两类以芴为中心的有机分子双光子吸收特性

在密度泛函理论水平上, 利用响应函数方法研究了实验新合成的两类以芴为π中心的分子(SK-G1和NT-G1)的双光子吸收特性. 计算结果表明, 这两类有机分子都具有较大的单光子和双光子光吸收强度. 在低能量范围内, NT-G1分子的最大单光子吸收峰相对于SK-G1分子来说发生了红移, 且其最大单光子吸收强度是SK-G1分子的两倍. SK-G1和NT-G1分子的最大双光子吸收均发生在第二激发态. NT-G1分子的最大双光子吸收截面约是SK-G1分子的五倍, 并且NT-G1分子存在一个较宽的双光子吸收带. NT-G1分子的较强光学性质与分子内较大的电荷转移过程有关. 采用Onsager模型计算了溶剂分子对溶质分子单光子吸收性质的影响, 理论计算结果和实验测量结果符合得较好.     

Experimental Investigations on Highly Conducting Solid Bio-Polymer Electrolytes Based on Latex of Calotropis gigantea Plant

The study has prepared highly conducting polymer electrolyte films using solution cast technique with poly(vinylidene fluoride-co-hexafluoropropylene) PVDF-HFP, mixture of ethylene carbonate (EC), and propylene carbonate (PC) as plasticizer and latex of Calotropis gigantea (CGL) as an ionic source. In this study, four films are prepared using PVDF-HFP:CGL in ratio 1:1 with the increasing concentration of EC+PC as 1, 2, 3, and 4 M named as 1:1:1, 1:1:2, 1:1:3, 1:1:4. The prepared polymer electrolyte is examined by polarized optical microscopy (POM), elemental dispersive X-ray technique (EDX), and complex impedance spectroscopy. EDX and POM are studied for the surface morphology of all prepared samples and to investigate the porous nature of films. The enhancement in ionic conductivity occurs due to CGL and increasing amount of EC-PC. Conductivity of highest composition (1:1:4) polymer electrolyte film is found to be ≈10⁻³ S cm⁻¹. The optimized polymer electrolyte film is considered as a promising candidate for application in supercapacitors.     

FTIR Studies on NO Adsorption on [Co+Mg(Sr)]/ZSM-5

IntroductionThe FTIR spectroscopy of NO adsorption on[Co +Mg(Sr) ]/ZSM- 5 has not been fullyelucidated yet.Previous researchers working onNO adsorption over Co/ZSM- 5 stated that thebands at 1 81 0 and 1 890 cm-1are due to dinitrosylspecies adsorbed on Co2 +[1] ,while the band at193 5 cm-1is attributable to mononitrosyl species.Aband near1 85 8cm-1(w) may be attributable tothe species of Co3O4 —NO[2 ] .Further,Zhu etal.[2 ]reported the bands at1 81 3 ,1 896 and1 93 9cm-1assigned to …     

The synthesis of 1-methyl-1-germaadamantane

The syntheses of 1-methyl-1-germaadamantane and 1-chloro-1-germaadamantane are described. Attempts to prepare the 1-methyl-1-stannaadamantane and the novel cage systems, 1-silatris-nor- and 1-silatris-homo-adamantanes are also described as well as the syntheses of a variety of Group IV 1,3,5-trisubstituted cyclohexanes.     

Relative reactivities of some dienes and acetylenes in copolymerization with sulfur dioxide

The reactivities of isoprene, piperylene,2,3-dimethylbutadiene, hex-1-yne, and phenylacetylene, at ?20°C, relative to that of cyclohexene, have been determined for the radical-initiated copolymerization with sulfur dioxide to form 1:1 polysulfones. The unsaturated hydrocarbons were copolymerized with sulfur dioxide in pairs and the composition of the terpolymers determined from the 100 MHz NMR spectra. The dienes react 11–15 times as fast as hex-1-ene, while hex-1-yne reacts 16 times more slowly. Phenylacetylene reacts 21 times as fast as hex-1-yne. The relative reactivities are interpreted mainly in terms of the effect of electron delocalization on the stability of the product radical.     

硅烷化TS-1对环己烷均相氧化反应的促进作用

考察了钛硅分子筛(TS-1)以及硅烷化钛硅分子筛(TS-1-S)上环烷酸钴(Co-nap)催化环己烷氧化反应性能.结果表明,TS-1和TS-1-S对该反应均具有显著的促进作用,环己烷转化率由无TS-1时的3.6%分别提高至6.4%和7.9%,产物选择性保持在80%左右,反应时间由300 min可缩短为130min.进一...     

Biodegradation of n-hexadecane by bacterial strains B1 and B2 isolated from petroleum-contaminated soil

Two hydrocarbon-biodegrading bacterial strains,B1 and B2,were isolated from petroleum-contaminated soil collected from Tianjin,China.The strains were identified as Pseudomonas aeruginosa(B1) and Acinetobacter junii(B2).The degradation rate of n-hexadecane by B1 and B2 reached 96% and 78% respectively after 7 days,though the strains employed different mechanisms of degradation.The results showed that B2 was not able to use glucose as carbon source.B1 could produce glycolipid surfactants using glucose as the carbon source,according to the results of blue agar plate analysis and thin layer chromatography(TLC),and the bacterial culture of B1 had a high oil discharge and emulsification activity.Both B1 and B2 could produce biosurfactants with hexadecane as the sole carbon source,but their modes of action were different.The carbon source was found to affect the cell surface hydrophobicity.Cell surface hydrophobicity was poor with glucose as the carbon source,but enhanced when hexadecane was used as the carbon source.     

不同TS-1分子筛含量条状催化剂的丙烯环氧化性能

环氧丙烷(PO)是重要的有机化工原料，主要用于生产聚醚多元醇、丙二醇及其它化工产品。现在工业上主要采用氯醇法和Halcon法生产环氧丙烷，但分别存在污染和联产物量大等问题，人们在改进原有工艺的同时，致力于寻找流程短、副产少、无污染的新工艺。TS-1分子筛的成功合成^[1]及其在以     

Struktur-Reaktivitäts-Beziehungen bei koordinativ-ungesättigten Chelatkomplexen. VI. Synthese,Adduktbildung, Redoxpotentiale und photochrome lodderivate von Eisen(II)-Komplexen Schiffscher Basen mit elektronenziehenden Substituenten

Structure Reactivity Correlations in Coordinatively Unsaturated Chelate Complexes. VI. Synthesis, Adduct Formation, Redox Potentials, and Photochromic Iodine Derivatives of Iron(II) Complexes with Schiff Base Ligands Possessing Electron-Withdrawing Substituents Iron(II) complexes of the type 1 have been prepared by different synthetic methods. In contrast to similar chelates of the “saloph” and “salen” types, the high-spin complexes 1 form stable high-spin diadducts ( 1a – 1d ) and an unusual triadduct ( 1e ) with pyridine. The oxidation potentials of the Fe^II/Fe^III couple as measured by cyclic voltammetry are dependent on the solvent as well as the equatorial ligand substituents. The potentials are more positive in pyridine than in DMF, indicating a stabilization of Fe^II by pyridine. The redox potentials are discussed with respect to those of other metals in the same ligand environment. The complexes form iodine derivatives which show photochromic behaviour in THF solution. The rate of the reaction with dioxygen in the solid state as well as in pyridine solution decreases in the order 1f > 1a ≈ 1b > 1c ≈ 1d > 1e and correlates with the increasing oxidation potentials.     

Synthesis and anti-peptic activity of compounds related to the metabolites of sodium 3-ethyl-7-isopropyl-1-azulenesulfonate (KT1-32).

The metabolites of sodium 3-ethyl-7-isopropyl-1-azulenesulfonate (KT1-32, 1), a candidate as an anti-ulcer drug, and related compounds were synthesized. The effects of the compounds on anti-peptic activity were determined as compared to that of 1.     

Diarylurea-linked zinc porphyrin dimer as a dual-mode artificial receptor: supramolecular control of complexation-facilitated photoinduced electron transfer

A novel porphyrinic receptor 1 in which two zinc porphyrins are bridged by two diarylurea linkers was developed for recognition of a viologen derivative (hexyl viologen, HV). The electronic absorption spectra as well as the 1H NMR experiments revealed that the HV molecule was bound to the cleft in 1 mainly through carbonyl dipole-charge interactions to afford a 1:1 complex. From the steady-state fluorescence spectroscopic study, the photoinduced electron transfer (PET) from 1 to HV was extremely facilitated by the receptor-substrate complexation. The receptor 1 also formed a 1:1 complex with 1,4-diazabicyclo[2.2.2]octane (DABCO) through two Zn-N coordination interactions, and, using DABCO as an inhibitor, we suppressed the PET reaction via the substrate exchange.     

Diversity of Chlamydomonas channelrhodopsins

Channelrhodopsins act as photoreceptors for control of motility behavior in flagellates and are widely used as genetically targeted tools to optically manipulate the membrane potential of specific cell populations ("optogenetics"). The first two channelrhodopsins were obtained from the model organism Chlamydomonas reinhardtii (CrChR1 and CrChR2). By homology cloning we identified three new channelrhodopsin sequences from the same genus, CaChR1, CyChR1 and CraChR2, from C. augustae, C. yellowstonensis and C. raudensis, respectively. CaChR1 and CyChR1 were functionally expressed in HEK293 cells, where they acted as light-gated ion channels similar to CrChR1. However, both, which are similar to each other, differed from CrChR1 in current kinetics, inactivation, light intensity dependence, spectral sensitivity and dependence on the external pH. These results show that extensive channelrhodopsin diversity exists even within the same genus, Chlamydomonas. The maximal spectral sensitivity of CaChR1 was at 520 nm at pH 7.4, about 40 nm redshifted as compared to that of CrChR1 under the same conditions. CaChR1 was successfully expressed in Pichia pastoris and exhibited an absorption spectrum identical to the action spectrum of CaChR1-generated photocurrents. The redshifted spectra and the lack of fast inactivation in CaChR1- and CyChR1-generated currents are features desirable for optogenetics applications.     

甘露聚糖肽的结构鉴定

采用离子交换柱层析和凝胶柱层析从甘露聚糖肽原料中分离纯化得到4种均一糖肽MT1-A,MT1-B,MT2-A和MT2-B;通过单糖组成分析、甲基化分析、氢核磁共振谱(~1H NMR)、红外光谱(IR)和氨基酸组成分析等手段对均一糖肽MT1-A,MT1-B和MT2-B的结构进行了鉴定.结果表明,3种均一糖肽的单糖组成、糖残基的连接方式与MT2-A相同,但是分子量以及氨基酸总量有所不同.测定了不同批次甘露聚糖肽原料的~1H NMR谱,以MT2-A的~1H NMR谱图为标准谱,以异头氢区域为鉴定区域,通过计算不同批次甘露聚糖肽原料以及其它3种均一糖肽与MT2-A的~1H NMR谱的相关系数,定量评价了不同批次甘露聚糖肽原料与4种均一糖肽的相似程度.结果表明,甘露聚糖肽是由糖链结构一致、分子量和氨基酸含量不同的几种均一糖肽构成的混合物.     

Enzymatic esterification and phase behavior in ionic microemulsions with different alcohols

The esterification of hexanoic acid and 1-pentanol catalyzed by the lipase fromChromobacterium viscosum was studied at 298.2 K using different Winsor systems as reaction medium. The microemulsion systems consisted of brine and alkane stabilized by the anionic surfactant sodium dodecylsulphate and a short-chained alcohol. The alcohol acts both as a reactant and as a part of the reaction medium. Therefore, it is of great fundamental interest to know the phase behavior of the used microemulsion systems. Partial phase diagrams were determined and the efficiency of different alcohols on the transition from a Winsor I system to a Winsor III or a Winsor IV system with bicontinuous structure and further to a Winsor II system was investigated. The investigated alcohols were 2-methyl-1-propanol, 1-butanol, 2-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 4-methyl-1-pentanol, and 1-hexanol. The aqueous medium consisted of 0.5 m NaCl(aq) or a phosphate buffer (pH=7) and the organic medium of octane or 2,2,4-trimethyl pentane. A long alkyl chain of the alcohol or a branching far from the hydroxyl group gives a more efficient cosurfactant and a transition from Winsor I to Winsor III or Winsor IV at lower alcohol contents. In the Winsor III system the yield of 1-pentyl hexanoate is twice as high as the yield in the bicontinuous Winsor IV system.     

An artificial molecular chaperone: poly-pseudo-rotaxane with an extensible axle

Poly-pseudo-rotaxanes CDs contains as a subset 1 (CDs; cyclodextrins, 1; poly(delta-valerolactone) having single beta-CD at the end of the polymer chain) initiate polymerization of delta-valerolactone (delta-VL) in the solid state when CDs (alpha-CD, beta-CD, and 2,6-di-O-methyl-beta-CD) are threaded onto the polymer chain. 1 without threaded CDs did not show any polymerization ability for delta-VL. An adamantane molecule (Ad) inhibited the polymerization ability of CDs contains as a subset 1 for delta-VL, indicating that beta-CD at the end of CDs contains as a subset 1 could not bind delta-VL because the beta-CD cavity was occupied by Ad. It should be noted that the insertion reaction and the polymerization took place inside the beta-CD cavity at the end of CDs contains as a subset 1 and that the formation of poly-pseudo-rotaxane is necessary for the initiation of delta-VL. The structures of beta-CD contains as a subset 1 and 1 were characterized by powder X-ray diffraction measurements and solid-state NMR spectroscopies. The polymer chain of beta-CD contains as a subset 1 was found to elongate in the solid state, whereas the polymer chain of 1 formed a random coil conformation. 1 was deactivated for the polymerization by blocking the active cavity of beta-CD with the polymer chain. CDs threaded onto 1 are immune to the initiation of delta-VL directly but have an essential role to fold the polymer chain in a proper way as an artificial chaperone.     

Red and yellow color aspects of compound 3-dicyclopropylmethylene-5-dicyanomethylene-4-diphenylmethylenetetrahydrofuran-2-one:Chromism effect

The title compound exists as yellow （1Y） and red （1R） crystals, but both gave red solutions. The intermolecular interactions between the CN parts of the crystals in IY are very weak. By the mechanical crushing as well as in solution 1Y again becomes red due to the absence of intermolecular interactions. We explain this color behavior by crystallochromism and solvation chromism.     

Molecular dynamics in polyethylene and ethylene-1-butene copolymer investigated by NMR methods

1H and 13C NMR spectra and 1H spin-lattice relaxation times T₁ and T_1ρ have been employed to study the structure and molecular dynamics in polyethylene and ethylene-1-butene copolymer in the temperature range from 100 to 370 K. Results are interpreted in terms of α, β and γ -relaxation, as well as methyl group rotation. The activation energies for all motions were established. The incorporation of 1-butene into ethylene chain leads to an increase of mobility in amorphous and crystalline phases as well as appearance the 13C resonance characteristic to the monoclinic structure in addition to the orthorhombic observed in both polymers. The crystallinity degree derived from T_1ρ in studied polymers is close to that determined using DSC method.     

Rhenium(I) tricarbonyl polypyridine complexes showing strong absorption of visible light and long-lived triplet excited states as a triplet photosensitizer for triplet-triplet annihilation upconversion

The preparation of rhenium(I) tricarbonyl polypyridine complexes that show a strong absorption of visible light and long-lived triplet excited state and the application of these complexes as triplet photosensitizers for triplet-triplet annihilation (TTA) based upconversion are reported. Imidazole-fused phenanthroline was used as the N^N coordination ligand, on which different aryl groups were attached (Phenyl, Re-0; Coumarin, Re-1 and naphthyl, Re-2). Re-1 shows strong absorption of visible light (ε = 60,800 M(-1) cm(-1) at 473 nm). Both Re-1 and Re-2 show long-lived T(1) states (lifetime, τ(T), is up to 86.0 μs and 64.0 μs, respectively). These properties are in contrast to the weak absorption of visible light and short-lived triplet excited states of the normal rhenium(I) tricarbonyl polypyridine complexes, such as Re-0 (ε = 5100 M(-1) cm(-1) at 439 nm, τ(T) = 2.2 μs). The photophysical properties of the complexes were fully studied with steady state and time-resolved absorption and emission spectroscopes, as well as DFT calculations. The intra-ligand triplet excited state is proposed to be responsible for the exceptionally long-lived T(1) states of Re-1 and Re-2. The Re(I) complexes were used as triplet photosensitizers for TTA based upconversion and an upconversion quantum yield up to 17.0% was observed.     

Optically active antifungal azoles. XIII. Synthesis of stereoisomers and metabolites of 1-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone (TAK-456)

1-[(1R,2R)-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone [(1R,2R)-1: TAK-456] is a new antifungal agent selected as a candidate for clinical trials. The three stereoisomers [(1S,2R)-, (1S,2S)- and (1R,2S)-1] of this compound were prepared as authentic samples to determine the enantiomeric and diastereomeric purity of TAK-456 as well as to compare their in vitro antifungal activity. Pharmacokinetic studies of TAK-456 using rats identified the existence of metabolites in the liver homogenate. The structures of the major metabolites were assigned as 4-hydroxy-2-imidazolidinone (3) and/or 5-hydroxy-2-imidazolidinone (4), based on HPLC and LC/MS/MS analyses. These hydroxylated compounds, 3 and 4, were prepared by reduction of the corresponding imidazolidinediones, 11 and 12, and confirmed to be identical to the metabolites by HPLC. In vitro antifungal activities of the three stereoisomers and the synthesized metabolites were considerably weaker than TAK-456.     

A new chiral probe for sulfate anion: UV,CD, fluorescence,and NMR spectral studies of 1:1 and 2:1 complex formation and structure of chiral guanidinium-p-dimethylaminobenzoate conjugate with sulfate anion

A new chiral chromophoric host 1, possessing a 4-(N,N-dimethylamino)benzoate (DMAB) group tethered to a chiral bicyclic guanidinium subunit, was synthesized and applied to the probe for sulfate anion. Host 1 showed typical successive 1:1 and 2:1 host:guest complexation behavior toward the divalent sulfate anion, as revealed by UV-vis, CD, fluorescence, and 1H NMR spectroscopic studies. The DMAB chromophore was shown to be a sensitive CD spectral probe for assessing not only the complexation behavior but also complex stoichiometry and structure. The stepwise 1:1 and 2:1 complexation constants (K1 and K2) were determined as 1.53 x 10(6) and 4.84 x 10(4) M(-1), respectively, by NMR titration in CD3CN. The CD exciton chirality method allowed us to determine the chiral sense (spatial arrangement) of the two DMAB moieties in the 2:1 complex as negative (counterclockwise). The dual fluorescence behavior of DMAB was employed for elucidating the role of the countercation upon complexation of host 1 with sulfates possessing lipophilic countercation(s) such as tetrabutylammonium.