具有金属-金属作用单核自组装体的合成及其对Suzuki偶联反应的高效催化

以配体二苯乙酰丙酮（L）与金属组装子[（bpy）Pd（NO₃）]NO₃、[（bpy）Pt（NO₃）]NO₃和[（phen）Pd（NO₃）]NO₃在溶液中通过自组装配位作用,自发去质子形成了一系列单核组装体[（bpy）Pd（L）]NO₃（1·NO₃·H₂O）、[（bpy）Pt（L）]NO₃（2·NO₃·H₂O）和[（phen）Pd（L）]NO₃（3·NO₃·H₂O）（其中,bpy=2,2''-联吡啶,phen=1,10-菲咯啉）。这些组装体在含有KPF₆的水溶液中能够有效的将NO₃^-置换成PF₆^-。NMR和ESI-MS分析确定了这3个组装体的单核结构。1·PF₆·CH₃CN化合物的单晶X射线衍射分析表明分子间π-π堆积作用与弱的Pd…Pd键（0.322 4 nm）相互作用使化合物形成二聚体结构。更为重要的是,这些组装体可作为新颖、高效的Suzuki偶联反应催化剂。     

具有金属-金属作用单核自组装体的合成及其对Suzuki偶联反应的高效催化

以配体二苯乙酰丙酮（L）与金属组装子[（bpy）Pd（NO₃）]NO₃、[（bpy）Pt（NO₃）]NO₃和[（phen）Pd（NO₃）]NO₃在溶液中通过自组装配位作用,自发去质子形成了一系列单核组装体[（bpy）Pd（L）]NO₃（1·NO₃·H₂O）、[（bpy）Pt（L）]NO₃（2·NO₃·H₂O）和[（phen）Pd（L）]NO₃（3·NO₃·H₂O）（其中,bpy=2,2''-联吡啶,phen=1,10-菲咯啉）。这些组装体在含有KPF₆的水溶液中能够有效的将NO₃^-置换成PF₆^-。NMR和ESI-MS分析确定了这3个组装体的单核结构。1·PF₆·CH₃CN化合物的单晶X射线衍射分析表明分子间π-π堆积作用与弱的Pd…Pd键（0.322 4 nm）相互作用使化合物形成二聚体结构。更为重要的是,这些组装体可作为新颖、高效的Suzuki偶联反应催化剂。     

水热法合成球花状二硫化钼及其电化学性能

采用二水钼酸钠（Na₂MoO₄·2H₂O）和硫脲（CS（NH₂）₂）分别作为钼源和硫源,通过水热合成法获得球花状二硫化钼,其较佳的水热条件为：180℃下反应48 h,钼硫原子比为1：4,反应物浓度为0.001 mol·L^-1,在100 mL反应釜中的填充体积为90 mL。采用X射线衍射（XRD）、扫描电镜（SEM）和透射电镜（TEM）、对样品的物相和形貌进行了表征,并利用低温氮吸附BET模型测试了样品的比表面积。结果表明,合成的二硫化钼结晶性良好,平均粒径约为1 μm,比表面积约为87 m²·g^-1,分布均匀且无明显团聚。通过循环伏安（CV）曲线、恒电流充放电曲线（GCD）、阻抗谱图（EIS）表征其电化学性能,测试表明：在3 mol·L^-1 KOH水相电解液中,单电极比电容可达130.6 F·g^-1（扫速为5 mV·s^-1）和110.9 F·g^-1（电流密度为0.1 A·g^-1）,界面转移电阻R_ct为0.33 Ω;循环1 000圈后比电容损失为14.7%。说明采用该水热法合成的二硫化钼可以成为超级电容器电极的理想材料。     

双层SiO2包覆Fe3O4复合材料的制备及其染料吸附性能

采用改进的Stober法合成了多孔结构的双层SiO₂包覆Fe₃O₄复合材料,利用TEM、XRD、VSM和氮吸附-脱附实验对其结构与性能进行分析,进而研究其对染料的吸附性能。研究结果表明,双层SiO₂包覆Fe₃O₄复合材料的比表面积和磁饱和强度分别为308 m²·g^-1和45.5 emu·g^-1;当罗丹明B的初始浓度从25 mg·L^-1提高到250 mg·L^-1时,复合材料对其饱和吸附量从24.0 mg·g^-1增大到112.4 mg·g^-1,而亚甲基蓝的初始浓度从25 mg·L^-1提高到500 mg·L^-1时,对其饱和吸附量从22.0 mg·g^-1增大到235.1 mg·g^-1;随着溶液pH值增大,复合材料对罗丹明B的饱和吸附量增加,而对亚甲基蓝的饱和吸附量变化不明显;温度在20~40 ℃范围内复合材料的吸附量较大。     

碳酸盐共沉淀法可控制备超高倍率锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2

采用碳酸盐共沉淀法通过调节NH₃·H₂O用量来实现可控制备超高倍率纳米结构LiNi_1/3Co_1/3Mn_1/3O₂正极材料。NH₃·H₂O用量会对颗粒的形貌、粒径、晶体结构以及材料电化学性能产生较大的影响。X射线衍射（XRD）分析和扫描电镜（SEM）结果表明,随着NH₃·H₂O用量的降低,一次颗粒形貌由纳米片状逐渐过渡到纳米球状,且n_NH3·H2O：（n_Ni+n_Co+n_Mn）=1：2样品晶体层状结构最完善、Li⁺/Ni²⁺阳离子混排程度最低。电化学性能测试结果也证实了n_NH3·H2O：（n_Ni+n_Co+n_Mn）=1：2样品具有最优异的循环稳定性和超高倍率性能。具体而言,在2.7~4.3 V,1C下循环300次后的放电比容量为119 mAh·g^-1,容量保持率为81%,中值电压基本无衰减（保持率为97%）。在100C（18 Ah·g^-1）的超高倍率下,放电比容量还能达到56 mAh·g^-1,具有应用于高功率型锂离子电池的前景。此NH₃·H₂O比例值对于共沉淀法制备其他高倍率、高容量的正/负极氧化物材料具有一定的工艺参考价值。     

同构MOFs复合氧化石墨烯电极材料构筑高性能超级电容器

在水热条件下一步自组装合成系列同构X-MOF （X₆O （TATB）₄（H⁺）₂·（H₂O）₈·（DMF）₂,X=Zn、Co、Ni; H₃TATB=4,4'',4″-s-triazine-2,4,6-triyl-tribenzoic acid; DMF=N,N-二甲基甲酰胺）和氧化石墨烯（GO）的复合材料（X-MOF@GO）,并探究其作为超级电容器电极材料的电化学性能。通过X射线粉末衍射、X射线光电子能谱和扫描电子显微镜测试证明GO和MOFs复合成功。其中,性能最优的Ni-MOFs@1.5GO （GO的添加量为1.5 mL）的比电容高达694.8 F·g^-1（0.5 A·g^-1）,约是Ni-MOF的2倍。电化学测试结果表明：复合材料X-MOF@1.0GO较其原MOF表现出更大的比电容和更好的倍率性能。在3.5 A·g^-1的电流密度下,1 000次循环充放电后,Ni-MOFs@1.0GO仍保持初始比电容量的81.2%。与活性炭（AC）组装的非对称超级电容器Ni-MOF@1.5GO//AC的性能最优,其功率密度为754.3 W·kg^-1时,能量密度为15.4 Wh·kg^-1,且循环3 000次后比电容保持率约为70.0%,显示出较长的循环寿命。     

双层SiO2包覆Fe3O4复合材料的制备及其染料吸附性能

采用改进的Stober法合成了多孔结构的双层SiO₂包覆Fe₃O₄复合材料,利用TEM、XRD、VSM和氮吸附-脱附实验对其结构与性能进行分析,进而研究其对染料的吸附性能。研究结果表明,双层SiO₂包覆Fe₃O₄复合材料的比表面积和磁饱和强度分别为308 m²·g^-1和45.5 emu·g^-1;当罗丹明B的初始浓度从25 mg·L^-1提高到250 mg·L^-1时,复合材料对其饱和吸附量从24.0 mg·g^-1增大到112.4 mg·g^-1,而亚甲基蓝的初始浓度从25 mg·L^-1提高到500 mg·L^-1时,对其饱和吸附量从22.0 mg·g^-1增大到235.1 mg·g^-1;随着溶液pH值增大,复合材料对罗丹明B的饱和吸附量增加,而对亚甲基蓝的饱和吸附量变化不明显;温度在20~40 ℃范围内复合材料的吸附量较大。     

高比表面积介孔Cr2O3：制备及高效催化氧化去除甲苯

采用Cr(NO₃)₃·9H₂O作金属源,葡萄糖作模板剂,通过葡萄糖辅助固态热分解法制备得到高比表面积的虫孔状介孔Cr₂O₃,采用XRD、TEM、TPR和N₂吸脱附技术表征其物理化学性质,并考察了介孔Cr₂O₃上催化氧化去除甲苯的性能。结果表明,经过500℃灼烧处理的m-Cr-5催化剂比表面积高达162m₂·g^-1,平均孔径为6.2nm,且具有优良的低温还原性和多价态铬物种并存,使其催化氧化去除甲苯的活性最好。     

自组装的四(4-N,N-二乙胺基苯基)卟啉/多酸(钠)有机/无机复合薄膜及其气敏性质

选择Keggin型12-磷钨酸（TPA）及其钠盐（NaTP）水溶液为亚相,用四（4-N,N-二乙胺基苯基）卟啉化合物（H₂TNPP）自组装膜为功能模板,釆用低成本的QLS法成功制备了2种新型有机/无机复合材料：H₂TNPP/TPA,H₂TNPP/NaTP QLS薄膜。薄膜结构、形貌及半导体性质测试发现：H₂TNPP分子在H₂TNPP/TPA,H₂TNPP/NaTP复合膜中均采取H-聚集模式,TPA亚相上H-聚集程度更大。而在纯H₂TNPP膜中其为J-聚集模式。3种薄膜表面均为纳米颗粒形貌,以H₂TNPP/NaTP膜表面颗粒均一,颗粒尺寸最小（~60 nm）,H₂TNPP/TPA膜表面缺陷较多,颗粒尺寸最大（~150 nm）。薄膜导电性依次为H₂TNPP/NaTP（3.00×10^-5 S·cm^-1）>H₂TNPP/TPA（2.49×10^-5 S·cm^-1）>H₂TNPP膜（1.53×10^-5 S·cm^-1）。常温气敏测试发现：3种薄膜在30 s内对浓度小于1.88 mg·m^-3的NO₂气体都有响应,灵敏度依次为H₂TNPP/NaTP（43%）>H₂TNPP膜（16%）>H₂TNPP/TPA（4.5%）。具有最小颗粒尺寸和最高导电性的H₂TNPP/NaTP复合薄膜具有最高的灵敏度,并且对NO₂检测限低至0.094 mg·m^-3。显示出了非常高的实际应用价值。本研究为制备低成本、高灵敏度、环境友好的快速室温NO₂气敏器件提供了一种新的策略。     

扫帚状氧化铈制备及其对Pt基阳极催化剂催化性能的影响

采用水热合成法,合成了比表面积为175 m²·g^-1,孔径在2~4nm范围内的扫帚状CeO₂。通过微波辅助乙二醇还原氯铂酸法制备了Pt-CeO₂/RGO催化剂,探究扫帚状CeO₂的添加对Pt基催化剂电催化性能的影响。利用X射线衍射仪（XRD）、扫描电镜（SEM）、N₂吸附-脱附、X射线光电子能谱（XPS）对所制备的CeO₂及催化剂进行表征。利用电化学工作站对催化剂进行电化学性能测试。结果表明,催化剂中CeO₂保持原有扫帚状,Pt纳米粒子均匀分布于石墨烯载体表面;当m_RGO∶m_CeO2=1∶2时,添加了扫帚状CeO₂的Pt-CeO₂/RGO催化剂的电催化性能最优,电化学活性表面积为102.83 m²·g^-1,对乙醇氧化的峰值电流密度为757.17 A·g^-1,1 000 s的稳态电流密度为108.17 A·g^-1,对乙醇催化氧化反应的电荷转移电阻最小,活化能最低。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。