γ-苄基膦酸-磷酸锆的合成、表征及插层性能研究

于220℃水热晶化下制备了高结晶度的γ-ZrP,合成了3种γ-苄基膦酸-磷酸锆层状化合物Zr(PO₄).(H₂PO₄)_0.15(C₆H₅CH₂PO₃H)_0.85·0.4H₂O(1,d=1.86nm),Zr(PO₄)(H₂PO₄)_0.30(C₆H₅CH₂PO₃H)_0.70·0.6H₂O(2,d=1.78nm)和Zr(PO₄)(H₂PO₄)_0.50(C₆H₅CH₂PO₃H)_0.50·0.7H₂O(3,d=1.66nm).用X射线粉末衍射和³¹P固态核磁共振等手段表征其结构,并研究了其与α-苯乙胺的插层性能.     

含氮螯合配体过渡金属配合物修饰的缺位型Keggin多酸盐

在常温条件下合成了铜-邻菲啰啉修饰的结构独特的多酸衍生物H₄[Cu(phen)(H₂O)][Cu(phen)][α-SiW₁₁O₃₉]·3H₂O(1). 该化合物分子中2个独立的非二聚体的铜-邻菲啰啉平行地与缺位多酸空穴外的氧配位键合, 通过元素分析、红外光谱、热重分析和X射线单晶衍射对其结构进行了表征. 结果表明, 该化合物属三斜晶系, P1空间群, 晶胞参数a=1.3624(2) nm, b=1.4133(2) nm, c=2.0470(3) nm, α=97.840(3)°, β=95.117(3)°, γ=112.483(3)°.     

高氯酸铕的双亚砜配合物研究

本文报告了高氯酸铕的高、低熔点双(正-辛基亚砜)乙烷和双(苯基亚砜)乙烷的四个配合物:Eu(ClO₄)₃(α-BOSE)₃·2H₂O(Ⅰ)、Eu(ClO₄)₃(β-BOSE)₄·2H₂O(Ⅱ)、Eu(ClO₄)₃(α-BPhSE)₃(Ⅲ)和Eu(ClO₄)₃(β-BPhSE)₄·2H₂O(Ⅳ)的合成及性质。     

2,6-二甲基-3,5-二（吡唑-3-基）吡啶构筑的新型八钼酸盐的合成及其电化学性质

利用六水合硫酸锌（ZnSO₄· 6H₂O）、七钼酸铵［(NH₄)₆Mo₇O₂₄· 4H₂O］和2,6-二甲基-3,5-二（吡唑-3-基）吡啶（H₂L）为原料，通过水热反应，合成了一个新型的八钼酸盐［Zn(H₃L)₂(H₄Mo₈O28), 1）］，其结构和性能经IR、元素分析,X 射线单晶衍射和TGA表征。结果表明:〖STHZ〗1〖STBZ〗(CCDC: 1860339)属三斜晶系，P₁空间群，晶胞参数a=9.421(5) , b=10.737(5) , c=11.826(5) , α=100.340(5)°, β=97.939(5)°, γ=100.053(5)°, V=1140.9(4) ³, Z=1, R₁=0.029 2, wR₂=0.0769。1的结构中，锌离子被质子化的有机配体H₃L⁺连接形成一维链结构，同多钼酸簇{Mo₈O₂₈}将相邻的一维链连接起来形成二维层结构。电化学分析结果表明：1对亚硝酸根离子还原具有较好的催化作用，当亚硝酸根离子浓度为5 mmol·L^-1时，催化效率为61%。     

新型苯并咪唑-5,6-二羧酸锌配合物的合成及其性能研究

以ZnSO₄·7H₂O和苯并咪唑-5,6-二羧酸为原料，采用水热法合成了一种新型的锌配合物{\[Zn(H₂-bidc)₂(H₂O)₄]·(H₂O)₄}_n[1 (CCDC: 1007038), H₃-bidc=苯并咪唑-5,6-羧酸]，产率48%，其结构经IR,元素分析和X-射线单晶衍射表征。结果表明：1属正交晶系，Pnnm空间群，晶胞参数a=9.6451(19) ， b=19.459(4) ， c=6.6895(13) ，α=β=γ=90°， V=1255.5(4) ³， Dc=1.634 g·cm^-3， Z=8。采用FL和TGA研究了1的性能。结果表明：1具有一定的热稳定性，最大发射峰位于420 nm和416 nm， 1的荧光发射属于发射配体荧光。     

新型己二胺四甲叉膦酸钠配位化合物的合成及其晶体结构

氢氧化钠与己二胺四甲叉膦酸（H₈L）在水溶液中反应合成了一个新型的配合物[Na₃(H₆L)₂(H₂O)₈][Na(H₂O)₆]·8H₂O（1）,其结构经IR和X-射线单晶衍射表征。结果表明1属P-1空间群,晶胞参数a=7.705 9(1) , b=11.655 6(2) , c=18.119 7(3) ,α=97.247(1)°,β=94.797(1)°, γ=101.827(1)°。 1中部分钠离子通过与四膦酸配体中的氧原子配位,形成一维链状结构{[Na₃(H₆L)₂(H₂O)₈]^-}_∞,该阴离子链的电荷被孤立离子团[Na(H2O)⁶]⁺平衡。在未配位的膦酸基团、氨基、配位水分子、结晶水分子之间的氢键相互作用下,化合物堆积形成一个结构致密的三维超分子结构。     

一种镉(ΙΙ)配位聚合物的合成及其作为Fe3+和Mn2+双响应荧光化学传感器的表现

以三（4-（1H-咪唑-1-基）-苯基）胺（Tipa）,富马酸（H₂fuma）和Cd(NO₃)₂·6H₂O为原料,溶剂热法在100℃下合成了一种新的Cd(ΙΙ)配合物[Cd(fuma)(Tipa)₃Cl]_n（CP1）,其结构经X-射线单晶衍射,IR,元素分析表征。CP1属单斜晶系,C 2/c空间群,晶胞参数a=21.5503(10) Å,b=14.9847(6) Å,c=18.2554(10) Å,α=90°,β=99.687(5)°,γ=90°。固体荧光激发依赖测试结果显示配合物CP1对激发光具有依赖性,并研究了其变温荧光,液体荧光的测试结果显示,CP1可以作为检测Fe³⁺和Mn^{2 +}离子的双响应荧光化学传感器。      

大环多胺配体BDBPH的设计合成及其晶体结构

用Pb(SN)₂作模板,2,6-二甲酰基对甲苯酚与二亚乙基三胺通过[2+2]缩合反应,经NaBH₄还原、脱Pb²⁺、酸化等操作,得晶体BDBPH·6HBr·4H₂O.晶体属单斜晶系,P2_1/c空间群,晶体学参数:a=1.4441(5)nm,b=1.1482(4)nm,c=1.2090(6)nm,α=90°,β=96.92°,γ=90°,V=1.9900nm³大环分子采取椅式构型,6个Br-和4个H₂O分子对称分布于大环两侧.该大环配体结构新颖,可用于多种金属配合物的研究,对进一步了解金属酶活性中心的结构及其催化作用机理具有重要价值.     

Ca2+离子掺杂对γ-Ce2S3合成温度及热稳定性的影响

以CeCl₃·7H₂O、CaCl₂·2H₂O和C₂H₂O₄·2H₂O为原料,在制备钙铈氧化物前驱体基础上,再以Ar气为载气、CS₂为硫源对钙铈氧化物前驱体进行硫化合成Ca²⁺掺杂的γ-Ce₂S₃色料。 通过X射线衍射(XRD)、紫外-可见漫反射光谱(UV-Vis)及差热-热重分析(TG-DTA)等技术手段表征了色料的结构和性能。 结果表明,Ca²⁺掺杂能够明显降低γ-Ce₂S₃的合成温度,当n(Ca²⁺):n(Ce³⁺)≥0.16时,在900 ℃硫化150 min即可获得纯相的γ-Ce₂S₃,与不掺杂时合成γ-Ce₂S₃的温度相比降低了300 ℃左右。 同时,Ca²⁺掺杂能够提升γ-Ce₂S₃的抗氧化能力,当n(Ca²⁺):n(Ce³⁺)=0.64时,氧化放热峰的温度由不掺杂时的490.6 ℃提高至541.0 ℃。     

不同晶体结构MnO2纳米催化剂低温NH3-SCR性能研究

为了探究催化剂的结构和催化活性的关系,采用水热法制备了四种不同晶体结构的MnO₂纳米催化剂（α-MnO₂、β-MnO₂、γ-MnO₂和δ-MnO₂）,并考察了其低温NH₃-SCR活性。结果表明,不同晶体结构催化剂的活性不同,依次为γ-MnO₂ > α-MnO₂ > β-MnO₂ > δ-MnO₂,γ-MnO₂表现出最高的催化活性,NO_x转化率在150-260℃超过90%。随后,通过X射线衍射（XRD）、扫描电子显微镜（SEM）、N₂吸附-脱附、热重（TG）、红外光谱（FT-IR）、程序升温还原（H₂-TPR）及吡啶吸附红外光谱（Py-FTIR）等表征手段对催化剂的结构和性质进行分析。结果表明,α-MnO₂和β-MnO₂为纳米棒,γ-MnO₂和δ-MnO₂为纳米针,催化剂的比表面积并不是影响低温NH₃-SCR活性的主导因素。γ-MnO₂具有适宜的孔道结构、较强的氧化还原能力、丰富的化学氧含量和Lewis酸酸性位点,是其具有最高低温NH₃-SCR活性的原因。     

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.