稀土脯氨酸配合物[RE_2(L-Pro)_6(H_2O)_4](ClO_4)_6的标准生成焓测定

合成了两种稀土高氯酸盐与Ｌ－脯氨酸配合物的晶体．经热重、差热、化学分析及对比有关文献,知其组成 是［Ｐｒ２（Ｌ－Ｐｒｏ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６和［Ｅｒ２（Ｌ－ＰｒＯ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６,质量分数为９９．２４％和９８．２０％．选用ＲＥ（ＮＯ３）· ６Ｈ２Ｏ（ＲＥ＝Ｐｒ,Ｅｒ）、ＬＰｒｏ、ＮａＣｌＯ４·Ｈ２Ｏ和 ＮａＮＯ３作辅助物,使用具有恒温环境的反应热量计,以 ２ ｍｏｌ·Ｌ－１ＨＣｌ 作溶剂,分别测定了［２ＲＥ（ＮＯ３）３·６Ｈ２Ｏ＋６Ｌ－ＰｒＯ＋６ＮａＣｌＯ４·Ｈ２Ｏ］和｛ ［ＲＥ２（Ｌ－ＰｒＯ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６＋６ＮａＮＯ３｝在 ２９８．１５ Ｋ时的溶解热．设计一热化学循环求得化学反应的反应焓ｒＨ分别是：６３．９０４ ｋＪ·ｍｏｌ－１和 ９１．０１７ ｋＪ·ｍｏｌ－１,经计算得配合物［ＲＥ２（Ｌ－Ｐｒｏ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６（ｓ）在 ２９８．１５ Ｋ时的标准生成焓（２９８．１５ Ｋ）分别 是－６ ５９４．７８ ｋＪ·ｍｏｌ－１和－６ ５３２．８７ ｋＪ·ｍｏｌ－１。     

稀土元素与NEB二元配合物的pH电位法分析

氨三乙氧基三苯甲酸(ＮＥＢ)(ＮＥＢ·ＨＣｌ的分子结构式见下图)作为有立体选择性的配体,它与铀酰离子ＵＯ2(Ⅱ)配位作用已有报导[1]。在对ＮＥＢ质子化常数及二元体系Ｍ(Ⅱ)-ＮＥＢ·ＨＣｌ(Ｍ=Ｃｄ、Ｃｏ、Ｎｉ、Ｃｕ和Ｚｎ)配合物的稳定常数测定的基础上[2],本文在25℃及离子强度为0 2ｍｏｌ/ＬＫＮＯ3的条件下,用精密ｐＨ电位法考察二元体系ＲＥ(ＩＩＩ)—ＮＥＢ(ＲＥ=Ｌａ→Ｎｄ,Ｓｍ→Ｌｕ,Ｙ)中存在的配合物物种及其稳定常数。ＮＥＢ·ＨＣｌ结构式1　实验部分1 1　试剂和仪器ＮＥＢ·ＨＣｌ(Ｈ3Ｌ·ＨＣｌ,Ｌ3-=Ｃ27Ｈ24ＮＯ9)…     

吸光光度法测定硝酸银中微量铜

硝酸银制成后测定杂质含量是鉴定纯度的一个重要环节。杂质铜的含量多少直接影响到硝酸银的纯度。本文研究了 0 .1～ 0 .3ｍｏｌ·Ｌ- 1ＫＯＨ介质中 ,用ＫＩＯ4 作为显色剂 ,采用巯基棉分离 ,吸光光度法测定了硝酸银中微量铜 ,结果满意。1　试验部分1.1　主要仪器与试剂756ＭＣ紫外可见分光光度计 (上海第三分析仪器厂 )Ｃｕ2 +标准溶液 :称取ＣｕＳＯ4 ·Ｈ2 Ｏ 1.96 4 4 ｇ于烧杯中 ,加水溶解后 ,再加几滴硫酸 ,移入 50 0ｍｌ容量瓶 ,稀至刻度 ,配成 1ｍｇ·ｍｌ- 1储备液。逐级稀释成10 μｇ·ｍｌ- 1工作液。ＫＩＯ4 溶液 :称取ＫＩＯ4…     

单茂钛催化剂的丙烯无规聚合反应及其动力学研究

比较了不同钛化合物／甲基铝氧烷（ＭＡＯ）催化体系的丙烯无规聚合，催化活性次序为ＣｐＴｉ（ＯＲ）３＞ＣｐＴｉ（ＯＰｈ）３＞ＣｐＴｉＣｌ３＞Ｃｐ２ＴｉＣｌ２＞Ｔｉ（ＯＢｕ）４＞ＴｉＣｌ４＞Ｔｉ（ＯＢｕ）２Ｃｌ２，所得聚丙烯用沸庚烷抽提８ｈ，溶解９５％以上，可溶部分经１３Ｃ ＮＭＲ、ＷＡＤＸ、ＦＴＩＲ等分析证明为无规聚丙烯（ａＰＰ），是没有结晶性的弹性体．ＧＰＣ测出其分子量Ｍｗ＝８．０～１０．０×１０４，Ｍｗ／Ｍｎ≈２．０．探索了催化体系ＣｐＴｉ（Ｏ ｎ Ｐｒ）３／ＭＡＯ中钛的浓度、［Ａｌ］／［Ｔｉ］摩尔比，丙烯聚合压力，聚合温度和时间对丙烯聚合反应的影响．研究了该催化体系丙烯聚合反应动力学规律，表观聚合反应速率对催化剂浓度和单体压力（浓度）都呈一级反应关系，表观聚合速率常数ＫＰ＝２９２×１０５ｍｏｌ／Ｌ·ｈ（４０℃）．活化能ΔＥ＝－７．８８×１０３Ｊ·ｍｏｌ－１，碰撞因子Ａ＝１．４１×１０－４ｍｏｌ／Ｌ·ｈ．     

最新电化学技术应用文献摘引

能量储存与转移用于锂电池的层状ｘＬｉＭＯ2 ·( 1 -ｘ)Ｌｉ2 Ｍ′Ｏ3 电极 :0 .95ＬｉＭｎ0 .5Ｎｉ0 .5Ｏ2·0 .0 5Ｌｉ2 ＴｉＯ3 的研究　Ｋｉｍ ,Ｊ .＿Ｓ .;Ｊｏｈｎｓｏｎ ,Ｃ .Ｓ .;Ｔｈａｃｋｅｒａｙ ,Ｍ .Ｍ . ,ＥｌｅｃｔｒｏｃｈｅｍｉｓｔｒｙＣｏｍｍｕｎｉｃａｔｉｏｎｓ ,2 0 0 2 ,4( 3) ,2 0 5～ 2 0 9一种作为锂嵌入电极新的聚吡咯 /磁赤铁混合物　Ｋｗｏｎ ,Ｃｈａｉ＿Ｗｏｎ ;Ｐｏｑｕｅｔ ,Ａｒｍｅｌ;Ｍｏｒｎｅｔ,Ｓｔ啨ｐｈａｎｅ ;Ｃａｍｐｅｔ ,Ｇｕｙ ;Ｐｏｒｔｉｅｒ ,Ｊｏｓｉｋ ;Ｃｈｏｙ ,Ｊｉｎ＿Ｈｏ ,Ｅ…     

水热法合成纳米氧化铜粉体及其性能表征

氧化铜粉体广泛用于电极材料[1 ] 、玻璃、催化剂 (载体 )等领域。粒子的超细化 ,可以显著的改善氧化铜的应用性能。制备纳米氧化铜的方法有固相合成法[2 ] 、沉淀转化法[3] 和络合沉淀法[4] 。本文采用水热法一步合成了纳米氧化铜粉体 ,所得粉体粒度均匀 ,操作简便 ,易于工业化生产。1　实验部分1 1　样品制备将硝酸铜 (分析纯 ,北京化工二厂 )配成浓度为 1 .0ｍｏｌ·Ｌ- 1 的溶液 ,按物质的量比为 2∶1加入浓度为 1 .0ｍｏｌ·Ｌ- 1 的尿素 (分析纯 ,上海试剂一厂 )溶液 ,然后在 95℃～ 1 2 5℃下加热溶液进行反应。由于水溶液在 1 0 0…     

单元练习一参考答案及提示

单元练习一参考答案及提示一、二、三、选择题四、填空题２７·ａ＋６,Ｍ—１７ａ—４８,ｌ,ａ＋６—７,ａ为正整数,高氯酸ＨＣＩＯ;,高锰酸ＨＭｎＯ。,ＣＩ。Ｏ,、Ｍｎ。Ｏ。（Ｒ。Ｏａ＋６）２８．ｎ／３１Ｖ摩／升、ｍ／１３Ｖ摩／升２９．ＮａＯＨ、ＣＨａＣ...     

NO和O_2的反应

无色ＮＯ和空气中Ｏ2 一经接触即生成红棕色的ＮＯ2 。ＮＯ + 12 Ｏ2 =ＮＯ2 　ΔｒＨｍ =- 5 6 5ｋＪ/ｍｏｌ,ΔｒＳｍ =- 73Ｊ/Ｋ·ｍｏｌ,不同温度下的平衡常数见表 1。由平衡常数知 :低于 15 0℃ ,ＮＯ可以较完全转化为ＮＯ2 ,高于 80 0℃事实上“不能”生成ＮＯ。表 1　平衡常数Ｔ/Ｋ 2 9840 0 5 0 0 70 0 77410 0 10 73Ｋ 1 4× 10 6 4 3× 10 2 1 3× 10 2 2 41 0 0 14 9 4× 10 - 2　　ＮＯ和Ｏ2 转化成ＮＯ2 需要时间 ,如原料气中ＮＯ为 9 92 % (体积 )、Ｏ2 为 5 6 8% (体积 ) ,在不同温度、压强下 ,ＮＯ转化速度和转化所需时…     

自制简易气体量管系列在中学科学素质教育中的应用(三)——Al-Mg合金的测定

3　Ａｌ-Ｍｇ合金的测定3.1　简易气体量管的制作 (第 9期原图 1所示 )3.2　测定原理 (第 9期原图 2 - 3所示 )设 :(Ｚ1,Ｚ2 分别为Ｍｅ1Ｍｅ2 价态 ,物质的量之比为Ｘ∶Ｙ)由反应 (Ｍｅ1Ｍｅ2 ) +ｍＨＣｌ→Ｍｅ1ＣｌＺ1·Ｍｅ1ＣｌＺ2 +(Ｚ1Ｘ +Ｚ2 Ｙ) 1 2Ｈ2 ↑(ａ)反应前 :Ｐ空 Ｖ0 =ｎ0 ＲＴ0 (克氏方程 )　Ｐ水 =Ｈ ＬＰ空 +Ｐ水 =1ｎ0 ＲＴ0 =(1-Ｈ Ｌ)Ｖ0 (1)(ｂ)反应终了 :Ｗｉ(ｇ)合金与过量 5ｍｏｌ Ｌ的ＨＣｌ反应 ,生成Ｈ2的物质的量为ｎｉ 水位下降了Ｙｉ ｃｍ可有 (2 )成立 :　　Ｐ混(Ｖ0 +ＳＹｉ) =(ｎ0 +ｎｉ)ＲＴ0Ｐ’水…     

[Mn2(TNR)2(CHZ)2(H2O)4]·2H2O的合成和晶体结构

将ＭｎＣＯ３与２,４,６－三硝基间苯二酚（斯蒂芬酸、ＴＮＲ）分散于蒸馏水中,加热搅拌制备出斯蒂酚酸锰溶液,再与碳酰肼（ＣＨＺ）水溶液反应制备〖Ｍｎ２（ＴＮＲ）２（ＣＨＺ）２（Ｈ２Ｏ）４〗·２Ｈ２Ｏ（Ｃ１４Ｈ２６Ｍｎ２Ｎ１４Ｏ２４,Ｍｒ＝８８４．３６）,并对其进行了元素分析和红外表征,利用单晶分析测定了晶体结构。该化合物为双核配合物,属三斜晶系,空间群为＾－Ｐ１,晶体学数据如下：ａ＝７．２８０（１）     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.