1-benzoyl-2-(2-naphthyl)-selenourea

During our synthesis of N-benzoyl-N'-aryl selenourea derivatives, we isolated the title compound. One of them was selected optically for the diffraction study. The crystal belongs to the Monoclinic space group P21/n, Mr = 353.27, a = 11.073(1)? , b = 5.745(1) ?, c = 24.356(5) ?, β = 92.10 (1) , V = 1548.3 (4) ?3, Z = 4, Dx=1.515 Mg/m3,λ(Mo Kα)=0.71073 ?,θ = 1.67-25,μ o = 2.428 mm-1 , T = 296 (2) K. View of the molecule showing the labeling of the non-H atoms are described as: The se…     

CS2 +( 2 Πg )的(1+1)光解离动力学研究

在气束条件下,利用483.2 nm的激光(3+1)共振增强多光子电离(REMPI)CS2分子以产生CS2+离子源,用另一束可调谐激光在424～482 nm内,通过对CS2+( 2 Πg)(1+1)双光子共振解离产生的碎片离子激发谱的探测,来获取CS2+ 的光解离动力学信息.光解离碎片S+的激发谱 (PHOFEX)可归属为CS2+ ( 2 Πu,3/2 (v′=0～4, v′=v1′+ (1/2)v2′) ← 2 Πg,3/2 (0,0,0))和 ( 2 Πu,1/2(v′=0～4)← 2 Πg,1/2(0,0,0))的跃迁.对CS2+光解离动力学的研究表明,其产生S+的通道为:(i)CS2+吸收一个光子从基态 2 Πg共振激发至 2 Πu态,(ii)已布居的 2 Πu态的振动能级和 2 Πg态的高振动能级产生耦合, (iii)吸收第二个光子从上述耦合的振动能级进一步激发至 2 Σu +态,再通过 2 Σu +态与4Σ- 态间的自旋-轨道相互作用,经由4Σ- 排斥态解离产生S++CS.     

DiastereoselectiveandEnantioselectiveSynthesisof(1S,2S)-2-Ethyl-1-aminocyclopropaneCarboxylicAcid

During the last decade, 1-aminocyclopropanecarboxylic acid and its derivatives (ACCS) have attracted increasing attention of organic and bioorganic chemists due to their outstanding biological properties, ranging from antimicrobial, insecticidal, plant growth and fruit ripening controls, etc.1. Moreover, the three-membered carbocycle provides building blocks of unprecedented synthetic potential because it undergoes selective ring opening, ring enlargement or cycloaddition reactions2. The mo…     

New polynuclear molecular ferromagnetic complex {Co3((η2-NH2)2C6H2Me2)2(μ-OOCCMe3)2(η1-OOCCMe3)2(η2-OOCCMe3)2(HOOCCMe3)2}{Co((η2-NH2)2C6H2Me2)2(η1-OOCCMe3)2}

Russian Chemical Bulletin -     

Synthesis of 2-(3-hydroxy-2-methyl-1-alkenyl)-1-pyrrolines and 2-(3-hydroxybutyl)-1-pyrroline using α-lithiated 2-methyl-1-pyrroline

Condensation of 2-methyl-1-pyrroline with chloroacetone or 3-chloro-2-butanone using LDA in THF afforded novel 2-(3-hydroxy-2-methyl-1-alkenyl)-1-pyrrolines via a peculiar reaction mechanism instead of the anticipated 2-(3-oxobutyl)-1-pyrrolines. The intermediacy of 2-(2,3-epoxy-2-methylalkyl)-1-pyrrolines in the latter transformation was demonstrated by immediate reductive epoxide ring opening utilizing lithium aluminium hydride in diethyl ether. Furthermore, 2-(3-oxobutyl)-1-pyrroline was prepared via an alternative approach through alkylation of 2-methyl-1-pyrroline with 3-chloro-2-(methoxymethyloxy)-1-propene using LDA in THF, followed by acid hydrolysis. Reduction of 2-(3-oxobutyl)-1-pyrroline by sodium borohydride in methanol afforded the corresponding 2-(3-hydroxybutyl)-1-pyrroline in good yield.     

Ab initio Study of H2O–HCl (1:1, 1:2, 2:1) Complexes

This paper reports on an ab initio (6-31G**) study of 1:1, 1:2, and 2:1 (H₂O) _n (HCl) _m complexes. Stable configurations of the 1:2 and 2:1 (H₂O) _n (HCl) _m complexes and their geometrical and energy characteristics were determined. The vibrational analysis of the complexes was carried out. The effect of hydrogen bonding due to S₁S₀ and T₀T₁ electronic excitations is considered.     

Synthesis and Crystal Structure of (2S,2'S,4'R)-2-(1-Hydroxy-1-ethylpropyl)-1-[(1'-p-tosyl-4'-hydroxypyrrolidin-2'-yl)methyl]pyrrolidine

1 INTRODUCTION In recent years, chiral β-amino alcohols have attracted much attention due to their special bio- logical functions and catalytic activities. Chiral β- amino alcohol moieties are usually found not only in natural products (e.g., cinchona alkaloids, ephe- drine, toxal, etc.) with special biological activities[1, 2], but also critical structural segments of some syn- thesized biologically active compounds, such as adrenergic agonists or antagolist[3, 4] and inhibitors for HI…     

荧光探针Ru(phen)2(dppx)2+测定H1N1禽流感病毒DNA

利用荧光探针Ru(phen)2dppx2+与ssDNA作用时不产生荧光或荧光很弱,而与dsDNA作用时荧光增强的机理,将H1N1禽流感病毒ssDNA与其完全互补ssDNA杂交形成dsDNA实现Ru(phen)2dppx2+对H1N1禽流感病毒DNA特定序列（5’-CTA CCA TGC GAA CAA TTC AAC CGA CAC TGT T-3’）的定量检测。在优化的实验条件下,测定H1N1禽流感病毒 DNA的线性范围为9.3×10-10～7.4×10-8 mol/L,线性关系：y = 3.3829x + 8.3948,R2 =0.9982,检出限为5.3×10-10 mol/L。该方法具有操作简单,检测快速,灵敏度高和选择好等优点。     

Al(2~P_u) H_2(X1~∑_g~ )的分子反应动力学

基于多体展式方法所导出的ＡＩＨ_２（Ｘ ~２Ａ_１）分析势能函数,用准经典的Ｍｏｎｔｅ－Ｃａｒｌｏ轨迹法对ＡＩ（~２Ｐ_ｕ）＋Ｈ_２（Ｘ~１∑_ｇ~＋,ｖ＝ｊ＝０）的分子反应动力学过程进行了计算．结果表明,此反应的主产物为交换反应ＡＩ（~２Ｐ_ｕ）＋Ｈ_２（Ｘ~１∑_ｇ~＋ ｖ＝ｊ＝０）→ＡＩＨ（Ｘ ~１∑~＋,ｖ~＇,ｊ~＇）＋Ｈ（~２Ｓ_ｇ）的ＡＩＨ（Ｘ ~１∑~＋,ｖ~’,ｊ~’）,没有发现 ＡｌＨ_２（ Ｘ~２ Ａ_１）络合物．而从反应的反应截面σ_ｒ与相对平动能Ｅ_ｔ的关系发现,该反应为有阈能反应,阈能值为 ３１４ ＫＪ·ｍｏｌ~(－１)．同时,由于 ＡＩ的质量比氢的大,发生的是直接碰撞,产物散射角分布是向前散射的．     

Excited-state dynamics of trans,trans-1,3,5,7-octatetraene: estimation of decay rate constants of 1(1)B(u) ⇝ 2(1)A(g) and 2(1)A(g) ⇝ 1(1)A(g) internal conversions

The general expressions we previously derived for calculating internal conversion rate constants between two adiabatic displaced-distorted-rotated potential energy surfaces, by including all vibratinal modes, are applied to estimate the decay rate constants of 1(1)B(u) ? 2(1)A(g) and 2(1)A(g) ? 1(1)A(g) internal conversions in trans,trans-1,3,5,7-octatetraene molecule. The minimal models with respect to the number and types of vibrational modes are determined for these processes. Our calculations show that in the low temperature limit the 1(1)B(u) ? 2(1)A(g) internal conversion takes place on a 232-290 fs time scale in the condensed phase and 2 ps in the gas phase, whereas 2(1)A(g) ? 1(1)A(g) internal conversion takes place on a 2 μs time scale under the isolated conditions.     

Regioselective silylation of 5-(2′-hydroxyethyl)cyclopent-2-en-1-ol and 6-(2′-hydroxyethyl)cyclohex-2-en-1-ol

Herein we report regioselective and mild reactions for the tert-butyldimethylsilyl mono-protection of 5-(2′-hydroxyethyl)cyclopent-2-en-1-ol (2) and 6-(2′-hydroxyethyl)cycohex-2-en-1-ol (5) at the primary hydroxyl group or at the secondary allylic hydroxyl group. The different steric environment surrounding the secondary allylic and saturated primary alcohols is mainly invoked to rationalize the observed regioselectivity.     

CS2 分子 1 B2(1 Σ+u )态预解离动力学研究

The predissociation dynamics of CS2 at the g vibrational level of the 1B2(1Σu+) state has been studied, by measuring the predissociation lifetimes from the photofragment CS excitation (PHOFEX) spectrum and the ro vibrational populations of CS fragment from the laser induced fluorescence(LIF) spectrum. It is found that the angular momentum quantum number K of the g level accelerates the dissociation speed of CS2 at the 1B2(1Σu+) state, and increases the branching ratio of S(1D2)/S(3PJ) for the two dissociation channels, CS(X 1Σ+)+S(1D2) and CS(X 1Σ+)+S(3PJ). The dissociation mechanism was discussed based upon the observations.     

电子激发态SO2(A^1A2, B^1B1)分子的碰撞猝灭动力学研究

用四倍频YAG激光(266nm)把SO2分子从电子基态X^1A1激励到电子激发态A^1A2和B^1B1的高振动耦合区, 通过检测自发辐射SO2(B^1B1→X^1A1)的时间分辨信号, 测定了室温(290K)下SO2(A^1A2, B^1B1)被He, 氯代甲烷分子和某些烷烃分子猝灭的速率常数。此外, 还从碰撞配合物模型出发, 对SO2(A^1A2, B^1B1)的猝灭机制进行了讨论。     

Synthesis,Structure and Biological Activities of 2-(1H- 1,2,3-Benzotriazol-1-yl)-1-(4-methylphenyl)-2- (1H-1,2,4-triazol-1-yl)-1-ethanone

IntroductionTriazole derivatives have become the most rapidlyexpanding group of antifungal compounds with advanta-ges of lowtoxicity, high oral bioavailability and broad-spectrum antifungal activity, which can be used againstfungi including most yeasts an…     

Sr(Ag1−xLix)2Se2 and [Sr3Se2][(Ag1−xLix)2Se2] Tunable Direct Band Gap Semiconductors

Synthesizing solids in molten fluxes enables the rapid diffusion of soluble species at temperatures lower than in solid-state reactions, leading to crystal formation of kinetically stable compounds. In this study, we demonstrate the effectiveness of mixed hydroxide and halide fluxes in synthesizing complex Sr/Ag/Se in mixed LiOH/LiCl. We have accessed a series of two-dimensional Sr(Ag_1−xLi_x)₂Se₂ layered phases. With increased LiOH/LiCl ratio or reaction temperature, Li partially substituted Ag to form solid solutions of Sr(Ag_1−xLi_x)₂Se₂ with x up to 0.45. In addition, a new type of intergrowth compound [Sr₃Se₂][(Ag_1−xLi_x)₂Se₂] was synthesized upon further reaction of Sr(Ag_1−xLi_x)₂Se₂ with SrSe. Both Sr(Ag_1−xLi_x)₂Se₂ and [Sr₃Se₂][(Ag_1−xLi_x)₂Se₂] exhibit a direct band gap, which increases with increasing Li substitution (x). Therefore, the band gap of Sr(Ag_1−xLi_x)₂Se₂ can be precisely tuned via fine-tuning x that is controlled by only the flux ratio and temperature.     

H atom adsorption and diffusion on Si(110)-(1×1) and (2×1) surfaces

We present a periodic density-functional study of hydrogen adsorption and diffusion on the Si(110)-(1×1) and (2×1) surfaces, and identify a local reconstruction that stabilizes the clean Si(110)-(1×1) by 0.51 eV. Hydrogen saturates the dangling bonds of surface Si atoms on both reconstructions and the different structures can be identified from their simulated scanning tunneling microscopy/current image tunneling spectroscopy (STM/CITS) images. Hydrogen diffusion on both reconstructions will proceed preferentially along zigzag rows, in between two adjacent rows. The mobility of the hydrogen atom is higher on the (2×1) reconstruction. Diffusion of a hydrogen vacancy on a monohydride Si(110) surface will proceed along one zigzag row and is slightly more difficult (0.2 eV and 0.6 eV on (1×1) and (2×1), respectively) than hydrogen atom diffusion on the clean surface.     

_(a_1)_(d_1)-A_(a_2)D_(d_2)型氢键体系的网络结构参数

利用溶胶-凝胶分配理论对氢键溶液的模型体系进行研究,给出了体系的凝胶化条件以及凝胶点后氢键网络中各类结构参数的计算方案,并进行了相应的数值计算.结果表明,当两类质子受体基团的活性不同时,质子受体基团的竞争作用对网络结构有一定影响.这为控制氢键网络结构特征提供了可能的理论线索.     

Synthesis and Crystal Structure of a New Dinuclear Copper(Ⅱ) Polymer: [Cu2(bipy)2(Hbtc)2(H2O)2]·(H2O)1/2

A new dinuclear copper(Ⅱ) polymer [Cu2(bipy)2(Hbtc)2(H2O)2]·(H2O)1/2 1 (bipy=2,2'-bipyridine, H3btc = benzene-1,3,5-tricarboxylic acid) was obtained by the hydrothermal single-crystal X-ray diffraction analysis and identified using elemental analysis and IR spectrum.The title complex crystallizes in monoclinic system, space group P21/c with a = 7.2880(5), b =18.4778(13), c = 13.5465(10)(A), β = 95.9580(10)°, C19H14.50CuN2O7.25, Mr = 450.37, V= 1814.4(2)(A)3, Z=4, Dc = 1.649 g/cm3, μ = 1.253 mm-1, F(000) = 918, Rint = 0.0185, the final R = 0.0271and wR = 0.0710 for 2773 observed reflections (I＞2σ(I)). The study results reveal that a pair of distorted square-pyramidal Cu2+ ions are interlinked by bis-monodentate bridging Hbtc2- ligands to constitute a 16-membered ring.     

A_(a_1)B_(b_1)—A_(a_2)B_(b_2)缩聚反应的分布函数和高分子矩

本文用概率统计方法,得到了A_(a1)B_(b1)—A_(a2)B_(b2)缩聚反应的分布函数。应用分布函数定义了高分子各类矩。用直接微商法,得到了计算矩的循环公式。解决了用矩表征这类反应的问题。本文也得到了凝胶化条件。