Electrical conductivity of lyotropic phases of dodecylbenzenesulphonates with Li+, Na+, and K+ ions in water

The electrical conductivity of dodecylbenzenesulphonate (DoBS) ionic lyotropic liquid crystal of the systems: LiDoBS (dodecylbenzenesulphonic acid lithium salt)/water, NaDoBS (dodecylbenzenesulphonic acid sodium salt)/water, and KDoBS (dodecylbenzenesulphonic acid potassium salt)/water were investigated by impedance spectroscopy in the frequency range from 0.5 Hz to 0.5 MHz. The electrical conductivity of lyotropic LiDoBS was higher than that of isotropic phase. The electrical conductivity isotropic KDoBS and NaDoBS was higher than the conductivity of lyotropic ones. The temperature dependence of electrical conductivity was investigated in the systems LiDoBS/water and KDoBS/water for different phases. The activation energy of electrical conductivity is lowest for the normal hexagonal phase LiDoBS/water. Such systems based on anionic surfactants are of interest as the electrolyte for the supercapacitors.     

Thermal Study of A2O–(MoO3)2–P2O5 (A=Li, Na) Glasses

Alkali phosphomolybdate glasses have been prepared by quenching melted mixtures of P₂O₅, MoO₃ and A₂O(A=Li, Na). The composition dependence of the transition temperature of glasses belonging to ternary A₂O–(MoO₃)₂–P₂O₅ (A=Li, Na) systems is studied for several series of glasses corresponding to either a fixed A₂O rate or a constant Mo/P ratio. The interpretation of the results is based on the presence of different types of molybdenum and phosphorous structural groups and P–O–M (M=P, Mo) linkages in glasses. This revised version was published online in August 2006 with corrections to the Cover Date.     

Raman and infrared spectra of6Li2C2O4 and7Li2C2O4

Raman and infrared spectra of polycrystalline⁶Li₂C₂O₄ and⁷Li₂C₂O₄ have been investigated in the wavenumber region from 1,800 to 40 cm^–1. The internal C₂O₄ ^–2 vibrations have been studied on the basis of a D_2h molecular structure and the correlation field splittings have been found to be about 40 cm^–1 for the stretching modes and about 15 cm^–1 for the bending modes. The external vibrations of the Li⁺ and C₂O₄ ^–2 sites have been discussed by considering the results of the factor group analysis and the⁶Li/⁷Li isotope effect on the normal vibrations.

---

Raman- und Infrarot-Spektren von⁶Li₂C₂O₄ und⁷Li₂C₂O₄

Zusammenfassung Es wurdenRaman- und IR-Spektren von polykristallinem⁶Li₂C₂O₄ und⁷Li₂C₂O₄ im Bereich der Wellenzahlen von 1800 bis 40 cm^–1 untersucht. Die internen Schwingungen wurden auf der Basis einer D_2h Molekülstruktur analysiert. Für die Streckschwingungen wurde eine Korrelationsaufspaltung von etwa 40 cm^–1 gefunden, für die Deformationsschwingungen etwa 15 cm^–1. Die Diskussion der externen Schwingungen von Li⁺ und C₂O₄ ^–2 erfolgte unter Berücksichtigung der Resultate der Faktorgruppenanalyse und des⁶Li/⁷Li Isotopeneffekts auf die Normalschwingungen.

     

A 3-D Supramolecular Framework with Open Channels Constructed from Lanthanide Ions and Mixed Ligands

A 3-D supramolecular framework, [Er（pybz）2（Hnds）（H2O）2]·H2O （1, Hpybz = 4- pyridin-4-yl-benzoic acid, H2nds = naphthalene-1,5-disulfonic acid）, based on lanthanide ions and mixed ligands has been hydrothermally synthesized. The structure was determined by single-crystal X-ray diffraction and further characterized by IR, elemental analysis and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic system, space group P21/n with a = 9.849（2）, b = 22.526（5）, c = 17.167（4） A, β =105.461（4）° and V = 3670.9（2） A^3. In 1, two seven-coordinated Er^3＋ ions are bridged by two pybz^- ligands to form a dimeric [Er2（COO）2] unit, which is further orderly linked by carboxyl of pybz^-ligand to obtain a 1-D chain running along the a axis. Interestingly, significant H-bonding and π-π stacking interactions link the neighboring parallel chains leading to a 3-D supramolecular network structure which displays 1-D rhombus open channels （17.2A× 22.5A）.     

尖晶石对β／β″—Al2O3膜相组成和离子导电性的影响

以wag／P”－AI。O。为固体电解质的CO。、SO。、NO。等气体传感器的研究已有很多报道［‘－‘］，多采用的是个AI。O。结构的电解质。AI刀。和p”－AI刃。的结构具有一定的相似性，但后者具有更高的迁移离子浓度和更开放的晶体结构，表现出更好的离子导电性‘’‘．由于卢”－AI。O。为介稳结构，需要加入如Li。O、MgO等作为稳定剂才能稳定存在．以Li对稳定的产”－al。O。烧结较容易，P”－AI。O。相转化率高，但以MsO为稳定剂制备的”－AI刃。其显微结构和抗吸湿性能更为优越．LJLi对和MgO共同稳定的产”－AI。O。可以…     

Conductance Study of 1 : 1 19-Crown-6 Complexes with Various Mono- and Bivalent Metal Ions in Water

Formation constants (ML) of 1 : 1 19-crown-6 (19C6) complexes with mono- (M+) and bivalent metal ions (M2+) were determined in water at 25 °C by conductometry. The KML value of 19C6 for M+ and M2+ decreases in the order Rb+ K+ > Tl+ > Na+ = Ag+ > Li+ Cs+ and Pb2+ > Ba2+ > Sr2+ > Cd2+ > Ca2+, respectively. The selectivity for the neighboring alkali metal ions in the periodic table is lower for 19C6 than for 18-crown-6 (18C6) except for the case of Rb+ and Cs+. The same is true for the alkaline earth metal ions. Generally, the KML values of 19C6 with M2+ are greater than those with M+. For Na+ and the ions which are smaller in size than Na+ (Li+, Ca2+, Cd2+), the KML value is larger for 19C6 than for 18C6, but the contrary holds for all the other ions of larger sizes than Na+. The limiting ionic molar conductivity (°) of the 19C6–K+ complex in water at 25 °C was determined to be 43. Although 19C6 is larger than 18C6, the 19C6–K+ complex is much more mobile in water than the 18C6–K+ complex.     

Na/Mn摩尔比对层状O2结构Liy[Li1/6Mn5/6]O2的晶体结构及化学组成的影响

层状材料;Na/Mn摩尔比对层状O2结构Liy[Li1/6Mn5/6]O2的晶体结构及化学组成的影响     

介孔结构多酸掺杂-锐钛矿纳米晶Na4W10O32/TiO2的制备及其可见光光催化性能研究

作为一种先进的氧化技术 ,光催化化学在有机污染物的降解和精细有机合成中发挥着巨大的作用 .目前 ,光催化领域中广泛使用的两类绿色光催化剂分别为二氧化钛 (锐钛矿结构 )和多金属氧酸盐 [1～ 3] .但其还存在催化活性组分在反应过程中流失和催化剂必须采用近紫外光活化等不完善之处 ,而后者是影响光催化技术实际应用的最大障碍 .因为太阳光中仅存在 2 %～ 3%的紫外光 ,太阳能的利用率极低 .因此 ,有效利用太阳光来实现光能向化学能的转换 ,进而在温和的实验条件下顺利完成无机物或有机物的光催化反应 ,是对发展未来新型光催化材料的挑战 .…     

Enhanced visible photocatalytic degradation of diclofen over N-doped TiO2 assisted with H2O2: A kinetic and pathway study

Increasing discharge and inadequate removal of pharmaceutical compounds pose significant concerns over global aquatic systems and human health. The accomplishment of affordable and safe water requires a stringent elimination of these micropollutants. This study evaluated the performance of Visible/N-doped TiO₂ and Visible/N-doped TiO₂/H₂O₂ processes using a submerged photocatalytic membrane reactor (SMPR) with suspended N-doped TiO₂ to address the removal of diclofenac (DCF). The kinetic and pathway of photodegradation of DCF were of particular interest in this study. The initial DCF concentrations upon the experiments were also examined using a wide range of 5–50 mg/L and 20–100 mg L⁻¹ for Vis/N-doped TiO₂, and Vis/N-doped TiO₂/H₂O₂ process, respectively. The results indicated that higher initial concentration reduces the efficiency of the process, but one with H₂O₂ demonstrated an enhanced performance. The experimental data were found to fit well a pseudo-first-order kinetic model. Our findings demonstrated the analogous pathways of DCF for both processes. The Vis/N-doped TiO₂/H₂O₂ process tends to hasten the degradation rate as evidenced by the disappearance of some DCF byproducts at a similar irradiation period as compared to the other. The study provided useful information of the degradation rate and the potential formation of DCF intermediates upon the hybrid photocatalytic systems, therefore being of importance for scaling-up as well as evaluating potential detoxification of DCF upon the novel photocatalytic system.     

层状磷酸铝化合物Na4[Al4P4O18]·H2O的合成及质子电导性能研究

在无有机模板剂的条件下, 以Na⁺离子为结构导向剂, 通过水热合成法制备了一种与利用1,3-丙二胺合成的Uio-14具有相同层结构的二维磷酸铝化合物Na₄[Al₄P₄O₁₈]·H₂O(1), 通过单晶X射线衍射确定了其拓扑结构. 利用粉末X射线衍射、 扫描电子显微镜、 电感耦合等离子体( ICP)元素分析和热重分析等对其物理化学性质进行了表征. 结果表明, 化合物1属于单斜晶系, 空间群为P2₁/c, 晶胞参数a=1.00887(9) nm, b=0.86747(8) nm, c=0.97580(9) nm, V=0.77387(12) nm³, Z=2, 其阴离子层由铝氧三角双锥(AlO₅)和磷氧四面体(PO₄)构成, 层间通过Na⁺离子平衡电荷; 与Uio-14相比, 化合物1具有更高的热稳定性, 在400 ℃空气条件下煅烧后结构仍然保持完好. 对化合物1的质子电导性能测试结果表明, 相比于传统的分子筛类材料, 化合物1展现出优异的质子电导性能, 在55 ℃下质子电导率可达到1.19×10^-3 S/cm.     

A (4,2)-connected niobium phosphate Na13Nb3P6O28F2 with a unique 6.12-net layer: synthesis, structure and ion exchange properties

A severely interrupted (4,2)-connected niobium phosphate, Na(13)Nb(3)P(6)O(28)F(2), with a unique 6.12-net topology sheet and novel structure type has been synthesized under mild hydrothermal conditions, and its ion exchange properties preliminarily investigated.     

Polarised IR and Raman spectra of non-centrosymmetric Na3Li(SeO4)2.6H2O crystal--a new Raman laser material

Polarised IR and Raman spectra of Na₃Li(SeO₄)₂·6H₂O single crystal have been recorded. Discussion of the results has been based on the factor group approach for the trigonal R3c (C_3v⁶) space group with Z = 2. The obtained results for the spontaneous Raman scattering have been used in the discussion of the stimulated Raman spectra of the material studied—a new Raman laser crystal.     

A series of Mixed-Valent Molybdenum Monophosphates,isotypic with leucophosphite represented by CsMo2P2O10 and K1.5Mo2P2O10 · H2O

The structure of two mixed valent molybdenum phosphates, CsMo₂P₂O₁₀ and K_1.5Mo₂P₂O₁₀ · H₂O has been solved from single crystals by X-ray diffraction in the space group P2₁/c with a = 9.428(1), b = 9.943(2), c = 12.348(2) Å and β = 127.38(1)° for CsMo₂P₂O₁₀ and a = 9.721(2), b = 9.805(3), c = 12.329(3) Å and β = 128.73(2)° for K_1.5Mo₂P₂O₁₀ · H₂O. These compounds isotypic with NH₄Mo₂P₂O₁₀ · H₂O and RbMo₂P₂O₁₀ · (1 ? x)H₂O exhibit the leucophosphite structure. The possibility of cationic non stoichiometry in this structure is also shown by the synthesis of two isotypic compounds A_1.5Mo₂P₂O₁₀ · xH₂O (A = Rb, Tl). In these monophosphates, one site Mo(1) is fully occupied by Mo^V, whereas the other octahedral site Mo(2) exhibits a variable valency Mo^III? Mo^IV to Mo^V. The main difference between these different phosphates deals with the distribution of the A cations inside the tunnels, depending upon their size and their content.