新型N-苯甲酰基-脱氢枞胺衍生物的电喷雾离子阱质谱行为研究

利用电喷雾离子阱质谱(ESI-IT-MS)技术,对8个具有潜在杀菌、抗癌生物活性的三类新型N-苯甲酰基-脱氢枞胺衍生物进行了ESI质谱行为研究。结果表明,由于7位、12位及苯甲酰基上取代基的不同,三类衍生物呈现出一定的电离及碎裂特性。在(±)-ESI-MS过程中,7-肟基类衍生物(A)和12-硝基类衍生物(C)比7-羟基类衍生物(B)更易产生二聚体;A易产生[M-H_2O+H]~+,C则更易负离子化。在(+)-ESIMS/MS过程中,A中7-肟基的存在使其易产生特征离子碎裂峰[M-35+H]~+和[M-H_2O+H]~+;A的18位酰基脱水离子峰[M-H_2O+H]~+失去一分子取代苯甲腈产生系列偶数碎裂离子峰;A的7-肟基脱水离子峰[M-H_2O+H]~+失去一分子取代苯甲醛产生系列奇数碎裂离子峰。在(-)-ESI-MS/MS过程中,B比C更稳定,在较高的碰撞能作用下获得的碎裂片段较少;均可通过丢失中性分子N-取代苯甲酰基亚甲胺、取代苯甲醛或取代苯产生系列碎裂离子片段;C的强吸电子基团12-硝基及4'-硝基的存在使其丢失的中性分子易捕获电子而离子化。     

脱氢枞胺-取代水杨醛Schiff碱的电喷雾串联质谱研究

 采用电喷雾电离串联质谱技术对7种最新合成的脱氢枞胺-取代水杨醛Schiff碱(DASSSB)样品进行了研究。结果显示,这些化合物的ESI-MS/MS裂解方式与它们分子中水杨醛苯环上取代基的性质和位置有关：当水杨醛苯环上4位连接供电子取代基时,分子以C=N双键断裂为主,生成 ［M+H-283］⁺ 碎片离子;当水杨醛苯环上5位连接吸电子取代基时,分子以C=N双键β位的C-C键发生断裂为主,生成 ［M+H-254］⁺ 碎片离子。DASSSB二级质谱产生的特征子离子可作为对此类化合物进行定性定量分析的依据。     

电喷雾质谱法研究N-苯甲酰基-脱氢枞胺-7-酮与DNA的相互作用

采用电喷雾质谱(ESI-MS)法研究了N-苯甲酰基-脱氢枞胺-7-酮与4种DNA—dC6,dT6,dA6,d(AT)3的相互作用,考察了N-苯甲酰基-脱氢枞胺-7-酮与DNA形成复合物的电喷雾质谱行为及N-苯甲酰基-脱氢枞胺-7-酮-DNA复合物-4价离子的二级质谱(MS/MS)行为。结果表明,N-苯甲酰基-脱氢枞胺-7-酮与4种DNA均可形成非共价复合物,且复合物离子主要以-4价形式存在;N-苯甲酰基-脱氢枞胺-7-酮与4种不同的DNA形成的-4价复合物离子均在碰撞能(CE)约20%时发生裂解,并且具有大致相同的裂解方式。     

Synthesis and characterization of new calix[4]arene amino acid ester derivatives and their metal extraction properties

A new type of calix[4]arenes containing amino acid ester derivatives has been synthesized. Their¹H NMR characteristics are discussed. Metal ion extraction experimental has shown that calix[4]arene amino acid esters (2a, 2b) possess good extraction efficiency for transition metal ions (Cu²⁺, Ni²⁺, Zn²⁺) and poor extraction efficiency for alkali metal ions (Na⁺, K⁺). Foundation item: Supported by the Ziqang Science Foundation of Wuhan University Biography: MENG Ling-zhi(1947-), female, Associate professor.     

Supermolecular layered double hydroxides

Research progresses in the layered double hydroxides [M _(1-x ^)/2+ M _x ³⁺ (OH)₂] ^x+ A _x ^n/n− ·mH₂O intercalated with metal coordinate ions or oxometalates in the last ten years are reviewed. These layered double hydroxides are mainly intercalated with polyoxometalate (POM) ions, a LiAl-LDH photochemical assembly containing TiO₂ and CH₃(CH₂)₁₂COO⁻ anions, together with Zn(TPPC) (porphyrin derivate) and macrocyclic ligand-containing porphyrin derivate anions. Emphasis is put on the synthesis methods for intercalation of the anions into the interlayer regions, the characterization techniques and structures for the layered compounds and the newest research progress in the fields such as catalysis. The review also forecasts the prospects of the field.     

聚氧乙烯型非离子表面活性剂的电喷雾质谱行为

聚氧乙烯型表面活性剂是一类重要的非离子型表面活性剂,易与阳离子形成加合离子[M＋X]^＋。应用电喷雾飞行时间质谱仪（ESI—TOF—MS）,以直接进样的方式,对壬基酚聚氧乙烯醚加合离子进行了研究。通常在谱图中可见钠、钾加合离子[M＋-Na]^＋、[M＋K]^＋。样品中的钠、钾离子的浓度影响对应加合离子的谱峰强度。样品中加入．MgCl2,可在谱图上观察到[M＋MgCl]^＋离子的谱峰。用高分辨电喷雾质谱确定[M＋18]^＋峰对应于[M＋NH4]^＋。     

大黄蒽醌类化合物电喷雾质谱研究

采用电喷雾-离子阱质谱(ESI-ITMS)法,通过一级质谱全扫描和二级质谱碰撞诱导解离技术,研究5种大黄蒽醌衍生物(大黄素、芦荟大黄素、大黄酸、大黄素甲醚、大黄酚)的质谱行为及分子结构与裂解规律间的关系,并对大黄药材中总游离蒽醌提取物进行了电喷雾质谱检测.实验结果显示,5种大黄蒽醌类化合物一级质谱负离子出峰较好,被测样品均为基峰或第二强峰,未发现聚合体离子及加合离子产生,二级质谱各碎片离子归属明确,特征性强.实验结果可应用于大黄蒽醌类化合物的结构分析及进一步的代谢产物研究,并为大黄药材有效成分的鉴定提供了一种快速,灵敏的检测方法.     

Composition of substituents on pyrrole ring of high-carbon-number geoporphyrins and its dealkylation

Geoporphyrins, isolated from source rock, were analyzed on electron ionization mass spectrometry (EIMS) and Tandem mass spectrometry (MS/MS). The spectrum of EIMS shows that the geoporphyrins are mainly composed of two types: DPEP and eito. Most of the porphyrin carbon numbers are greater than C₃₂. The daughter spectra of the molecular ions (C_34-36DPEPs) display the loss of methyl and ethyl groups, which indicate there are ethyl and propyl groups in the mother ions. The average condensed structural formulae, derived from the data of the spectra on MS/MS, have clearly shown the composition of the substituents on the porphyrin pyrrole ring, and the regular changes of the substituents reveal the characteristics of the dealkylation of the porphyrins in the geosphere.     

苯甲酸型芳香小分子的电喷雾多级质谱裂解规律

采用电喷雾多级质谱技术研究11种苯甲酸型芳香小分子化合物的裂解途径,解释苯环上取代基的一般裂解规律。对所有的化合物均同时采用正离子和负离子检测模式进行扫描,取[M+H]~+和[M-H]~-准分子离子峰进行多级碰撞诱导解离,通过分析母离子和碎片离子的关系来确定这些化合物的裂解途径。研究结果表明,苯甲酸型芳香小分子优先断裂脱去主要的官能团,再断裂苯环上的羟基和甲氧基,最后是苯环的裂解。     

莽草酸的质谱学研究

利用电子轰击质谱(EIMS)、电喷雾质谱(ESIMS)和多级质谱(MS/MS)研究莽草酸质谱学.探讨该化合物的质谱特征离子与裂解途径,提供莽草酸的质谱学基础.     

Synthesis and luminescence properties of Ca2SiO4-based red phosphors with Sm3+ doping for white LEDs

Sm³⁺-activated Ca₂SiO₄ red phosphors were prepared by the conventional high-temperature solid-state reaction method, and the effects of sodium (Na⁺) and samarium (Sm³⁺) ions doping concentrations on their crystal structure and luminescent properties were investigated by X-ray diffraction (XRD) and fluorescent spectrofluorometer. XRD patterns demonstrate that a well-crystalline structure forms in the phosphors when they are treated by calcination at 1200°C for 4 h, and the excitation spectra exhibit good absorption in the range between 350 and 420 nm. Under the irradiation of 405 nm near-ultraviolet (NUV) light, the spectra of the phosphors show a main emission peak at 601 nm attributed to the ⁴G_5/2??⁶H_7/2 transition of Sm³⁺ ions, and its intensity is greatly influenced by the concentrations of Sm³⁺ and Na₂CO₃. When the concentrations of Sm³⁺ ions and Na₂CO₃ are 2mol% and 6mol%, respectively, the optimal emission intensity can be obtained. From strong absorption in the near ultraviolet zone, the Na_0.06Sm_0.02Ca_1.92SiO₄ phosphor is a promising red-emitting phosphor for white light emitting diodes (W-LEDs).     

Enhancement of magnetism of Zn0.95Co0.05O films by p-type Cu+ doping

Organic solar cells withμ-oxo-bridged gallium phthalocyanine dimer(GaPc dimer) and fullerene were produced by an evaporation method.A device based on the GaPc dimer provided a conversion efficiency of 4.2×10~(-3)%,which is better compared to a device based on phthalocyanine monomer.Dimerization effect was discussed with a molecular orbital calculation,and the crystalline phases of the present solar cells were investigated by X-ray diffraction.Further improvement of the efficiency was discussed on the bas...     

应用密度泛函理论研究舒坦电喷雾质谱行为

为准确认识质谱数据所反映的化合物质谱行为和结构特点,以电喷雾质谱检测结果为依据,应用密度泛函理论计算方法,研究舒巴坦的离子化方式、裂解方式和裂解机理。结果表明:舒巴坦与质子和钠离子结合离子化方式分别与其电子排布和分子结构特点有关;在负离子检测模式下,羧基与磺酰基间相互影响,对维持五元环的稳定起到了重要的作用;四元环和五元环在正电荷体系中比负电荷更稳定。该研究为质谱的理论研究和舒巴坦的分析检测提供了理论参考。     

Photoluminescence and cathodoluminescence properties of a novel CaLaGa307：Dy3＋ phosphor

A single host white emitting phosphor, CaLaGa3O7:Dy3+, was synthesized by chemical co-precipitation. Field emission scanning electron microscopy, X-ray diffraction, laser particle size analysis, and photoluminescence and cathodoluminescence spectra were used to investigate the structural and optical properties of the phosphor. The phosphor particles were composed of microspheres with a slight tendency to agglomerate, and an average diameter was of about 1.0 μm. The Dy3+ ions acted as luminescent centers, and substituted La3+ ions in the single crystal lattice of CaLaGa3O7 where they were located in Cs sites. Under excitation with ultraviolet light and a low voltage electron beam, the CaLaGa3O7:Dy3+ phosphor exhibited the characteristic emission of Dy3+ (4F9/2-6H15/2 and 4F9/2-6H13/2 transitions) with intense yellow emission at about 573 nm. The chromaticity coordinates for the phosphor were in the white region. The relevant luminescence mechanisms of the phosphor are investigated. This phosphor may be applied in both field emission displays and white light-emitting diodes.     

Relation between standard entropies of elements and electronic configurations

A close relationship has been found between the standard entropies of elements and their electronic configurations. Based on the positions of elements in the periodic table and the variation in the standard entropies of elements, the standard entropies of elements can be expressed as the sum of two functions:S ⁰=f(N) +f(E), whereS ⁰ is the standard entropy of an element,N the principal quantum number, andE the number of outermost electrons. And the specific formula isS ⁰ = 99.05N ^1/3 + [0.32(sp −4)⁴ -119.76] + [-56.56N ^1/3+ 0.70(sd ∼-7)² −42.12] + [−11.95 × 10⁻⁴(df-8)⁻⁴ -105.70], wheresp, sd, df are the numbers of the outermost electrons in thesp, sd, df regions of the periodic table, respectively. This formula helps reveal the essence of the standard entropies of elements and deepens our understanding of the thermodynamic characteristics of compounds.     

Xe30+在Au下表面退激辐射的Ｘ射线谱

报导了1.0-3.0MeV的Xe₃₀₊离子与1.0MeV的Xe₂₆₊离子入射Au表面发射的X射线谱,考虑到探测器Be窗对射线的非均匀衰减,还原了1.0MeV的Xe₃₀₊离子产生X射线谱。通过用经典过垒模型及两体碰撞模型的分析表明：动能1.0-3.0MeV的Xe₃₀₊离子入射Au靶,下表面空心原子M壳层空穴退激发射了能量0.7-1.75keV的Xe M X射线,下表面空心原子N壳层空穴退激发射了能量0.5-0.7keV的Xe N X射线。     

Enhanced dielectric performance of Dy - substituted YMn2O5 for high-frequency applications

The dielectric performances as well as the effects of Dy³⁺ ions content at A sites of YMn₂O₅ (YMO) [x ​= ​0 (YDM₀) and x ​= ​0.4 (YDM_0.4)] polycrystalline samples were explored. These compounds were synthesized via sol–gel method. X-Ray diffraction and Raman measurements proved the high quality of the compounds that crystallized in an orthorhombic structure with the Pbam space group. Besides, impedance spectroscopy and electrical modulus studies revealed that both samples exhibited a non-Debye's type of relaxation. The decrease of impedance for YDM_0.4 compared to the pure YDM₀, may be attributed to the decrease in charge transfer resistance. Concerning the fit of impedance spectra, they confirmed that both compounds were simultaneously capacitive and resistive. Furthermore, the activation energies obtained from Modulus and complex impedance were proven to be neighboring, suggesting that the relaxation process refers to electron hopping. For each compound, the evolution of ε' and tan ​δ with temperature indicated a clearer relaxor behavior, namely the existence of two relaxations. The first one detected at low temperature is related to the charge carriers hopping between Mn³⁺ and Mn⁴⁺ and the second at high temperature is associated with oxygen vacancies. The reduced hopping rate with Dy³⁺ substitution for Y³⁺ ions at A sites is responsible for the decrease in dielectric constant and dielectric loss. These significant findings demonstrate that these materials can be invested in a fruitful use in UV photo-detector and power applications in high frequency as microwave, millimeter wave signal processing, for civilian, military and space applications.     

5,7-二取代-[1,2,4]三唑[1,5-a]嘧啶衍生物的合成及其抗癫痫活性

通过合成一系列5,7-二取代-[1,2,4]三唑[1,5-a]嘧啶衍生物,对其体内抗癫痫活性进行研究.各种查尔酮和3-氨基-1,2,4-三氮唑在二甲基甲酰胺中加热反应分别得到5,7-二取代-4,7-二氢-[1,2,4]三唑[1,5-a]嘧啶(2a-2e)和它们的脱氢产物5,7-二取代-[1,2,4]三唑[1,5-a]嘧...     

Synthesis and characterization of novel bridged porphyrins

The reaction of 5-(4-hydroxyphenyl)-10,15,20-triphenyl porphyrin with 2,6-dibromomethylpyridine and 4,4‘-dicarboxyl-2,2‘-bipyridine respectively gave 2,6-bis-[5,10,15-triphenyl-20-( 4-phenoxymethyl )-porphyrin-yl]-pyridine(3) and 4, 4‘-di-[5,10,15-triphenyl-20-( p-phenoxycarbonyl)-porphyrin-yl]-2,2‘-bipyridine (4). 5-[4-(4‘- Bromobutoxy) phenyl]-10, 15, 20-triphenyl porphyrin reacted with 2,6-dihydroxymethyl pyridine to give 2,6-bis-[5,10,15-triphenyl- 20-(4-(p-phenoxy)-butoxymethyl)-porphyrin-yl]-pyridine(5). Those new compounds have been identified by ^1H NMR, IR, MS and UV-visible spectra, and elemental analysis.     

穗花杉双黄酮罗伯斯特双黄酮质谱裂解特征研究

采用负离子检测模式下的电喷雾多级串联质谱(ESI-MS)方法对穗花杉双黄酮和罗伯斯特双黄酮的质谱行为进行研究,讨论C3′—C8″与C3′—C6″连接的双黄酮类化合物结构特征与质谱裂解行为之间的异同。实验结果表明:2种C—C连接的双黄酮类化合物在相同的质谱条件下均可以在C环发生0,4键断裂,生成质荷比m/z=375的碎片离子。此离子峰为C—C连接的双黄酮类化合物共有的特征离子峰;但是由于C—C连接位置的不同,这一对同分异构体的裂解途径也存在着明显差异。C3′—C6″连接的罗伯斯特双黄酮,由于空间构型的影响,在质谱条件下,C4′位的羟基更易于与C5″或者C7″位上的羟基发生分子内脱水,生成丰度响应值较高的碎片离子m/z为519和309。这2个碎片离子是罗伯斯特双黄酮的特征碎片离子,可用于区分穗花杉双黄酮和罗伯斯特双黄酮。