α-和β-四烷氧取代酞菁的合成及性能研究

利用 3 烷氧取代邻苯二腈和 4 烷氧取代邻苯二腈与相应的金属盐反应制备了两大系列 (α 和 β )四烷氧取代酞菁 .讨论了温度对中间体烷氧取代邻苯二腈合成的影响 ,探讨了酞菁的两种环合方法 ,并对 β 烷氧酞菁的环合历程进行了初步的考察 .研究了不同取代位置和酞菁的最大吸收波长之间的关系 ,结果表明 ,α 取代烷氧取代酞菁导致λmax红移值较大 ,而相应 β位取代情况下红移值较小 ,说明给电子基团在α位对酞菁骨架的π共轭结构微扰作用比 β位大 .同时研究了溶解度及热失重与酞菁结构的关系     

甘氨酸存在条件下水热合成可层离双氢氧化物

在甘氨酸存在条件下,经混合金属盐溶液在pH为10．0时共沉淀后的水热反应,可成功合成甘氨酸插层的镁铝双氢氧化物(Gly-LDHHTT)．产物以XRD、IR、TEM／SEM、TG／DTA等技术进行表征．结果表明,120℃水热合成10 h的产物晶型完善,沿a和c方向的晶粒尺寸最大,产物热稳定性好．TEM观察晶粒呈明显的六边形,SEM形貌呈现边缘略有卷曲的团聚薄片．通过进一步探讨甘氨酸插层镁铝双氢氧化物层离的机制后,获得了在室温下实现水热合成产物快速层离的方法,为层离-吸附法成功运用于双氢氧化物／聚合物纳米复合材料制备体系中提供重要的实验基础．     

1,11,15,25-四羟基-4,8,18,22-二（桥联二丙羧基）酞菁铜的合成及性质研究

对新型取代基酞菁和酞菁晶体合成和性质进行了研究。因为酞菁在信息、医疗、化工等众多领域有很广泛的应用,所以近百年来一直是科学家研究的热点课题。酞菁经过近百年的研究,科学家已经合成了上万种酞菁衍生物,但是,随着科技的不断进步,人类社会不断发展的需求,具有新特性的新型酞菁的获得仍是相关科技工作者孜孜以求的目标。为此,在本论文中,我们改进了合成方法,合成了新型的桥联酞菁材料：1,11,15,25-四羟基-4,8,18,22-二（桥联二丙羧基）酞菁铜,表征其结构。并研究电化学性质。首先以丙二酸和3,6-二羟基邻苯二腈为起始原料,以水为溶剂,加入浓硫酸作为催化剂,先合成前体,即丙二酸3,3′-二(6–羟基邻苯二腈)脂。然后再用丙二酸 3,3′-二(6-羟基邻苯二腈)脂与一水合乙酸铜,以正戊醇为溶剂,以DBU为催化剂,合成了1,11,15,25-四羟基-4,8,18,22-二（桥联二丙羧基）酞菁铜,其分子式是C₃₈H₁₆N₈O₁₂Cu。对1,11,15,25-四羟基-4,8,18,22–二（桥联二丙羧基）酞菁铜进行紫外吸收及荧光光谱测定,证明合成产物是目标产物,并研究了1,11,15,25-四羟基-4,8,18,22-二（桥联二丙羧基）酞菁铜的电化学性质。     

两亲性金属酞菁的催化性能研究

采用耗氧法研究了4种金属酞菁配合物[α-四(对羧基苯氧基)金属酞菁(Zn,Co)、β-四(对羧基苯氧基)金属酞菁(Zn,Co)]对0.1mol.L-1亚硫酸钠的催化氧化性能,考察了配合物中心金属和取代基的位置对催化活性的影响。研究结果表明中心离子相同时,β位四取代(对羧基苯氧基)金属酞菁的催化活性优于α位;取代基位置相同时,酞菁钴的催化氧化性优于酞菁锌。且β-四(对羧基苯氧基)酞菁钴的浓度为1.00×10-4mol.L-1时,对亚硫酸钠的催化氧化性能最高。     

查尔酮及其与丙二酸二乙酯Michael加成产物的合成与光谱学性质

以取代苯甲醛和苯乙酮,用水作溶剂,以碳酸钠为催化剂,制备了一系列查尔酮化合物.将所得查尔酮与丙二酸二乙酯及碳酸钾置于玛瑙研钵中常温无溶剂研磨,得到相应的Michael加成产物.采用紫外光谱和红外光谱法对合成出的查尔酮化合物以及相应的查尔酮与丙二酸二乙酯的Michael加成产物进行了分析,研究不同取代基对紫外吸收波长和红...     

4-[(E)-2-(3, 4-二甲氧基苯基)乙烯基]苯氧基乙酸乙酯的合成及其NMR研究

以对硝基甲苯、3, 4-二甲氧基苯甲醛为起始原料,经过缩合,还原,重氮化水解,亲核取代反应,最终合成了新的化合物4-[(E)-2-(3, 4-二甲氧基苯基)乙烯基]苯氧基乙酸乙酯,用¹H 和¹³C NMR及多种二维核磁共振谱确定了该化合物的结构,完成了¹H 和¹³C NMR的归属,给出了分子中各氢,碳原子的准确化学位移.     

在SO42-/ZrO2上苯与丙烯的烷基化反应

制备了SO42 -/ZrO2 催化剂并采用X射线衍射、红外光谱仪测定、Py IR测定等技术对其进行了表征 .反应在自制高压流动床 (具有控温和冷凝 )装置上进行 ,原料以苯∶丙烯为 8∶1的比例配置于贮罐中 ,4 .0MPaN2 恒压 ,压入计量器后 ,用 8.0MPaN2 恒压 .反应后收集的液相产物由气相色谱 质谱 (GC MS)分析 ,产物分析在SE 5 4型毛细管色谱议上进行 .考察了苯与丙烯气相流动烷基化反应以及制备条件对催化活性的影响 ,结果表明 ,适当条件下制得的SO42 -/ZrO2 催化剂可用于合成异丙苯反应 ,并有高的丙烷转化率 (99.2 % )和高的异丙苯选择性(93.3% ) .     

磷酸苯基二乙基酯的合成及NMR和ESI-MS/MS测定

在冰盐浴条件下,将DEPH和CCl₄混合液滴加到由苯酚、三乙胺、二氧六环组成的混合液中或由水杨酸乙酯, 三乙胺、二氧六环组成的混合液中. 分别用二乙基亚磷酸酯（DEPH)对苯酚和水杨酸乙酯进行磷酰化. 经电喷雾质谱（ESI-MS)及核磁共振检测,目标产物存在, 其分别为磷酸苯基二乙基酯和o-(邻乙氧甲酰（基）苯基)磷酸二乙酯.     

2(3)-四-(2-异丙基-5-甲基苯氧基)钛氧酞菁的合成及其近红外发光特性

通过分步合成的方法,在钛氧酞菁的外围引入了四个苯氧基团,合成了一种2(3)-四-(2-异丙基-5-甲基苯氧基)钛氧酞菁.通过质谱、核磁、元素分析、紫外可见吸收光谱、近红外光荧光谱和循环伏安法对其结构和性质进行了表征,并利用旋涂加真空热蒸发的方法制得了该材料的电致发光器件(ITO/PVK:TiOPc/BCP/LiF/Al).结果表明,四取代的钛氧酞菁固态的近红外光荧光峰值在1080nm左右;其近红外电致发光的峰值波长落在1050nm左右.在PVK掺杂的器件中,钛氧酞菁的质量分数为30%时有较强的发光强度.     

新型含能富勒烯衍生物的合成研究

 利用N-甲基甘氨酸、2,4-二硝基苯甲醛和C₆₀反应,合成分离出了含有两个硝基的新型富勒烯吡咯烷衍生物1,并对其工艺条件进行了研究,探讨了反应物剂量比、温度和时间对产物1产率的影响,得到了合成产物1的最佳工艺条件：反应物剂量比为1∶2∶6、温度为95 ℃、反应时间为40 h,此时产物1产率可达到65.8%（以消耗的C₆₀计）。同时用¹H NMR、FT-IR、MS、UV-Vis等光谱手段确定了产物1的分子结构。     

Ester-functionalized soluble single-walled carbon nanotubes

We report the preparation of soluble ester- functionalized single-wall carbon nanotubes (sSWNT-COO(CH₂)₁₇CH₃). By use of solution phase IR spectroscopy we are able to compare the ratio of the carbon atoms in the SWNT backbone to the carbon atoms in the ester and amide functionalities of s-SWNTs. Received: 16 July 2001 / Accepted: 3 December 2001 / Published online: 4 March 2002     

Radiation damage produced in powder of α-(methylamino)isobutyric acid, α -aminoisobutyric acid methyl ester hydrochloride and diethylmalonic acid

The electron paramagnetic resonance spectra of γ-irradiated powders of α-(methylamino)isobutyric acid – CH₃NHC(CH₃)₂COOH, α -aminoisobutyric acid methyl ester hydrochloride – NH₂(CH₃)₂CCOOCH₃ HCl, and diethylmalonic acid – (CH₃CH₂)₂C(COOH)₂ have been investigated at room temperature. It has been found that γ -irradiation produces the (CH₃)₂C˙COOH radical in the first, the (CH₃)₂C˙COOCH₃ radical in the second and the (CH₃CH₂)₂C˙COOH radical in the third compound. The spectra were computer-simulated. The g values and the hyperfine coupling constants of the unpaired electron with the environmental methyl, methylene protons and OH proton were determined. The results were found to be in good agreement with the existing literature data and theoretical predictions.     

Interaction Energy in Polymer Blends Containing N-1-Alkylitaconamic Acids Moiety

Abstract

Analysis of the interaction energy of N-1-alkylitaconamic acids to explain the miscibility behavior of polymers containing this moiety is performed. In order to calculate the interaction energy, many conformations of the N-1-alkylitaconamic acid fragments containing ethyl, propyl, butyl, hexyl, octyl, decyl, and dodecyl were selected randomly from molecular dynamic simulations. It was assumed that miscibility and other properties are determined by the enthalpy of mixing, ΔH_mix, that ΔH_mix is dominated by the local interactions between segments of the polymer chains, and, furthermore, that PΔV_mix contribution can be ignored. The polymer miscibility is discussed by using interaction energies calculated from molecular mechanics studies on pairs of small polymer fragments. By this method and by using the Blend package (Accelrys), good correlations between the interaction energy and the Gordon Taylor constant (K_GT) values for blends of poly(N-1-alkylitaconamic acids) and poly(4-vinylpyridine) previously reported are obtained. The analysis of the energies shows that Coulombic energies decay rapidly being almost “zero” as the side-chain lengths reach near eight carbon atoms. On the contrary, the van der Waals interaction (VDW) energies decay in a linear way as the length of the side chain increases. The slope of the VDW energies is an estimation of the energetic contribution per methylene unit to the blending process. The slope in this case is 570 cal/mol, which is a value very close to that experimentally reported in the literature for related systems. The blend energy was calculated, and good correlation with the experimental results is obtained.     

Structure and rotational dynamics of methyl propionate studied by microwave spectroscopy

We report on the rotational spectra of the most abundant conformer of methyl propionate, CH₃CH₂COOCH₃, recorded with a Fourier transform microwave spectrometer under molecular beam conditions. We present accurate rotational constants and centrifugal distortion constants. For the propionyl CH₃ CH₂CO– methyl group and the methoxy –OCH₃ methyl group, barriers of 820.46(99)?cm^?1 and 429.324(23)?cm^?1, respectively, were found. For spectral analysis, two different computer programs were used, the code BELGI-C_s-2tops based on the rho axis method (RAM) and the code XIAM based on the combined axis method (CAM). The results are compared. The experimental work was supplemented by quantum chemical calculations. Potential energy functions for the rotation of the terminal methyl groups and also of the entire ethyl group were parametrized.     

Effect of glycine substitution on the ferroelectric phase of betaine arsenate [(CH3)3NCH2COO·H3AsO4]

The present work reports an experimental investigation on the influence of glycine (NH₂CH₂COOH) substitution in the polar properties and the critical dynamics of the molecular ferroelectric betaine arsenate, (CH₃)₃NCH₂COO·H₃AsO₄. The dielectric dispersion (20 Hz<ν<3 MHz) and the thermally induced displacement currents are investigated in detail over the extended Curie region of the system (130 K<T<100 K). The results obtained for a single crystal with nominal glycine content of 20% are analyzed, compared with those obtained for pure betaine arsenate and discussed within the scope of a phenomenological Landau model previously used to describe a system with competing ferroelectric and structural instabilities.     

Configuration dependence of photon stimulated ion desorption from methyl ester compounds induced by core excitation

Photon stimulated ion desorption (PSID) from methyl ester terminated self-assembled monolayer (MHDA-SAM, HS(CH₂)₁₅COOCH₃) and methyl mercaptoacetate (MA, HSCH₂COOCH₃) on Ag has been investigated using soft X-ray in the C and O K-edge regions. In MHDA-SAM on Ag, site-selective ion desorption has been clearly observed at resonant core excitations of C_1s, O_1s(OCH₃) → σ^∗(OCH₃) and O_1s(OCH₃) → σ^∗(COCH₃). Ion intensity in MA on Ag is obviously reduced for (n = 1-3) at C_1s, O_1s(OCH₃) → σ^∗(OCH₃) excitations, and no site-selective reaction at O_1s(OCH₃) → σ^∗(COCH₃) excitations has been observed. These reactions may be influenced by configurational difference of reactive sites. It is suggested that surface effects on the selective reaction due to positioning methyl ester group near the surface plays an important role.     

3.508 μ-HeXe-laser line absorption by CH3COOCH3, CH3, and NO2 and infrared emission at 6.89 μ by CH3COOCH3 and CH3 at elevated temperatures

Shock-tube HeXe-laser absorption data at ω_L=2850.633 cm^-1 for CH₃COOCH₃ at 757≤T, °K≤1344, NO₂at 412≤T, °K≤1859, andCH₃at 1283≤T, °K≤1562 are presented. Approximate models are used for the effective spectral absorption coefficient of vibration-rotation lines for analytical representations of the results around atmospheric pressures. For CH₃COOCH₃, an equivalent Voigt-profile for an isolated line was adopted in order to account for a dependence on total pressure of the laser absorption coefficient. Shock-tube emission data at λ=6.890 μ(Δλ=0.197μ) forCH₃COOCH₃at 814≤T, °K≤1651 and for CH₃at 1377≤T, °K≤1562 in the v₄-fundamental of the H-bond bending mode of the CH₃-group are well described at atmospheric pressures by approximations of just-overlapping-line models for polyatomic molecules. The adopted models are useful for concentration-time history measurements of methyl acetate, nitrogen dioxide, and methyl radicals behind shock waves.     

2D-NMR Studies on Bis(Amidinohydrazones). I. A Proton-Carbon Heteronuclear Shift Correlation Study on the Enzyme Inhibitors Methylpropylglyoxal Bis(Amidinohydrazone) and Butylmethylglyoxal Bis(Amidinohydrazone)

The first 2D-NMR study on bis(amidinohydrazones) [‘(guanylhydrazones)’] is reported. Heteronuclear shift correlation (HETCOR) experiments were performed on the enzyme inhibitors methylpropylglyoxal bis(amidinohydrazone) (MPGBG) and butylmethylglyoxal bis(amidinohydrazone) (BMGBG). The results obtained made possible the unambiguous assignment of the previously unassigned resonances of the side-chain carbon atoms of MPGBG. The results indicate that the chemical shifts of the protons of the propyl side chain of MPGBG are positively correlated to the ¹³C chemical shifts of the corresponding carbon atoms. The chemical shifts of the carbon atoms of the propyl side chain decrease as a function of the position of the atom in the side chain, the terminal methyl group having the lowest shift value. These results are in full agreement with previous results on the analogous compound dipropylglyoxal bis(amidinohydra- zone), whose side-chain carbon resonances were assigned using totally different techniques. In the case of BMGBG, however, HETCOR contour plots clearly indicate that there is no correlation between the chemical shifts of the protons of the butyl side chain and the 13C chemical shifts of the corresponding carbons. Because the 200 MHz proton spectrum of BMGBG is not fist-order, only the 1 3 resonance～ of the methyl substituent and the resonances of carbons 1 and 4 (but not those of carbons 2 and 3) of the butyl side chain could be assigned on the basis of the HETCOR study. Yet, the results gave a rough estimate of the previously unknown chemical shifts of the protons bound to butyl carbon atoms 2 and 3.     

Probing the low-temperature chemistry of methyl hexanoate: Insights from oxygenate intermediates

Understanding the combustion of methyl esters is crucial to elucidate kinetic pathways and predict combustion parameters, soot yields, and fuel performance of biodiesel, however most kinetic studies of methyl esters have focused on smaller, surrogate model esters. Methyl hexanoate is a larger methyl ester approaching the chain length of methyl esters found in biodiesel and has not received as much research attention as other smaller esters. The purpose of this work is to present the first atmospheric pressure combustion data of methyl hexanoate, CH₃CH₂CH₂CH₂CH₂COOCH₃. Mixtures of 2% methyl hexanoate in O₂ and N₂ are studied using a plug flow reactor at atmospheric pressure, wall temperatures from 573 to 973 K, residence times from roughly 1-2 s., and fuel equivalence ratios of 1, 1.5, and 2. Exhaust gases are analyzed by a gas chromatograph-mass spectrometer system and species mole fractions are presented. The literature model shows satisfactory agreement with the experimental species profiles and improvements for future mechanistic studies are suggested. In particular, this work proposes new unimolecular decomposition pathways of methyl hexanoate to form methanol or methyl acetate. Furthermore, the experiment detected three unsaturated esters that are direct products of the low temperature oxidation chemistry and it provides more insight into branching ratios for the formation of methyl hexanoate radicals and for the decomposition of hydroperoxyalkyl radicals.     

EPR and Quantum Chemical Studies of the pH-sensitive Imidazoline and Imidazolidine Nitroxides with Bulky Substituents

The X- and W-band electron paramagnetic resonance (EPR) spectroscopies were employed to investigate a series of imidazolidine nitroxide radicals with different number of ethyl and methyl substituents at positions 2 and 5 of a heterocycle in liquid and frozen solutions. The influence of the substituents on the line shape and width was studied experimentally and analyzed using quantum chemical calculations. Each pair of the geminal ethyl groups in the positions 2 or 5 of the imidazolidine ring was found to produce an additional hyperfine splitting (hfs) of about 0.2 mT in the EPR spectra of the nitroxides. The effect was attributed to the hfs constant of only one of four methylene hydrogen atoms of two geminal ethyl substituents not fully averaged by ethyl group rotation and ring puckering. In accordance with this assumption, the substitution of hydrogen atoms of CH₂ groups in 2,2,5,5-tetraethyl-substituted imidazolidine nitroxides by deuterium leads to the substantial narrowing of EPR lines which could be useful for many biochemical and biomedical applications, including pH-monitoring. W-band EPR spectra of 2,2,5,5-tetraethyl-substituted imidazolidine nitroxide and its 2,2,5,5-tetraethyl–d₈ deuterium-substituted analog measured at low temperatures demonstrated high sensitivity of their g-factors to pH, which indicates their applicability as spin labels possessing high stability.