多酸基共价有机骨架材料的合成与氧化脱硫性能研究在实验教学中的设计与探究

化石燃料燃烧带来的硫排放将导致酸雨的产生,因而实现燃油深度脱硫显得至关重要。多酸（POM）基共价有机骨架材料具有氧化还原性、可调的亲疏水性、可循环再生等特点,被认为是燃油氧化脱硫的一种优异催化材料。本实验在科研成果的基础上创新设计了一个综合实验。通过离子交换法将强氧化型多酸分子（NH₄）₅H₆PMo₄V₈O₄₀ （简写为PMo₄V₈）引入共价有机骨架（COF）,合成了一种多酸基共价有机骨架材料（POM@EB-COF,EB代表溴化乙啶）。利用X射线衍射、红外光谱、元素分析等表征手段对材料结构进行解析。以含有二苯并噻吩的十氢萘作为模型燃油,体系中通入氧气,在PMo₄V₈@EB-COF固体材料表面进行二苯并噻吩的氧化反应,考察其氧化脱硫性能。研究结果表明,以PMo₄V₈@EB-COF作为氧化脱硫催化剂,反应温度为100°C,反应时间...     

H2WO4/GO的制备及其超声-氧化脱除模拟油中的硫化物

以钨酸和氧化石墨烯为原料,利用浸渍法将钨酸负载到氧化石墨烯上制得H₂WO₄/GO。采用XRD、FT-IR、SEM、BET表征确定H₂WO₄/GO的形态及其结构。以H₂WO₄/GO作为催化剂,H₂O₂作为氧化剂,乙腈作为萃取剂超声氧化脱除模拟油中的二苯并噻吩（DBT）。实验表明,在模拟油为5 mL,钨酸的负载量为30%（质量分数）,催化剂为0.02 g,乙腈为1 mL,H₂O₂/S（mol ratio）为8,反应温度为50℃,超声功率为150 W的最佳反应条件下,二苯并噻吩（DBT）、4,6-二甲基二苯并噻吩（4,6-DMDBT）、苯并噻吩（BT）的脱除率分别达到96.6%、81.2%、72.8%。同时,考察了催化剂的循环使用性能,并对超声氧化脱硫机理进行了研究。     

有机-无机杂多酸类离子液体催化汽油超声氧化脱硫

合成了一系列有机-无机杂多酸类离子液体, 并将其应用于超声作用下的催化模拟汽油氧化脱硫反应. 结果表明, 在超声波辅助下, 不仅反应时间大大缩短, 而且脱硫效率也大幅提高. 在合成的一系列催化剂中, Zr_0.25[BMIM]HPW₁₂O₄₀表现出最佳的催化活性. 考察了超声波功率、 超声/间隙时间、 催化剂用量、 H₂O₂用量、 反应温度及反应时间等因素对脱硫效果的影响. 以Zr_0.25[BMIM]HPW₁₂O₄₀为催化剂, 在优化的条件下[n(Cat.)=0.008 mmol, V(H₂O₂)=40 μL, V(模拟油)=10 mL, V(乙腈)=1 mL, 温度25 ℃, 时间10 min, 超声功率300 W, 超声时间2 s, 间隙时间1.5 s], 二苯并噻吩(DBT)的脱硫率达到97.8%; 该催化剂循环使用5次后, 脱硫率仍为81.9%; 其对不同硫化物的催化活性顺序为DBT>4,6-二甲基苯并噻吩(4,6-DMDBT)>乙硫醚>苯硫醚>正丁硫醇>甲基苯基硫醚>苯并噻吩(BT)>噻吩.     

EMIES/p-TsOH型低共熔溶剂的合成及其氧化脱硫性能的研究

通过1-乙基-3-甲基咪唑硫酸乙酯离子液体（EMIES）和对甲苯磺酸（p-TsOH）的混合物制备EMIES/p-TsOH型低共熔溶剂。其结构特征通过红外光谱、氢谱和热重技术进行了分析。并以EMIES/p-TsOH作为催化剂与萃取剂,H₂O₂作为氧化剂研究了其对模拟油中的硫化物的脱除性能。考察了反应温度、n（H₂O₂）/n（S）比、低共熔溶剂加入量及硫化物类型对脱硫效果的影响。在最佳的条件下,模拟油中二苯并噻吩（DBT）、4,6-二甲基二苯并噻吩（4,6-DMDBT）和苯并噻吩（BT）的脱除率分别为96.2%、92.2%和88.8%。经过五次循环使用后,DBT的脱除率仍达到93.6%。对该脱硫体系进行了动力学分析,其表观活化能为66.4kJ/mol。     

四甲基二硅桥联茚基环戊二烯基四羰基二铁的合成、结构及热重排反应

ClMe₂SiSiMe₂Cl顺序与茚基锂和环戊二烯基锂作用,生成(1-C₉H₇)Me₂SiSiMe₂C₅H₅.后者进一步与五羰基铁反应,得到硅硅桥联茚基环戊二烯基化合物[η⁵,η⁵-(1-C₉H₆)Me₂SiSiMe₂C₅H₄]Fe₂(CO)₄ (2).化合物2在加热条件下发生重排反应,给出硅硅键和铁铁键复分解产物([-)Me₂Si(η⁵-1-C₉H₆)Fe(CO)₂SiMe2(η⁵-C₅H₄)Fe(CO)₂(]-) (3).利用X射线衍射法,测定了2和3的分子结构.     

trz-Cl-Cu-PMo12的合成、 表征及催化氧化碘离子性能

以H₃PMo₁₂O₄₀为前驱体, 采用水热法使1,2,4-三氮唑-3-甲酸进行原位脱羧后, 合成了1,2,4-三氮唑修饰的Keggin型多金属氧酸盐基金属-有机框架化合物(trz-Cl-Cu-PMo₁₂), 并通过X射线单晶衍射、 红外光谱(IR)、 热重分析(TG)、 X射线衍射(XRD)、 扫描电子显微镜(SEM)及元素分析等手段对其进行了表征. X射线单晶衍射及元素分析表明, 该晶体化合物的结构式为[Cu₆Cl_0.5(C₂H₂N₃)₄][PMo₁₂O₄₀][Cu₆Cl_0.5(C₂H₂N₃)₄], 且由1个经典的 Keggin 型[PMo₁₂O₄₀]^3-和2个[Cu₆Cl_0.5(C₂H₂N₃)₄]^1.5+以近似中心对称的方式构成, 各组分之间通过超分子作用形成一维(1D)~三维(3D)结构. 催化性能研究结果表明, 该非均相催化剂在催化过氧化氢氧化碘离子为碘单质的反应中, 经4 min 35 s到达终点时, 反应速率高达1.42×10^-5 mol·L^-1· s^-1, 碘单质生成速率提高了约551倍. 催化剂重复使用8次, 转化率仍然高达99.6%, 表现出优异的催化活性, 且具有良好的可重复性.     

硅宾/有机铝的Lewis酸碱对体系及其丙烯酸酯聚合的引发性能

研究了硅宾/有机铝组成的Lewis酸碱对(LP)体系引发丙烯酸酯类单体聚合的性能,合成了4种硅宾:L(Ph₂P)Si(Si-1, L=Ph C(N^tBu)₂)、L[4-MeC₆H₄(Ph₂P)N]Si (Si-2)、L[2,6-ⁱPr₂C₆H₃(1,5-C₈H₁₄B)N]Si (Si-3)、L(LSi)Si (Si-4)和6种有机铝:Al(C₆F₅)₃、AlMe(BHT)₂、AlⁱBu(BHT)₂、AlⁱBu₂(BHT)、AlⁱBu(BHT*)₂、AlⁱBu₂(BHT...     

Fabrication of nanoreactors based on polyoxoperoxometalates and enhancement of their catalytic activity

The nanoreactors were fabricated by reacting amphiphilic quaternary ammoniums and polyoxoperoxometalates K_n[PW_12-xTi_x- O_40-x（O₂）_x]（x=1,2 and 3;n = 5,7 and 9）(K₅[PW₁₁TiO₃₉（O₂）],K₇[PW₁₀Ti₂O₃₈（O₂）₂]and K₉[PW₉Ti₃O₃₇（O₂）₃]).Fourier transform infrared spectroscopy（FT-IR）,transmission electron microscopy（TEM） were used to characterize the resulting samples. This kind of nanocatalysts could promote NH₄SCN’ degradation into simple inorganic compounds such as SO₄^2-,HCO₃^- and NO₃^- only using oxygen as an oxidant under room conditions.     

新型桥联双四面体簇合物的合成与表征

利用(μ₃-CCO₂Et)Co₃(CO)₉与单阴离子试剂[Mo(CO)₃(η⁵-C₅H₄R)]-[R=H,C(O)Me]的反应合成了2个新的含CCo₂Mo骨架的簇合物(μ₃-CCO₂Et)Co₂Mo(CO)₈(η⁵-C₅H₄R)[R=H(1);R=C(O)Me(2)],进而用其与双阴离子试剂{-M(CO)₃[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,W]反应合成了4个双四面体簇合物{(μ₃-CCO₂Et)CoMoM(CO)₇(η⁵-C₅H₄R)[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,R=H(3);M=Mo,R=C(O)Me(4);M=W,R=H(5);M=W,R=C(O)Me(6)].这6个化合物的C和H元素分析,IR,¹HNMR等表征都与其结构一致.晶体X射线衍射分析表明,化合物2属单斜晶系,C₂/c空间群,晶胞参数a=1.1264(3)nm,b=1.1879(3)nm,c=3.3565(10)nm,β=93.320(5)°,V=4.484(2)nm₃,Z=8,D_c=1.867g·cm^-3,F(000)=2480,R=0.0369,wR=0.1150.     

系列Ln(Ⅲ)配位聚合物(Ln=Eu,Sm,Tb,Pr,Gd)的合成及其荧光分析

采用水热法合成了4个具有1D结构的Ln(Ⅲ)配位聚合物,[Eu₂(C₉H₇O₂)₆(C₉H₇O₂H)(C₂H₅OH)]n(1)、[Sm(C₉H₇O₂)₃]n(2)、[Tb(C₉H₇O₂)₃]n(3)和[Gd(C₉H₇O₂)₃]n(4)(C₉H₈O₂=肉桂酸)。 通过X射线单晶衍射确定了它们的结构。 这4个Ln(Ⅲ)配合物中,Ln(Ⅲ)的配位数均为9,桥配体均为肉桂酸根,但其配位方式有差异。 对配合物进行了IR、UV-Vis-NIR和荧光光谱等表征。 分析了各配合物的荧光发射,结果表明,在可见区,配合物1发射较明显的红光,配合物2、3发射绿光,配合物4发射蓝光,但很弱。 讨论了具有刚柔相混杂性质的肉桂酸配体对配位聚合物的构筑及稀土离子发光的影响。     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.