Studies on the Preparation and Properties of Thiol Derivatives of Biscyclopentadienyl Molybdenum (VI) and Bisindenyl Molybdenum (VI) Oxide Dichloride

Biscyclopentadienyl molybdenum (VI) oxide dichloride (I) and bisindenyl molybdenum (VI) oxide dichloride (II) react with various thiols in tetrahydrofuran and from the complexes of the type (C₃H₅)₂MoO (R₂) and (C₉H₇)₂MoO (R₂) wherein R may be S CH₈, S C₂H₅, S C₃H^N₇, S C₃H₇, S C₄Hⁿ₉, or S C₄H₃ or S C₃H₁₁. The preparation, thermal stabilities, physical characteristics and infrared spectra of these complexes have been studied in this paper.     

Studies on the Preparation and Properties of Some Phenolic Derivatives of Tricyclopentadienyl Cerium (IV) and Bisindenyl Cerium (IV)

Reactions of tricyclopentadienyl cerium (IV) chloride (I) and bisindenyl cerium (TV) dichloride (II) with mono-, di-, and trihydroxy phenols have been studied and some phenoxide derivatives of (I) and (II) have been isolated. Infrared spectra and some physical characteristics of all these compounds are Reported.     

Pseudo-Halide Complexes of Biscyclopentadienyl Niobium(IV) and Bisindenyl Niobium(IV) Dichloride

Reactions of biscyclopentadienyl niobium(IV) dichloride and bisindenyl niobium(IV) dichloride with sodium or potassium salts of various pseudohalides have been studied and the pseudohalide complexes so formed of the formulae (C₅H₅)₂Nb(Ps)₂ and (C₂H₇)₂Nb(Ps)₂ where Ps may be NC, NCO, NCS, or N₃, have been isolated. The complexes have been characterised on the basis of physical measurements, analytical data and infrared spectral studies.     

Thiocarboxylato Complexes of Biscyclopentadienyl and Bisindenyl Titanium (IV)

Reactions of biscyclopentadienyl (and bisindenyl) titanium (IV) dichlorides with sodium salts of various thiocarboxylic acids in tetrahydrofuran medium, yield the complexes of the general formula (D) ²Ti(SCOR) ² where D is cyclopentadienyl or indenyl group and R? H, CH₃, C₂H₅, C⁴H⁵ or p-C⁴H⁴CH³ group. The foul smelling complexes are monomeric in nature. The IR spectra, thermal stabilities and Some physical characteristics of these complexes have been studied.     

Phenoxy Derivatives of Dicyclopentadienyl Tungsten(VI) Oxydichloride and Bisindenyl Tungsten (VI) Oxydichloride

Phenoxy complexes containing π-bonded cyclopentadienyl and indenyl groups attached to metals ytterbium¹⁾, titanium¹⁾, and cerium¹⁾. are reported in the literature. These phenoxide derivatives were prepared by the actious of various phenols on the cyclopentadienyl or indenyl metal halide complexes in benzene or tetrahydrofuran. There is no mention the literature about the prepartion and characterization of phenolic derivatives of π-cyclopentadienyl and π-indenyl oxotungsten (VI). The effect of electron releasing or electron attracting substiuents in the phenols on the nature of the complexes and the metal-phenoxide bond has not been reported. The possibility of formation of hydrogen bond between hydrogen atom of the free hydroxyl group of a polyhydric phenoxide group and the oxygen atom attached to the metal atom has not also been explored. This communication deals with such an attempt and reports the synthesis and characterization of 26 phenoxy derivatives of dicyclopentadienyl and bisindenyltungsten (VI) oxydichlorides and conclusions derived from their infrared spectral study.     

Studies on Carboxylato Complexes of Tricyclopentadienyl Cerium (IV) Chloride and Bisindenyl Cerium (IV) Dichloride

Tricyclopentadienyl Cerium (IV) chloride and bisindenyl cerium (IV) dichloride have been treated with sodium salts of the appropriate carboxylic acids in benzene or tetrahydrofuran medium to give (C₅H₃)₃ Ce(R) and (C₉H₇)₂Ce(R)₂ wherein R is HCOO, CH₃COO, C₂H₅COO, C₃H₇COO and C₆H₅COO. The infrared spectra, thermal stabilities and other characteristics of the above compounds have been studied and reported.     

Studies on Hydrated Stannic Oxide. Part VI. Thin-Layer Chromatography of Some Anions on Hydrated Stannic Oxide: Quantitative Separation of Cr(VI) from Some Ores and Alloys

Abstract

The analytical applications of hydrated stannic oxide as an ion-exchanger have been investigated by thin-layer chromatographic (TLC) technique. Binder-free thin-layers of hydrated stannic oxide are useful for some binary separations. Quantitative separation of Cr(VI) and Mo(VI) from some binary mixtures have been achieved. The method is applied to separate microgram-quantities of Cr(VI) quantitatively from several ores and alloys in ammonia buffer (pH 10) system.     

二(甲基环戊二烯基)二氯化钛及某些取代苯氧基衍生物的合成

二(甲基环戊二烯基)二氯化钛[(MeCp)₂TiCl₂](Ⅰ),Wilkinson等人^[1]曾用四氯化钛和甲基环戊二烯基钠反应来制备,产率26％.后来Brantly^[2]用四氯化钛和MeC₅H₄MgCl在乙醚-苯混合溶液中于-70℃反应.以上两种方法不但操作复杂,且条件苛刻,产率低.最近吴绍祖等^[3]用二乙胺作为氯化氢的接受体,四氢呋喃作溶剂,由TiCl₄和甲基环戊二烯直接反应来合成.产率43％.我们采用甲基环戊二烯基锂与TiCl₄反应来合成,产率为63％.     

二苄基二氯化锡三苯基氧膦的合成及晶体结构研究

利用二苄基二氯化锡与三苯基氧膦反应 ,合成了目标化合物二苄基二氯化锡三苯基氧膦 ,其结构经元素分析表征。用X 射线单晶衍射测定其晶体结构属于三方晶系 ,空间群为P2 1,a =2 .0 2 7( 4 )nm ,b =0 .9714 ( 17)nm ,c =1.5 5 9( 3)nm ,α =90° ,β =90° ,γ =90° ,Z =4 ,V =3.0 4 9( 10 )nm3 ,Dc =1.4 0 7mg·m-3 ,u =1.0 81mm-1,F( 0 0 0 )=1312 ,R1=0 .0 370 ,wR2 =0 .0 6 88,晶体中心的Sn原子为五配位的畸变三角双锥构型     

Solid and Solution Structural Studies of Dimeric and Tetrameric Molybdenum（VI） Malate Complexes

Reactions of potassium molybdate with racemic malic acid （H3mal = C4H6O5） result in the isolation of two mesomeric molybdenum malate complexes K8[（MoO2）2O（R-mal）2][（MoO2）2O（Smal）2]-4H2O 1 and （Him）2K6[（MoO2）4O3（R-mal）2][（MoOE）4O3（S-mal）2]-8H2O 2. Complex 1 belongs to the monoclinic system, space group C2/c with a = 14.8637（3）, b = 6.9544（1）, c = 19.6783（5）A, β = 100.081（2）°, V = 2002.70（7） A^3, Mr = 1452.88, Z = 2, F（000） = 1416, T = 173 K, Dc = 2.409 g/cm3, fl（MoKa＇） = 2.167, R = 0.0283 and wR = 0.0733.2 is of triclinic system, space group P1^- with a = 8.7707（2）, b = 9.3310（3）, c = 17.9093（7）A, α= 83.781（3）, β = 85.626（2）, y= 84.822（2）°, V = 1447.84（8）A^3, Mr = 2160.68, Z = 1, F（000） = 1048, T = 173 K, Dc = 2.478 g/cm^3,μ（MoKα） = 2.230, R = 0.0234 and wR = 0.0584.1 is the first isolated dinuclear molybdenum（VI） malato complex in 1：1 molar ratio. The molybdenum atoms in the two complexes are six-coordinated in an approximately octahedral geometry. Two malates coordinate tridentately with the Mo atom via their α-alkoxy, α-carboxy and α-carboxy groups in 1 and 2. β-Carboxy group in 2 further links with the other two Mo atoms to give a tetrameric unit. The solution ^1H and ^13C NMR spectra indicate that dimeric malate molybdenum in 1 dissociates partly in solution and exists in an equilibrium with tetrameric species, while 2 is stable and retains its tetrameric structure without any dissociation.     

Adsorption and Kinetics Studies of Cr (VI) by Graphene Oxide and Reduced Graphene Oxide-Zinc Oxide Nanocomposite

In this work, graphene oxide (GO) and its reduced graphene oxide-zinc oxide nanocomposite (rGO-ZnO) was used for the removal of Cr (VI) from aqueous medium. By employing a variety of characterization techniques, morphological and structural properties of the adsorbents were determined. The adsorption study was done by varying concentration, temperature, pH, time, and amount of adsorbent. The results obtained confirmed that rGO-ZnO is a more economical and promising adsorbent for removing Cr (VI) as compared to GO. Kinetic study was also performed, which suggested that sorption of Cr (VI) follows the pseudo-first-order model. For equilibrium study, non-linear Langmuir was found a better fitted model than its linearized form. The maximum adsorption capacity calculated for GO and rGO-ZnO nanocomposite were 19.49 mg/g and 25.45 mg/g, respectively. Endothermic and spontaneous nature of adsorption was detected with positive values of ΔS (change in entropy), which reflects the structural changes happening at the liquid/solid interface.     

树枝形聚合物修饰双8-羟基喹啉衍生物的合成及稳态光物理性质研究

设计合成了1 3代芳醚骨架树枝形聚合物修饰的双8 羟基喹啉衍生物.对这些化合物在不同溶剂中的荧光光谱研究表明,随着代数的增加,目标树枝形聚合物的荧光量子产率增大,树枝形聚合物对核心发色团具有一定的隔离作用,并且目标分子内可以发生从骨架向核心发色团的能量传递.     

聚并苯和取代聚并苯电子性质的量子化学研究

准一维聚并苯体系是一类典型的梯形结构有机导体材料．采用量子化学一维紧束缚自洽场晶体轨道ＣＮＤＯ／２　方法，研究了顺、反式聚并苯和取代聚并苯的结构、能量和电子布居．计算了甲基、甲氧基、氯和羟基取代聚并苯的电子能带，与聚并苯进行了分析比较．结果表明：（１）单取代使对称性明显降低，对聚并苯的能带结构影响较大，使能隙值普遍增大，导电性能降低．（２）双取代虽使电荷重新分布，但基本保持聚并苯自身结构特征．取代聚并苯与聚并苯比较能隙值变化不大．对于不同的取代基影响规律不同．对位双取代与间位双取代也表现出差异．（３）顺式和反式结构聚并苯的电子性质略有差异，取代后变化较大．     

Studies on Polymeric Base Derivatives of Some Copper(II) Orthohydroxy Thiosemicarbazones

Polymeric complexes of copper (II) with some orthohydroxy thiosemicarbazones (H₂L), such as 2-OH-5-Me (C1), aceto/propiophenone thiosemicarbazones with some bases (B), viz., pyridine; α-, β-, γ-picolines; piperidine; morpholine and bidentate bases; bipy and o-phen, have been isolated and characterized. The analytical data shows them to have 1: 1: 1 composition of Cu:L:B. Their thermal, spectral, and magnetic properties are studied.     

Electrical and Spectral Properties of Manganese Dichloride Complexes with N-Oxides of Pyridine Derivatives

Polycrystalline complexes of MnCl₂ with N-oxides of pyridine, 2-picoline, and 2,6-lutidine contain a molecule of strongly retained crystallization water; two types of the labile networks of hydrogen bonds are formed on the crystal surface. Under solar radiation the long-lived F-centers are formed in the crystals, imparting a specific color to the compounds. The thermal motion of MnCl₂ complexes with lutidine N-oxide in the unit cells can be described as gas-like motion. At low temperatures the electrical conductivity is predominantly maintained by protons, whereas at high temperatures another mechanism of conductivity arises.     

Dispersion and Structure Studies of Molybdenum Oxide on Anatase TiO2

X-ray photoelectron spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS) were used to characterize the structure of the mixture of molybdenum oxide and anatase calcined at 723 K. The resuits indicate that molybdenum oxide can disperse onto the surface of anatase (TiO2) and the dispersion threshold is 11.2 mg in per gram of MoO3 or 4.8 Mo atoms/nm^2 TiO2. When the coment of MoO3 is below the dispersion threshold, MoO3 species is in highly dispersed state interacting strongly with TiO2 support and in discrete tetrahedral coordination. [MoO4], on the surface of TiO2. When the MoO3 loading is above this value, MoO3 exists in both dispersed phase and crystalline phase. MoO3 in dispersed phase is still a discrete [MoO4] tetrahedron; MoO3 in crystal phase is in octahedral coordination.