Mass Spectral Fragmentation Patterns of Some Substituted 10,Ll-Dihydro-5H-Dibenzo[A,D] Cycloheptene-5-One and 9,10-Dihydro-4H-Benzo [4,5]Cyclohepta[1,2-B]Thiophene-4-One

Electron impact mass spectra of some substituted 10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-one and 9,10-dihydro-4H-benzo[4,5] cyclohepta[1,2-b] thiophene-4-one have been recorded and the identity of various ions in the mass spectra established. Substituted dibenzosuberones (2-6) exhibit one main fragmentation route, which include the elimination of the tropolone molecule from the dibenzosuberone fragment cation. Their monothiophene analogues(7-11) exhibit characteristic CO elimination from the molecular ion and formation of corresponding naphtho[1,2-b]thiophene radical cation which after elimination of CS or HCS from the thiophene nuclei give rise to the benzotrophyne radical cation.     

1H and 13C NMR Spectra of Alditolyl Derivatives of 3-Hydrazino-5-Methyl[1,2,4]triazino[5,6-b]indole and Their Cyclized Products.

The ¹H and ¹³C NMR spectra of sugar (5-methyl [1, 2, 4]-triazino [5, 6-b] indol-3-yl) hydrazones (1), per-0-acetyl aldehydo sugar 1-acetyl-1-(5-methyl [1, 2, 4] triazino [5, 6-b]-indol-3-yl) hydrazones (2), l- (penta-0-acetyl-pentitol-1-yl)-10-methyl [l, 2, 4] triazolo [3′, 4′:3, 4] [l, 2, 4] triazino [5, 6-b]-indoles (3) have been investigated. The 2 D NMR (H, C COSY) spectrum of 2a has been studied.     

Theoretical Study of Mechanism and Regioselectivity of 1,3-dipolar Cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] Nitrilimine with Dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate

采用活化能和基于密度泛函理论B3LYP/6-31G(d)水平的计算方法研究了5-硝基-2-呋喃甲醛-N-甲腙和7-氧杂双环[2,2,1]-2,5-二烯基-2,3-庚二酸甲酯的1,3-偶极环加成反应的机理以及区域选择性,计算结果与实验值一致. 该反应通过异步协同机制进行.     

Chiral Fluorescence Recognition by Anthracene Fluorescent Dyes ⊂ Water-Soluble Pillar[5] arene containing Phosphonic Acid Group (PWP[5])

Chirality plays a pivotal role in drugs, agrochemicals and food additives et al. The enantiomers of a chiral molecule often show huge difference in bioactivity, metabolism, and toxicity et al. thereby, the recognition of chiral molecules shows an increasingly important priority. In this paper, a novel method for chiral fluorescence recognition based on anthracene fluorescent dyes (AD)???water-soluble pillar[5] arene containing phosphonic acid group (PWP[5]) is developed. The AD as guest molecule can complex with PWP [5] to form 1:1 AD???PWP[5] assembly, and this assembly can be further used as a fluorescent probe to identify D/L-phenylalanine and D/L-phenylalaninol by fluorescent titration. The fluorescence intensity of the assembly was significantly reduced for D-phenylalanine and D-phenylalaninol, while L-phenylalanine or L-phenylalaninol was added to AD???PWP[5] assembly, the fluorescence intensity of the assembly almost unchanged. Hence, the chiral recognition based on assembly between the achiral fused ring fluorescent dye and achiral PWP[5] was developed.

     

3-[5-(α-萘)-2H-四唑-2-甲撐-4-苯基-1,2,4-三唑啉-5-硫酮13C-NMR的研究

本文研究了5-(α-萘)-四唑(Ⅱ),5-(α-萘)-2H-四唑-2-乙酸甲酯(Ⅲ),5-(α-萘)-2H-四唑-2-乙酰肼(Ⅳ),1-[5-(α-萘)-2H-四唑-2-乙酰]-4-苯基氨基硫脲(V)以及3-[5-(α-萘)-2H-四唑-2-甲撐]-4-苯基-1,2,4-三唑啉-5-硫酮(Ⅵ)的¹³C核磁共振谱和各种¹³C-NMR化学位移。根据化学位移理论、讯号强度以及同模型化合物化学位移的比较,辨认其归属。     

Diastereoselective synthesis of fused [1,3]thiazolo[1,3]oxazins and [1,3]oxazino[2,3-b][1,3]benzothiazoles

An efficient diastereoselective synthesis of 7-ethyl 5,6-dialkyl 7H-[1,3]thiazolo[2,3-b][1,3]oxazin-5,6, 7-tricarboxylates and 2-ethyl 3,4-dialkyl 2H-[1,3]oxazino [2,3-b][1,3]benzothiazole-2,3,4-tricarboxylates via reaction of thiazole and benzothiazole with dialkyl acetylenedicarboxylates in the presence of ethyl pyruvate is described.     

Photoelectron spectroscopy of carbonyls. Bicyclo[2.2.1]-heptane-2,3-diones and bicyclo [2.2.1] hept-5-ene-2,3-diones

The HeI photoelectron spectra (UPS) of several bicyclo [2.2.1] heptane-2,3-diones and bicyclo[2.2.1] hept-5-ene-2,3-diones are presented. Interpretations are based on CNDO/s computations and empirical correlations. The n₊ orbital of the two carbonyl groups interacts strongly with, the π orbital of the 5-ene moiety in bicyclo[2.2.1]hept-5-ene-2,3-diones. This interaction is dominantly “through-bond”, there being little or no direct (i.e. “through-space”) overlap. The net result is that insertion of 5-ene unsaturation increases the splitting of the n₊ and n_? orbitals from ca. 1.9 to ca. 2.4 eV. Finally, the π* (CO) ← n₊ electronic absorption spectra of the [5-ene] -compounds, which are geometrically suited to an investigation of π/π* (CO) interactions, suggest that such mixing is negligible.     

Cation-mediated sandwich formation between benzene and pillar[5]arene: a DFT study

Cation–π interactions in alkali metal ion (Li⁺, Na⁺ and K⁺)–pillar[5]arene complexes and sandwiches of pillar[5]arene and benzene formed via alkali metal ions are studied in the light of density functional theory. Several possible modes of interaction between metal ions and pillar[5]arene have been studied. Results suggest that interaction is stronger in the complexes with the metal ion present inside the cavity of the pillar[5]arene as compared to that where the metal ion is outside the cavity. The calculated interaction energy further reveals that though cation–π complexes with larger number of alkali metal ions are unstable, however, corresponding sandwiches are stable, which further support the fact that pillar[5]arene–metal ion complexes can interact with other π–electron-rich species. Absorption spectra of the complexes formed undergo both blue and red shifts as compared to the pillar[5]arene.     

Perception of the [m]-[n] distinction in CV syllables

The contribution of the nasal murmur and the vocalic formant transitions to perception of the [m]-[n] distinction in utterance-initial position preceding [i,a,u] was investigated, extending the recent work of Kurowski and Blumstein [J. Acoust. Soc. Am. 76, 383-390 (1984)]. A variety of waveform-editing procedures were applied to syllables produced by six different talkers. Listeners' judgments of the edited stimuli confirmed that the nasal murmur makes a significant contribution to place of articulation perception. Murmur and transition information appeared to be integrated at a genuinely perceptual, not an abstract cognitive, level. This was particularly evident in [-i] context, where only the simultaneous presence of murmur and transition components permitted accurate place of articulation identification. The perceptual information seemed to be purely relational in this case. It also seemed to be context specific, since the spectral change from the murmur to the vowel onset did not follow an invariant pattern across front and back vowels.     

New pyrazolyl-dibenzo[b,e][1,4]diazepinones: room temperature one-pot synthesis and biological evaluation

Molecular Diversity - Several new (5-aryloxy-pyrazolyl)- and (5-aryl/olefin-sulfanyl-pyrazolyl)-dibenzo[b,e] [1,4] diazepinone scaffolds have been synthesized, by assembling 5-substituted...     

Computational studies on cyclic [n]paraphenyleneacetylenes using homodesmotic reactions

Cyclic [n]paraphenyleneacetylenes ([n]CPPAs) are potentially useful compounds for molecular electronics. In this article, a homodesmotic reaction scheme coupled with density functional theory has been used to estimate theoretically strain energies and heats of formation of [n]CPPAs. Calculations have been done for a series of [n]CPPAs, containing up to ten phenylacetylene units. Strain energies of [n]CPPAs decrease, while heats of formation increase steadily with the increase in the number of phenylacetylene units using homodesmotic reaction schemes. B3LYP and mPW1PW91 functionals have been used with the Pople basis set 6-31G* to analyze the trends. The results are sensitive to the scheme of homodesmotic reaction chosen, thereby necessitating careful chemical consideration before spending considerable computational resources for higher [n]CPPAs not considered here. Computational estimates for the ring diameter of [n]CPPAs and absolute entropy have also been obtained here. The HOMO-LUMO gaps of the belt shaped [n]CPPAs show an odd–even difference. In addition, the HOMOs of the [3]CPPA, [5]CPPA, [7]CPPA and [9]CPPA are doubly degenerate.     

Spectroscopy of nickel chloride: Identification of the [15.0] Π3/2 and [15.0] Δ5/2 states

Vibrational bands belonging to the [15.0] ²Δ_5/2-A²Δ_5/2, [15.0] ²Δ_5/2-X²Π_3/2, and [15.0] ²Π_3/2-X²Π_3/2 electronic transitions of NiCl have been observed in the 14 000-16 000 cm⁻¹ region. The [15.0] ²Δ_5/2 and [15.0] ²Π_3/2 states are identified for the first time. The observed bands have been recorded at high spectral resolution using several techniques, which include intracavity laser spectroscopy (ILS), Fourier transform emission spectroscopy (FTS), and laser induced fluorescence (LIF) spectroscopy. For the ILS absorption spectra, NiCl molecules were produced in a nickel hollow cathode operated with a small amount of CCl₄. For the FTS emission spectra, excited NiCl molecules were produced in a King-type carbon tube furnace loaded with NiCl₂ and heated to 1600 °C. In the LIF work, NiCl molecules were produced by reacting laser-ablated nickel with PCl₃ seeded in argon. Detailed analysis of rotational transition lines indicates that the observed [15.0] ²Δ_5/2 and [15.0] ²Π_3/2 states are only separated by 10 cm⁻¹ and are interacting with each other. Molecular constants for these newly observed electronic states are reported.     

Ultrasound promoted copper-, ligand- and amine-free synthesis of benzo[b]furans/nitro benzo[b]furans via Sonogashira coupling-5-endo-dig-cyclization

This method describes the results of the optimized conditions for the one-pot synthesis of benzo[b]furans/nitro benzo[b]furans via Sonogashira coupling-5-endo-dig-cyclization under ultrasonic irradiation at ambient temperature in the absence of copper, ligand and amine. The protocol tolerates wide range of functional groups present in both the coupling components, especially base labile nitro group was not affected under these mild conditions giving excellent yields of the nitro benzo[b]furans. The formation of Pd(0) nanoparticles as the active species has been shown by TEM analysis and the unique role of ultrasound in promoting the total sonochemical protocol has been substantiated by way of control experiments.     

超高泵浦功率下的Xe(6p[1/2]0, 6p[3/2]2, 和6p[5/2]2)原子的能量转移过程

本文研究了Xe(6p[1/2]₀, 6p[3/2]₂, and 6p[5/2]₂)原子在聚焦条件下的动力学过程. 激发能级的原子密度在聚焦条件下会显著地增加,因此两个高激发态原子之间的energy-pooling碰撞的概率也会增加. 这种energy-pooling碰撞主要有三种类型. 第一种类型为energy-pooling碰撞导致的电离. 一旦将激发激光聚焦,就可以从侧面的窗口观察到非常明显的电离现象,不论激发能级是6p[1/2]₀、6p[3/2]₂或6p[5/2]₂能级. 这种电离的产生机理是energy-pooling电离或者一个Xe^*原子再吸收一个光子产生电离. 第二种类型为跨越较大能极差的energy-pooling碰撞. 当激发能级为6p[1/2]₀能级的情况下,两个6p[1/2]₀原子碰撞会产生一个5d[3/2]₁原子和一个6s''[1/2]₀原子. 第三种类型为跨越较小能级差的energy-pooling碰撞. 以5个二次产生的6p能级为上能级的荧光强度都变得更强,并且这些荧光的上升沿都变得更陡峭. 产生这些6p原子的主要机理是energy-pooling碰撞并非简单的碰撞弛豫. 基于理想气体原子之间的碰撞概率公式,推导出两个6p[1/2]₀原子的energy-pooling碰撞速率为6.39x10⁸s^-1. 此外,6s原子在聚焦条件下的密度也会增加. 因此所有的荧光曲线会因为辐射俘获效应而出现非常严重的拖尾.     

Theoretical investigation of the diboranyl radical [Bdot]2H5

Based on the structure of the neutral diboranyl ([Bdot]₂H₅) radical, which was proposed from the analysis of E.S.R. spectra, the dipolar coupling tensors of the boron, the bridging hydrogen and the terminal hydrogens in this radical have been calculated by means of the analytical formulae for the dipolar integrals used by Barfield and others. The calculated dipolar tensors were found to be in good agreement with the experimental results. The calculations confirm the configuration proposed by Hasegawa and Sohma for the [Bdot]₂H₅ radical.     

一维链状配合物[BrBzPy][Ni(dmit)2]的合成和红外光谱研究

合成了一种新的化合物[BrBzPy][Ni(dmit)2](1),并进行了红外光谱表征.晶体的结构结果表明它的空间点群为P21/c,a=0.627 5(1)nm,b=1.743 8(3)nm,c=2.283 9(3)nm,α=90°,β=9.187(1)nm,γ=90°,V=2.497(7)nm3,Z=4,Mr=700.57,Dc=1.863 g·cm-3.晶体中[Ni(dmit)2]-非常接近平面,共轭性相当显著,且成为一维链状结构.     

Study of J/psi-->pp[over],LambdaLambda[over] and observation of eta(c)-->LambdaLambda[over] at Belle

We study the baryonic charmonium decays of B mesons B+-->etacK+ and B+-->J/psiK+, where the etac and J/psi subsequently decay into a pp[over] or LambdaLambda[over] pair. We measure the J/psi-->pp[over] and LambdaLambda[over] anisotropy parameters alphaB=-0.60+/-0.13+/-0.14 (pp[over]), -0.44+/-0.51+/-0.31 (LambdaLambda[over ]) and compare to results from e;{+}e;{-}-->J/psi formation experiments. We also report the first observation of etac-->LambdaLambda[over]. The measured branching fraction is B(etac-->LambdaLambda[over ])=(0.87(+0.24)/(-0.21)(stat)(+0.09/-0.14) (syst)+/-0.27(PDG))x10-3. This study is based on a 357 fb-1 data sample recorded on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ e- collider.     

具有双分子结构的[2-(5-甲基-2-羟基苯基)苯并噻唑]锌的单晶结构和光学性能(英文)

合成了一种具有双分子结构的[2-(5-甲基-2-羟基苯基)苯并噻唑]锌[Zn(5-MeBTZ)2]。通过X射线单晶衍射的方法确定了它的分子结构。单晶数据如下:空间群为三斜,P-1晶系,a=0.971 9(2)nm,b=1.124 8(2)nm, c=1.190 2(2)nm;α=73.099(3)°,β=81.498(3)°,γ=76.476(3)°。两个分子间存在有π-π相互作用。Zn(5-MeBTZ)2具有良好的热稳定性,熔点为319℃。以Zn(5-MeBTZ)2为发光层,NPB为空穴传输层材料的双层结构器件的电致发光光谱有较大的半峰全宽,几乎覆盖整个可见光区域。这种宽的EL谱是由于在NPB和Zn(5-MeBTZ)2界面的激基复合物产生的。优化的OLED器件结构和性能将在以后的论文中介绍。     

Perception of the [m]-[n] distinction in VC syllables

This study complements earlier experiments on the perception of the [m]-[n] distinction in CV syllables [B. H. Repp, J. Acoust. Soc. Am. 79, 1987-1999 (1986); B. H. Repp, J. Acoust. Soc. Am. 82, 1525-1538 (1987)]. Six talkers produced VC syllables consisting of [m] or [n] preceded by [i, a, u]. In listening experiments, these syllables were truncated from the beginning and/or from the end, or waveform portions surrounding the point of closure were replaced with noise, so as to map out the distribution of the place of articulation information for consonant perception. These manipulations revealed that the vocalic formant transitions alone conveyed about as much place of articulation information as did the nasal murmur alone, and both signal portions were about as informative in VC as in CV syllables. Nevertheless, full VC syllables were less accurately identified than full CV syllables, especially in female speech. The reason for this was hypothesized to be the relative absence of a salient spectral change between the vowel and the murmur in VC syllables. This hypothesis was supported by the relative ineffectiveness of two additional manipulations meant to disrupt the perception of relational spectral information (channel separation or temporal separation of vowel and murmur) and by subjects' poor identification scores for brief excerpts including the point of maximal spectral change. While, in CV syllables, the abrupt spectral change from the murmur to the vowel provides important additional place of articulation information, for VC syllables it seems as if the format transitions in the vowel and the murmur spectrum functioned as independent cues.     

Surface Reconstruction with a Fractional Hole: (sqrt[5] x sqrt[5])R26.6 degrees LaAlO3 (001)

The structure of the (sqrt[5] x sqrt[5])R26.6 degrees reconstruction of LaAlO3 (001) has been determined using transmission electron diffraction combined with direct methods. It has a lanthanum oxide termination with one lanthanum vacancy per surface unit cell. Density functional calculations indicate that charge compensation occurs by a fractional number of highly delocalized holes, and that the surface contains no oxygen vacancies and the holes are not filled with hydrogen. The reconstruction can be understood in terms of expulsion of the more electropositive cation from the surface and increased covalency.