Metal exchange reaction between Mg(II) and Cd(II) octa(4-bromophenyl)tetraazaporphyrinates with manganese(II) chloride in dimethylformamide

Reaction of metal exchange of Mg(II) and Cd(II) octa(4-bromophenyl)tetraazaporphyrinates with MnCl₂ in dimethylformamide has been studied by means of spectrophotometry. Kinetic parameters of the reaction have been determined; the reaction stoichiometry mechanism has been suggested.     

Bis(methoxo)titan(IV)-dichlorid

Bis(methoxo)titanium(IV) Dichloride [CH₃O]₂TiCl₂ has been prepared by reaction between TiCl₄ and methanol. It has been characterized by different methods.     

Extraction chromatographic study of aluminium(III) and mutual separation of aluminium(III), gallium(III), indium(III) and thallium(III) with N-n-octylaniline

A selective method has been developed for extraction chromatographic studies of aluminium(III) and its separation from several metal ions with a chromatographic column containing N-n-octylaniline (liquid anion exchanger) coated on silanized silica gel as a stationary phase. The aluminium(III) was quantitatively extracted with the 0.065 mol/L N-n-octylaninine from 0.013 to 0.05 mol/L sodium succinate at a flow rate of 1.0 mL/min. The extracted metal ion has been recovered by eluting with 25.0 mL of 0.05 mol/L hydrochloric acid and estimated spectrophotometrically with aurintricarboxylic acid. The effects of the acid concentration, the reagent concentration, the flow rate and the eluting agents have been investigated. The log-log plots of distribution coefficient (KdAl(III)) versus N-n-octylaniline concentrationin 0.005 and 0.007 mol/L sodium succinate gave theslopes 0.5 and 0.7 respectively and showed theprobable composition of theextracted species was 1:1 (metal to amine ratio) and the nature of extracted species is [RR''NH2+ Al succinate2-] org. .The extraction of aluminium(III) was carried out in the presence of various ions to ascertain the tolerance limit of individual ions. Aluminium(III) has been separated from multicomponent mixtures, pharmaceutical samples and synthetic mixtures corresponding to alloys. A scheme for mutual separation of aluminium(III), indium(III), gallium(III) and thallium(III) has been developed by using suitable masking agents. The method is fast, accurate and precise.     

Thermal carbosilylation of endohedral dimetallofullerene La(2)@I(h)-C(80) with silirane

Thermal carbosilylation of endohedral dimetallofullerene La(2)@I(h)-C(80) with silirane (silacyclopropane) is reported herein for the first time. Two diastereomers of the carbosilylated La(2)@I(h)-C(80) have been isolated and characterized. The fascinating molecular structure of one diastereomer of the carbosilylated derivatives has been determined unambiguously using X-ray crystallographic analysis. Detailed characteristics of the molecular structures including their metal atom movements have also been revealed using NMR spectroscopic studies and computational calculations. Results revealed that two La atoms move dynamically inside the carbon sphere. Furthermore, electrochemical study has demonstrated that carbosilylation is effective to fine-tune the La(2)@I(h)-C(80) electronic properties.     

3He NMR study of (3)He@C(60)H(6) and (3)He@C(70)H(2)(-)(10)

The (3)He NMR of (3)He@C(60)H(6), (3)He@C(70)H(2), (3)He@C(70)H(4), (3)He@C(70)H(8), and (3)He@C(70)H(10) have been investigated. A new, unidentified C(60)H(6) isomer has been found by using (3)He NMR. (3)He@C(70)H(10) shows the most downfield-shifted (3)He NMR resonance among the neutral C(70) derivatives.     

Diverse evolution of [[Ph(2)P(CH(2))(n)PPh(2)]Pt(mu-S)(2)Pt[Ph(2)P(CH(2))(n)PPh(2)]] (n = 2, 3) metalloligands in CH(2)Cl(2)

The nucleophilicity of the [Pt(2)S(2)] core in [[Ph(2)P(CH(2))(n)PPh(2)]Pt(mu-S)(2)Pt[Ph(2)P(CH(2))(n)PPh(2)]] (n = 3, dppp (1); n = 2, dppe (2)) metalloligands toward the CH(2)Cl(2) solvent has been thoroughly studied. Complex 1, which has been obtained and characterized by X-ray diffraction, is structurally related to 2 and consists of dinuclear molecules with a hinged [Pt(2)S(2)] central ring. The reaction of 1 and 2 with CH(2)Cl(2) has been followed by means of (31)P, (1)H, and (13)C NMR, electrospray ionization mass spectrometry, and X-ray data. Although both reactions proceed at different rates, the first steps are common and lead to a mixture of the corresponding mononuclear complexes [Pt[Ph(2)P(CH(2))(n)PPh(2)](S(2)CH(2))], n = 3 (7), 2 (8), and [Pt[Ph(2)P(CH(2))(n)PPh(2)]Cl(2)], n = 3 (9), 2 (10). Theoretical calculations give support to the proposed pathway for the disintegration process of the [Pt(2)S(2)] ring. Only in the case of 1, the reaction proceeds further yielding [Pt(2)(dppp)(2)[mu-(SCH(2)SCH(2)S)-S,S']]Cl(2) (11). To confirm the sequence of the reactions leading from 1 and 2 to the final products 9 and 11 or 8 and 10, respectively, complexes 7, 8, and 11 have been synthesized and structurally characterized. Additional experiments have allowed elucidation of the reaction mechanism involved from 7 to 11, and thus, the origin of the CH(2) groups that participate in the expansion of the (SCH(2)S)(2-) ligand in 7 to afford the bridging (SCH(2)SCH(2)S)(2-) ligand in 11 has been established. The X-ray structure of 11 is totally unprecedented and consists of a hinged [(dppp)Pt(mu-S)(2)Pt(dppp)] core capped by a CH(2)SCH(2) fragment.     

Polyfluorocyloalkenes Part XI Perfluoro - bicyclo(3,3,0) oct-7(8)-ene, - bicyclo(4,3,0)-non-8(9)-ene and - bicyclo (4,4,0)-dec-9(10)-ene and some derivatives

Tetradecafluorobicyclo (4,3,0) non-8(9)-ene has been prepared by cobaltic fluoride fluorination of decafluoro indane. The reactivities of the double bonds in dodecafluorobicyclo (3,3,0) oct-7(8)-ene and hexadecafluorobicyclo (4,4,0) dec-9(10)-ene have been studied qualitatively by the use of chlorine, methanol, cobaltic fluoride, ammonia and dimethylamine and the derivatives so obtained have been characterised.     

Hydrolysis and etherification of (o-carboranylisopropyl)dichloro(methyl)silane

The behavior of (o-carboranylisopropyl)dichloro(methyl)silane in hydrolysis and etherification reactions has been studied. (o-Carboranylisopropyl)(methyl)silanediol and (o-carboranylisopropyl)diethoxy(methyl)silane have been obtained for the first time and characterized.     

Polarographic determination of osmium with the osmium(VIII)-cerium(IV)-arsenic(III) system

A highly sensitive and novel polarographic method has been developed for determination of ultratrace amounts of osmium, based on the catalysis of the cerium(IV)-arsenic(III) reaction by osmium(VIII). The reaction rate is monitored by measuring the arsenic(III) with a single-sweep oscillopolarograph. Osmium concentrations from 7.0 x 10(-11) to 5.0 x 10(-9)M can be determined by the initial rate method. The method has been applied to determination of osmium in refined ore and chlorination residues with satisfactory results.     

Kinetic effect of zinc(II) and cadmium(II) ions on configurational inversion of deltaLLL-fac(S)-tris(L-cysteinato-N,S)cobalt(III) complex.

It has been confirmed from circular dichroism (CD) spectral changes of aqueous solutions of deltaLLL-fac(S)-[Co(L-cys-N,S)3]3- that the absolute configurational inversion to the ALLL isomer is remarkably accelerated by zinc(II), while it is retarded by cadmium(II). In the diluted solutions of these metal ions containing excess deltaLLL-fac(S)-[Co(L-cys-N,S)3]3-, the observed inversion rate constant linearly depends on the zinc(II) concentration with an intercept, while it is not affected by the cadmium(II) concentration. The kinetic behavior has been explained by difference between zinc(II)- and cadmium(II)-interactions with lone pairs on sulfur donor atoms of fac(S)-[Co(L-cys-N,S)3]3-. It has also been proposed that concentrations of zinc(II) and cadmium(II) can be simultaneously determined by the kinetic measurements.     

The Synthesis and Structure of (1-(Diphenylphosphino)-1 - (Phenylthio)Ferrocene)Tricarbonyliron(O) (ptppf)Fe(CO)3

The complex (ptppf)Fe(CO)₃ has been prepared in high yield by the reaction of ptppf, l-(diphenyl-phosphino)-l'-(phenylthio)ferrocene, with (cis-cyclooctene)₂-Fe(CO)₃ in THF at ?60°C. The complex has been characterized by IR, ³¹P NMR, mass spectrometry and single-crystal X-ray diffraction. This compound is the first example of a ferrocenyl ligand having both sulfur and phosphorus donor atoms bound to a Fe(CO)₃ moiety. X-ray crystallography shows that the two cyclopentadienyl rings are approximately eclipsed, a rotation of 13° from exactly eclipsed conformation. The tricarbonyl iron center has a trigonal bipyramidal geometry with sulfur occupying the equatorial site and phosphorus the axial site. Crystals of (ptppf)Fe(CO)₃ are monoclinic, with a = 11.645(2), b = 14.304(1), c = 17.075(2) Å,β = 109.23(3)°, Z = 4, and space group P 2₁/n. The structure was solved according to the heavy-atom method and refined by full-matrix least-squares procedures to R = 0.037 for 2098 reflections with I ≥ 2.5σ(I).     

Arylgold(I) and aryl(triphenylphosphine)gold(I)compounds

Novel monomeric benzyl- and aryl-gold(I) triphenylphosphine complexes have been prepared. Pure, uncomplexed 2-[(dimethylamino)methyl]-phenylgold(I) has been isolated from the reaction of tetranuclear bis {2-[(dimethylamino)methyl]phenyl}goldlithium (R₄ Au₂ Li₂) with trimethyltin bromide.     

Melting point depression in poly (ethylene oxide)-poly (methyl methacrylate) blends

Thermo-optical analysis of solution cast mixtures of poly (ethylene oxide) (POE) and poly (methyl methacrylate) (PMMA) has been carried out. Melting point depression was observed for increasing proportion of PMMA in the mixture. An analytical expression appropriate to the crystallineamorphous polymer pair has been applied to explain the melting point depression in terms of thermodynamic quantities. From this expression, the interaction parameter for the mixture has been evaluated. The influence of $\text{M}$_w of POE on the binary interaction parameter has been studied.     

Synthesis and characterization of a new three-dimensional lanthanide carboxyphosphonate: Ln(4)(H(2)O)(7)[O(2)C-C(5)H(10)N-CH(2)(-)PO(3)](4)(H(2)O)(5)

The first open-framework lanthanide carboxyphosphonate has been obtained under hydrothermal conditions. The three-dimensional structure of MIL-84(Pr) (MIL = Material Institut Lavoisier) or Pr(4)(H(2)O)(7)[O(2)C-C(5)H(10)N-CH(2)(-)PO(3)](4)(H(2)O)(5) has been solved from X-ray diffraction single-crystal data (a = 23.481(1) A, b = 10.159(1) A, c = 23.006(1) A, beta = 105.63(1) degrees, V = 5284.6(6) A(3), space group Cc (No. 9)). Its framework is built up from chains of edged-sharing eight or nine-coordinated monocapped square antiprism polyhedra and carboxyphosphonate anions, creating a three-dimensional structure with small pores filled with water molecules. The thermal behavior of MIL-84(Pr) has been investigated using TGA and X-ray thermodiffractometry and indicates that MIL-84(Pr) is stable up to 523 K with a reversible hydration-dehydration process. The optical study of its yttrium analogue doped at 3.4% with europium (MIL-84(Y,Eu)) reveals a significant red-orange emission under UV radiation.     

Acid-base properties of bis(hydrazinocarbonylmethyl) sulfoxide and its complex formation with copper(II) and nickel(II)

Behavior of physiologically active compound, bis(hydrazinocarbonylmethyl) sulfoxide, in aqueous solution has been studied by means of potentiometry, spectrophotometry, and mathematical simulation. Protolytic properties of bis(hydrazinocarbonylmethyl) sulfoxide have been described, and the formation of sodium salt has been confirmed. Composition and stability constants of bis(hydrazinocarbonylmethyl) sulfoxide complexes with copper(II) and nickel(II) have been determined, and the complexes structures have been simulated by molecular mechanics method.     

Emission analysis of Dy(3+):Ca(4)GdO(BO(3))(3) powder phosphor

Emission spectrum of Dy(3+):Ca(4)GdO(BO(3))(3) powder phosphor has been analyzed. Two emission bands at 492 and 588 nm with lambda(exci)=311 nm ((6)H(15/2)-->(4)L(19/2)) have been measured from this phosphor. For the intense yellow emission at 588 nm ((4)F(9/2)-->(6)H(13/2)), its lifetime has been measured. Emission performance of this phosphor has been explained in terms of an energy level diagram. Besides carrying out the emission analysis, XRD, SEM and FTIR studies have also been carried out in order to understand the nature and structural details of the optical material studied.     

Structure,cyclic voltammetry and DNA-binding properties of the bis(pyridine)bis(sparfloxacinato)nickel(II) complex

The neutral mononuclear nickel(II) complex with the quinolone third-generation antibacterial drug sparfloxacin in the presence of the nitrogen-donor heterocyclic ligand pyridine has been synthesized and characterized. Sparfloxacin is deprotonated acting as a bidentate ligand coordinated to the Ni(II) ion through the ketone oxygen and a carboxylato oxygen. The crystal structure of bis(sparfloxacinato)bis(pyridine)nickel(II), 1, has been determined with X-ray crystallography. The cyclic voltammograms of the complex have been recorded in dmso solution and in 1/2 dmso/buffer (containing 150 mM NaCl and 15 mM trisodium citrate at pH 7.0) solution and the corresponding redox potentials have been estimated. The biological activity of the complex has been evaluated by examining its ability to bind to calf-thymus DNA (CT DNA) with UV and fluorescence spectroscopies and cyclic voltammetry. UV study of the DNA-interaction of the complex has shown that it can bind to CT DNA and the DNA-binding constant has also been calculated. The cyclic voltammograms of the complex in the presence of CT DNA have shown that the complex can bind to CT DNA by the intercalative mode. Competitive study with ethidium bromide (EB) has shown that the complex can displace the DNA-bound EB indicating that the complex binds to DNA in strong competition with EB for the intercalative binding site.     

Preparation and characterization of bis(acetonitrile)bis(acetylacetonato)technetium(III)

A new chemical species of bis(acetonitrile)bis(acetylacetonato)technetium(III), [Tc(acac)₂(CH₃CN)₂]⁺, has been prepared by the reaction of tris(acetylacetonato)technetium(III) with acetonitrile in the presence of a strong acid, perchloric or hydrochloric acid. The reaction kinetics were followed by observing spectral change of Tc(acac)₃ in the UV-visible region. The complex has been characterized by combination of elemental analyses, IR and UV-visible spectrophotometry, ion-exchange chromatography, and paper electrophoresis. Applicability of this substance to synthesize mixed-ligand technetium(III) complexes was discussed based on the solubility of this complex and the ease of substitution of the acetonitrile ligand.     

Interaction of Poly(benzoyl thiocarbamate)-Modified Hyperbranched Polyester with Co(II) and Cu(II) Nitrates

The interaction of Co(NO3)2 and Cu(NO3)2 with hyperbranched polyester containing 7 terminal benzoyl thiocarbamate groups has been studied by IR-Fourier and electron absorption spectroscopy. А new polynuclear complexes of Co(II) and Cu(II) with poly(benzoyl thiocarbamate)-modified hyperbranched polyester have been synthesized. It has been found that the oxygen and sulfur atoms of the peripheral benzoyl thiocarbamate fragments of the macroligand are involved in coordination with metal ions, the metal to ligand ratio being 7 : 1.     

Ag(2)(C(33)H(26)N(2)O(2))(H(2)O)(2)(SO(3)CF(3))(2)].0.5C(6)H(6): a luminescent supramolecular silver(I) complex based on metal-carbon and metal-heteroatom interactions

A novel fulvene-type bidentate ligand 1 has been synthesized by an aroylation reaction of cyclohexyl-substituted cyclopentadienyl anions. Compound 1 crystallizes in the triclinic space group P(-)1, with a = 7.0419(5) A, b = 11.9360(8) A, c = 15.6470(11) A, alpha = 85.1440(10) degrees, beta = 78.1140(10) degrees, gamma = 74.5360(10) degrees, V = 1239.76(15) A(3), and Z = 2. The coordination chemistry of 1 was investigated, and a novel Ag-containing coordination polymer (2), linked by both Ag-heteroatom and Ag-carbon interactions, has been synthesized. The coordination polymer has been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. Compound 2 crystallizes in the triclinic space group P(-)1, with a = 7.1654(5) A, b = 15.7277(11) A, c = 18.8157(13) A, alpha = 73.5150(10) degrees, beta = 89.0410(10) degrees, gamma = 89.0970(10) degrees, V = 1355.19(14) A(3), and Z = 2. The solid-state structure of 2 features a one-dimensional double-chain motif. These double chains are in turn cross-linked to each other via strong interchain O-H...O hydrogen bonds, forming a novel two-dimensional network with remarkably large cavities (effective cross section of ca. 21 x 15 A) that are occupied by benzene guest molecules. Both compounds 1 and 2 are luminescent in the solid state, and a large blue-shift in the emission between the free ligand 1 and the ligand incorporated into complex 2 is observed.