CCl2(A1B1)被O2及取代甲烷类分子猝灭的动力学研究

对CCl4／Ar混合气体放电产生CCl2自由基，再用541.52nm激光将电子基态CCl2激发到激发态A^1B1（0，4，0）振动态k=0能级上，通过检测 激发态CCl2时间分辨荧光信号，测得室温下CCl2(A^1B1)被O2，CF4，CF2Cl，CH3NO2，CH2Br2等分子猝灭的实验结果，用改进的三能级模型分析处理实验数据，获得态分辨速常数KA和Ka值，并对实验结果进行了讨论。     

Synthesis and Structure Investigations of Potential Sedative and Anticonvulsant Hydroxy- and Acetoxy-N-(3-oxobutyl)-pyrido[2,3-d]pyridazinonesa

Summary.  Novel N-(3-oxobutyl)-hydroxy- and acetoxypyrido[2,3-d]pyridazinones were synthesized and tested in vivo for their sedative and anticonvulsant activity. The Michael-type reaction of quinolinic acid hydrazide and methyl vinyl ketone afforded a mixture of two isomers, 5-hydroxy-N ⁷-(3-oxobutyl)-pyrido[2,3-d]pyridazin-8(7H)-one and 8-hydroxy-N ⁶-(3-oxobutyl)-pyrido[2,3,-d]pyridazin-5-(6H)-one, in a ratio of 2:1 which were separated by crystallization. Subsequent acetylation of both isomers yielded the corresponding 5- and 8-acetoxy compounds. The structures of the compounds were proven and completely assigned on the basis of ¹H, ¹³C, ¹⁵N NMR, and 1D NOE difference spectra as well as 2D C,H-correlation experiments. Preliminary pharmacological tests showed low acute toxicity with a LD ₅₀ > 1000 mg/kg in the mouse and sedative activity for the title compounds. 5-Acetoxy-N ⁷- (3-oxobutyl)-pyrido[2,3-d]pyridazin-8(7H)-one displayed a borderline anticonvulsant activity in the metrazole test model. Corresponding author. E-mail: edith.goessnitzer@uni-graz.at Received March 20, 2002; accepted April 3, 2002     

Simultaneous hydrogen and peroxide production by photocatalytic water splitting

Photocatalytic oxidation of water is a promising method to realize large-scale H₂O₂ production without a hazardous and energy-intensive process. In this study, we introduce a Pt/TiO₂(anatase) photocatalyst to construct a simple and environmentally friendly system to achieve simultaneous H₂ and H₂O₂ production. Both H₂ and H₂O₂ are high-value chemicals, and their separation is automatic. Even without the assistance of a sacrificial agent, the system can reach an efficiency of 7410 and 5096 μmol g^–1 h^–1 (first 1 h) for H₂ and H₂O₂, respectively, which is much higher than that of a commercial Pt/TiO₂(anatase) system that has a similar morphology. This exceptional activity is attributed to the more favorable two-electron oxidation of water to H₂O₂, compared with the four-electron oxidation of water to O₂.     

纳米CeO2基固溶体催化柴油机碳颗粒物燃烧性能

采用柠檬酸溶胶鄄凝胶法制备CeO2基固溶体催化剂(Ce0.7Zr0.3O2-δ、Ce0.7Pr0.3O2-δ和Ce0.7Gd0.3O2-δ), 并考察了固溶体和三种常用载体(TiO2、SiO2和Al2O3)及其负载KNO3后的催化碳黑燃烧活性. 结果表明, CeO2基固溶体催化剂具有很高的催化燃烧活性, 其活性接近TiO2、SiO2和Al2O3负载30%KNO3催化剂的活性. 因为纳米CeO2基固溶体的形成, 提高了催化剂的抗烧结能力, 使氧更活泼, 从而提高氧化还原性能, 有利于碳颗粒燃烧. 由于CeO2基固溶体本身的高活性, 因此KNO3的添加不能明显提高CeO2基固溶体催化剂(尤其是Ce0.7Zr0.3O2-δ和Ce0.7Pr0.3O2-δ)的催化燃烧活性, 但KNO3能显著提高TiO2, SiO2和Al2O3的催化燃烧活性.     

On the chemistry of pyrrole pigments,XCIV: 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-ylidene)-1-propene — a novelb-vinylogous verdin chromophore

Summary 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-ylidene)-propene, ab-vinylogous verdin, was synthesized by condensation of 3-(dipyrrinon-9-yl)-propenal with a dipyrrinone unsubstituted in position 9. By condensing the latter with dimedone or squaric acid,b-vinylogous verdin pigments with restricted configurational and conformational degrees of freedom were obtained. The chemical and spectroscopic properties of these novel systems are discussed.

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Zur Chemie von Pyrrolpigmenten, 94. Mitt.: 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-yliden)-1-propen — Ein neuerb-vinyloger Verdinchromophor

Zusammenfassung 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-yliden)-propen, einb-vinyloges Verdin, wurde durch Kondensation von 3-(Dipyrrinon-9-yl)-propenal mit einem in Position 9 unsubstituierten Dipyrrinon dargestellt. Kondensation des Letzteren mit Dimedon oder Quadratsäure lieferte vinyloge Pigmente, welche in ihren konfigurationellen und konformationellen Freiheiten eingeschränkt sind. Die chemischen und spektroskopischen Eigenschaften dieser neuen Systeme werden diskutiert.

     

微机在“醋酸,磷酸电位滴定”实验中的应用

微机在“醋酸、磷酸电位滴定”实验中的应用王苏文（南京师范大学化学系南京２１００２４）袁立新（南京师范大学物理系南京２１００２４）关键词计算机，Ａ／Ｄ模数转换器，电位滴定许多化学实验使用传统的方法对实验数据进行人工读数、记录、处理等。在这一过程中就必定...     

镓改性ZSM-5沸石中镓活性中心的形成与表征

采用脉冲微反体系研究了经不同程度还原和不同镓含量的GaZSM-5沸石的芳构化性能与吡啶吸附红外光谱特征谱带吸收度的关联，证实了1458 cm~(-1)吸收带的用于表征与Ga物种有关的活性中心，并研究了沸石的硅铝比对Ga中心形成和Ga的价态对芳构化性能的影响。结果表明，对Ga含量相同的样品来说，硅铝比愈低，起始Ga中心生成量愈多，高价态与低价态的Ga中心对丙烷芳构化反应都有促进作用。     

钙钛矿型LaNiO3、LaMnO3的形成条件

用混合硝酸盐分解法和柠檬酸络合法分别制取了单一钙铁矿型多晶粉末LaNiO_3和LaMnO_3. XRD分析表明LaNiO_3的形成经历了混合氧化物转化为LaNiO_3的同相反应; 而LaMnO_3晶相直接由无定形相转化而来。根据DTA、TG、IR分析两者的形成, NO_3~-离子都起了重要作用. 同时讨论了络合剂柠檬酸的作用.     

分光光度法研究镧与间乙酰基偶氮氯膦(CPAmA)配合物的形成反应

本文用分光光度法研究了间乙酰基偶氮氯膦试剂在水溶液中的离解作用和质子化作用;镧与间乙酰基偶氮氯膦配合物的组成和β型配合物形成反应的条件和动力学特征,并测定了α型配合物的积累稳定常数     

Fused heterocycles,VI: Reactions of 3-arylidenechromanones and -1-thiochromanones with thiourea

Summary Reactions of 3-arylidenechromanones (1 – 4) and -1-thiochromanones (5 – 8) with thiourea gave thiazines (9 – 16) under acidic and pyrimidine derivatives (17 – 21) under alkaline reaction conditions

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Kondensierte Heterocyclen, VI: Umsetzungen von 3-Arylidenchromanonen und-1-thiochromanonen mit Thioharnstoff

Zusammenfassung Die Umsetzung von 3-Arylidenchromanonen1 – 4 und -1-thiochromanonen5 – 8 mit Thioharnstoff liefert unter sauren Bedingungen die Thiazine9 – 16 und in basischem Milieu die Pyrimidine17 – 21.