Improving the use of mercury bis(phenyltellurolate) as efficient start for the synthesis of ternary clusters and polymers

Hg(TePh)₂ reacts with AgCl/PMe₂Ph and AgClO₄/PPh₃ to give the ternary clusters [(PhTe)₄Ag₂Hg₂(Cl)₂]_n (1) and [(PhTe)₁₆Ag₄Hg₆Py₄] · H₂O (2). While 1 assembles polymeric, bidimensional layers, 2 attains high symmetric moieties in which the occupational relationship is 40%/60% for the Ag⁺ and Hg²⁺ ions, respectively.     

Mercury mediated synthesis of bis(carboxy)iodobenzenes

Iodobenzene dibenzoates and acetoxylates can be conveniently prepared from iodobenzene dichloride and the corresponding mercuric carboxylate generated $\text{in}$ $\text{situ}$. Especially noteworthy is the high yield preparation of bis(trifluoro-acetoxy) iodobenzene.     

The bis(p-sulfonatophenyl)phenylphosphine-assisted synthesis and phase transfer of ultrafine gold nanoclusters

The behavior of Couette flow of nanofluids composed of negatively-charged nanoparticles dispersed in aqueous NaCl solutions is studied theoretically. The equation for calculating the Couette flow velocity profiles is derived. The induced electric fields and velocity profiles are calculated as a function of key parameters including nanoparticle size and volume fraction. We have found for the first time that the velocity profile of nanofluids containing charged nanoparticles deviates significantly from the classical linear velocity profile for Couette flow. This previously unseen flow phenomenon is attributed to the dominance of the electric field strength induced by the flow of charged nanoparticles. This new mechanism of nanoparticle-induced microfluidic transport could lead to novel microfluidic and tribological applications.     

DNA as a template for synthesis of fluorescent gold nanoclusters

Water-soluble blue-emitting gold nanoclusters have been synthesized using dsDNA as a template without any additional reducing agent. The features of the formed nanoclusters have been revealed by fluorescence and electronic absorption spectroscopy as well as transmission electron microscopy. The prepared gold nanoclusters have been highly stable at physiological pH without any further modification.     

2,5-Bis-(butyltelluro) thiophene as a convenient precursor for the synthesis of 2,5-bis-(acetylenic) thiophenes

Both symmetrically and unsymmetrically substituted 2,5-bis-(acetylenic) thiophene derivatives were obtained in good yields under mild conditions through palladium-catalyzed cross coupling reaction of 2,5-bis-(butyltelluro) thiophene 2 and terminal alkynes. The methodology represents a general and efficient protocol for carrying out the synthesis of thiophene derivatives with potential biological activities.     

Trans-selective hydrogermylation of alkynes promoted by methyliron and bis(germyl)hydridoiron complexes as a catalyst precursor

Catalytic trans-selective hydrogermylation of terminal and internal alkynes was attained by a methyliron complex, CpFe(CO)(2)(Me), and a bis(germyl)hydridoiron(IV) complex as a catalyst precursor. The structures of (Z)-triphenyl-(2-phenylethenyl)germane and the bis(germyl)hydridoiron(IV) complexes CpFe(CO)(H)(GeR(3))(2) (R = Et, Ph) were confirmed by single crystal X-ray diffraction studies.     

Electronic structure and stability of binary and ternary aluminum‐bismuth‐nitrogen nanoclusters

The electronic structure and stability in binary and ternary aluminum‐bismuth‐nitrogen nanoclusters up to six atoms are studied using density functional theory (DFT). The lowest energy geometries were obtained by sampling the geometrical space with a Monte Carlo method and geometry optimizations, at DFT level, with M06L functional. The clusters stability is analyzed using formation and fragmentation energies. Our results show that a high concentration of nitrogen presents a tendency to form nitrogen clusters. highest occupied molecular orbital‐lowest unoccupied molecular orbital gaps show the well‐known oscillation as the number of atoms is increased. Bonding between Al, Bi, and N has mainly a π character. Bismuth and aluminum atoms tend to promote high multiplicity states in small clusters. These new binary and ternary materials provide a potential new field in optoelectronics and high energetic material compounds. © 2014 Wiley Periodicals, Inc.     

One-minute synthesis of crystalline binary and ternary metal oxide nanoparticles

Highly crystalline metal oxide nanoparticles such as CoO, ZnO, Fe(3)O(4), MnO, Mn(3)O(4), and BaTiO(3) were synthesized in just a few minutes by reacting metal alkoxides, acetates or acetylacetonates with benzyl alcohol under microwave heating.     

Micropartioning and solubilization enhancement of 1,2-bis(bis(4-chlorophenyl) methyl)diselane in mixed micelles of binary and ternary cationic-nonionic surfactant mixtures

The aqueous solubilization of the organoselenium compound viz., 1,2-bis(bis(4-chlorophenyl)methyl)diselane [(ClC(6)H(4))(2)CHSe](2) has been investigated experimentally in micellar solutions of two cationic (hexadecyltrimethylammonium bromide, CTAB, hexadecyltrimethylammonium chloride, CTAC) and one nonionic (polyoxyethylene(20)mono-n-hexadecyl ether, Brij 58) surfactants possessing the same hydrocarbon "tail" length and in their single as well as equimolar binary and ternary mixed states. Solubilization capacity determined with spectrophotometry and tensiometry has been quantified in terms of molar solubilization ratio and micelle-water partition coefficient. FTIR, UV-vis, fluorescence and zeta potential measurements have been utilized to ascertain the interaction of organochalcogen compound with surfactants. Equimolar cationic-nonionic surfactant combinations show better solubilization capacity than pure cationics or nonionics, whereas equimolar cationic-cationic-nonionic ternary surfactant systems exhibit intermediate solubilization efficiency between their single and binary counterparts. Locus of solubilization of [(ClC(6)H(4))(2)CHSe](2) in different micellar solutions was probed by UV-visible spectroscopy. The investigation has presented precious information for the preference of mixed surfactants for solubilizing water-insoluble compounds. Indeed the solubilization aptitude of these surfactants is not merely related to molar capacity. The results furnish adequate support to justify comprehensive exploration of the surfactant properties that influence solubilization.     

pH-Metric studies on the binary and ternary complexes of oxovanadium(IV)

The interaction of oxovanadium(IV) with some hydroxy acids, salicylic (SA), 5-sulphosalicylic (SSA) and 8-hydroxyquinoline-5-sulphonic (HQSA) acids, has been studied potentiometrically. Further, pH-metric studies of the ternary systems, VO²⁺?HQSA-dicarboxylic or hydroxy acids (where dicarboxylic acids = phthalic and maleic acids and hydroxy acids =SA andSSA) have been carried out and the formation of 1∶1∶1 mixed complexes inferred from the potentiometric curves. The equilibrium, chelate formation and hydrolysis constants have been calculated in the case of binary systems. The ternary complexes have been found to be more stable as indicated by their formation constants.     

A novel diamine adduct of zinc bis(2-thenoyl-trifluoroacetonate) as a promising precursor for MOCVD of zinc oxide films

A novel diamine (N,N,N',N'-tetramethyletilendiamine) adduct of zinc bis(2-thenoyl-trifluoroacetonate) has been synthesized in a single-step reaction. Single-crystal X-ray diffraction studies of Zn(tta)(2).tmeda provide evidence of a mononuclear structure with a six-coordinated zinc ion. The thermal behavior of this adduct points to mass-transport properties suitable for its application to MOCVD processes. This novel compound has been successfully applied as a precursor for the deposition of ZnO films on (100) Si and quartz substrates. The good quality of the deposited films indicates that the adduct is a very attractive precursor for MOCVD applications.     

Tetrabutylammonium tribromide as efficient catalyst in the synthesis of bis(indolyl)methanes

An efficient procedure has been developed for the synthesis of bis(indolyl)methane derivatives by condensation of aldehydes with indole in the presence of tetrabutylammonium tribromide as catalyst.     

Chemical equilibria in the binary and ternary uranyl(VI)-hydroxide-peroxide systems

The composition and equilibrium constants of the complexes formed in the binary U(VI)-hydroxide and the ternary U(VI)-hydroxide-peroxide systems have been studied using potentiometric and spectrophotometric data at 25 °C in a 0.100 M tetramethylammonium nitrate medium. The data for the binary U(VI) hydroxide complexes were in good agreement with previous studies. In the ternary system two complexes were identified, [UO(2)(OH)(O(2))](-) and [(UO(2))(2)(OH)(O(2))(2)](-). Under our experimental conditions the former is predominant over a broad p[H(+)] region from 9.5 to 11.5, while the second is found in significant amounts at p[H(+)] < 10.5. The formation of the ternary peroxide complexes results in a strong increase in the molar absorptivity of the test solutions. The absorption spectrum for [(UO(2))(2)(OH)(O(2))(2)](-) was resolved into two components with peaks at 353 and 308 nm with molar absorptivity of 16200 and 20300 M(-1) cm(-1), respectively, suggesting that the electronic transitions are dipole allowed. The molar absorptivity of [(UO(2))(OH)(O(2))](-) at the same wave lengths are significantly lower, but still about one to two orders of magnitude larger than the values for UO(2)(2+)(aq) and the binary uranyl(VI) hydroxide complexes. It is of interest to note that [(UO(2))(OH)(O(2))](-) might be the building block in cluster compounds such as [UO(2)(OH)(O(2))](60)(60-) studied by Burns et al. (P. C. Burns, K. A. Kubatko, G. Sigmon, B. J. Fryer, J. E. Gagnon, M. R. Antonio and L. Soderholm, Angew. Chem. 2005, 117, 2173-2177). Speciation calculations using the known equilibrium constants for the U(vi) hydroxide and peroxide complexes show that the latter are important in alkaline solutions even at very low total concentrations of peroxide, suggesting that they may be involved when the uranium minerals Studtite and meta-Studtite are formed by α-radiolysis of water. Radiolysis will be much larger in repositories for spent nuclear fuel where hydrogen peroxide might contribute both to the corrosion of the fuel and to transport of uranium in a ground water system.     

Mercury exchange between diphenylmercury and bis(p-chlorophenyl)mercury

Experimental methods for investigating mercury exchange between diphenyl mercury and bis(p-chlorophenyl)mercury have been evaluated and kinetic parameters determined using a novel partition technique. An octahedral transition state has been proposed. The investigation was complicated by a relatively fast reaction rate, and the kinetic interference of impurities or hydrolysis products.     

A method for the synthesis of nickel(0) bis(carbene) complexes

A new method leading to Ni(NHC)2 (NHC = IMes, IPri, SIPr(i), SIBu(t)) complexes in moderate to good yields, involves the reaction of NHC (pre-formed or generated in situ) with Ni(CH3)2(tmed), tmed = N,N'-tetramethylethylenediamine; in one case, the intermediate Ni[I(Me2)Pr(i)]2(CH3)2, I(Me2)Pr(i) = N,N'-diisopropyl-4,5-dimethylimidazol-2-ylidene, has been isolated and structurally characterised.     

Iron(III)(salen)Cl as an efficient catalyst for synthesis of bis(indolyl)methanes

[Fe(III)(salen)]Cl (salen = N,N′-ethylenebis(salicylimine)) is an efficient catalyst for the electrophilic substitution of indole with carbonyl compounds to afford the corresponding bis(indolyl)methanes in good yields in molten tetrabutylammonium bromide as an ionic liquid. Notable features of this new procedure are shorter reaction times, cleaner reaction profiles, and simple experimental and work-up procedures.     

Studies on the syntheses of polymetalloxanes and their properties as a precursor for amorphous oxide. VII. Preparation and properties of polyzirconoxanes as a precursor for zirconia fibers by the hydrolysis of bis (ethyl acetoacetato) zirconium dialkoxide

Acid-catalyzed hydolysis of bis(ethyl acetoacetato) zirconium dialkoxide in methanol or THF was investigated. The hydrolysis of the chelates in the molar ratios of H₂O/ chelate = 1.0–2.0 and HCl/chelate = 0.1–0.2 provided concentrated solutions (ca. 83 wt %) of polyzirconoxanes (PZO) which showed excellent spinnability and stability to self-condensation. Continuous gel fibers were prepared by dry spinning the solutions. Polyzirconoxanes were isolated as powders when the concentrated solution was precipitated with hexane. Silylation allowed the investigation of the structure of PZO. It was confirmed to be the polymers of a low degree of polymerization with the ligand and hydroxy group as pendants. © 1992 John Wiley & Sons, Inc.     

Chemoenzymatic synthesis of asymmetrized bis(hydroxymethyl)propanoates (BHYMP) as a new family of chiral building blocks

A series of asymmetrized bis(hydroxymethyl)propanoates (BHYMP^*) has been prepared in both enantiomeric forms through a chemoenzymatic methodology involving complementary diacetate monohydrolyses and diol monoacetylations catalyzed by lipases.     

Controlled synthesis of ternary II-II'-VI nanoclusters and the effects of metal ion distribution on their spectral properties

The reaction of [(3,5-Me(2)-C(5)H(3)N)(2)Zn(ESiMe(3))(2)] (E = Se, Te) with cadmium(II) acetate in the presence of PhESiMe(3) and P(n)Pr(3) at low temperature leads to the formation of single crystals of the ternary nanoclusters [Zn(x)()Cd(10)(-)(x)()E(4)-(EPh)(12)(P(n)()Pr(3))(4)] [E = Se, x = 1.8 (2a), 2.6 (2b); Te, x = 1.8 (3a), 2.6 (3b)] in good yield. The clusters [Zn(3)Hg(7)Se(4)(SePh)(12)(P(n)()Pr(3))(4)] (4) and [Cd(3.7)Hg(6.3)Se(4)(SePh)(12)(P(n)()Pr(3))(4)] (5) can be accessed by similar reactions involving [(3,5-Me(2)-C(5)H(3)N)(2)Zn(SeSiMe(3))(2)] or [(N,N'-tmeda)Cd(SeSiMe(3))(2)] (1) and mercury(II) chloride. The metal silylchalcogenolate reagents are efficient delivery sources of {ME(2)} in cluster synthesis, and thus, the metal ion content of these clusters can be readily moderated by controlling the reaction stoichiometry. The reaction of cadmium acetate with [(3,5-Me(2)-C(5)H(3)N)(2)Zn(SSiMe(3))(2)], PhSSiMe(3), and P(n)()Pr(3) affords the larger nanocluster [Zn(2.3)Cd(14.7)S(4)(SPh)(26)(P(n)()Pr(3))(2)] (6). The incorporation of Zn(II) into {Cd(10)E} (E = Se, Te) and Zn(II) or Cd(II) into {Hg(10)Se} nanoclusters results in a significant blue shift in the energy of the first "excitonic" transition. Solid-state thermolysis of complexes 2 and 3 reveals that these clusters can be used as single-source precursors to bulk ternary Zn(x)Cd(1)(-)(x)E materials as well as larger intermediate clusters and that the metal ion ratio is retained during these reactions.