连续流动化学发光法在线定量检测二氧化钛光催化产生的O_2~(·-)和H_2O_2及其生成动力学研究

O2·-和H2O2是Ti O2光催化反应过程中产生的重要活性氧物种.本文使用鲁米诺作为化学发光探针,针对两者寿命不同,建立了连续流动化学发光在线定量检测方法.对于O2·-,由于寿命短,标准品不易得到,将光照后Ti O2样品10s内与鲁米诺混合产生化学发光,根据鲁米诺和O2·-化学计量关系,将该发光强度对应的鲁米诺浓度转换成O2·-的浓度,实现间接定量;对于H2O2,将光照后的Ti O2溶液于黑暗处30 min后进行定量.该方法测得Ti O2光催化产生O2·-和H2O2的浓度范围分别为7.5~30 nmol/L和0.60~3.0μmol/L,检测限分别为1.95 nmol/L和18.0 nmol/L.O2·-和H2O2的生成动力学研究发现,两者的生成均符合指数衰减函数增长,通过拟合计算,其生成速率常数(kf)分别为0.0653nmol·s-1和15.0 nmol·s-1,表明在Ti O2光催化反应中H2O2的生成速率高于O2·-.     

Effect of Pyridinecarboxylic Acid on the Molecular Packing Architectures of Disc-shaped 2,3,6,7,10,11-Hexahydroxytriphenylene with Both Large π System and Hydrogen Bond Sites

Co-crystallization of 2,3,6,7,10,11-hexahydroxytriphenylene(L) with nicotinic acid(3-pyaH) and isonicotinic acid(4-pyaH) offers L·(3-pyaH)·5 H_2O(1) and L·2(4-pya H)·5 H_2O(2), respectively. In 1, each L links three neighboring L molecules via O-H···O and C-H···O hydrogen bonds, furnishing a 1 D chain. The hydrogen bonding and p-p stacking deriving from 3-pyaH and L extend the chains to a 2D layer. Lattice water molecules are interconnected to 3-pyaH via hydrogen bonds into a 1 D [(3-pya H)×5 H_2O]$ chain. While in 2, Hydrogen bonding between L and 4-pyaH produces a 2D net with triangle and parallelogram grids. Water molecules locate in interlayer and grids, and O(1 w) and O(2 w) link 4-pyaH into a 1 D [(4-pyaH)×2 H_2O]$ chain.     

三种纳米片组装的α-4CaO·5B_2O_3·7H_2O纳米结构的可控制备、表征及其阻燃性能

以Ca(NO3)2·4H2O和Na2B4O7·10H2O为原料,水和乙醇为混合溶剂,在水热120℃条件下,可控制备了α-4CaO·5B2O3·7H2O纳米片以及由纳米片组装成的球形和蚕蛹状α-4CaO·5B2O3·7H2O纳米结构,通过X射线粉晶衍射(XRD)、X射线能谱分析(EDS)、红外光谱(FT-IR)和扫描电子显微镜(SEM)等手段对产物进行了表征.考察了反应温度、反应时间、溶剂及表面活性剂等条件对硼酸钙α-4CaO·5B2O3·7H2O形貌及尺寸的影响,提出了α-4CaO·5B2O3·7H2O纳米结构的可能形成机理.通过热分析法研究了三种不同形貌硼酸钙α-4CaO·5B2O3·7H2O样品的阻燃性能,结果表明其阻燃性能比非纳米样品好.     

Mg2+,K+//Cl-,B4O2-7-H2O四元体系288 K固液相平衡

采用等温溶解平衡法研究了288 K时Mg2+,K+//Cl-,B4O2-7-H2O四元体系的相平衡关系,测定该体系在288 K时平衡液相的溶解度和密度.依据实验测定的平衡溶解度数据及对应的平衡固相,绘制了该四元体系的平衡相图以及其密度-组成图.研究结果表明,四元体系Mg2+,K+//Cl-,B4O2-7-H2O 288 K时的固液相平衡实验中,有复盐KCI·MgCl2·6H2O生成,平衡相图中有3个共饱点,7条单变量曲线,5个结晶区,对应的平衡固相分别为MgB4O7·9H2O,K2B4O7·4H2O,KCl,MgCl2·6H2O,KCl·Mgcl2·6H2O.简要讨论了实验结果.     

Syntheses, Crystal Structures and Fluorescence Properties of Two Triazolyl Derivatives with Biphenyl Links

Two novel triazolyl derivatives with biphenyl links, namely 4,4-bis（1,2,4-triazol-1-ylmethyl）biphenylene 1 and 4,4-bis（3,5-dimethyl-1,2,4-triazol-1-ylmethyl）biphenylene 2, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Compounds 1·H2O·HCl and 2·2H2O·2HCl crystallize in the monoclinic system with space group C2/c and P21/c, respectively. The dihedral angles of the two phenyl rings are 30.26（6）° in 1·H2O·HCl, while co-planar （0.00（7）°） in 2·2H2O·2HCl. In 1·H2O·HCl, the N-H…O hydrogen bonds link 1 to form chain-like structures which are further connected by O-H…Cl, C-H…Cl, C-H…O and π-π supramolecular interactions. The hydrogen bonds of O-H…Cl in 2·2H2O·2HCl provide distinguishing P/M helical chains along the b axis, and these chains are further connected by N-H…O hydrogen bonds to generate a 2D structure. Compounds 1 and 2 in methanol solution show much stronger emission bands at 319 nm than biphenyl at 316 nm under excitation at 260 nm.     

负载Cr_2O_3的H_2Ti_2O_5·H_2O纳米管的制备及其作为锂离子电池正极材料的电化学性能

限制纳米电极材料倍率性能的一个重要因素是,在大电流下充放电时,纳米结构可能坍塌,造成容量迅速衰减.通过异价离子的掺杂或第二相的负载有可能弥补纳米材料的这一缺陷.本文以含有Cr2O3的锐钛矿TiO2为原料,通过超声化学-水热法,制备了负载Cr2O3的H2Ti2O5·H2O纳米管.采用X射线衍射(XRD)和透射电镜(TEM)对制得的H2Ti2O5·H2O/Cr2O3纳米管的晶体结构和微观形貌进行了表征和分析.恒流充放电测试显示,H2Ti2O5·H2O/Cr2O3(5%(w,质量分数))纳米管作为锂离子电池阳极材料具有优异的循环稳定性及倍率性能.在150mA·g-1的电流密度下,H2Ti2O5·H2O/Cr2O3纳米管的首次放电容量达到288mAh·g-1;120次循环后,充放电容量仍保持在145mAh·g-1.在1500mA·g-1的电流密度下,首次放电容量为178mAh·g-1;600次循环后,充放电容量保持在80mAh·g-1以上;继续在150mA·g-1电流密度下充放电30个循环,充放电容量达到155mAh·g-1,显示出充放电容量的可回复性.循环伏安测试结果表明,H2Ti2O5·H2O/Cr2O3纳米管的充放电过程由法拉第赝电容反应控制.该一维纳米结构在锂离子电池和非对称电容器领域显示出良好的应用前景.     

Two Cd(Ⅱ) and Cu(Ⅱ) Complexes Based on 1-Butylbenzimidazole: Crystal Structures and Weak Interactions

1-Butylbenzimidazole L reacted with Cd(NO3)2·4H2O to afford complex [CdL(NO3)3H2O]·[HL] 1. The heptacoordinated Cd(Ⅱ) center adopts a distorted pentagongal bipyramidal geometry, and complex [CdL(NO3)3H2O]-entity and the protonated benzimidazium salt [HL]+ are connected via N-H···O hydrogen bond to form a dimeric unit [CdL(NO3)3H2O]·[HL]. A 3-D supramolecular network of 1 is formed through N-H···O and O-H···O hydrogen bonds together with π-π stacking interactions. Reaction of L with CuCl2 afforded a mononuclear complex, [CuL2Cl2] 2, in which the tetracoordinated Cu(II) center adopts a distorted tetrahedral geometry. In contrast, 2-D supramolecular layers of 2 are formed by C-H···Cl hydrogen bonds. The fluorescent emission spectra of L, 1 and 2 are described.     

非晶态镍硼酸盐结构的EXAFS研究(英文)

由摩尔比分别为1:2和1:8的NiCl2·6H2O和Na2B4O7·10H2O作为反应物,合成两种非晶态镍硼酸盐,同时通过水热法合成β-Ni(OH)2.化学分析和热重-微商热重法(TG-DTG)分析结果确定两种非晶态镍硼酸盐的分子组成分别为NiO·0.8B2O3·4.5H2O和NiO·B2O3·3H2O.激光拉曼(Raman)实验结果表明镍硼酸盐样品中主要存在的硼氧阴离子为B3O3(OH)52-和B2O(OH)62-.同步辐射扩展X射线吸收精细结构(EXAFS)方法对样品进行结构解析,通过数据拟合给出样品中Ni原子周围近邻配位原子种类、配位数以及原子间距离.用不同晶体结构作为标准对两种非晶态镍硼酸盐进行拟合的结果表明,样品中Ni原子周围局域结构与Ni3B2O6晶体(ICSD No.31387)中的吻合较好.Ni原子周围配位原子为O、B和Ni,对于NiO·0.8B2O3·4.5H2O,配位数分别为5.7、3.8和3.8,配位距离分别为0.208、0.263和0.311 nm;对于NiO·B2O3·3H2O,配位数分别为6.0、4.0和4.0,配位距离分别为0.207、0.262和0.310 nm.     

四苯基卟啉氧合配合物的室温固相合成、表征及氧合性能

采用固相反应合成了四苯基卟啉与Fe2 、Co2 的配合物.在室温下,将其与分子O2作用,提纯后得到两种固态氧合配合物.通过元素分析、红外光谱、核磁共振氢谱、电导、热分析(TG/DTA)、紫外光谱等测试手段确定了氧合配合物的组成为[Co·TPP·O2](NO3):·2H2O、[Fe·TPP·O2]Cl2·2H2O,可知1mol配合物吸收了1mol O2.采用失重法测定了氧合配合物中的配位氧,确定1mol金属配合物吸收1mol O2形成超氧配合物.     

NH4+-Mg2+-pO3-4-H+-H2O体系的优势区相图

通过优势区相图的构建对NH4+-Mg2+-PO43-H+-H2O体系的热力学平衡关系进行了研究.在不同镁、磷物质的量比和离子强度的条件下绘制了lgCT,Mg-lgC,T,P和lgCT,p-pH相图,确定了MgNH4PO4·6H2O、Mg3(PO4)2· 8H2O、MgHPO4· 3H2O和Mg(OH)2的热力学稳定区.结果表明,在相当广的pH范围内,MgNH4PO4·6H2O和Mg3(PO4)2·8H2O都是主要存在的固相;在较低pH和较高磷浓度的条件下,MgNH4PO4·6H2O和MgHPO4· 3H2O可以共存;而MgNH4PO4·6H2O和Mg(OH)2在碱性条件下更为稳定.当MgNH4PO4·6H2O、Mg3(PO4)2· 8H2O与液相共存、pH=9.08～9.52时,溶液总氮浓度达到最低值.lgCT,Mg-lgCT,P和lgCT,P-pH相图可以用于指导磷酸铵镁的沉淀-溶解平衡过程,有利于废水中氨氮的脱除和回收.     

A Ga_2O·11Al_2O_3 nanonet prepared by interfacial reaction growth approach and its application in fabricating GaN nanowires

A Ga2O·11Al2O3 nanonet was synthesized by using Ga2O3 powder as the precursor to generate Ga2O vapor in H2 atmosphere which further reacted with Al2O3 at 730 °C to form Ga2O·11Al2O3 at the interfaces of a porous anodic aluminum oxide (AAO) template. The prepared Ga2O·11Al2O3 nanonet then served as a Ga2O-stablizing reservoir to fabricate single crystal GaN nanowires. The residual Ga2O3 powder at the surface of the produced Ga2O·11Al2O3 nanonet and the metallic Ga or Ga2O from the Ga2O·11Al2O3 decomposition ...     

LaFeO3修饰和O3处理对Au／Al2O3催化剂在CO氧化反应中热稳定性的影响

通过等体积浸渍法并分别经过H2和O3活化制备了系列1·1%Au/LaFeOx/Al2O3催化剂,考察了其在550℃经1·0%CO原料气处理后的CO氧化活性.Fe和La的引入虽然使1·1%Au/Al2O3的初始活性降低,但提高了其高温稳定性.在550℃经1·0%CO原料气预处理2h后,H2活化的1·1%Au/Al2O3在室温完全失活,而同样条件处理的1·1%Au/2%LaFeO3/Al2O3仍能将65%CO转化;这可能是由于LaFeO3以钙钛矿形式单层分散在Al2O3表面而导致的.O3活化能进一步提高催化剂的稳定性,在550℃经原料气预处理后,O3活化的1·1%Au/2%LaFeO3/Al2O3的活性高于1·1%Au/Al2O3和H2活化的1·1%Au/2%LaFeO3/Al2O3.1·0%CO原料气预处理10h后,H2活化的1·1%Au/2%LaFeO3/Al2O3完全失活,而O3活化的催化剂仍具有40%的转化率,这可能是由于O活化使得催化剂中存在部分氧化的金,增强了金属与载体间的相互作用.     

Transesterification Reaction of Dimethyl Terephthalate by 2-Ethylhexanol in the Presence of Heterogeneous Catalysts under Solvent-free Condition

In this study, the synthesis of bis-（2-ethylhexyl） terephthalate, via the transesterification reaction of dimethyl terephthalate （DMT） by 2-ethylhexanol in the presence of different heterogeneous catalysts, such as Pb（OAc）2·3H2O, Cd（OAc）2·2H2O, Zn（OAc）2·2H2O, Hg（OAc）2·Ca（OAc）2·H2O, Cu（OAc）2·H2O, NaOAc, CaCO3, CaO, ZnSO4·7H2O, and sulfated zirconia, has been investigated. The reactivity of the catalysts in the reaction progress has been studied and compared. It was found that, hydrated cadmium acetate and sulfated zirconia were reactive catalysts to this reaction. The extent of transesterification of methyl ester groups reached up to 93% and 85.6% using these catalysts, respectively.     

Syntheses,Crystal Structures,and Magnetic Properties of the Cobalt(Ⅱ) and Nickel(Ⅱ) Coordination Polymers Constructed from 5-Halonicotinate and 2,2ˊ-Biimidazole

Two coordination polymers, namely [Co(5-Clnic)2(H2biim)]n 1 and {[Ni(5-Clnic)(Hbiim)]·H2O}n 2(5-Clnic H = 5-halonicotinic acid, H2 biim = 2,2ˊ-biimidazole), were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a 1D chain coordination network, which is further extended into a 3D supramolecular architecture via N–H···O hydrogen bonds and π-π packing interactions. Compound 2 features a 1D chain structure based on the hexanuclear macrocycles. The adjacent 1D chains are held together into a 3D supramolecular framework via N–H···O and O–H···O hydrogen bonding interactions. Thermal stability and magnetic properties of both compounds were studied and discussed.     

A Series of Mononuclear Complexes Constructed from Transition Metals and Amino Acid Derived Ligands: Syntheses, Structures and Photoluminescence

Eight neutral mononuclear complexes constructed from transition metals （M = Co（Ⅱ）, Ni（Ⅱ）, Cu（Ⅱ）, Zn（Ⅱ）, Cd（Ⅱ）） and ligands N-（2-pyridylmethyl）-L-phenylalanine （L-Hpmpa） and N-（2-pyridylmethyl）-L-tyrosine （L-Hpmtyr） have been synthesized by both hydrothermal and conventional room temperature reactions. Four of them have been structurally characterized by single-crystal X-ray diffractions. They are： [Co（L-pmpa）2·2H2O] 1, [Ni（L-pmpa）2·2H2O] 2, [Cu（L-pmpa）2·2H2O] 3 and [Cu（L-pmtyr）2·2H2O] 4. Single-crystal X-ray analysis, IR and elemental analysis revealed that complexes 1, 2 and 3 are isostructural. Powder X-ray diffraction, IR and elemental analysis revealed that complexes 4, 5 （Zn[L-pmtyr]2·2H2O）, 6 （Cd[L-pmtyr]2·2H2O）, 7 （Co[L-pmtyr]2·2H2O） and 8 （Ni[L-pmtyr]2·2H2O） are isostructural. The photoluminescence properties of L-Hpmtyr ligand, compounds 5 and 6 were also investigated.     

Syntheses,Crystal Structures and Magnetic Properties of Ni(Ⅱ) and Mn(Ⅱ) Coordination Polymers Constructed from 5-(2'-Carboxylphenyl) Nicotate and 2,2'-Biimidazole

Two coordination polymers, namely {[Ni(cpna)(H2biim)(H2O)]·H2O}n(1) and {[Mn(cpna)(H2biim)]·H2O}n(2)(H2cpna = 5-(2'-carboxylphenyl) nicotic acid, H2biim = 2,2'-biimidazole),have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, magnetic properties, and single-crystal X-ray diffraction. Compound 1 exhibits a one- dimensional(1D) step-like chain structure, which further builds a three-dimensional(3D) supramolecular architecture via O–H···O and N–H···O hydrogen-bonding and π-π stacking interactions. Compound 2 possesses a one-dimensional(1D) double chain structure, which is further assembled into a 3D supramolecular framework by N–H···O hydrogen bonding and π-π stacking interactions. Magnetic susceptibility measurement indicates that compound 1 shows a weak antiferromagnetic coupling between the nearest Ni(II) centers, with g = 2.11 and J = –1.87 cm–1.     

五元体系Li+,Na+//CO32-,So42-,B4O72-H2O 288 K介稳相平衡研究

采用等温蒸发法研究五元体系Li+,Na+//CO32-,SO42-,B4O72--H2O 288 K介稳相平衡关系,测定在288 K条件下的介稳平衡溶液中各组分的溶解度和溶液密度,根据实验数据绘制相应的介稳平衡相图及密度组成图.研究结果表明该五元体系介稳相平衡中有复盐Na3Li(SO4)2·6H2O生成,其介稳相图中有4个共饱点,9条单变量曲线,6个Li2CO3饱和的结晶区分别为LiBO2·8H2O,Na284O7·10H2O,Na2CO3·10H2O,Na2SO4,Li2O4·H2O和复盐Na3Li(SO4)2·6H2O.     

Novel Perchlorate and Sulphate Salts of 2-Aminonicotinic Acid: Synthesis,Characterization, Thermal Studies and Hirshfeld Surface Analysis

Since 2-aminonicotinic acid is a zwitterionic molecule,the salt or co-crystal strategy was used for the precipitation under identical conditions and obtained two novel salts: salt 1 with 2:1:2 stoichiometry of 2-aminonicotinic acid:perchloric acid:H_2O and salt 2 with 2:1:3 stoichiometry of 2-aminonicotinic acid:sulfuric acid:H_2O. Their crystal structures were characterized by single-crystal X-ray diffraction,differential scanning calorimetry(DSC) and thermogravimetric analyses(TGA). The structure determination shows that two salts are both primarily stabilized by the strong N–H···O hydrogen bonding interaction between 2-aminonicotinic acid and its corresponding acids. Constituents of the salt-crystalline phase were also investigated in terms of Hirshfeld surfaces. In the crystal lattice,a three-dimensional hydrogen-bonded network is observed,including the formation of a two-dimensional molecular scaffolding motif. Hirshfeld surfaces and fingerprint plots of two salts show that the structures are stabilized by H···H,O–H···O and C–O···π intermolecular interactions.     

离子液体中过氧钨配合物催化氧化燃油脱硫

合成了一种含D,L-丙氨酸配体的钨的过氧配合物WO(O2)2·2C3H7NO2·H2O催化剂.以WO(O2)2·2C3H7NO2·H2O/[Bmim]PF6/H2O2体系为研究模型,考察了反应时间、温度和催化剂用量等因素对燃油脱硫率的影响.结果表明,在70℃反应2h,n(H2O2)∶n(二苯并噻吩)∶n(催化剂)=30...     

Synthesis,Crystal Structure and Photoluminescent Property of a Novel Dy~(3+) Coordination Compound Containing Rare(H_2O)_(22) Clusters

A novel Dy~(3+) coordination compound,(H_2pipz)(H_3O)[Dy(pydc)_3]·11H_2O(1,pipz = piperazine and H_2pydc = pyridine-2,6-dicarboxylic acid),has been hydrothermally synthesized and characterized by X-ray single-crystal diffraction,elemental analysis. It is interesting that the packing structure of compound 1 contains 22-core water clusters. Compound 1 is extended into a threedimensional supramolecular structure via O···H···O hydrogen bonding interactions. Furthermore,the luminescent property of compound 1 was also investigated.