一个基于[Cu4(μ2-OH)2N12]的10-连接3D配合物的合成、结构和光催化性质

通过扩散法合成了一个新的配位聚合物{[Cu₂（OH）（btre）_1.5（1,2,4-btc）]·13H₂O}_n（1·13H₂O）（btre=1,2-二（4H-1,2,4-三唑）乙烷,1,2,4-btc=1,2,4-苯三甲酸根）。测试了1·13H₂O的晶体结构,并用红外光谱、元素分析、粉末X射线衍射对其进行表征。单晶X射线衍射表明1是基于四核铜簇[Cu₄（μ₂-OH）₂N₁₂]构筑的10-连接的3D框架,其拓扑符号为3¹²·4²⁸·5⁵。研究了1·13H₂O的热稳定性以及对甲基橙的催化降解作用。     

1-乙基-3-甲基咪唑丙氨酸离子液体热力学性质的研究

用中和法合成了氨基酸离子液体1-乙基-3-甲基咪唑丙氨酸([C₂mim][Ala]),并利用恒温环境的溶解反应热量计,在(288.15±0.01) K-(308.15±0.01) K温度范围内每隔5 K,测定不同质量摩尔浓度离子液体在水中的溶解焓(Δ_solH_m^θ).根据Archer的方法,通过线性拟合得到了该离子液体的标准摩尔溶解焓(Δ_sol),并计算了其相对表观摩尔溶解焓(^ΦL).在298.15 K下,根据Glasser经验方法得到了格子能U_POT = 566 kJ·mol^-1,并计算了其阴阳离子水化焓值(ΔH⁺ + ΔH^-) = -620 kJ·mol^-1及阴离子水化焓ΔH^-([Ala]^-) = -387 kJ·mol^-1.此外,估算了[C₂mim][Ala]水溶液的热容(C_p(sol))和表观摩尔热容(^ΦC_p).     

一种多孔配位聚合物的氢键协同客体响应

由硝酸锌、 吡唑-3,5-二羧酸（H₃pzdc）和2-氨基对苯二甲酸（H₂abdc）在溶剂热条件下反应得到一种多孔配位聚合物(Me₂NH₂)[Zn₂(pzdc)(abdc)]·H₂O·DMF(1·g), 其中Me₂NH₂⁺由溶剂N,N-二甲基甲酰胺（DMF）水解得到, 1可视为平行排列的平整带状{Zn₂(pzdc)}⁺链被abdc^2-柱子交错支撑而成的三维多孔框架. 通过脱附/吸附溶剂分子, 中心对称的配位聚合物1·g可以可逆转变成手性的(Me₂NH₂)[Zn₂(pzdc)(abdc)](1′). 单晶结构分析表明, 在客体响应过程中, 基于框架、 抗衡离子和客体分子之间的氢键协作与竞争, 抗衡离子发生了显著的移动 和转动, 导致{Zn₂(pzdc)}⁺链扭曲和转动, 伴随着超过10%的晶胞体积和孔洞率变化. 气体吸附测试表明, 化合物1'对N₂和CO₂存在不同的结构响应行为.     

C60吡咯烷羧酸衍生物的合成及其在水溶液中的聚集行为

C60与亚氨基二乙酸甲酯[NH(CH₂COOMe)₂]的光化学反应制得2,5-双(甲氧羰基)富勒烯吡咯烷(1), 产率为52% (基于已反应的C60). C60吡咯烷衍生物1与氯乙酸甲酯(ClCH₂COOCH₃)的N-烃基化反应, 在微波辐射、无溶剂及相转移条件下, 得到2,5-双(甲氧羰基)-N-(甲氧羰基)甲基富勒烯吡咯烷(2), 产率47%(基于C60吡咯烷衍生物1). C60吡咯烷衍生物1和2用NaH, CH₃OH水解后, 经盐酸酸化得相应的二羧酸衍生物3和三羧酸衍生物4, 产率分别为65%和53% (基于C60吡咯烷衍生物1和2). C60吡咯烷衍生物1～4的结构由¹H NMR, ¹³C NMR, IR, FAB-MS和元素分析证实. 用电导法测定了C60吡咯烷二羧酸3和三羧酸4钠盐的临界聚集浓度(CAC), 分别为3.58×10^－4 mol/L (3)和3.33×10^－4 mol/L (4). 这一结果被C60吡咯烷衍生物3和4, 在临界聚集浓度(CAC)附近的UV-Vis光谱的特征变化所支持. 透射电子显微镜(TEM)和静态光散射(SLS)等方法也被用于检测C60吡咯烷衍生物3和4在临界聚集浓度(CAC)时的聚集行为, 结果显示, C60吡咯烷衍生物3在缓冲溶液中(0.001 mol/L NaCO₃-NaHCO₃), 其聚集体粒径的大小(R_g≈21 nm)不同于C60吡咯烷衍生物4 (R_g≈23 nm). C60吡咯烷二羧酸3钠盐的临界聚集浓度(CAC)比C60吡咯烷三羧酸4钠盐的临界聚集浓度(CAC)大, 聚集体粒径大小的不同, 表明C60单加成衍生物加成基团中羧基(COOH)数目的多少对其聚集行为的影响. 用化学发光法分别检测了C60吡咯烷二羧酸3和C60吡咯烷三羧酸4在缓冲溶液(0.05 mol/L NaCO₃-NaHCO₃)中对邻苯三酚自氧化产生的超氧阴离子(O₂^－·)的清除活性. C60衍生物3和4对 O₂^－· 的清除呈现有明显的剂量效应, 但当超过一定浓度时(3: ～3.50×10^－4 mol/L, 4: ～3.25×10^－4 mol/L), 清除效率出现转折, 并下降. 这一现象与电导率测定时出现的CAC现象相一致, 进一步证实了C60吡咯烷二羧酸3和C60吡咯烷三羧酸4在较高浓度的水溶液中有聚集的倾向, 也说明了C60吡咯烷二羧酸3和C60吡咯烷三羧酸4的聚集会影响其清除超氧阴离子(O₂^－·)的活性.     

NH3R++NHR2(R=H,CH3)体系质子传递反应的从头算研究

用从头计算法在HF/6-31G^*基组水平上研究了NH₄⁺+NH₃→NH₃+NH₄⁺,NH₄⁺+NH₂CH₃→NH₃+NH₃CH₃⁺,NH₄⁺+NH(CH₃)₂→NH₃+NH₂(CH₃)₂⁺以及NH₃CH₃⁺+NH₂CH₃→NH₂CH₃+NH₃CH₃⁺等4个体系的质子传递反应的机理.结果表明:(1)上述质子传递反应均具有双阱型的势能面,质子沿N(1)、N(2)连线直接传递;(2)质子受体分子中的甲基对质子传递起促进作用,而质子给体离子中的甲基则阻碍质子的传递。     

系列Ti4L6-笼基配合物的合成与结构研究

金属有机笼（Metal-Organic Cages，MOCs）作为一种新型的分子容器，因其具有特殊的空腔结构及其在分子识别/分离、药物传输和催化等方面具有诱人的应用前景而受到学者广泛地关注.但是，在过去几十年里，化学家们主要致力于构筑各种具有特定功能的MOCs，而进一步将MOCs组装成先进的超分子材料，在这方面研究较少.在前期工作中，本课题组构筑了一例可溶于水、超稳定且具有配位组装功能的钛-有机四面体笼（Ti₄L₆，L=帕莫酸），并利用Ti₄L₆笼作为原料，通过两步反应实现了与不同金属离子的配位组装.在本项工作中，在不同溶剂热的条件下，利用Ti₄L₆笼分别与Mn²⁺、Nd³⁺、Ba²⁺和Ca²⁺离子反应，得到了系列Ti₄L₆-笼基配合物，分别为：（Me₂NH₂）₉（Me₄N）[Mn₃（Ti₄L₆）₂-（H₂O）₉（DMF）₆]·Guests（PTC-241，DMF=N，N-二甲基甲酰胺）；（Me₂NH₂）₅[Nd（Ti₄L₆）（H₂O）₂（DMF）₅]·Guests（PTC-242）；（Me₂NH₂）₂[Ba₄（Ti₄L₆）（OH）₂（H₂O）₈（TEA）₅]·Guests（PTC-243，TEA=三乙醇胺）；（Me₂NH₂）₂[Ca₃（Ti₄L₆）（H₂O）₈（DEA）₂]·Guests（PTC-244，DEA=二乙醇胺）；（Me₂NH₂）₂[Ca₃（Ti₄L₆）（H₂O）₁₅]·Guests（PTC-245），并采用X射线单晶衍射、红外（IR）光谱分析、热分析仪（TGA）和X射线粉末衍射（PXRD）等方法对这些化合物进行了结构表征.X射线单晶衍射结果表明，PTC-241是由ΔΔΔΔ-[Ti₄L₆]和ΔΔΔΔ-[Ti₄L₆]-Mn₃笼通过弱作用力（氢键和π-π堆积）交错堆积形成的超分子手性化合物；PTC-242是由Ti₄L₆-Nd笼通过氢键作用堆积形成的超分子化合物；PTC-243是一条直线形的Ti₄L₆-Ba₄链；而PTC-244和PTC-245则是两个具有峰窝状结构的二维Ti₄L₆-Ca₃层.另外，我们还研究了PTC-244和PTC-245的荧光性质.     

第一性原理研究HC(NH2)2PbI3钙钛矿(三方相VS六方相)的结构及光电特性

采用第一性原理,研究三方及六方相FAPbI₃（FA=HC（NH₂）₂⁺）钙钛矿的结构及光电特性.结果表明,FAPbI₃钙钛矿由三方到六方的形变能够扭转PbI₃骨架,改变Pb-I键合特性,进而改变其禁带宽度值.两种晶体均属于直接带隙半导体,三方相FAPbI₃的直接带隙点位于布里渊区Z（0,0,0.5）对称点,具有较为理想的约1.50 eV的禁带宽度;六方相FAPbI₃的直接带隙点位于Γ（0,0,0）对称点,具有约2.50 eV的禁带宽度.FA离子不直接参与电子跃迁过程,仅仅充当电荷供体为PbI₃骨架提供超过0.7 e的电荷.相比于六方相晶体,三方相FAPbI₃具有更小的载流子有效质量,吸收光谱发生了显著的红移,并且其吸收特性优于六方相FAPbI₃和四方相MAPbI₃（MA=CH₃NH₃⁺）钙钛矿.六方相FAPbI₃比三方相晶系更稳定,FA和PbI₃骨架之间的结合作用力强于MA和PbI₃骨架之间的作用力.     

新型富勒烯C60有机钴配合物(η2-C60)(η5-RC5H4)CoPPh3 (R=H,CO2Et)的合成及性质研究

鉴于富勒烯C₆₀所具有的缺电子烯烃的特性¹以及CpCo(PPh₃)₂可与烯或炔反应生成钴杂环有机化合物,^2,3 因此我们设想如果用C₆₀代替烯、炔,令其与η⁵-RC₅H₄Co(PPh₃)₂(1) 或η⁵-RC₅H₄Co(PPh₃)(PhC≡CPh)(2)反应,则应得到一类新型的富勒烯C₆₀有机钴杂环化合物。然而与这一设想不同的是,上述反应并未得到预期的C₆₀钴杂环有机物,所得到的却是另一类新型的有机钴C₆₀衍生物(η²-C₆₀)(η⁵-RC₅H₄)CoPPh₃(3).此外,我们发现当3或2同I₂反应时,可生成C₆₀或PhC≡CPh配体被I₂置换产物η⁵-RC₅H₄Co(PPh₃)I₂(4)。     

PbO-PbI2复合物膜转化的CH3NH3PbI3钙钛矿薄膜及其光电特性

有机-无机卤化物钙钛矿是一类优异的光电材料. 在过去四年内, 基于有机-无机卤化物钙钛矿的光电器件实现了超过15%的光电转换效率. 而有机-无机卤化物钙钛矿材料的可控制备是保证其在光电器件中应用的基础. 本文采用新的沉积方法在玻璃衬底表面制备了一种典型的有机-无机卤化物钙钛矿CH₃NH₃PbI₃薄膜. 其制备过程是: 采用超声辅助的连续离子吸附与反应法在玻璃衬底表面沉积PbO-PbI₂复合物膜, 之后与CH3NH3I蒸汽在110 ℃环境下反应, 将PbO-PbI₂复合物膜转化成CH₃NH₃PbI₃钙钛矿薄膜. 对CH₃NH₃PbI₃薄膜的微观结构, 结晶性及其光电性能等进行了表征. 结果表明, CH₃NH₃PbI₃薄膜呈晶态, 具有典型的钙钛矿晶体结构. 薄膜表面形貌均匀, 晶粒尺寸超过400 nm. 在可见光范围, CH₃NH₃PbI₃薄膜透过率低于10%, 能带宽度为1.58eV. 电学性能研究表明CH₃NH₃PbI₃薄膜表面电阻率高达1000 MΩ. 高表面电阻率表明CH₃NH₃PbI₃薄膜具有一定的介电性能, 其介电常数(ε_r)在100 Hz时达到155. 本研究提出了一种制备高质量CH₃NH₃PbI₃钙钛矿薄膜的新方法, 所得CH₃NH₃PbI₃薄膜可望在光、电及光电器件中得到应用.     

A novel chemosensor-bipyridyl end capped hyperbranched conjugated polymer

A novel hyperbranched conjugated chemosensor with bipyridyl groups as periphery groups（BPY-HPV） was synthesized.BPY-HPV was highly sensitive to metal ions(Cu²⁺,Ni²⁺) for the strong coordination interaction(K_sv at the order of 10⁷ mol^-1 L) monitored by fluorescence spectroscopy.Moreover,by hydrogen bonds and charge transfer interaction,BPY-HPV shows strong interaction with 1,1,2,2-tetrachloroethane whatever in CH₂Cl₂(K_sv～10⁶ mol^-1 L) or film.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.