铁、钴、镍/磷二元团簇离子的形成与光解

利用激光直接溅射法产生了铁、钴、镍／磷二元团簇正负离子,并用串级飞行时间质谱仪研究了团族离子的组份和激光光解规律,质谱研究表明,铁、钴、镍易与磷结合成簇,而且样品中磷含量的增加有助于大尺寸团簇离子的生成,当形成的团族簇离子中含金属原子数目较少时,磷原子数目可在较大范围内变动,其中ＭＰ２＾＋、ＭＰ４＾＋、Ｍ２Ｐ４＾＋（Ｍ＝Ｆｅ、Ｃｏ、Ｎｉ,ｎ＝２、３、４）团簇离子均具有较高的丰度;随着金属原子数目的     

DyF3—LiF系熔体结构的计算机模拟研究

用Ｍｏｎｔｅ Ｃａｒｌｏ法计算机模拟研究ＤｙＦ３－ＬｉＦ系熔体，得到了径向分布函数和局部结构等信息。研究表明，Ｆ＾－紧密聚集在Ｄｙ＾３＋周围，而与Ｌｉ＾＋之间却存在一定的缝隙。该熔体中主要存在着二种离子类型：以ＤｙＦ＾３－ｎｎ型络离子（以ＤｙＦ＾３－６的八面体络离子为主）和“游离状”的Ｌｉ＾＋离子。同时，由于Ｆ＾－的聚集，一些ＤｙＦ＾３－ｎｎ型络离子通过“氟桥”组成ＤｙｍＦ＾３ｍ－ｎｍ型更加复杂的     

钴硫团簇ConS^＋n—1（n=2,3）的结构和稳定性

用ａｂ ｉｎｉｔｉｏ分子轨道方法（ＲＨＦ,ＵＨＦ）和密度泛涵（ＤＦＴ）方法研究了团簇Ｃｏ２Ｓ＾＋,Ｃｏ３Ｓ＾＋２的各种可能的几何构型和电子结构,并计算了相应的较稳定构型的振动光谱,发现Ｃｏ２Ｓ＾＋和Ｃｏ３Ｓ＾＋２团簇最稳定结构均具有Ｃｓ对称性。对团簇的成键作用机理进行了理论分析。     

C4H5N-(NH3)n氢键团簇的多光子电力与从头计算

在３５５和５３２ｎｍ激光波长下用ＴＯＦ质谱仪研究了Ｃ４Ｈ５Ｎ－（ＮＨ３）ｎ系列氢键团簇体系的多光子电离,实验发现,两波长下除了得到一系列团簇离子Ｃ４Ｈ５Ｎ－（ＮＨ３）ｎ＾＋外,还观测到一系列质子化产物Ｃ４Ｈ５Ｎ－（ＮＨ３）ｎ－Ｈ＾＋,这些质子化产物来自于光电离过程中团簇内部的质子转移反应;Ｃ４Ｈ５Ｎ－（ＮＨ３）ｎ＾＋系列离子出现反常强度变化,即Ｃ４Ｈ５Ｎ－（ＮＨ３）２＾＋离子强度较Ｃ４Ｈ５Ｎ－（Ｎ     

1,4-二氧六环和氨分子氢键团簇的从头算

在不同基组水平上,对１,４－二氧六环和氨分子氢键团簇体系进行了从头算分子转道法研究,优化得到中性团簇,离子团簇和碎片离子（质子化团簇离子和非质子化团簇离子）平衡几何构型,研究结果表明：中性团簇最稳定构型为Ｒ－ＨＮ２－ＨＮＮ２（Ｒ：１,４－二氧六环）,离子团簇由于发生质子转移,其构型与中 团簇有较大的淡同,两类碎片离子Ｒ（ＮＨ３）＋和Ｒ（ＮＨ３）Ｈ＾＋与中性团簇Ｒ（ＮＨ３）的结构也有所不同     

碳/磷二元团簇的激光溅射产生、光解及结构研究

在串级飞行时间质谱仪上用５３２ｎｍ激光溅射碳／磷混合样品,所得团簇分为两类：碳／磷二元团簇离子和纯碳团簇离子的相对强度随样品中磷含量的增加而变强,说明磷对纯碳团簇离子的形成具有重要作用,而在所形成的碳／磷二元团簇中,正离子主要有ＣｎＰ＾＋２（０〈ｎ〈３０）,ＣｎＰ＾＋３（０〈ｎ〈２２）两类,而负离子则较多,有ＣｎＰ＾－（０〈ｎ〈２０）,ＣｎＰ＾－２（０〈ｎ〈３０）,ＣｎＰ＾－３（ｎ为２－３０间的偶     

钒硫团簇V2S2^＋,V3S4S^＋的结构和稳定性

用ａｂｉｎｉｔｉｏ分子轨道方法（ＲＨＦ,ＵＨＦ）和密度泛函（ＤＦＴ）方法研究了团簇Ｖ２Ｓ２＾＋、Ｖ３Ｓ４＾＋的各种可能的几何构型和电子结构,所得理论能较好地解释有关实验结果。     

HcnS^—与HSC^—n簇离子的量子化学从头计算

应用量子化学从头计算能量解析梯度法，以ＨＦ６／３１Ｇ为基组优化了ＨＣｎＳ＾－与ＨＳＣ＾－ｎ（ｎ＝１～９）同分异构团簇离子的几何结构，计算了它们的电子总能量，结果显示ＨＣｎＳ＾－比相应的ＨＳＣ＾－ｎ稳定，从相邻簇离子的能量差及簇离子的平均原子结构能可知ｎ为偶数的ＨＣｎＳ＾－与ＨＳＣｎ＾－较ｎ为奇数的簇离子稳定，能量的差异随着ｎ的增加而逐渐减小，计算和实验结果完全相符，还分别计算了ＨＣｎＳ＾－失去Ｈ，     

碱金属团簇结构和稳定性的Hueckel—Hubbard方法研究

用Ｈｕｅｃｋｅｌ－Ｈｕｂｂａｒｄ理论及作者所建议的参数化方法，对碱金属团簇Ａｎ，Ａ＾＋ｎ，Ａ＾－ｎ的结构和碎化进行计算和分析，结果表明：ｎ≤５时团簇呈平面结构，几率大的碎化对应着中性单原子或中性二聚物的生成，团簇的稳定性随ｎ的变化呈出奇偶性，中性簇与离子簇的奇偶性上反，这些定性结果与实验及其它更精确算法的结果基本一致。     

离子束混合条件下Fe—Dy多层膜的非晶化

在超高真空（１０＾－７Ｐａ）条件下用双源蒸镀法在单晶Ｓｉ和ＮａＣｌ衬底上制备了一系列Ｆｅ，Ｄｙ原子配比的成分调制多层膜。用卢瑟福背散射（ＲＢＳ）和俄歇能谱（ＡＥＳ）分析成分沿厚度的分布，并用掠入射Ｘ射线衍射分析（ＸＲＤ）离子束混合前后的结构。结果表明，随Ａｒ＾＋离子剂量的增加混合量增加，在１０＾１７Ａｒ＾＋／ｃｍ＾２达到均匀混合，同时混合还诱发非晶化，平均成分约为Ｆｅ６０Ｄｙ４０的多晶膜完全转变为     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.