Sub-Doppler rotationally resolved spectroscopy of lower vibronic bands of benzene with Zeeman effects

Sub-Doppler high-resolution excitation spectra and the Zeeman effects of the 6(0)(1), 1(0)(1)6(0)(1), and 1(0)(2)6(0)(1) bands of the S1(1)B2u<--S(0)(1)A1g transition of benzene were measured by crossing laser beam perpendicular to a collimated molecular beam. 1593 rotational lines of the 1(0) (1)6(0) (1) band and 928 lines of the 1(0)(2)6(0)(1) band were assigned, and the molecular constants of the excited states were determined. Energy shifts were observed for the S1(1)B2u(v1=1,v6=1,J,Kl=-11) levels, and those were identified as originating from a perpendicular Coriolis interaction. Many energy shifts were observed for the S1(1)B2u(v1=2,v6=1,J,Kl) levels. The Zeeman splitting of a given J level was observed to increase with K and reach the maximum at K=J, which demonstrates that the magnetic moment lies perpendicular to the molecular plane. The Zeeman splittings of the K=J levels were observed to increase linearly with J. From the analysis, the magnetic moment is shown to be originating mostly from mixing of the S1(1)B2u and S2(1)B1u states by the J-L coupling (electronic Coriolis interaction). The number of perturbations was observed to increase as the excess energy increases, and all the perturbing levels were found to be a singlet state from the Zeeman spectra.     

含能笼型碳硼烷衍生物的合成及其热性能

以DMSO或DMF为溶剂,1-溴甲基碳硼烷(1)分别与亚硝酸钠和叠氮钠发生亲核取代反应,合成了两种新型的含能笼型碳硼烷——1-硝基甲基碳硼烷(2)和1-叠氮基甲基碳硼烷(3),其结构经1H NMR和FT-IR表征。用DSC分析了1~3的热性能,结果表明:1和2分别在162.2℃和168.7℃分解,分解热分别为130.4 J.g-1和245.6 J.g-1。     

Head-to-head vinyl polymers. IV. Preparation and characterization of equimolar head-to-head copolymers of acrylic acid and its esters

The alternating copolymer of ethylene with maleic anhydride was esterified with a number of aliphatic alcohols to yield its monoesters, which correspond structurally to equimolar (1:1) head-to-head (h-h) copolymers of acrylic acid with alkyl acrylates. In addition, they were methylated with diazomethane to 1:1 h-h copolymers of methyl acrylate with alkyl acrylates. For comparison the 1:1 head-to-tail (h-t) copolymers of methyl acrylate with alkyl acrylates were prepared by radical copolymerizations. Some chemical, physical, and thermal properties of these 1:1 h-h and h-t copolymers were evaluated and compared. The softening and glass transition temperatures of the 1:1 h-h copolymers were somewhat higher than those of the corresponding 1:1 h-t copolymers, which indicated that the h-h replacements made the polymer chain stiffer and less flexible. The 1:1 h-h copolymers were also observed to degrade thermally at somewhat higher temperatures and with higher rates than the 1:1 h-t copolymers. The ratio of alcohol to monomer found in the pyrolysis products was higher for the 1:1 h-h than for its respective 1:1 h-t copolymer.     

Characterization of Chitosan/Alginate Self-Assembled Nanoparticles as a Protein Carrier

The aim of this study was to evaluate the effect of the polymeric ratios on the characteristics of chitosan/alginate (ch/alg) self-assembled nanoparticles and their potential as protein delivery vehicle. The nanoparticles were prepared using proper mixing of polymers in presence or absence of bovine serum albumin (BSA) as a protein model. Three formulations of nanoparticles comprising ch/alg ratios of 2:1, 1:1, and 1:2 were prepared. Size, shape and zeta potential of the formulations were studied by scanning electron microscopy (SEM) and nanosizer instruments. FTIR, and differential scanning calorimetery (DSC) studies were performed to investigate polymer-polymer or polymer-protein interactions. Release profiles and entrapment efficiencies of the nanoparticles were determined by calorimetric technique using appropriate techniques. Entrapment efficiency was 70% for ch/alg ratio of 1:1, 65% for 1:2, and 60% for 2:1. The z-average size of the nanoparticles were 403, 205, and 318 nm for ch/alg ratios of 2:1, 1:1, and 1:2, respectively. Average zeta potentials were ?47, +15, ?25 mV for 2:1, 1:1, and 1:2 as well. Considering the favorable features required for protein delivery systems, ch/alg (1:1) due to its smallest size, highest loading, and most homogenous shape was regarded as the best ratio.     

新型含1,2,4-三唑基的1,5-苯并硫氮杂的合成和表征

以α-溴代苯乙酮为原料,在三乙胺作用下制备α-(1,2,4-三唑-1-基)-芳基乙酮(1a～1c),再与芳香醛发生羟醛缩合反应制备相应的含三唑基的查尔酮2a～2l,将中间体2a～2l同邻氨基硫酚合成新型的2,4-二芳基-3-(1,2,4-三唑-1-基)-2,3-二氢-1,5-苯并硫氮杂(3a～3l).所得化合物的结构经元素分析,IR,MS和1HNMR确认,同时用X射线衍射法测定了化合物2a和3a的晶体结构.     

咪喹莫特的波谱学数据与结构表征

对咪喹莫特的红外(IR)、紫外(UV)、质谱(MS)、氢-氢相关谱(^1H--^1H COSY)、碳氢相关谱(HMQC)、碳氢远程相关谱(HMBC)予以解析并进行了报道。对所有的^1H NMR、^13C NMR谱的信号进行了归属；讨论了质谱的主要碎片离子的可能的裂解方式和红外特征吸收峰所对应的官能团的振动形式。     

Structural analysis of the N-linked oligosaccharides from human urinary trypsin inhibitor.

The N-linked oligosaccharides from human urinary trypsin inhibitor were purified and their structures were investigated by compositional analysis, the two-dimensional sugar map method and 500 MHz 1H-NMR. The results revealed that they were composed of disialosyl, monosialosyl and asialosyl oligosaccharides, which have the common biantennary core structure; Gal1-4GlcNAc1-2Man1-3(Gal1-4GlcNAc1-2Man1-6)M an1-4GlcNAc1-4GlcNAc.     

A COMPARISON OF PHOTO-KILLING AMONG CAROTENE AND CYTOCHROME c ACCUMULATING STRAINS OF THE SMUT FUNGUS Ustilago violacea AT SPECIFIC WAVELENGTHS FROM 400 TO 650 nm

Abstract— Variously pigmented strains of Ustilago violacea were exposed to monochromatic light from 400 to 650 nm in 50-nm increments to determine which wavelengths were most effective for photo-killing. In addition, liquid nitrogen temperature absorption spectra were determined for intact cells of the fungal strains. The high cytochrome c containing pink strains 1.C429, AB278a-1, 1.C425 and 2.C427 were more sensitive to cytochrome absorption wavelengths than were their low cytochrome c counterparts 15.10, 1.C2 y , 1.C2 w and 1.C427, while the carotene accumulating strains 1.C2 y and AB278a-1 were more resistant to photo-killing than their carotene lacking counterparts 15.10, 1.C2 w , 1.C427 and 1.C429, 1.C415, 2.C428 even at wavelengths not absorbed by carotenes. The results suggest that cytochrome c and other cytochromes are photosensitizers and that carotene-related protection is through the quenching of the photosensitizers as well as by absorption.     

新型水溶性超支化聚酰胺-酯的合成

均苯四甲酸酐与二乙醇胺经酰化反应制得中心核(4);4与AB2单体2,2-二羟甲基丙酸经熔融缩聚合成了一种新型水溶性的二代超支化聚酰胺-酯(1),其结构与性能经FT-IR,GPC,粘度法,化学滴定等表征。4的Mn=1 683,Mw=1 911,Mw/Mn=1.14,[ηinh]=0.067 6 dL·g-1;1的Mn=3 750,Mw=4 904,Mw/Mn=1.31,[ηinh]=0.086 1 dL·g-1。     

PMMA-b-QPDMAEMA的合成及其抗菌活性

以α-溴代丙酸乙酯为引发剂,CuCl/二乙烯三胺为催化剂,采用ATRP法制得5个不同分子量的聚甲基丙烯酸甲酯-聚甲基丙烯酸二甲氨乙酯嵌段共聚物(PMMA-b-PDMAEMA, P¹~P⁵); P¹~P⁵经溴代辛烷季铵化合成了5个聚季铵盐(Q¹~Q⁵),其结构和性能经¹H NMR, FT-IR, GPC和DSC表征。结果表明：P⁴和Q⁴的玻璃化转变温度分别为109.67 ℃和117.95 ℃。采用平板活菌计数法研究了Q¹~Q⁵对金黄色葡萄球菌(S. aureus)和大肠杆菌(E. coli)的抗菌活性。结果表明：Q¹~Q⁵对S. aureus的抗菌活性优于E. coli,其MIC值分别为300 mg·L^-1, 250 mg·L^-1, 275 mg·L^-1, 225 mg·L^-1和150 mg·L^-1。     

1,1'-不同酰基二茂铁衍生物的合成和波谱研究

以乙酰基二茂铁和相应的乙酰氯在三氯化铝存在下在 流室温条件下合成了不对称二乙酰基二茂铁衍生物; 1-乙酰基-1'-卤素取代苯甲酰基二茂铁, 除了获得预期产品以外, 当反应在 流温度下进行时, 还得到1,3-二(二茂铁基)-丁烯-2-酮-1, 用同样方法还合成了1-乙酰基-1'-棕榈酰二茂铁和1-苯甲酰-1'-棕榈酰基二茂铁.     

Stereochemistry of epimeric 1-hydroxy-N-methylquinolizidinium iodides

The methiodides of epimeric 1-hydroxy, 1-hydroxy-1-phenyl, and 1-hydroxy-1-methylquinolizidines were prepared from their respective bases. The previously described but not separated epimeric 1-hydroxy-1-methylquinolizidines were prepared and their configurations elucidated by the use of nuclear magnetic resonance (NMR) and infrared data. Structural assignments of the quinolizidinium iodides were made on the basis of NMR data.     

3-杂环硫亚甲基头孢菌素衍生物的半合成及抗菌活性研究

通过取代噁二唑硫酮、噻二唑硫酮及三唑硫酮分别和头孢菌素母体7-ACA反应,制得14种7-氨基-3-杂环硫亚甲基头孢菌素新母体2a-2n,用1-芳基-5-甲基-1H-1,2,3-三唑-4-甲酰氯与头孢菌素新母体缩合,制得2种新的7β-(1-芳基-5-甲基-1H-1,2,3-三唑-4-甲酰胺基)-3-(2-取代1,3,4-bI二唑-5-硫亚甲基)头孢菌素4c,4d.新化合物结构经元素分析、IR、¹HNMR及FAB-MS确认.初步体外抗菌结果表明,新母体化合物2对革兰氏阳性菌有抑制活性且在相同浓度下比7-ACA强20倍,而头孢菌素4c,4d对革兰氏阳性和阴性菌都有显著抑制活性.     

Experimental and theoretical studies of fused-ring persistent [1,2,4]thiadiazinyl radicals

Five persistent radicals 1a-1e were generated by the oxidation of 4H-[1,2,4]thiadiazines 2a-2e and studied with ESR and UV-vis spectroscopy. Three of the radicals, 1a, 1d, and 1e, were generated in high yields (>90%) using either SO(2)Cl(2)/amine in toluene or AgO/K(2)CO(3) in a toluene/MeCN mixture. Halogenated radicals 1d and 1e were sufficiently stable for chromatographic isolation and vacuum sublimation. The solution stability of the fluorinated 1d was measured at t(1/2) approximately 4 months in the absence of oxygen, and 1e at t(1/2) approximately 40 min in the presence of air. The crystal and molecular structures of 1d were determined by X-ray crystallography showing columns of parallel almost evenly spaced planar heterocycles connected by infinite ...N...S... chains. Cyclic voltammetry of 1d and 1e shows reversible reduction waves at about 0 V and irreversible oxidations at about 1.2 V. Spectral and electrochemical properties of 1 were well reproduced by DFT methods.     

苯并咪唑萘酰亚胺类化合物的合成与结构确证

本文合成并分离提纯了1位和4位单取代的苯并咪唑萘酰亚胺(NBI)类化合物1~4,对化合物1的紫外-可见光谱、红外光谱、质谱、核磁共振谱(包括1H NMR、13C NMR、DEPT、1H-13C HSQC、1H-13C HMBC、1H-1HCOSY多种NMR技术)进行了详细解析,对其所有的1H和13C NMR信号进行了归属,并使用了GIAO和CSGT两种方法量化计算核磁位移,通过多种波谱学技术确证了化合物的结构。     

Doppler-free two-photon excitation spectroscopy and the Zeeman effects of the S1 1B1u(v21=1) <-- S0 1Ag(v=0) band of naphthalene-d8

Doppler-free two-photon excitation spectrum and the Zeeman effect of the S1 1B1u(v21=1) <-- S0 1Ag(v=0) transition of naphthalene-d8 have been measured. 908 lines of Q(Ka)Q(J)KaKc transition of J=0-41, Ka=0-20 were assigned, and the molecular constants of the S1 1B1u(v21=1) state were determined. Perturbations were observed, and those were identified as originating from Coriolis interaction. No perturbation originating from an interaction with triplet state was observed. The Zeeman splittings from lines of a given J were observed to increase with Kc, and those of the Kc=J levels increased linearly with J. The Zeeman effects are shown to be originating from the magnetic moment of the S1 1B1u state, which is along the c axis and is induced by mixing of the S2 1B3u state to the S1 1B1u state by J-L coupling. Rotationally resolved levels were found not to be mixed with a triplet state from the Zeeman spectra. Accordingly, it is concluded that nonradiative decay of an isolated naphthalene excited to low rovibronic levels in the S1 1B1u state does not occur through the intersystem mixing. This is at variance with generally accepted understanding of the pathways of the nonradiative decay.     

Fluorescence spectroscopic properties and crystal structure of a series of donor-acceptor diphenylpolyenes

A series of p-nitro-p'-alkoxy(OR)-substituted (E,E,E)-1,6-diphenyl-1,3,5-hexatrienes (1a, R = Me; 1b, R = Et; 1c, R = n-Pr; 1d, R = n-Bu) were prepared. The absorption and fluorescence spectra in solution were almost independent of the alkoxy chain length. The absorption maximum showed only a small dependence on the solvent polarity, whereas the fluorescence maximum red-shifted largely as the polarity increased. The solid-state absorption and fluorescence spectra were red-shifted relative to those in low polar solvents and were clearly dependent on the alkoxy chain length. The fluorescence maxima for the crystals of 1b and 1d were observed at 635-650 nm, which were red-shifted by 40-50 nm relative to those for 1a and 1c. The Stokes shifts were all relatively small (3000-3500 cm-1). For all four compounds, the fluorescence decay curves in the solid state were able to be analyzed by single-exponential fitting to give the lifetimes of 1.1-1.3 ns. This indicates that the emission of 1a-d is not originated from an excimer or molecular aggregates, but from only one emitting monomeric species. The fluorescence quantum yields of 1a-d were considerably high compared with the values for organic solids, which is consistent with their monomeric origin of emission. Single-crystal X-ray structure analyses of 1a, 1c, and 1d showed that the crystal packing was dependent on the alkoxy chain length. The crystals of 1a and 1c had herringbone structure, whereas that of 1d had pi-stacked structure. Strong pi-pi interaction in the crystal of 1d would be the cause of the spectral red shifts relative to those for 1a and 1c. No observation of excimer fluorescence from crystal 1d can be attributed to the limited overlap between the pi-planes of the molecules due to its "slipped-parallel" structure.     

三联吡啶修饰的新型苯并二噻吩电子给-受体分子的合成及性能研究

以4,8-二酮苯并［1,2-b：4,5-b′］二噻吩为原料,合成了两种新型的2,2′ ∶6′,2″-三联吡啶修饰的苯并二噻吩电子给-受体结构分子(M1和M2),其结构经¹H NMR, ¹³C NMR, IR和元素分析表征。用UV-Vis, FL, TGA和CV研究了M1和M2的性能。结果表明：M1和M2均具有良好的热稳定性,热分解温度(T₅)分别为335 ℃和430 ℃。由于电子给-受体结构的存在,M1和M2均表现出明显的分子内电荷转移跃迁(ICT),其最大吸收峰分别为446 nm和468 nm,荧光发射峰分别为517 nm和552 nm;起始还原电位分别为-0.57 eV和-0.62 eV,起始氧化电位分别为0.69 eV和0.87 eV。     

双季铵盐化合物的结构表征与抗菌性能测试

将N,N-二甲基乙醇胺、N-甲基二乙醇胺分别接枝到1,3-二溴丙烷的两端进行季铵化反应,得到N1,N3-二羟乙基-N1,N1,N3,N3-四甲基-1,3-丙二胺二溴盐(QAS-1)和N1,N1,N3,N3-四羟乙基-N1,N3-二甲基-1,3-丙二胺二溴盐(QAS-2)。采用傅立叶变换红外光谱(FTIR)、核磁共振(NMR)和元素分析确证了其结构,以抑菌圈法和试管二倍稀释法评价了两者对5种菌株的抗菌活性。结果显示,它们对所选菌株均具有一定的抗菌活性,其中对白色念珠菌的最小抑菌浓度(MIC)分别为100 mg·L~(-1)和50 mg·L~(-1)。扫描电子显微镜(SEM)和透射电子显微镜(TEM)显示,QAS-1对金黄色葡萄球菌的抗菌作用机理可能为,带正电荷的季铵盐吸附在细菌表面,破坏细胞膜,导致细胞质外流从而杀灭细菌。细胞毒性显示QAS-1对人正常肝细胞(LO2)和人永生化表皮细胞(HaCat)的IC_(50)值分别为110.34 mg·L~(-1)和92.68 mg·L~(-1),细胞毒性显著低于阳性药。该研究说明该类季铵盐在抗菌领域具有潜在的应用价值。     

1-乙酰胺基丙叉-1,1-二膦酸和1-丙酰胺基乙叉-1,1-二膦酸与碱土金属离子的螯合作用

用pH电位法研究了1-乙酰胺基丙叉-1,1-二膦酸(S-186)和1-丙酰胺基乙叉-1,1-二膦酸(S-106)与碱土金属的螯合作用(30±O.1℃).当金属离子与配体的摩尔浓度比为10∶1、1∶1和1∶2时,在水溶液中形成了MHL、ML、ML_2和M_2L等几种类型的配合物.分别测定了它们的稳定常数,其中S-186配合物稍高于S-106,说明配合物稳定性与螯合剂的碱度有平行关系.值得注意的是,这两种螯合剂与Sr~(2 )形成的双核配合物的稳定性均较其它碱土金属离子的为高.