A TRICHLORO-BRIDGED DIRUTHENIUM (II,III) COMPLEX: PREPARATION,PROPERTIES AND X-RAY STRUCTURE OF TRI(-μ-CHLORO) DICHLOROCARBONYLTRIS (TRIPHENYLPHOSPHINE)DIRUTHENIUM(II,III)

Abstract

The triply chloro-bridged binuclear complex [Ru₂Cl₅(CO)(PPh₃)₃]·CH₂Cl₂, (PPh₃ = triphenylphosphine), M_r = 1279.23, prepared from the precursor compound [RuCl₃(PPh₃)₂DMA]·DMA (DMA = N,N′-dimethylacetamide) and crystallizes in the monoclinic space group P2₁/c. The structure was solved from 6994 independent reflections for which I > 3σ(I) by Patterson and difference Fourier techniques and refined to a final R = 0.042. The complex is formed by two Ru atoms bridged through three chloride anions. One Ru atom is further coordinated to two non-bridging Cl atoms and a triphenylphosphine ligand, whereas the other is bonded to two PPh₃ ligands and a carbon monoxide molecule. The presence of Ru^III was confirmed by EPR data. The absence of an intervalence charge-transfer transition (IT) in the near-infrared spectrum suggests that the binuclear complex is of a localized valence type. The IR spectrum shows a ν_CO band at 1964cm^? and ν_Ru-Cl bands at 328, 280 cm^?1, corresponding to chlorides at terminal positions and 250, 225 cm^?1 for the bridged ones. Two redox processes, Ru^II/Ru^II (E_1/2 = -0.29 V) ← Ru^II/Ru^III ← (E_1/2 = 1.19 V) Ru^III/Ru^III, were observed by cyclic voltammetry.     

Die Bestimmung von Uran(VI) neben Uran(IV), Eisen(II, III), Vanadium (III, IV, V), Molybd?n (IV, VI) und Kupfer (II)

Ohne Zusammenfassung     

Ion-Exchange Processes M(II) → Fe(III) and Fe(III) → M(II) in Metal Hexacyanoferrate(II) Gelatin-Immobilized Matrices (M = Mn,Co, Ni,Cu, Zn,Cd)

Ion-exchange reactions M²⁺ Fe³⁺ and Fe³⁺ M²⁺ (M = Mn, Co, Ni, Cu, Zn, Cd) were studied in metal(II) hexacyanoferrate(II) gelatin-immobilized matrices M₂[Fe(CN)₆] in contact with aqueous FeCl₃ solutions and Fe₄[Fe(CN)₆]₃ in contact with aqueous MCl₂ solutions. It was shown that in both cases, M²⁺ was replaced by Fe³⁺ and Fe³⁺ was replaced by M²⁺ to some extent, but no complete replacement was observed in the M₂[Fe(CN)₆]–FeCl₃ or Fe₄[Fe(CN)₆]₃–MCl₂ systems under study. No electrophilic substitution Fe³⁺ Mn²⁺ was found to occur in any noticeable degree during the contact of Fe₄[Fe(CN)₆]₃ with aqueous MnCl₂ solutions even when this contact occurred for 1 h and longer.     

FERROMAGNETICALLY COUPLED Gd(III)Cu(II)Gd(III)TRINUCLEAR COMPLEXES

ＦＥＲＲＯＭＡＧＮＥＴＩＣＡＬＬＹ ＣＯＵＰＬＥＤ Ｇｄ（ＩＩＩ）Ｃｕ（ＩＩ）Ｇｄ（ＩＩＩ） ＴＲＩＮＵＣＬＥＡＲ ＣＯＭＰＬＥＸＥＳ￥ＭｉｎｇＭｉｎｇＭＩＡＯ；ＤａｉＺｈｅｎｇＬＩＡＯ；ＺｏｎｅＨｕｉＪＩＡＮＧ；ａｎｄＧｅｎｇＬｉｎＷＡＮＧ（Ｄｅｐ...     

Methoden zur ma?analytischen Bestimmung von Hexacyanoferrat(II), Hexacyanoferrat(III) und Hexacyanocobaltat(III)

Ohne Zusammenfassung     

Zur polarographischen Bestimmung Ton 2-?thylanthrachinon(I), Tetrahydro-2-?tbylanthrachinon (II)und Octahydro-2-?thylanthrachinon(III)

Ohne Zusammenfassung     

Complexes of N-phenyl-N′-2-furanthiocarbohydrazide with oxovanadium(IV), manganese(III), iron(III), cobalt(II), nickel(II), copper(II) and zinc(II)

A new ligand, N-phenyl-N -2-furanthiocarbohydrazide (HPhfth), and its complexes with VO^IV, Mn^III, Fe^III, Co^II, Ni^II, Cu^II and Zn^II have been prepared and characterized by elemental analyses, magnetic susceptibility measurements, i.r., n.m.r., u.v.–vis., mass and FAB mass spectral data. The room temperature e.s.r. spectra of the VO^IV, Fe^III and Cu^II complexes yield <g> values characteristic of square pyramidal VO^IV, octahedral Fe^III and square planar Cu^II, respectively. The Ni^II and Cu^II complexes semiconduct, but the Zn^II complex is an insulator at room temperature. However, the conductivity increases as the temperature increases from 303–383 K, with a band gap of 0.21–1.01 eV. HPhfth and its soluble complexes have been screened against several bacteria and fungi.     

Solvatochromism and piezochromism of pentacyanoferrates(II) and of mixed valence iron(II)—iron(III) and ruthenium(II)—ruthenium(III) species

Pressure effects on the MLCT bands of the pyrazine- and 4-cyanopyridine-pentacyanoferrate(II) anions have been established. The relation of these piezochromic effects to the solvatochromism of each complex is put into the correlation between these parameters developed for other d⁶ ternary complexes. The conformance of piezochromic and solvatochromic efrects on MMCT bands for diiron and diruthenium mixed valence complexes to this correlation is examined.     

Tetrachlormethan (I), Chloroform (II) und Dichlormethan (III) in Salzs?ure

Ohne Zusammenfassung     

Tunability of the M(II)M(III)/M(II)(2) and M(III)(2)/M(II)M(III) (M=Mn, Co) couples in bis-μ-O,O'-carboxylato-μ-OR bridged complexes

A comparison of the electrochemical properties of a series of dinuclear complexes [M(2)(L)(RCO(2))(2)](+) with M = Mn or Co, L = 2,6-bis(N,N-bis-(2-pyridylmethyl)-sulfonamido)-4-methylphenolato (bpsmp(-)) or 2,6-bis(N,N-bis(2-pyridylmethyl)aminomethyl)-4-tert-butylphenolato (bpbp(-)) and R = H, CH(3), CF(3) or 3,4-dimethoxybenzoate demonstrates: (i) The electron-withdrawing sulfonyl groups in the backbone of bpsmp(-) stabilize the [M(2)(bpsmp)(RCO(2))(2)](+) complexes in their M(II)(2) oxidation state compared to their [M(2)(bpbp)(RCO(2))(2)](+) analogues. Manganese complexes are stabilised by approximately 550 mV and cobalt complexes by 650 mV. (ii) The auxiliary bridging carboxylato ligands further attenuate the metal-based redox chemistry. Substitution of two acetato for two trifluoroacetato ligands shifts redox couples by 300-400 mV. Within the working potential window, reversible or quasi-reversible M(II)M(III)? M(II)(2) processes range from 0.31 to 1.41 V for the [Co(2)(L)(RCO(2))(2)](+/2+) complexes and from 0.54 to 1.41 V for the [Mn(2)(L)(RCO(2))(2)](+/2+) complexes versus Ag/AgCl for E(M(II)M(III)/M(II)(2)). The extreme limits are defined by the complexes [M(2)(bpbp)(CH(3)CO(2))(2)](+) and [M(2)(bpsmp)(CF(3)CO(2))(2)](+) for both metal ions. Thus, tuning the ligand field in these dinuclear complexes makes possible a range of around 0.9 V and 1.49 V for the one-electron E(M(II)M(III)/M(II)(2)) couple of the Mn and Co complexes, respectively. The second one-electron process, M(II)M(III)? M(III)(2) was also observed in some cases. The lowest potential recorded for the E°(M(III)(2)/M(II)M(III)) couple was 0.63 V for [Co(2)(bpbp)(CH(3)CO(2))(2)](2+) and the highest measurable potential was 2.23 V versus Ag/AgCl for [Co(2)(bpsmp)(CF(3)CO(2))(2)](2+).     

Heterobinuclear copper(II)–lanthanoid(III) complexes bridged by N,N′-oxamidobis(benzoato)cuprate(II)

Eight new -oxamido-bridged copper(II)–lanthanoid(III) heterobinuclear complexes described by the overall formula Cu(obbz)Ln(Me-phen)₂NO₃ (Ln = Y, La, Nd, Eu, Gd, Tb, Ho, Er), where obbz denotes the oxamidobis(benzoato) and Me-phen represents 5-methyl-1,10-phenanthroline (Me-phen), have been synthesized and characterized by the elemental analyses, spectroscopic (i.r., u.v., e.s.r.) studies, magnetic moments (at room temperature) and by molar conductivity measurements. The temperature dependence of the magnetic susceptibility of Cu(obbz)Gd(Me-phen)₂NO₃ has also been measured over the 4.2 300 K range. The least-squares fit of the experimental susceptibilities based on the spin Hamiltonian operator, = –2 J ₁ · ₂, yielded J = + 2.18 cm^–1. The observed Gd^III–Cu^II coupling is ferromagnetic. A plausible mechanism for a ferromagnetic coupling between Gd^III–Cu^II is discussed in terms of spin-polarization.     

Zur Bestimmung von ?thylenoxid (I) in Gegenwart von Methacryl-S?ure (II) und Eisensalzen (III)

Ohne Zusammenfassung     

Synthesis,Spectra and Crystal Structure of Tetrakis(Triphenylarsine Oxide)Iron(III)-μ-Oxo-Tribromoiron(III) Tetrabromoferrate(III)-Acetonitrile

The oxidation of triphenylarsine with dioxygen in reaction systems containing some iron compound and Br^- anions in acetonitrile leads to the formation of a novel unsymmetrical oxo-bridged diiron(III) complex [(OAsPh₃)₄ Fe(μ-O)FeBr₃]⁺ [FeBr₄]^- ·CH₃CN, where OAsPh₃ is triphenylarsine oxide. The title complex is also formed by direct reaction of iron(III) bromide and OAsPh₃ with dioxygen in acetonitrile solution. The crystal structure of the complex was solved by X-ray diffraction techniques. The cation contains two unsymmetrical species with an Fe-O-Fe bond angle of 159.2(2)°; one iron atom is pentacoordinated by four OAsPh₃ ligands and a γ-oxo ligand which connects the tetracoordinated Fe atom with the FeBr₃O chromophore. Structural parameters and IR spectra of similar complexes are compared and discussed.     

Complexes of N-nicotinoyl-N′-2-furanthiocarbohydrazide with oxovanadium(IV), manganese(II), iron(II & III), cobalt(II), nickel(II), copper(II) and zinc(II)

A new potential tetradentate ligand, N-nicotinoyl-N-2-furanthiocarbohydrazide (H₂Nfth), and its complexes with VO^IV, Mn^II, Fe^II,III, Co^II, Ni^II, Cu^II and Zn^II have been prepared and characterized by elemental analyses, magnetic susceptibility measurements, u.v.–vis, i.r., n.m.r., ES⁺ and FAB mass spectral data. The room temperature e.s.r spectra of the VO^IV and Fe^III complexes yield g values, characteristic of octahedral complexes. The Mössbauer spectra of [Fe(HNfth)₂] and [Fe₂(Nfth)₃] at room temperature and at 78 K suggest the presence of high-spin iron(II) and iron(III), respectively. The complexes are electrically insulating at room temperature, however, their conductivities increase as the temperature increases from 333–383 K, with a band gap of 0.46–0.77 eV, indicating their semiconducting behaviour. H₂Nfth and its soluble complexes have been screened against several bacteria and fungi.     

Maleins?ure (I), o-Toluylaldehyd (II) und Formaldehyd (III) in Gemischen mit Phthals?ure (IV)

Ohne Zusammenfassung     

The preparation of trichlorotris(hydrogen-salicylato)rhodate(III) and tetra-μ-(hydrogen-salicylato)diaquadirhodium(II)

The preparation of a new example of a salicylato divalent rhodium complex, namely, tetra--(Hsal)diaquadirhodium(II), and a new trivalent complex, the trichlorotris(Hsal)rhodium(III) ion are reported. The complexes were isolated and characterized by spectrochemical methods including FT-Raman and n.m.r. spectroscopies. The trivalent complex has a monodentate Hsal ligand bonded through a carboxyl oxygen with a facial configuration.     

Ferrocene-containing ligands in the self-assembly of trinuclear μ3-oxocentered carboxylate complexes of chromium(III, III, III)carboxylate complexes of chromium(III, III, III)

New trinuclear μ₃-oxocentered chromium(III, III, III) complexes were obtained by the self-assembly of ferrocenecarboxylate ligands and the Cr₃O fragment. The complexes were investigated by fast-atom bombardment (FAB) mass spectrometry, cyclic voltammetry, and electronic and IR spectroscopy. V. I. Vernadskii Institute of General and Inorganic Chemistry, National Academy of Sciences of Ukraine, 32/34 Prospekt Akademika Vernadskogo, Kiev 03142, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 36, No. 4, pp. 233–237, July–August, 2000.     

Eisen(II)-?thylendiaminsulfat als reduktometrisches Reagens

Ohne Zusammenfassung