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.     

Reaction of 1, 1-Di-p-methoxyphenyl-2, 2-dinitroethylene and 1, 1-Di-O-methoxyphenyl-2, 2-dinitroethylene with 1-Benzyl-1, 4-dihydronicotinamide： Evidence for Concerted Electron-hydrogen Atom Transfer Mechanism

1,1-Di-p-methoxyphenyl-2, 2-dinitroethylene reacts with 1-benzyl-1, 4-dihydronicotinamide (BNAH) in deaerated acetonitrile to give 1,1-di-p-methoxyphenyl-2, 2-dinitroethane,while 1,1-di-O-methoxyphenyl-2, 2-dinitroethylene fails to react with BNAH under the same conditions, which provides evidence for a concerted electron-hydrogen atom transfer mechanism.     

A_a_1,A_a_2-B_b_1B_b_2缩聚反应的固化理论

本文讨论了A_(a_1),A_(a_2)-B_(b_1)B_(b_2)型缩聚反应的固化理论。给出了溶胶-凝胶分配公式、凝胶化条件、分布函数及适合固化全过程的高分子矩的循环公式和k次矩的解析表示式。     

Synthesis and Crystal Structure of 1-Methylsulfinyl-1-methylthio-2-cyano-2-phenylethylene

1　ＩＮＴＲＯＤＵＣＴＩＯＮＤｉｔｈｉｏａｃｅｔａｌｓ[1 3]ｈａｖｅｄｅｍｏｎｓｔｒａｔｅｄｔｈｅｉｒｐｏｔｅｎｔｉａｌｆｏｒｔｈｅｓｙｎｔｈｅｓｉｓｏｆｈｅｔｅｒｏｃｙ ｃｌｅｓ,ｔｈｅｒｅｆｏｒｅ ,ｔｈｅｉｒｓｙｎｔｈｅｓｉｓａｎｄｒｅａｃｔｉｏｎｓｈａｖｅａｔｔｒａｃｔｅｄｍｕｃｈａｔｔｅｎｔｉｏｎ ,ｂｕｔｖｅｒｙｌｉｔｔｌｅｈａｓｂｅｅｎｒｅｐｏｒｔｅｄａｂｏｕｔｔｈｅｏｘｉｄａｔｉｏｎｏｆｄｉｔｈｉｏａｃｅｔａｌｓ[4].Ａｃｃｏｒｄｉｎｇｔｏｔｈｅｐｒｅｖｉ ｏｕｓｒｅｐｏｒｔ,ｔｈｅｏｘｉｄ…     

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…     

Solubility of Oxygen in Some 1-1, 2-1, 1-2, and 2-2 Electrolytes as a Function of Concentration at 25°C

The solubility of oxygen has been measured in a number of electrolytes [(LiCl, KCl, RbCl, CsCl, NaF, NaBr, NaI, NaNO₃, KBr, KI, KNO₃, CaCl₂, SrCl₂, BaCl₂, Li₂SO₄, K₂SO₄, Mn(NO₃)₃)] as a function of concentration at 25°C. The solubilities, mol (kg-H₂O)^–1, have been fitted to a function of the molality m (standard deviation < 3mol-kg^–1)

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…     

李春艳1,李建华1,申贵隽2*

氰化物是一种快速、剧毒的化合物,能够引起组织衰竭以至机体死亡。氰化物一旦污染环境及食用源,会严重危害人体健康,当吸入或口服较大剂量氰化物时,会引起“闪电式”骤死,中毒者在10~60S内突然发出尖叫随即昏倒,出现强直性与阵发性痉挛,2-3min后呼吸停止而死亡[1]。因此加强对氰化物检测是一项重要的安全检测指标,为此,建立准确、快速,特别是能用于现场操作的氰化物测定方法有重要意义。     

Conductivities of 1∶1 salts in 2-cyanopyridine

Electrolytic conductivities of eight simple 11 electrolytes have been measured in dilute solutions of 2-cyanopyridine (2CNP) at 30°. Infinite dilution mobilities and association constants were calculated using the Fuoss-Hsia equation. With the exception of LiCF₃SO₃ all salts show very little association, consistent with the very high dielectric constant of 2CNP. The weak association which does occur is attributed to weak ion-solvent interactions. No evidence was found for triple ion formation. Conductivities of concentrated solutions of LiAsF₆ in 2CNP increase slowly with concentration reaching a maximum at a concentration of around 0.65 mol-dm^–3. These conductances are slightly lower than those in propylene carbonate which has a lower dielectric constant and a higher viscosity. Conductivities of concentrated LiAsF₆ solutions in 2CNP mixtures with acetonitrile vary monotonically, consistent with solution viscosities, and show no sign of the maximum commonly observed in mixed organic solvents.     

CONVERSION OF KETONES INTO1，1－DISUBSTITUTED－2，3，3－TRIFLUORO－2－PROPEN －1－OLSWITH1，1－DIBROMO－1，2，2，2－TETRLUORO ETHANE／MAGNESIUM REAGENT

ＣＯＮＶＥＲＳＩＯＮ　ＯＦ　ＫＥＴＯＮＥＳ　ＩＮＴＯ１，１－ＤＩＳＵＢＳＴＩＴＵＴＥＤ－２，３，３－ＴＲＩＦＬＵＯＲＯ－２－ＰＲＯＰＥＮ　－１－ＯＬＳＷＩＴＨ１，１－ＤＩＢＲＯＭＯ－１，２，２，２－ＴＥＴＲＬＵＯＲＯ　ＥＴＨＡＮＥ／ＭＡＧＮＥＳＩＵＭ...     

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.     

CHINESE JOURNAL OF CHEMISTRY Vol.2 0 No .1 1 November 2 0 0 2 AUTHOR INDEX

ＣＨＡＯ ,Ｈｕｉ 12 35………………ＣＨＥＮ ,Ｍｉｎｇ Ｄｅ 1149…………ＣＨＥＮ ,Ｑｉｎｇ Ｈｕａ 1340…………ＣＨＥＮ ,Ｗｅｉ 140 1………………ＣＨＥＮ ,Ｘｉａｏ Ｍｉｎ 1139…………ＣＨＥＮ ,Ｘｉａｏ Ｍｉｎｇ 140 6………ＣＨＥＮ ,Ｚｈｅｎ Ｃｈｕ 145 7………ＣＨＥＮＧ ,Ｊｉｎ Ｓｈｅｎｇ 132 6………ＣＨＥＮＧ ,Ｐｅｎｇ 12 4 9……………ＤＥＮＧ ,Ｇｕｏ Ｊｕｎ 1139…………ＤｅｓＭａｒｔｅａｕ ,Ｄ .Ｄ . 12 6 8………ＤＩＮＧ ,Ｋｕｉ Ｌｉｎｇ 130 0…………ＤＩＮＧ ,Ｙｕ 1415………………ＤＵ ,Ｃｈｅｎ Ｘ…     

Preparation and properties of the systems Co1−xRhxS2, Co1−xRuxS2, and Rh1−xRuxS2

Members of the systems Co_1−xRh_xS₂ (0 ≤ x ≤ 0.6) were prepared, and their crystallographic and magnetic properties studied. The observed ferromagnetic moments for compositions where x ≤ 0.2 indicate a ferromagnetic alignment between Co(3d⁷) and Rh(4d⁷) electrons. This is the first observation of localized behavior of 4d electrons in the pyrite structure. Members of the systems Co_1−xRu_xS₂ (0 ≤ x ≤ 1) and Rh_1−xRu_xS₂ (0.5 ≤ x ≤ 1) were also prepared and their crystallographic and magnetic properties studied. From comparison with the Co_1−xRh_xS₂ system, it appears that the 4d electrons of Rh(4d⁷) are localized in the presence of Co(3d⁷) but are delocalized in the presence of Ru(4d⁶). The magnetic susceptibility of the Co_1−xRu_xS₂ system is sensitive to the homogeneity of the products and indicates that Ru(4d⁶) behaves as a diamagnetic ion.     

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。     

2－羟基2＇烷氧基－1，1＇－联萘化合物的~1HMNR研究

研究了２－羟基－２＇－异丙氧基－１。１－联萘（３）等联萘化合物的~１ＨＮＭＲ谱或ＣＯＳＹ谱。此类化合物因２及２＇位取代基不同，两个萘环上同位质子不再等价，萘环质子峰增至１２组。化合物３~１ＨＮＭＲ谱峰的归属表明，萘环环电流各向异性对另一萘环质子的屏蔽作用与作者早期研究结果［１］一致。２（或２＇）位取代基上的质子的化学位移也与另一萘环平面相对位置有关。     

Photodissociation of CS2+( 2 Πg) via (1+1) Excitation

Photodissociation dynamics of CS2+molecular ions has been investigated by (1+two-photon resonance technique. CS2+were prepared by (3+1) resonance-enhanced multi-photon ionization (REMPI) of CS2molecules at 483. 2nm. The photofragment S+excitati (PHOFEX) spectra were recorded by scanning another laser in the 424~482nm region, and we assigned essentially to CS2+(~A2Πu,3/2(v′=0~4)←~X2Πg,3/2(0,0,0)) and (~A2Πu,1/2(v′=0,4)←~X2Πg,1/2(0,0,0)) (herev′=v1′+(1/2)v2′) transitions. The S+production channel wpreliminarily attributed to, (i) one-photon excitation CS2+from the ground state~X2Πgto texcited state~A2Πu; (ii) vibronic coupling between the~A2Πustate and the high vibrational lev in the~X2Πgstate; (iii) second photon excitation from the coupling vibrational levels to the excied state~B2Σu+and dissociation to produce S++ CS via the repulsive4Σ-state through spin-orb interaction between the~B2Σu+and4Σ-states.     

Helical secondary structures in 2:1 and 1:2 α/γ-peptide foldamers

Oligomers containing both α- and γ-amino acid residues in a 1:1 alternating pattern have recently been shown by several research groups to adopt helical secondary structures. We have begun to explore the folding behavior of oligomers with different α-residue/γ-residue backbone patterns. Previously we reported that the γ-amino acids bearing a cyclohexyl constraint at the C_β–C_γ bond and a variable side chain at C_α strongly promote a helical conformation containing 12-atom CO(i)?H–N(i+3) hydrogen bonds for 1:1 α:γ backbones. Here we report synthesis and crystallographic analysis of 2:1 and 1:2 α/γ-peptides that adopt CO(i)?H–N(i+3) hydrogen-bonded helical conformations.     

Synthese des 1-Methyl-2-äthyl- und des 1-Äthyl-2-methylnaphthalins

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