Theoretical Studies on S-Phenyl-thiabenzene,S-Phenyl-thianaphthalene,and S-Phenyl-thiaanthracene

The molecular structures of S-phenyl-thiabenzene 1, S-phenyl-1-thianaphthalene 2, S-phenyl-2-thianaphthalene 3, and S-phenyl-9-thiaanthracene 4 are studied by ab initio calculations using HF as well as DFT methods at the 6–311+G? level of theory. The non-planar boat conformers of 1–4 with 6π electrons in the heterocyclic ring appear to be more stable than the corresponding planar conformers with 8π electrons in the ring. The activation energy for the inversion at the sulfur atom is compared for 1–4. Conformational flexibility of 1–4 is studied.     

ClF-分子离子的结构与势能函数

采用单、双取代包括三重激发的二次组态相互作用[QCISD(T)]方法和单、双取代包括非迭代三重激发的耦合簇理论[CCSD(T)]方法, 结合相关一致基组aug-cc-pVXZ (X=D, T, Q, 5)对基态³⁵ClF^-和³⁷ClF^- (X²Σ⁺)分子离子进行了结构优化计算. 对CCSD(T)方法的计算结果用四种方法分别外推至基组极限, 得到了体系在基组极限的平衡结构常数. 在CCSD(T)/aug-cc-pVXZ (X=D, T, Q, 5)理论水平进行了单点能扫描. 对扫描计算结果进行基组外推并用Murrell-Sorbie 势能函数拟合得到了体系的解析势能函数表达式, 并进一步得到了³⁵ClF^-和³⁷ClF^-的光谱常数. 拟合所得势能曲线准确地再现了其离解能和平衡结构特征. 对ClF 中性自由基采用完全相同的理论方法进行了计算. 所得结果与有关文献中的实验结果符合得很好, 而且在一定程度上证明了将该理论方法应用于ClF^-分子离子的计算是合适而可靠的. ClF 自由基的优化计算结果还被用于计算其电子亲和能.ClF^-的垂直解离能也同时计算得出. 基于ClF^-的结构优化和单点能扫描计算结果, 通过求解核运动的径向薛定谔方程, 得到了无转动³⁵ClF^-和³⁷ClF^-(X²Σ⁺)的全部振动态及相应的分子常数.     

A characterization of almost simple K 3-groups

It is a well-known fact that characters of a finite group can give important information about the group's structure. Also it was proved by the third author of this article that a finite simple group can be uniquely determined by its character table. Here the authors attempt to investigate how to characterize a finite almost simple group by using less information of its character table, and successfully characterize the almost simple K₃-groups by their orders and at most three irreducible character degrees of their character tables.     

Two Aromatic Ester Organoimido Derivatives of Hexa­molybdate: Syntheses,Crystal Structures,and Spectroscopic Studies

Two alkylimido derivatives of hexamolybdate, (Bu₄N)₂[Mo₆O₁₈(≡N‐o‐COOCH₃C₆H₄)] ( 1 ) and (Bu₄N)₂[Mo₆O₁₈(≡N‐o‐COOCH₂CH₃C₆H₄)] ( 2 ), were synthesized in high purity and good yields by the reaction of [(C₄H₉)₄N]₄[α‐Mo₈O₂₆] and methyl anthranilate or ethyl‐o‐aminobenzoate hydrochloride with N,N′‐dicyclohexylcarbodiimide (DCC) as a dehydrating agent in dry acetonitrile solution, which were characterized by elemental analyses, IR, UV/Vis, and ¹H NMR spectroscopy as well as ESI‐MS, and single‐crystal X‐ray diffraction study. Compound 1 crystallizes in the monoclinic space group P2₁/n with one‐dimensional chain structure via intramolecular hydrogen bond. Compound 2 also crystallizes in the monoclinic space group P2₁/n with dimer structure by intramolecular hydrogen bonds and π–π interactions between the pairs of cluster anions.     

Macrocyclic ZnII and CuII complexes as guests of the hybrid composites based on the layered MnPS3 phase. Comparison of spectroscopic properties

A family of macrocyclic complexes [M₂LⁿCl₂] have been synthesized and characterized (M: Cu^II or Zn^II; Lⁿ: macrocyclic ligand derived from 2-hydroxy-5-methyl-1,3-benzenedicarbaldehyde and different aliphatic diamines and o-phenylenediamine). The influence of the aromaticity of the ligand and the metal center on the spectroscopic properties of the complexes (absorption and emission) has been studied. Making use of the weak interactions between hydrated potassium ions and the layers of the K_0.4Mn_0.8PS₃ precursor, the obtained macrocyclic complexes have been intercalated in the interlamellar space by a microwave assisted cationic exchange reaction. The optical properties of the obtained hybrid materials are reported. The absorption edge, recorded by solid state reflectance spectroscopy for Cu^II and the Zn^II macrocycle-based composites, is 1.67–1.76 eV, both shifted to lower energy compared with that of the pristine MnPS₃.     

Synthesis of new bis(thiosemicarbazone) derivatives and DFT analysis of antioxidant characteristics in relation to HAT and SET reactions

A series of new bis(thiosemicarbazones) have been synthesized from terephthalaldehyde and various thiosemicarbazides. IR, ¹H NMR, ¹³C NMR spectroscopic methods, and elemental analysis were used to characterize the identification of the synthesized compounds. The in vitro antioxidant activity determinations were made using the 1,1-Diphenyl-2-Picryl Hydrazil (DPPH) method. The compounds exhibited very different inhibition activities with the change of groups attached to the bis(thiosemicarbazone) structure. The spectral and electronic properties of the compounds were investigated by DFT calculation. Intramolecular interactions were analyzed by QTAIM and IRI calculations. Intrinsic bond strength index values of the N–H bonds, Fukui indices and the local electron affinities of the compounds were calculated, and the relationships between the compounds and their antioxidant activity properties were investigated. The SET and HAT mechanisms in the reactions of the compounds with DPPH were affected by the concentration of the compounds, and the possible effects of the parameters supporting the dominant characteristics in these reactions were examined using theoretical data.     

Phase diagram of P3HT:PC70BM thin films based on variable-temperature spectroscopic ellipsometry

In this article, we present the research on the influence of the composition of thin films of a blend of poly (3-hexylthiophene −2,5-diyl) - P3HT with fullerene derivatives [6,6]-phenyl-C71-butyric acid methyl ester – PC70BM and [6,6]-phenyl-C61-butyric acid methyl ester – PC60BM on their thermal transitions. The influence of molar mass (Mw) of P3HT (Mw = 65.2; 54.2 and 34.1 kDa) and PCBM (PC60BM – Mw = 911 g/mol and PC70BM – Mw = 1031 g/mol) is examined in details. The article presents significantly expanded research compared to our previous work on thermal transitions in thin films of blend P3HT (Mw = 65.2 kDa) with PC60BM. For this reason, we also compare current results with previous ones. Here, we present for the first time a phase diagram of thin films of the P3HT(Mw = 65.2 kDa):PC70BM blend using variable-temperature ellipsometry. Our research reveals the presence of characteristic temperatures of pure phases in thin films of P3HT: PCBM blends. It turns out that the cold crystallization temperature of the P3HT phase in P3HT(Mw = 65.2 kDa):PC70BM blend films is lower than corresponding temperature in P3HT(Mw = 65.2 kDa):PC60BM blend films. At the same time, the cold crystallization temperature of the PC70BM phase behaves inversely. We demonstrate also that variable-temperature spectroscopic ellipsometry is a very sensitive technique for studying thermal transitions in these thin films. In addition, we show that the entire phase diagram can be determined based on the raw ellipsometric data analysis, e.g. using a delta angle at wavelength λ = 280 nm.     

活性炭负载纳米TiO2光催化降解性能研究

本文研究活性炭负载纳米TiO2的光催化降解性能和影响甲基橙废水处理的主要因素。结果表明:用溶胶-凝胶法制备的TiO2-活性炭催化剂具有比表面积大、分散性高、光催化降解性能好、可重复利用等优点;采用30W高硼紫外光灯,TiO2-活性炭光催化降解浓度为1500mg/L甲基橙废水的最优工艺条件是:催化剂活化温度为700℃、用量为1.0g/L、废水起始pH值为1、反应温度为45℃、光照时间为50m in。在此条件下,甲基橙和CODC r的去除率分别达99.8%和99.7%。     

铒离子浓度对掺Er3+碲酸盐玻璃的Judd-Ofelt理论参数的影响

制备了四种不同铒离子掺杂浓度的碲酸盐玻璃,通过测定吸收光谱计算了吸收谱线的振子强度,根据Judd-Ofelt理论计算了不同浓度下Er3 离子发光光谱的强度参数Ωi(i=2,4,6),计算了自发辐射电偶和磁偶跃迁概率、辐射寿命、荧光分支比等参数,讨论了Er3 离子浓度变化对以上这些参数的影响.测试了Er3 :4I13/2→4I15/2跃迁对应的荧光光谱和Er3 :4I13/2能级荧光寿命.最后应用McCumber理论计算了玻璃中Er3 :4I13/2→415/2跃迁对应的受激发射截面大小.结果表明:振子强度基本上随Er3 离子浓度的增大而增强;随着Er3 离子浓度的增加,自发辐射跃迁概率A基本呈现出递增的趋势,但荧光分支比β却只有很小的变化;Er3 :4I13/2→4I15/2的发射截面随Er3 离子浓度的增大而改变很小,有效线宽都在50 nm左右.