Reactions of ruthenium(III), Rhodium(III) and Iridium(III) chlorides in molten nitrite eutectics

The reactions of ruthenium(III), rhodium(III) and iridium(III) chlorides in molten lithium nitrite—sodium nitrite, lithium nitrite—potassium nitrit and sodium nitrite—potassium nitrite eutectics were studied and compared with those of their first row congeners. Ruthenium(III) reacted to form hexanitroruthenate(II) with the evolution of nitrogen dioxide, whereas rhodium(III) and iridium(III) formed hexanitrorhodate(III) and hexanitroiridate(III), respectively. These complexes decomposed at higher temperatures to form ruthenium(IV), rhodium(III) and iridium(IV) oxides, respectively, with the evolution of nitrogen oxides. The stoichiometries of these reactions were established by thermogravimetry and the products were characterized by their IR, visible and UV spectra, and X-ray diffraction patterns.     

Cation-exchange behaviour of the platinum group and some other rare elements in hydrobromic acid-thiourea-acetone media

Ion-exchange distribution coefficients and elution curves are presented for copper(I), silver, gold(I), palladium, platinum(II), rhodium(III), iridium(III), ruthenium(III), osmium(III), mercury(II), thallium(I), tellurium(II), lead and bismuth in mixtures of thiourea, hydrobromic acid, acetone and water, with the cation-exchange resin AGW50W-X4. The system affords excellent separations of rhodium, mercury, silver (or copper), tellurium, gold, and palladium (or platinum) from each other.     

Luminescent cyclometalated Rh(III), Ir(III), and (DIP)2Ru(II) complexes with carboxylated bipyridyl ligands: synthesis, X-ray molecular structure, and photophysical properties

Luminescent cyclometalated rhodium(III) and iridium(III) complexes of the general formula [M(ppy) 2(N (wedge)N)][PF 6], with N (wedge)N = Hcmbpy = 4-carboxy-4'-methyl-2,2'-bipyridine and M = Rh ( 1), Ir ( 2) and N (wedge)N = H 2dcbpy = 4,4'-dicarboxy-2,2'-bipyridine and M = Rh ( 3), Ir ( 4), were prepared in high yields and fully characterized. The X-ray molecular structure of the monocarboxylic iridium complex [Ir(ppy) 2(Hcmbpy)][PF 6] ( 2) was also determined. The photophysical properties of these compounds were studied and showed that the photoluminescence of rhodium complexes 1 and 3 and iridium complexes 2 and 4 originates from intraligand charge-transfer (ILCT) and metal-to-ligand charge-transfer/ligand-centered MLCT/LC excited states, respectively. For comparison purposes, the mono- and dicarboxylic acid ruthenium complexes [Ru(DIP) 2(Hcmbpy)][Cl] 2 ( 5) and [Ru(DIP) 2(H 2dcbpy)][Cl] 2 ( 6), where DIP = 4,7-diphenyl-1,10-phenanthroline, were also prepared, whose emission is MLCT in nature. Comparison of the photophysical behavior of these rhodium(III), iridium(III), and ruthenium(II) complexes reveals the influence of the carboxylic groups that affect in different ways the ILCT, MLCT, and LC states.     

Chelate von β-dicarbonylverbindungen und ihren derivaten: Teil XLVII. Dünnschichtchromatographisches verhalten von metallchelaten mit thiodibenzoylmethan und acetylthioacetaniliden

The thin-layer chromatographic behaviour of thiodibenzoylmethane chelates with cobalt(III), zinc(II), mercury(II), palladium(II), platinum(II) and rhodium(III), and also of acetylthioacetanilide chelates with cobalt(III), nickel(II), zinc(II) and cadmium(II) on alumina is described. Different binary mixtures of eluents are used. The influence of solvent parameters and of the layer material, possible separations and the influence of substituents in the acetylthioacetanilides are discussed.     

Separation and concentration of some platinum metal ions with a new chelating resin containing thiosemicarbazide as functional group

A new chelating ion-exchange resin containing thiosemicarbazide as functional group and based on macroreticular polystyrene-divinylbenzene (8%) has been prepared. Its sorption characteristics for palladium(II), platinum(IV), rhodium(III), ruthenium(III) and iridium(III) have been studied. These platinum metal ions can be quantitatively separated by sorption on this chelating resin and selective elution. The resin is highly stable in acid and alkaline solution.     

Spectrophotometric determination of traces of metallic ions and their mixtures with 3-methyl-1,2-cyclopentanodione dithiosemicarbazone: I. Zinc,cadmium, and mercury

The properties of zinc, cadmium, and mercury complexes of 3-methyl-1,2-cyclopentanodione dithiosemicarbazone and the optimal conditions for their formation are described. The complexes were used with success in the photometric determination of traces of zinc, cadmium, and mercury. Seven procedures are proposed for the accurate analysis of Zn(II)-Cd(II), Zn(II)-Hg(II), Zn(II)-Bi(III), Cd(II)-Hg(II), Cd(II)-Bi(III), Hg(II)-Bi(III), and Zn(II)-Cd(II)-Hg(II) mixtures. Satisfactory results were obtained.     

The interaction of hexamethylenetetramine with platinum group metals

Summary Complexes of the geabneral formula MX_n · hmta [where hmta=hexamethylenetetramine; MX_n=rhodium(III), ruthenium(III) iridium(III), palladium(II), or platinum(II) halides; n=2 or 3] and other related complexes, have been prepared in aqueous or methanolic solution.The compounds were characterized by elemental analyses, i.r. spectra and conductivity measurements.     

Synthesis,characterization, and biological activity of metal complexes of azohydrazone ligand

A new azohydrazone, 2-hydroxy-N′-2-hydroxy-5-(phenyldiazenyl)benzohydrazide (H₃L) and its copper(II), nickel(II), cobalt(II), manganese(II), zinc(II), cadmium(II), mercury(II), vanadyl(II), uranyl(II), iron(III), and ruthenium(III) complexes have been prepared and characterized by elemental and thermal analyses as well as spectroscopic techniques (¹H-NMR, IR, UV-Vis, ESR), magnetic, and conductivity measurements. Spectral data showed a neutral bidentate, monobasic bidentate, monobasic tridentate, and dibasic tridentate bonding to metal ions via the carbonyl oxygen in ketonic or enolic form, azomethine nitrogen, and/or deprotonated phenolic hydroxyl oxygen. ESR spectra of solid vanadyl(II) complex (2), copper(II) complexes (3–5), and (7) and manganese(II) complex (10) at room temperature show isotropic spectra, while copper(II) complex (6) shows axial symmetry with covalent character. Biological results show that the ligand is biologically inactive but the complexes exhibit mild effect on Gram positive bacteria (Bacillus subtilis), some octahedral complexes exhibit moderate effect on Gram negative bacteria (Escherichia coli), and VO(II), Cd(II), UO(II), and Hg(II) complexes show higher effect on Fungus (Aspergillus niger). When compared to previous results, metal complexes of this hydrazone have a mild effect on microorganisms due to the presence of the azo group.     

TRENDS IN THE OPTICAL ROTATORY DISPERSION SPECTRA OF R-(−)-1,2-PROPYLENEDIAMINETETRAACETATO COMPLEXES OF GROUPS IIA,IIB,IIIA,IIIB,IVB AND SOME HEAVY METALS

Abstract

A general periodic trend was observed in the optical rotatory dispersion spectra of the R-(?)-1,2-propylenediamine-tetraacetato (R(?)PDTA) complexes of Group IIA metals: magnesium(II), calcium(II), strontium(II), and barium(II); Group IIIB metals: scandium(III), yttrium(III), and lanthanum(III); Group IVB metals: titanium(IV), zirconium(IV), and thorium(IV); Group IIB metals: zinc(II), cadmium(II), and mercury(II); Group IIIA metals: aluminum(III), indium(III), and thallium(III); and the heavy metals: mercury(II), thallium(III), lead(II), and bismuth(III). The periodic trend was related to the ionic potential of the metals within each group, in that as the ionic potential increases within a group, the molecular rotations decrease from a positive to a negative value at any given wavelength outside of a region of anomalous optical rotatory dispersion. Comparing the heavy metal, mercury(II), lead(II), thallium(III), and bismuth(III), complexes of R(?)PDTA, outside of the region of anomalous rotatory dispersion, the metal with the same charge but smaller ionic potential has the greater positive molecular rotation at any given wavelength.     

Systematic Study on the Cytotoxic Potency of Commonly Used Dimeric Metal Precursors in Human Cancer Cell Lines

The cytotoxicities of seven dimeric metal species of the general formula [M(arene)Cl₂]₂, commonly used as precursors for complex synthesis and deemed biologically inactive, are investigated in seven commonly employed human cancer cell lines. Four of these complexes featured a ruthenium(II) core, where p-cymene, toluene, benzene and indane were used as arenes. Furthermore, the osmium(II) p-cymene dimer, as well as the Cp* dimers of rhodium(III) and its heavier analogue iridium(III) were included in this work (Cp*=1,2,3,4,5-pentamethylcyclopentadienide). While the cytotoxic potencies of the ruthenium(II) and osmium(II) dimers are very low (or not even detectable at applicable concentrations), surprising activity, especially in cells from ovarian malignancies (with one or two-digit micromolar IC₅₀ values), have been found for the rhodium(III) and iridium(III) representatives. This publication is aimed at all researchers using synthetic procedures based on functionalization of these dimeric starting materials to rationalize changes in biological properties, especially cytotoxicity in cancer cells.     

Synthesis and characterization of transition metal complexes of N′-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)methylene]thiophene-2-carbohydrazide

A hydrazone ligand (HL) containing the thiophene moiety has been prepared via condensation of thiophene-2-carbohydrazide with 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carbaldehyde. The complexes of copper(II), nickel(II), cobalt(II), manganese(II), zinc(II), palladium(II), iron(III), ruthenium(III), uranyl(VI), and titanium(IV) with the ligand were prepared in good yield from the reaction of the ligand with the corresponding metal salts. The ligand and complexes were characterized using infrared, mass spectra, nuclear magnetic resonance, electronic absorption spectra, electron spin resonance, and magnetic moment measurements as well as elemental and thermal analyses. The results showed that the complexes are enolic by nature, whilst the ratio between the metal ion and the ligand depends on the acidity of the metallic ions and their oxidation numbers.     

Metal ion capillary zone electrophoresis with direct UV detection: Separation of metal cyanide complexes

Mixtures of cyanide complexes of iron(III), copper(I), iron(II), nickel(II), chromium(III), mercury(II), palladium(II), silver(I), cadmium(II), zinc(II), cobalt(II), and cobalt(III) have been separated by capillary zone electrophoresis using a fused silica capillary and 20 mM phosphate buffers containing 1–2 mM sodium cyanide. The complexes were detected by direct UV absorpticn at 214 nm; detection limits are in the mid ppb range for all metals except cadmium and zinc. The different detectability of various metal cyanide complexes enables the application of the method to the analysis of complex matrices such as cyanide plating bath solutions.     

Extraction of zinc thiocyanate complex by tributyl phosphate in benzene

The species extracted is shown to be Zn(SCN)X.2TBP, where X is a common anion. Good separation factors are obtained for extraction of zinc from solutions containing silver(I), manganese(II), cobalt(II), cadmium(II), mercury(II) and thallium(III).     

Spectrophotometric determination of osmium(IV), iridium(IV) and platinum(iv) and separation and determination of palladium(II) and ruthenium(III) in the presence of other platinum metals, with oximidobenzotetronic acid as reagent

Oximidobenzotetronic acid is suggested as a reagent for the spectrophotometric determination of osmium(IV), iridium(III), iridium(IV), platinum(IV) and for separation and determination of palladium(II) and ruthenium(III) in the presence of other platinum metals. Iridium(III) and (IV) can be estimated when present together.     

Derivatographische untersuchungen über die thermische zersetzung von pyridin,isochinolin, αα-dipyridyl und o-phenantrolin,bzw. bichromatoder chromat-ion enthaltenden metallkomplexen: II. Zink(II)-, cadmium(II)- und mangan(II)-komplexe III. Quecksilber(I und II)-, uranyl-, thorium-, lanthan- und eisen-komplexe

Complexes were prepared of zinc(II), cadmium(II), manganese(II) mercury (I and II), uranium, thorium(IV), lanthanum and iron ions with pyridine, isoquinoline, αα-dipyridyl, or o-phenanthroline ligands and bichromate or chromate ions as described on pp. 205–207 of Ref. 1.     

Study on the Interactions of Ruthenium(III), Rhodium(III) and Palladium(II) Ions with DNA

Fluorescence, absorption and circular dichroism spectra have been used in the interactions of ruthenium(III), rhodium(III) and palladium(II) ions with DNA with berberine as a probe (berberine, Scheme 1). The results are as follows: ruthenium(III) and rhodium(III) ions show different effects from that of the palladium(II) ion on the fluorescence spectra characteristics of berberine-DNA system. Quenching fluorescence is seen with palladium(II) ion addition, whereas increasing fluorescence is observed for ruthenium(III) and rhodium(III) ions. The addition of ruthenium(III), rhodium(III) and palladium(II) ions causes the increasing absorption of the DNA solution. The addition of ruthenium(III), rhodium(III) and palladium(II) ions to the DNA solution also causes the circular dichroism spectra to change. The above results suggest that different metal ions exhibit different affinity when binding to DNA, which could correlate well with the ions’ charge, structure and the ability to coordinate. There is a comparison between Pt(IV) and Pd(II) ions on the fluorescence of the berberine-DNA system.     

Synthesis and characterization of a hydrazone ligand containing antipyrine and its transition metal complexes

The coordination chemistry of N′-((1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)methylene)-2-hydroxybenzohydrazide with copper(II), nickel(II), cobalt(II), manganese(II), zinc(II), palladium(II), iron(III), ruthenium(III), uranyl(VI), and titanium(IV) has been studied. The ligand and its complexes was characterized by elemental and thermal analyses, magnetic moments and conductivity measurements as well as spectroscopic techniques such as infrared, mass spectra, nuclear magnetic resonance, electron spin resonance and electronic absorption spectra. The spectral data showed that the ligand is monobasic tridentate coordinated via the enolic carbonyl oxygen of the hydrazide moiety, azomethine nitrogen and pyrazolone oxygen atoms.     

Some uses of transition metal complexes as anti-cancer and anti-HIV agents

The success of the clinical uses of cisplatin, cis-[Pt(II)(NH(3))(2)Cl(2)], has stimulated considerable interest in using other metal complexes as new therapeutic agents. This perspective describes our recent work on several classes of gold(III), platinum(II), ruthenium(II, III, IV), iron(II) and vanadium(IV) complexes for anti-cancer and anti-HIV treatments.     

Catalytic method for determination of micro amounts of gold in iron ores

Summary Gold in iron ores has been determined by means of its catalytic action on the oxidation of mercury(I) by cerium(IV). The calibration curve is linear over the range 3–30 ng/ml. Only iridium(IV), platinum(IV), palladium(II), ruthenium(III) and gallium(III) interfere seriously, though some interference is experienced from lead(II), iron(III), osmium(VIII) and indium(III).

---

Zusammenfassung Gold wurde in Eisenerzen auf Grund seiner katalytischen Wirkung auf die Oxydation von Quecksilber(II) durch Cer(IV) bestimmt. Die Eichkurve verläuft von 2 bis 30 ng/ml linear. Nur Iridium(IV), Platin(IV), Palladium(II), Ruthenium(III) und Gallium(III) stören ernstlich, während eine geringfügige Störung auch durch Blei(II), Eisen(III), Osmium(VIII) und Indium(III) beobachtet wurde.

     

Synthesis, molecular modeling, thermal and spectral studies of metal complexes of hydrazone derived from 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)-dione and thiosemicarbazide

Metal complexes with the general formula [ML(H2O)(CH3OH)x]·nH2O·(CH3OH)y(NO3)z [M=Cu(II), Ni(II), Co(II), VO(IV), Cr(III), Cd(II), Zn(II) or UO2(VI); x=0-2; y=0,1; z=0,1; n=0-2, 6 and L=hydrazone (H2L) derived from condensation of thiosemicarbazide with 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)-dione. The synthesized ligand and its metal complexes have been characterized on the basis of elemental analyses, spectral and magnetic studies as well as thermal gravimetric analysis (TGA). The deprotonated ligand acts as a dibasic tridentate (ONS) via phenolate oxygen, azomethine (CN), and thiolate (C-S) groups. Copper(II) complex exhibits square planar geometry. Nickel(II), chromium(III) and dioxouranium(VI) complexes exhibit octahedral geometry. Cobalt(II), cadmium(II) and zinc(II) complexes showed tetrahedral geometry, whereas oxovanadium(IV) reveals square pyramidal geometry. Thermal analysis are investigated and showed either three or four thermal decomposition steps. Kinetic parameters (Ea, A, ΔH, ΔS and ΔG) of the thermal decomposition stages have been evaluated using Coats-Redfern equations. The molecular parameters of the ligand and its metal complexes have been calculated and correlated with the experimental data such as IR and TGA results.