氨三乙酸三脚架型配体的合成、结构表征及量子化学计算

以氨三乙酸和芳香胺(2a-2c)为原料,在N,N′-二环己基碳二亚胺(DCC),4-二甲基吡啶(DMAP)/1-羟基苯并三唑(HOBt)作用下合成了3个结构新颖的三脚架型配体(3a-3c),用IR,1H NMR及元素分析方法对配体进行了表征,并采用量子化学理论,在密度泛函理论(DFT)-B3LYP/6-31G(d)水平下优化了配体的空间构型,计算了其结构参数.为稀土配合物的合成研究提供参考.     

2,6-双[N-(1′,1′-二甲基-2′-羟基)甲酰胺]吡啶及镍(Ⅱ)配合物的合成与光谱学研究

合成并表征了有机配体2,6-双[N-(1′,1′-二甲基-2′-羟基)甲酰胺]吡啶(L)及其镍(Ⅱ)配合物,采用元素分析确定目标配合物组成为C15H21N3O4Ni.H2O,通过对比分析的方法讨论了配位前后游离配体L和镍(Ⅱ)配合物的核磁共振氢谱、核磁共振碳谱、红外吸收光谱和紫外-可见吸收光谱的谱学性质,进而推断出镍(Ⅱ)配合物的结构。结果表明,配体2,6-双[N-(1′,1′-二甲基-2′-羟基)甲酰胺]吡啶以2个酰胺负离子N和1个吡啶环N原子为配位原子,与中心金属离子Ni(Ⅱ)通过三齿形式配位;配合物中Ni(Ⅱ)采取dsp2杂化轨道方式与配位原子构成配位键,中心金属Ni(Ⅱ)的配位数为4,1个Ni(Ⅱ)与1个三齿配体L和1个水分子配位,形成平面正方形构型的低自旋镍(Ⅱ)配合物。     

2-羟基-N-甲基乙酰苯胺的合成和表征

以N-甲基苯胺、氯乙酰氯、无水醋酸钠、甲醇等为原料,经乙酰化,酯化及酯交换反应合成了2-羟基-N-甲基乙酰苯胺,三步总收率为88.0%.N-甲基苯胺、氯乙酰氯在三乙胺的催化下,按n(C6H5NHCH3):n[ClCH2C(O)Cl]:n[N(C2H5)3]=1:1.05:1,经乙酰化反应得到2-氯代-N-甲基乙酰苯胺(I),收率为93.8%;(I)与无水醋酸钠在相转移催化剂四丁基溴化铵的存在下,按n(I):n(NaOAc)=1:1.2,经酯化反应合成了2-乙酰氧基-N-甲基乙酰苯胺(Ⅱ),收率为97.3%;(Ⅱ)与甲醇按n(Ⅱ):n(CH3OH)=1:10,在氢氧化钾的催化下,进行了酯交换反应得到2-羟基-N-甲基乙酰苯胺(Ⅲ),收率为96.4%.并利用红外、质谱和元素分析,对各产物进行了表征,确认了分子结构.     

网胰藻中的含氮化合物

从中国南海网胰藻(Hydroclathrus Clathratus)中分离得到4个含氮化合物,经波谱技术鉴定为:N-(2'-羟基-1'-羟甲基十五烷基)二十脂肪酸酰胺(Ⅰ)、尿嘧啶(Ⅱ)、1-(2-脱氧-β-D-呋喃核糖-5-甲基-1,2,3,4-四氢-2,4-二酮(Ⅲ)和2-苯胺基-1,4-萘二酮(Ⅳ),其中化合物Ⅳ为首次从自然界中分离得到.     

西沙仙掌藻Halimeda Xishaensis的次级代谢产物

从采自西沙永兴岛的西沙仙掌藻Halimeda Xishaensis样品中分离鉴定了4个单羟基甾醇,5-烯-3α-胆甾醇(1),5-烯-3β-麦角甾醇(2),豆甾醇(3),β-谷甾醇(4)和4个单体化合物,1-正二十三碳酸甘油酯(5),豆甾-4-烯-3β,6β-二醇(6),N-(1-羟甲基-2-羟基-3E-十五碳烯)-正二十七酰胺(7)和1个丁四醇(8)。     

分光光度法测定3-氯-N-羟基-2,2-二甲基丙酰胺

在表面活性剂十二烷基磺酸钠存在下,于pH3.6的乙酸-乙酸钠缓冲溶液中,铁(Ⅲ)与3-氯-N-羟基-2,2-二甲基丙酰胺形成稳定的络合物,在490nm处有最大吸收,3-氯-N-羟基-2,2-二甲基丙酰胺浓度为2-160mg·L<'-1>范围内符合朗伯-比耳定律,ε<,490>=1.05×10<'4>L·mol<'-1>...     

4-二甲基对巯基苯胺吸附于银簇上的光诱导催化偶联反应机理研究

采用密度泛函理论(DFT)中的B3LYP方法对4-二甲基对巯基苯胺吸附在Ag簇上催化偶联生成4,4’-二巯基偶氮苯(4,4’-DMAB)的反应机理进行理论研究。对比研究了暗反应条件下和光照条件下4-二甲基对巯基苯胺吸附在Ag簇上发生催化偶联生成4,4’-二巯基偶氮苯(4,4’-DMAB)的反应机理。为了了解4-二甲基对巯基苯胺中的巯基端S原子吸附在银簇上对反应的影响,比较研究了4-二甲基对巯基苯胺中的N和S原子同时吸附和仅N原子吸附在银簇上两种条件下的化学反应机理。用自然键轨道（NBO）理论和分子中的原子理论(AIM)分析了分子轨道间相互作用和成键特征。研究结果发现：该反应的关键在于氨基端两个甲基的脱去;在暗反应和光照条件下,两端吸附时第二个甲基脱去所需活化能均很高,分别为57.95 、63.88 kcal/mol,表明光照在反应中没起到催化作用。暗反应条件下巯基端吸附起到助催化作用,反应为两端协同催化过程。光照条件下银簇两端协同催化过程表现得不明显。     

4-二甲基对巯基苯胺吸附于银簇上的光诱导催化偶联反应机理研究

采用密度泛函理论(DFT)中的B3LYP方法对4-二甲基对巯基苯胺吸附在Ag簇上催化偶联生成4,4’-二巯基偶氮苯(4,4’-DMAB)的反应机理进行理论研究.对比研究了暗反应条件下和光照条件下4-二甲基对巯基苯胺吸附在Ag簇上发生催化偶联生成4,4’-二巯基偶氮苯(4,4’-DMAB)的反应机理.为了了解4-二甲基对巯基苯胺中的巯基端S原子吸附在银簇上对反应的影响,比较研究了4-二甲基对巯基苯胺中的N和S原子同时吸附和仅N原子吸附在银簇上两种条件下的化学反应机理.用自然键轨道(NBO)理论和分子中的原子理论(AIM)分析了分子轨道间相互作用和成键特征.研究结果发现:该反应的关键在于氨基端两个甲基的脱去,在暗反应和光照条件下,两端吸附时第二个甲基脱去所需活化能均很高,分别为57.95、63.88 kcal/mol,表明光照在反应中没起到催化作用.暗反应条件下巯基端吸附起到助催化作用,反应为两端协同催化过程.光照条件下银簇两端协同催化过程表现得不明显.     

新型苯乙烯衍生物掺杂的蓝色及白色有机电致发光器件

研究了新型高效蓝色掺杂剂EBDP的电致发光性能. 分别以EBDP为掺杂剂制备了结构为氧化铟 锡(ITO)/酞菁铜(CuPc)/N,N′-二(1-萘基)-N,N′-二苯基-1,1′-联苯-4-4′-二胺(NPB)/2- 叔丁基-9,10-二-(2-萘基)蒽(TBADN):EBDP/8-羟基喹啉铝(Alq₃)/LiF/Al 与ITO /CuPc/NPB/TBADN:EBDP: 4-二氰亚甲基-2-叔丁基-6-(1,1,7,7-四甲基久咯呢定基-9-烯基)- 4H-吡喃/Alq_{3 关键词： 有机电致发光 蓝色掺杂剂 蓝色电致发光器件 白色电致发光器件}     

钕4,4′-二甲基-2,2′-联吡啶配合物液体激光介质的合成及其光学特性(英文)

合成并用元素分析、红外光谱法表征了一种4,4′-二甲基-2,2′-联吡啶五氟丙酸钕配合物—Nd(C2F5COO)3·Dmbp(Dmbp:4,4′-二甲基-2,2′-联吡啶).将该配合物溶解在N,N-二甲基甲酰胺中获得了液体介质,依据液体介质的吸收和荧光光谱,通过Judd-Ofelt理论计算获得了钕离子的谱线强度参数(Ω2,Ω4,Ω6)和受激发射截面.计算得到该配合物中钕离子4F3/2→4I11/2跃迁的受激发射截面为5.2×10-20 cm2,表明该钕配合物在液体基质中具有较好的发光特性.通过荧光发射光谱分析可知,Nd(C2F5COO)3·Dmbp将是一种有前途的光学增益材料.     

利用19F NMR与荧光光谱法检测高分子酰胺化反应

通过血红素上羧基与端氨基聚乳酸上的氨基之间进行酰胺化反应,制得了血红素-聚乳酸分子.利用六氟异丙醇与端羧基反应生成六氟异丙醇酯,结合19F NMR峰面积积分的方法测定羧基含量,以荧光胺作为荧光试剂,采用荧光光谱法测定伯胺端基.进而,采用端基分析方法计算了血红素-聚乳酸的数均分子量,检测了血红素与聚乳酸1∶1和1∶2投料...     

壳聚糖和N-羟基苯并三氮唑相互作用的NMR研究

运用液体¹H谱、固体高分辨13C谱以及脉冲梯度场测量自扩散系数等核磁共振技术,研究了壳聚糖（CS）和N-羟基苯并三氮唑（HOBt）的相互作用.结果表明,CS重复单元中2位碳上的-NH₂和HOBt唑环上的-OH之间存在较强的氢键作用,HOBt的存在可以促进CS在水溶液中的溶解,使得在水溶液中对CS进行化学改性成为可能.通过测量CS与HOBt混合溶液中HOBt的自扩散系数,计算出复合物结合与解离的平衡常数K.     

Development of practical methodologies for the synthesis of novel 3(4-oxo-4H-chromen-3-yl)acrylic acid hydrazides

We report a new environmentally-benign, convenient and facile methodology for the synthesis of new series of 3(4-oxo-4H-chromen-3-yl)acrylic acid hydrazides derivatives designed by exploring the molecular hybridization approach between isoniazide and 3(4-oxo-4H-chromen-3-yl)acrylic acids by using EDCl/HOBt under ultrasound irradiation in very short reaction time. Utilization of easy reaction conditions, isolation and purification makes this manipulation very interesting from an economic perspective.     

Doping of the Processable Conducting Poly(m-Aminophenol) with Inorganic Acids

Poly(m-aminophenol) (PmAP) was synthesized from m-aminophenol (mAP) in aqueous sodium hydroxide (NaOH) using ammonium persulfate (APS) as an oxidative initiator. Free standing PmAP films were cast from dimethyl sulfoxide (DMSO) solution of the polymer. Then the film was doped with various inorganic acids using a solution doping technique. Various inorganic acid doped PmAP films were characterized by ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), and energy dispersive X-ray (EDS) spectroscopies, X-ray diffraction (XRD) analysis and elemental (C, H, N, S, O) analysis. All the results were explained on a comparative basis and the doping scheme was proposed. The DC-conductivity of the inorganic acid doped films was measured using a standard four-probe method. From the DC-conductivity measurements it was found that sulfuric acid had a better doping effect in terms of conductivity than that of the other inorganic acids used, perchloric acid and phosphoric acid. An explanation of the reason for the better doping effect of sulfuric acid than that of the other inorganic acids is given.     

α-（5-氟尿嘧啶-1-基甲基甲酰基）氨基-2-甲基丁酸的合成及红外光谱研究

以5-氟尿嘧啶-1-基乙酸、二环己基碳二酰亚胺和L-缬氨酸为原料,1-羟基苯并三氮唑为辅助试剂,通过碳二亚胺法液相偶联法合成了一种新型的α-（5-氟尿嘧啶-1-基甲基甲酰基）氨基-2-甲基丁酸化合物。通过红外光谱、元素分析确证了该种＂5-氟尿嘧啶短肽化合物＂的结构。     

Green synthesis of gold and silver nanoparticles using gallic acid: catalytic activity and conversion yield toward the 4-nitrophenol reduction reaction

In the present report, gallic acid was used as both a reducing and stabilizing agent to synthesize gold and silver nanoparticles. The synthesized gold and silver nanoparticles exhibited characteristic surface plasmon resonance bands at 536 and 392 nm, respectively. Nanoparticles that were approximately spherical in shape were observed in high-resolution transmission electron microscopy and atomic force microscopy images. The hydrodynamic radius was determined to be 54.4 nm for gold nanoparticles and 33.7 nm for silver nanoparticles in aqueous medium. X-ray diffraction analyses confirmed that the synthesized nanoparticles possessed a face-centered cubic structure. FT-IR spectra demonstrated that the carboxylic acid functional groups of gallic acid contributed to the electrostatic binding onto the surface of the nanoparticles. Zeta potential values of ?41.98 mV for the gold nanoparticles and ?53.47 mV for the silver nanoparticles indicated that the synthesized nanoparticles possess excellent stability. On-the-shelf stability for 4 weeks also confirmed that the synthesized nanoparticles were quite stable without significant changes in their UV–visible spectra. The synthesized nanoparticles exhibited catalytic activity toward the reduction reaction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride. The rate constant of the silver nanoparticles was higher than that of the gold nanoparticles in the catalytic reaction. Furthermore, the conversion yield (%) of 4-nitrophenol to 4-aminophenol was determined using reversed-phase high-performance liquid chromatography with UV detection at 254 nm. The silver nanoparticles exhibited an excellent conversion yield (96.7–99.9 %), suggesting that the synthesized silver nanoparticles are highly efficient catalysts for the 4-nitrophenol reduction reaction.     

Fabrication of large-scale ultra-smooth metal surfaces by a replica technique

The IR double-resonance techniques IR/R2PI (infrared/resonant 2-photon ionization), IR/PIRI (infrared-photo-induced Rydberg ionization) and IR-photodissociation spectroscopy are valuable tools to investigate structure, vibrations, and dynamical processes of neutral and ionic hydrogen-bonded clusters containing aromatic molecules. In this paper we report on the application of the IR double-resonance techniques to determine the NH and OH stretching vibrations of 4-aminophenol and 4-aminophenol(H₂O)₁, both in the neutral (S₀) and ionic (D₀) ground state. All vibrational frequencies obtained for 4-aminophenol and the cluster are compared with the values obtained from ab initio and DFT calculations. In the S₀ state, a trans-linear arrangement of 4-aminophenol(H₂O)₁ is obtained containing an O-H·· O hydrogen bond. In the D₀ state an overlay of two spectra can be observed resulting from the trans-linear structure and a second structure which contains a N-H·· O hydrogen bond. The observation of these two structures within the ion is an interesting example of a rearrangement reaction in the ionic state. Received: 3 November 2000 / Accepted: 6 November 2000 / Published online: 9 February 2001     

A novel three-component reaction for the synthesis of 3-aryl-4H-benzo [1,4] oxazin-2-amine

A high yielding and fast method for the synthesis of 3-aryl-4H-benzo [1,4] oxazin-2-amine via one-pot, three component reaction of an aromatic aldehyde, isocyanide and o-aminophenol using p-toluene sulfonic acid as a catalyst is described.     

Effect on Structure,Processability, and Conductivity of Poly(m-aminophenol) of the Initial Acidity/Basicity of the Polymerization Medium

Poly(m-aminophenol) was synthesized chemically from aqueous solutions of the monomer meta-aminophenol (mAP) in the initially acidic or basic medium by using ammonium persulfate as an oxidant. The polymer (PmAPA) synthesized in initially aqueous HCl medium was insoluble in organic solvents even after dedoping, while the polymer (PmAPB) synthesized in initially aqueous NaOH solution was found to be soluble in high pH water, dimethyl sulfoxide (DMSO), and dimethylformamide. It was possible to obtain a stable, free-standing film from the DMSO solution of PmAPB but, due to insolubility and infusibility, film casting was not possible for PmAPA. The synthesized polymers were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analyses, X-ray diffraction spectroscopy, and four-probe DC electrical conductivity. A ladder-type structure was formed during the chemical polymerization of mAP in aqueous HCl, while a hydroxyl derivative of polyaniline was obtained in aqueous NaOH. The conductivity of sulfuric acid-doped PmAPB was 10⁴ times higher than that of in situ HCl-doped PmAPA. An explanation of the difference in properties of both polymers is given based on molecular modeling.