Behavior of nitrite forms of nitrosylruthenium on extraction and back extraction of heterometalic Ru/Zn complexes with trioctylphosphine oxide

The state of ruthenium in conjugated phases upon extraction of trans-[Ru(¹⁵NO)(¹⁵NO₂)₄(OH)]^2? complex with tri-n-octylphosphine oxide (TOPO) in the presence of Zn²⁺ and subsequent back extraction with H¹⁵NO₃ and NH₃(concd.) solutions was studied by ¹⁵N NMR. Binuclear complexes [Ru(NO)(NO₂)_5?n (μ-NO₂) _n?1(μ-OH)Zn(TOPO) _n ] and [Ru(NO)(NO₂)_4?n (ONO)(μ-NO₂) _n?1(μ-OH)Zn(TOPO) _n ], where n = 2, 3, are predominant forms in extract. Kinetic restrictions for ruthenium extraction with TOPO solution in hexane and its back extraction with aqueous solutions of nitric acid and ammonia are eliminated in the absence of direct coordination of extractant to ruthenium. fac-Dinitronitrosyl forms [Ru(NO)(H₂O)₃(NO₂)₂]⁺, [Ru(NO)(H₂O)₂(NO₂)₂(NO₃)]⁰ (3 and 6 M HNO₃) and [Ru(NO)(H₂O)(NO₂)₂(NO₃)₂]^? (6 M HNO₃) prevail in nitric acid back extracts. Equilibrium constant at ambient temperature (0.05 ± 0.01) was assessed for the coordination of second nitrate ion to nitrosylruthenium dinitronitrato complex. Complex species [Ru(NO)(NO₂)₄(OH)]^2? and [Ru(NO)(NO₂)₃(ONO)(OH)]^2? prevail in ammonia back extract.     

Electronic structures of heterometallic complexes [Ru(NO)(NO2)4(OH)ZnL n ] according to the data of quantum-chemical calculations and photoelectron spectroscopy

A new complex [Ru(NO)(NO₂)₄(OH)Zn(PyO)₂(H₂O)](PyO is pyridine-N-oxide) is synthesized and structurally characterized. The new complex has the face coordination of the [Ru(NO)(NO₂)₄(OH)]^2? anion to the Zn²⁺ cation similar to that in the earlier obtained complexes with other organic ligands. The methods of quantum chemistry and photoelectron spectroscopy show that the electronic structures of the [Ru(NO)(NO₂)₄(OH)ZnL _n ] heterometallic complexes depend weakly on the nature of the ligands (L = Ph₃PO, C₅H₅N, and C₅H₅N-O) coordinated to Zn²⁺ and are primarily determined by the electron density redistribution from the terminal nitro and nitroso groups of the ruthenium fragment to the zinc atom. The maximum change in the charge related to the nitroso group correlates with the strongest change in the energy of the occupied molecular orbital (HOMO-2 of the anion) oriented along the NO-Ru-OH coordinate.     

Heterometallic complexes of Co2+, Ni2+, and Zn2+ with the [RuNO(NO2)4OH]2? anion and pyridine: Synthesis, crystal structure, and thermolysis

Three new heteronuclear complexes [Ru(NO)(NO₂)₄(OH)M(Py)₃] (M = Co²⁺, Ni²⁺, Zn²⁺) were synthesized and structurally characterized. In all compounds, the [Ru(NO)(NO²)⁴(OH)] fragment is coordinated to the M atom by a bridging OH and two bridging NO₂ groups. The coordination environment of the metal also includes three pyridine nitrogen atoms. Thermal decomposition of cobalt and nickel complexes in an inert atmosphere yields bimetallic solid solutions. Original Russian Text ? G.A. Kostin, A.O. Borodin, Yu.V. Shubin, N.V. Kurat’eva, V.A. Emelyanov, P.E. Plyusnin, M.R. Gallyamov, 2009, published in Koordinatsionnaya Khimiya, 2009, Vol. 35, No. 1, pp. 57–64.     

Regulation of electron donating ability to metal center: isolation and characterization of ruthenium carbonyl complexes with N,N- and/or N,O-donor polypyridyl ligands

Polypyridyl ruthenium(II) dicarbonyl complexes with an N,O- and/or N,N-donor ligand, [Ru(pic)(CO)₂Cl₂]⁻ (1), [Ru(bpy)(pic)(CO)₂]⁺ (2), [Ru(pic)₂(CO)₂] (3), and [Ru(bpy)₂(CO)₂]²⁺ (4) (pic=2-pyridylcarboxylato, bpy=2,2′-bipyridine) were prepared for comparison of the electron donor ability of these ligands to the ruthenium center. A carbonyl group of [Ru(L1)(L2)(CO)₂]ⁿ (L1, L2=bpy, pic) successively reacted with one and two equivalents of OH⁻ to form [Ru(L1)(L2)(CO)(C(O)OH)]ⁿ⁻¹ and [Ru(L1)(L2)(CO)(CO₂)]ⁿ⁻². These three complexes exist as equilbrium mixtures in aqueous solutions and the equilibrium constants were determined potentiometrically. Electrochemical reduction of 2 in CO₂-saturated CH₃CN–H₂O at −1.5 V selectively produced CO.     

Synthesis, structures, and thermolysis of new heterometallic cobalt, nickel, and copper complexes with the [Ru(NO)(NO2)4(OH)]2− anion as a ligand

Heterometallic complexes with pyridine-N-oxide (PyO), Ru(NO)(NO₂)₄(OH)Ni(PyO)₂(H₂O)] · CH₃COCH₃ (I), [{Ru(NO)(NO₂)₂(μ-NO₂)₂(μ-OH)Co}₂(μ-PyO)] · H₂O · CH₃COCH (II), and [Ru(NO)(NO₂)₄(OH)Cu(PyO)₂ (III), are isolated in the reactions of Na₂[Ru(NO)(NO₂)₄(OH)] with nitrates of the corresponding metals in the presence of the organic ligand. The compounds synthesized are characterized by IR spectra, thermal analysis, and X-ray diffraction analysis. Depending on the M²⁺ cation, the ruthenium cation is coordinated through the bidentate (III, Cu²⁺) or tridentate (I, Ni²⁺ and II, CO₂₊) mode involving the bridging OH group and one or two NO₂ groups. The thermal decomposition of complex II results in the formation of a Co_0.5Ru_0.5 solid solution, which is thermodynamically stable under the decomposition conditions. The thermolysis of complexes I and III in a hydrogen atmosphere leads to the formation of metastable solid solutions.     

New method for the synthesis of trans-hydroxotetraamminenitrosoruthenium(II) dichloride and its characterization

A procedure for the synthesis of mpa h c-[Ru(NO)(NH₃)₄(OH)]Cl₂ in a nearly quantitative yield (～95%) comprising treatment of a solution of (NH₄)₂[Ru(NO)Cl₅] with ammonium carbonate at t ～80°C was developed. It was found that [Ru(NO)(NH₃)₄(H₂O)]Cl₃·H₂O and trans-[Ru(NO)(NH₃)₄Cl]Cl₂ formed in the reaction of [Ru(NO)(NH₃)₄(OH)]Cl₂ with hydrochloric acid at various temperatures most often contain some initial hydroxy complex. The former compound is unstable, even at room temperature, it slowly eliminates water and HCl. A procedure for preparing the latter compound in a pure state in 85–90% yield was proposed. The acidity constant of the complex trans-[Ru(NO)(NH₃)₄(H₂O)]³⁺ at room temperature (K _a = (4 ± 1) × 10^?2) was estimated by ¹⁴N NMR spectroscopy.     

Modeling the solvation shell of complexes in solution for quantum chemical calculations of electronic spectra

A procedure that allows for solvation effects is suggested; it is designed for quantum chemical calculations of the electronic spectra of complex compounds. Based on Monte Carlo (MC) simulation of the solvation shell one can calculate the electrostatic potential created by the solvation shell at the sites of all atoms of the complex; appropriate corrections are added to the diagonal elements of the Fock matrix and to the matrix elements of the Hamiltonian in the configuration interaction method. The method suggested has been implemented based on the semiempirical (CINDO) version of the CI (configuration interaction) technique and tested on the following compounds: [Ru(NH₃)₅(py)]²⁺, [Ru(NH₃)₅(pyz)]²⁺, [Ru(bpy)(CN)₄]^2?, [Ru(NO)(py)₄-NC-Ru(py)₄(CN)]³⁺.     

Synthesis and crystal structure of nitrosoruthenium aquadiammine complex, [Ru(NO)(NH3)2Cl2(H2O)]Cl·H2O

The reaction between [RuNO(NH₃)₂(NO₂)₂OH] and an excess of 3 M HCl leads to denitration of the starting complex and precipitation of [Ru(NO)(NH₃)₂Cl₃]. Crystals of the tittle complex have been obtained by evaporation of the mother liquor at ambient temperature. The crystal structure of the product has been determined. The linear nitroso group and a water molecule are coordinated in the trans positions, three nitrogen atoms from NO and NH₃ ligands occupy the coordination octahedron face.     

Nitrosoruthenium hydroxo and aqua complexes of the trans-dipyridine series: Synthesis,structures, and characterization

A procedure for the synthesis of trans-Ru(NO)(Py)₂Cl₂(OH) (I) from K₂[Ru(NO)Cl₅] was proposed. Treatment of hydroxo complex I with HCl or H₂SO₄ at room temperature gave the corresponding salts trans-[Ru(NO)(Py)₂Cl₂(H₂O)]Cl · 2H₂O (II) and trans-[Ru(NO)(Py)₂Cl₂(H₂O)]HSO₄ (III). All the complexes obtained were characterized by ¹H and ¹³C NMR and IR spectroscopy and elemental analysis; their structures were determined by X-ray diffraction. The structures are stabilized by π-stacking between the pyridine ligands of adjacent complex species.     

Electronic structure and spectra of binuclear bridged nitrosyl ruthenium complexes

The B3LYP method in the LanL2DZ basis set was used to carry out geometry optimization for the binuclear bridged complexes [RuCl₄(NO)(μ-Pyz)Ru(P)(CO)]^?, [Ru(Bipy)₂(NO)(μ-Pyz)Ru(NH₃)₅]⁵⁺, and [(NC)Ru(Py)₄(μ-CN)Ru(Py)₄NO]³⁺ (Pyz is pyrazine). The electronic spectra of the complexes were calculated by the TDDFT and CINDO-CI methods with allowance for solvation effects. The ground-state electronic configurations of the two ruthenium atoms in these compounds were shown to be different. Among the lower excited states of all complexes, states with essentially weakened Ru-NO bonds were found. The strong absorption in the visible region of the spectrum of [Ru(Py)₄NO-CN-Ru(Py)₄CN]³⁺ is due to the interfragment electron transfer Ru^II → {RuNO} accompanied by weakening of the bond between nitrogen oxide and the complex.     

Nitric oxide and singlet oxygen photo-generation by light irradiation in the phototherapeutic window of a nitrosyl ruthenium conjugated with a phthalocyanine rare earth complex

The photochemical, photophysical and photobiological studies of a mixture containing cis-[Ru(H-dcbpy⁻)₂(Cl)(NO)] (H₂-dcbpy = 4,4′-dicarboxy-2,2′-bipyridine) and Na₄[Tb(TsPc)(acac)] (TsPc = tetrasulfonated phthalocyanines; acac = acetylacetone), a system capable of improving photodynamic therapy (PDT), were accomplished. cis-[Ru(H-dcbpy⁻)₂(Cl)(NO)] was obtained from cis-[Ru(H₂-dcbpy)₂Cl₂]·2H₂O, whereas Na₄[Tb(TsPc)(acac)] was obtained by reacting phthalocyanine with terbium acetylacetonate. The UV–Vis spectrum of cis-[Ru(H-dcbpy⁻)₂(Cl)(NO)] displays a band in the region of 305 nm (λ_max in 0.1 mol L⁻¹ HCl)(π–π*) and a shoulder at 323 nm (MLCT), while the UV–Vis spectrum of Na₄[Tb(TsPc)(acac)] presents the typical phthalocyanine bands at 342 nm (Soret λ_max in H₂O) and 642, 682 (Q bands). The cis-[Ru(H-dcbpy⁻)₂(Cl)(NO)] FTIR spectrum displays a band at 1932 cm⁻¹ (Ru–NO⁺). The cyclic voltammogram of the cis-[Ru(H-dcbpy⁻)₂(Cl)(NO)] complex in aqueous solution presented peaks at E = 0.10 V (NO^+/0) and E = −0.50 V (NO^0/−) versus Ag/AgCl. The NO concentration and ¹O₂ quantum yield for light irradiation in the λ > 550 nm region were measured as [NO] = 1.21 ± 0.14 μmol L⁻¹ and ø_OS = 0.41, respectively. The amount of released NO seems to be dependent on oxygen concentration, once the NO concentration measured in aerated condition was 1.51 ± 0.11 μmol L⁻¹ The photochemical pathway of the cis-[Ru(H-dcbpy⁻)₂(Cl)(NO)]/Na₄[Tb(TsPc)(acac)] mixture could be attributed to a photoinduced electron transfer process. The cytotoxic assays of cis-[Ru(H-dcbpy^-)₂(Cl)(NO)] and of the mixture carried out with B16F10 cells show a decrease in cell viability to 80% in the dark and to 20% under light irradiation. Our results document that the simultaneous production of NO and ¹O₂ could improve PDT and be useful in cancer treatment.     

Synthesis and crystal structure of mixed-cation salt of trans-hydroxotetranitronitrosoruthenium(II) complex, KNa[Ru(NO)(NO2)4(OH)]·H2O

The mixed-cation complex salt KNa[Ru(NO)(NO₂)₄(OH)]·H₂O has been synthesized and studied with methods of IR-spectroscopy, X-ray phase and X-ray structural analysis. The crystallographic data for H₃KN₅NaO₁₁Ru are: a = 7.389(1) Å, b = 14.196(2) Å, c = 21.507(5) Å; V = 2256.0(7) ų, Z = 8, d _calc = 2.427 g/cm³, space group is P2₁2₁2₁. The structure is chiral and its absolute structural parameter equals 0.04. General motif of the arrangement of complex anions was determined by the translation sublattice method. Geometric characteristics for coordinate NO₂-groups in structurally characterized nitro complexes of ruthenium(II) have been analyzed.     

Metal‐catalyzed reversible conversion between chemical and electrical energy designed towards a sustainable society

Proton dissociation of an aqua‐Ru‐quinone complex, [Ru(trpy)(q)(OH₂)]²⁺ (trpy = 2,2′ : 6′,2″‐terpyridine, q = 3,5‐di‐t‐butylquinone) proceeded in two steps (pK_a = 5.5 and ca. 10.5). The first step simply produced [Ru(trpy)(q)(OH)]⁺, while the second one gave an unusual oxyl radical complex, [Ru(trpy)(sq)(O^?.)]⁰ (sq = 3,5‐di‐t‐butylsemiquinone), owing to an intramolecular electron transfer from the resultant O^2? to q. A dinuclear Ru complex bridged by an anthracene framework, [Ru₂(btpyan)(q)₂(OH)₂]²⁺ (btpyan = 1,8‐bis(2,2′‐terpyridyl)anthracene), was prepared to place two Ru(trpy)(q)(OH) groups at a close distance. Deprotonation of the two hydroxy protons of [Ru₂(btpyan)(q)₂(OH)₂]²⁺ generated two oxyl radical Ru‐O^?. groups, which worked as a precursor for O₂ evolution in the oxidation of water. The [Ru₂(btpyan)(q)₂(OH)₂](SbF₆)₂ modified ITO electrode effectively catalyzed four‐electron oxidation of water to evolve O₂ (TON = 33500) under electrolysis at +1.70 V in H₂O (pH 4.0). Various physical measurements and DFT calculations indicated that a radical coupling between two Ru(sq)(O^?.) groups forms a (cat)Ru‐O‐O‐Ru(sq) (cat = 3,5‐di‐t‐butylcathechol) framework with a μ‐superoxo bond. Successive removal of four electrons from the cat, sq, and superoxo groups of [Ru₂(btpyan)(cat)(sq)(μ‐O₂^?)]⁰ assisted with an attack of two water (or OH^?) to Ru centers, which causes smooth O₂ evolution with regeneration of [Ru₂(btpyan)(q)₂(OH)₂]²⁺. Deprotonation of an Ru‐quinone‐ammonia complex also gave the corresponding Ru‐semiquinone‐aminyl radical. The oxidized form of the latter showed a high catalytic activity towards the oxidation of methanol in the presence of base. Three complexes, [Ru(bpy)₂(CO)₂]²⁺, [Ru(bpy)₂(CO)(C(O)OH)]⁺, and [Ru(bpy)₂(CO)(CO₂)]⁰ exist as an equilibrium mixture in water. Treatment of [Ru(bpy)₂(CO)₂]²⁺ with BH₄^? gave [Ru(bpy)₂(CO)(C(O)H)]⁺, [Ru(bpy)₂(CO)(CH₂OH)]⁺, and [Ru(bpy)₂(CO)(OH₂)]²⁺ with generation of CH₃OH in aqueous conditions. Based on these results, a reasonable catalytic pathway from CO₂ to CH₃OH in electro‐ and photochemical CO₂ reduction is proposed. A new pbn (pbn = 2‐pyridylbenzo[b]‐1,5‐naphthyridine) ligand was designed as a renewable hydride donor for the six‐electron reduction of CO₂. A series of [Ru(bpy)_3‐n(pbn)_n]²⁺ (n = 1, 2, 3) complexes undergoes photochemical two‐ (n = 1), four‐ (n = 2), and six‐electron reductions (n = 3) under irradiation of visible light in the presence of N(CH₂CH₂OH)₃. © 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 169–186; 2009: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.200800039     

Dinitramidoborates: A Fascinating Case of Competing Oxygen and Nitrogen Donors and Tautomerism

Reactions of the BH₄⁻ anion with equimolar amounts of HN(NO₂)₂ or of BH₃⋅THF with K[N(NO₂)₂]⁻ produced a mono‐substituted [BH₃N(NO₂)₂]⁻ anion, which contains a B−N connected dinitramido ligand. The reaction of BH₄⁻ with two equivalents of HN(NO₂)₂ afforded the di‐substituted borate anion consisting of two isomers, one with both nitramido ligands attached to B through N and the other one with one ligand attached through N and the other one through O. The disubstituted dinitramidoborates are marginally stable under ambient conditions, and the isomer with two N‐connected ligands was characterized by its crystal structure. A tri‐substituted borate was tentatively identified by NMR in the reaction of BH₄⁻ with a large excess of HN(NO₂)₂. All of the anions are highly energetic. Theoretical calculations show that the energy differences between the B−N and B−O tautomers are small, explaining the formation of both.     

Preparation and Structural Characterization of [CpRu(1,10-phenanthroline)(CH3CN)][X] and Precursor Complexes (X=PF6, BArF,TRISPHAT-N)

Cationic [Ru(η⁵-C₅H₅)(CH₃CN)₃]⁺ complex, tris(acetonitrile)(cyclopentadienyl)ruthenium(II), gives rise to a very rich organometallic chemistry. Combined with diimine ligands, and 1,10-phenanthroline in particular, this system efficiently catalyzes diazo decomposition processes to generate metal-carbenes which undergo a series of original transformations in the presence of Lewis basic substrates. Herein, syntheses and characterizations of [CpRu(Phen)(L)] complexes with (large) lipophilic non-coordinating (PF₆⁻ and BAr_F⁻) and coordinating TRISPHAT-N⁻ anions are reported. Complex [CpRu(η⁶-naphthalene)][BAr_F] ( [1][BAr_F] ) is readily accessible, in high yield, by direct counterion exchange between [1][PF₆] and sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (NaBAr_F) salts. Ligand exchange of [1][BAr_F] in acetonitrile generated stable [Ru(η⁵-C₅H₅)(CH₃CN)₃][BAr_F] ( [2][BAr_F] ) complex in high yield. Then, the desired [CpRu(Phen)(CH₃CN)] ( [3] ) complexes were obtained from either the [1] or [2] complex in the presence of the 1,10-phenanthroline as ligand. For characterization and comparison purposes, the anionic hemilabile ligand TRISPHAT−N (TTN) was introduced on the ruthenium center, from the complex [3][PF₆] , to quantitatively generate the desired complex [CpRu(Phen)(TTN)] ( [4] ) by displacement of the remaining acetonitrile ligand and of the PF₆⁻ anion. Solid state structures of complexes [1][BAr_F] , [2][BAr_F] , [3][BAr_F] , [3][PF₆] and [4] were determined by X-ray diffraction studies and are discussed herein.     

Triangle Cl−Ag1−Cl Sites for Superior Photocatalytic Molecular Oxygen Activation and NO Oxidation of BiOCl

BiOCl photocatalysis shows great promise for molecular oxygen activation and NO oxidation, but its selective transformation of NO to immobilized nitrate without toxic NO₂ emission is still a great challenge, because of uncontrollable reaction intermediates and pathways. In this study, we demonstrate that the introduction of triangle Cl−Ag₁−Cl sites on a Cl-terminated, (001) facet-exposed BiOCl can selectively promote one-electron activation of reactant molecular oxygen to intermediate superoxide radicals (⋅O₂⁻), and also shift the adsorption configuration of product NO₃⁻ from the weak monodentate binding mode to a strong bidentate mode to avoid unfavorable photolysis. By simultaneously tuning intermediates and products, the Cl−Ag₁−Cl-landen BiOCl achieved >90 % NO conversion to favorable NO₃⁻ of high selectivity (>97 %) in 10 min under visible light, with the undesired NO₂ concentration below 20 ppb. Both the activity and the selectivity of Cl−Ag₁−Cl sites surpass those of BiOCl surface sites (38 % NO conversion, 67 % NO₃⁻ selectivity) or control O−Ag₁−O sites on a benchmark photocatalyst P25 (67 % NO conversion and 87 % NO₃⁻ selectivity). This study develops new single-atom sites for the performance enhancement of semiconductor photocatalysts, and also provides a facile pathway to manipulate the reactive oxygen species production for efficient pollutant removal.     

The kinetics and thermodynamics of a novel efficient mixed water–1,4-dioxan solvent for the effective complexation of a neutral ruthenium complex with carbon monoxide at atmospheric pressure

Kinetic and thermodynamic investigations were performed for a mixed aqueous-organic, 1:1 (v/v) water–1,4-dioxane medium, which was found to be an efficient solvent for the interaction of a neutral dichlorotris(triphenylphosphine) ruthenium(II), RuCl₂(PPh₃)₃ complex with carbon monoxide at atmospheric pressure. During the interaction, RuCl₂(PPh₃)₃ dissociates to a neutral complex dichlorobis(triphenylphosphine) ruthenium(II), RuCl₂(PPh₃)₂, by losing a coordinated PPh₃ ligand and RuCl₂(PPh₃)₂ coordinates with CO to form an in situ carbonyl complex RuCl₂(CO)(PPh₃)₂. The in situ formed carbonyl complex RuCl₂(CO)(PPh₃)₂ was thoroughly characterized by equilibrium, spectrophotometric, IR, and electrochemical techniques. Under equilibrium conditions, the rate and dissociation constants for the dissociation of PPh₃ from RuCl₂(PPh₃)₃ were found to be favorable for the formation of the carbonyl complex RuCl₂(CO)(PPh₃)₂. The rates of complexation for the formation of RuCl₂(CO)(PPh₃)₂ were found to follow an overall second-order kinetics being first order in terms of the concentrations of both carbon monoxide and RuCl₂(PPh₃)₂. The determined activation parameters corresponding to the rate constant (ΔH^# = 35.9 ± 2.5 kJ mol⁻¹ and ΔS^# = −122 ± 6 J K⁻¹ mol⁻¹) and thermodynamic parameters corresponding to the formation constant (ΔH° = −33.5 ± 4.5 kJ mol⁻¹, ΔS° = −25 ± 8 J K⁻¹ mol⁻¹, and ΔG° = −25.7 ± 2.0 kJ mol⁻¹) were found to be highly favorable for the formation of the complex RuCl2(CO)(PPh3)2. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 359–369, 2008     

Extraction of heterometallic complexes of ruthenium and nonprecious metals by phosphorylmethylated calix[4]arenes from nitrate solutions

Synergetic extraction of [RuNO(NO₂)₄OH]^2? by calix[4]arene phosphine oxides (L) in the form of Ru/M heterometallic complexes was studied in the presence of nonprecious metals (M²⁺). The main extraction laws were recognized for [M(NO₃)₂L _n ] and [RuNO(NO₂)₄OH])ML _m ], where M²⁺ = Zn²⁺, Cu²⁺, Co²⁺, or Ni²⁺ and n, m = 1 or 2; extraction constants were determined for these metals. The variation row of the extraction constants with varying metal (Zn²⁺ > Cu²⁺ > Co²⁺ > Ni²⁺) coincides with the Irving-Williams row. Two or three PO groups of extractant L and the OH and NO₂ groups of the ruthenium anion are coordinated to the M²⁺ atom in Ru/M complexes. The conditions for generation of the Ru/Zn complex and its complete extraction were optimized as applied to the extraction of fission ruthenium from nitrated nitric acid and imitation solutions.     

Spectroscopic and kinetic study of the reaction of trans-nitrosylchlorobis(dimethylglyoximate)ruthenium(II) with acetone in the presence of amines

Summary The complex trans-[Ru(NO)(dmgH)₂Cl] (dmgH = dimethylglyoximate ion) reacts with Me₂CO in the presence of NH₃ or substituted amines such as MeNH₂ and 4-NH₂CH₂py (py = pyridine), to yield intermediate addition compounds of the general formula trans-[Ru(dmgH)₂Cl{N(OH)CHC(NHR)Me}]^-. The kinetic, analytical and spectroscopic (electronic, resonance Raman and i.r.) results are consistent with nucleophilic attack by enamines, e.g. CH₂=C(NHR)Me, on the coordinated NO⁺ ligand.     

Versatility of copper(II) coordination compounds with 2,3-bis(2-pyridyl)pyrazine mediated by temperature,solvents and anions choice

Tuning reaction temperatures as well as the variation in starting copper salts and solvents led to the formation of a new series of Cu(II) coordination compounds with 2,3-bis(2-pyridyl)pyrazine (dpp): a mononuclear [Cu(acac)(dpp)(NO₃)] (1) complex, two dinuclear [Cu₂(acac)₂(dpp)(NO₃)(H₂O)]NO₃ (2) and [Cu₂(Hdpp)₂(ox)(Cl)₂(H₂O)₂]Cl₂·6(H₂O) (4) complexes, and four coordination polymers {[Cu₄(dpp)₂(ox)(Cl)₆]}_n (3), {[Cu₄(dpp)₂(ox)(NO₃)₆(H₂O)₂]∙1.2(H₂O)}_n (5), {[Cu(dpp)(NO₃)](NO₃)·(H₂O)}_n (6) and {[Cu(dpp)(SO₄)(H₂O)₂]}_n (7), where acac⁻ = acetylacetonate, ox²⁻ = oxalate. Remarkably, the treatment of Cu(II) chloride dihydrate with dpp in methanol solution led to an unusual in situ condensation of dpp with acac⁻ to produce [Cu₂(acdpp)₂(Cl)₄]·2(MeOH) (8). The structure of 1 consists of neutral, mononuclear [Cu(acac)(dpp)(NO₃)] units with acac⁻ and dpp acting as bidentate ligands. In 2, the dpp ligand coordinates in a bis-chelating mode to two Cu(II) ions and bridges them into a dimeric entity, whereas an oxalate linker joins [Cu(Hdpp)(Cl)₂(H₂O)]⁺ units into a dimer in 4. Compounds 3, 5, 6 and 7 are 1D chain coordination polymers, which incorporate two symmetry independent metal centers and different bridging ligands: Hdpp⁺ as a protonated cationic or dpp as a neutral chelating ligand and oxalate, Cl⁻ anions or sulfate di-anions as bridging ligands. Magnetic studies were performed on samples 1 and 2, and the analysis reveals a very weak magnetic exchange coupling mediated via the dpp ligand.