohydride (GaH) molecule and its positive ion were theoretically investigated by abinitio molecular orbital calculations with a flexible basis set including g-type functions on the Ga atom. Electron correlations among not only the valence electrons of Ga 4s4p and H 1s but also the semi-core electrons of Ga 3d were incorporated by a size-consistent scheme of the coupled pair approximation. The contribution of the 3d electron correlation was found to be considerable on spectroscopic constants of both GaH and GaH⁺, especially on the bond length. Received: 25 July 1997 / Accepted: 13 November 1997     

Muttiphoton Ionization of Benzene-Ammonia Clusters: Intracluster Reaction and Cluster Ion Stability

Neutral benzene-ammonia clusters, prepared in a supersonic expansion, were ionized using multiphoton ionization. The cluster ions were investigated with a time-of-flight mass spectrometer. The observed major cluster ions, under 355-nm laser irradiation, resulting from prompt intracluster ion-molecule reaction and fragmentation following ionization are (C₆H₆)_m(NH₃)_nH⁺, m = 1–6, n = 1–4 and (C₆H₆)_m⁺, m = 1–3. The results of isotopic labeling experiments clearly indicate that C₆H₆ does not participate in intracluster ion-molecule reactions to form (C₆H₆)_m(NH₃)_nH⁺. A local maximum appears at n = 2 in the intensity distribution of (C₆H₆)_m(NH₃) _nH⁺ for each value of m under all experimental conditions. This finding indicates that (C₆H₆)_m(NH₃)₂H⁺ is more stable than any other (C₆H₅)_m(NH₃)_mH⁺ (n = 1,3,4) for m = 1–6.     

Pitzer理论在含有机物的HCl-H2SO4-葡萄糖多组分电解质水溶液中的应用

在298.15K,以葡萄糖质量分数(0.15)恒定的葡萄糖+水混合物为溶剂,测定了电池Pt,H2(101.325kPa)|HCl(m1),H2SO4(m2),Glucose(x),H2O(1-x)|AgCl-Ag的电动势.用所得数据确定了H2SO4在该混合溶剂中的二级解离常数(K2)和一级介质效应.用带有中性分子与各离子相互作用项的Pitzer方程表示Owen定义的总介质效应可较好地处理含有机物的多组分电解质水溶液体系,并用此法处理了文献中HCl在各混合溶剂中的活度系数实验数据,确定了HCl与有机物分子相互作用的Pitzer参数.     

Cun,Agn,Aun（n=2,3,4）原子簇结构的理论分析

在应用ＤＶ－Ｘａ自洽场方法研究Ｃｕｎ，Ａｇｎ，Ａｕｎ原子簇电子结构基础上，分析了原子簇中原子轨道间的相互作用及其大小随几何构型的变化，并讨论了原子簇的Ｘａ总能量与原子簇几何构型的关系，采用单、双过渡态理论方法分别计算原子簇分子轨道的电离能和分子轨道的电子跃迁能，结果表明Ａｇｎ的电离能计算值与实验值符合较好，而Ａｕｎ原子簇则有一定偏差，这可能是由Ａｕｎ的较大相论效应引起的，Ａｇ４的电子跃迁能与实验值