用色谱—质谱和质量以谱研究苯甲酸钐热分解反应

为合成某些芳香族有机化合物提供一种新途径，用色谱－质谱联用技术和质量色谱法研究了苯甲酸钐的热分解反应产物。其热分解产物溶入丙酮后有大量９，１０－蒽醌析出，其丙酮溶液中还含有１，２－二苯甲酰基苯（２５．６％）、苯甲酸（１８．７％）、二苯酮（１４．４％）、９－勿酮（８．２％）、９－苯甲勿（４．９％）、取苯（３．６％）、二苯甲烷（２．３％）、３－甲酰苯基联苯（２．１％）、二苯基乙二酮（１．９％）、４－甲     

SDM—1型耐硫催化剂甲烷化反应动力学：II.宏观动力学模型

本文以工业应用为目的，采用内循环无梯度反应器，在５７３－６７３Ｋ，０．３０－１．２０ＭＰａ的条件下，原料气组成为Ｈ２ ５０－５４％，ＣＯ１１．７－２０．７％，ＣＨ４ ２．１－１４．３％，ＣＯ２ ６．４－１１．５％，Ｎ２ １２．２－１８．１％范围内，研究了φ×３ｍｍＳＤＭ－１型城市煤气耐硫甲烷化催化剂的宏观动力学方程选择 ＣＯ＋３Ｈ２＝ＣＨ４＋Ｈ２Ｏ （１） ＣＯ＋Ｈ２Ｏ＝ＣＯ２＋Ｈ２ （２）     

毛细管电泳定量分析植物激素

详细研究了三种重要植物激素,生长素吲哚－３－乙酸,吲哚－３－丁酸,赤霉素ＧＡ３,ＧＡ４及激动素６－苄氨基嘌呤的毛细管电泳分离条件;１０ｍｉｎ内完成上述５组分分离;分离效率为５×１０＾５￣２．６×１０＾６,５组分检出限为４．５￣１８ｍｇ／Ｌ;迁移时间与峰高定量精度分别低于１．２％和２．４％,方法已用于香蕉叶中激素的测定。     

对土壤及玉米植株中均三氮苯类除草剂的残留分析

土壤或玉米植株样品用Ｖ（甲醇）∶Ｖ（乙腈）＝１∶１提取,提取液用石油醚净化后,浓缩液过Ｃ１８小柱净化,最后用Ｎｏｖａ－ＰａｋＣ１８柱进行ＨＰＬＣ分析。回收率：氰草津为８２．４％～９９．８％,莠去津为８５．６％～１０２．３％,西草净为８９．１％～１０８．４％。     

极谱法测定地质样品中痕量氯

提出了０．１％ＨＣＯＯＨ－８×１０＾３％百时香酚兰，－０．４ｍｏｌ／ＬＨＣｌＯ４－０．４％ＴｒｉｔｏｎＸ－１００极谱法痕量氯离子的新体系，检出限为０．１８μｇ／ｇ，ＲＳＤ为７．６％，标准样品测定结果与推荐值相吻合。     

牛颌下腺粘蛋白中糖组成的毛细管气相色谱分析

根据各种糖革键稳定性的差异，采用没的酸解方法，使各种单糖从牛颌下腺粘蛋白上游离下来。纯化后衍生成三甲基硅醚或糖醇乙酸酯，应用毛细管气相色谱技术分析。结果表明，牛颌下腺粘蛋白中含三类糖，即唾液酸、中性糖和氨基糖。每咱单糖的含量分别为５－Ｎ－乙酰神经氨酸４．３％；５－Ｎ＝乙醇酰神经氨酸１９．０％；岩藻糖３．２％；半乳糖５．１％；Ｎ－乙酰氨基半乳糖１８．４％；Ｎ－乙酰氨基葡萄糖８．７％。     

溶剂萃取石墨炉原子吸收光谱测定盐卤中痕量铷

采用石墨炉原子吸收光谱（ＧＦＡＡＳ）研究盐卤中铷的原子化行为和机理,建立了热解石墨管,ＫＮＯ３－ＮＨ４ＮＯ３基体改进剂,１８－冠－６,溴百里香酚蓝,氯仿萃取分离ＧＦＡＡＳ测定盐卤铷的方法。用于测定盐卤中痕量铷,特征质量１．１×１０＾－１０ｇ／０．００４４,加标回收率８９％￣１１０％;相对标准偏差６．２８％（ｎ＝１３）。     

高效液相色谱法测定人血浆中甲磺酸培氟沙星浓度

建立了一种测定人血浆中甲磺酸培氟沙星的匠相液相色谱方法,用的是ＺｏｒｂａｘＯＤＳＣ＿（１８）柱和用三乙醇胺调节成ｐＨ为３．０的甲醇－０．０４ｍｏｌ／ＬＨ＿３ＰＯ＿４溶液（８０：２０,Ｖ／Ｖ）的流动相,检测在２７６ｎｍ处进行,流量为１ｍＬ／ｍｉｎ,线性范围是６．０１×１０￣（－８）～３．０１×１０￣（－５）ｍｏｌ／Ｌ（γ＝０．９９９８）,检测极限为６．０１×１０￣（－８）ｍｏｌ／Ｌ,平均回收率为９７．５７±３．０４％,日内与日间的ＣＶ分别为３．２９％和５．０８％。     

相转移催化酯化反相高效液相色谱法测定食品中有机酸

在不预分离水相中有机酸的情况下，用α－溴苯乙酮作酯化试剂，以１８－冠醚－６作相转移催化剂直接酯化有机酸，酯化液直接用高效液相色谱分析，紫外检测器检测，操作简便、干扰小、变异系数ＣＶ％＝１．４－５．６％检测下限５－２０μｇ／Ｌ，实际样品回收率９０．９－１０３．３％。     

天然气和二氧化碳转化制合成气的研究：Ⅵ Ni／Al2O3催化剂再生的疏…

采用γ－Ａｌ２Ｏ３为载体，以硝酸镍，硝酸镁和稀土硝酸盐为原料，按常规浸渍法制备负载型催化剂，其中Ｎｉ含量为９．１７％，助剂ＲＥ２Ｏ３和Ｍｇ含量分别为５．１８％和１．８０％。该催化剂简称为Ｎ－５－ＲＭ。催化反应评价采用双套管石英反应器，在多功能固定床流动反应装置上进行。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Studies of Photoionization of CF3 I by Femtosecond Time-resolved Mass Spectrometry

The multi-photon dissociative photoionization dynamics of CF3I has been studied with femtosecond two-color pump-probe time of flight mass spectra at a pump pulse of 265 nm and a probe pulse of 398 nm. The life constants of CF3I+ and its fragment ions CF3+ and I+ are obtained as (96±7), (198±130) and (167±6)fs, respectively. The multi-photon dynamics leading to these ions differ. CF3I+ corresponds to a (1+2′) transition with one-photon pump excitation to the A band of CF3I. CF3+ are mainly formed by a tow-photon probe excitation to the CF3+ with subsequent dissociation of parent ions. I+ are produced in (2+2′) combined with (1+1′+2′) process. The results provide information on the multi-photon pathways involved.