Complex formation of gallium(III) with 8-hydroxy-7-iodoquinoline-5-sulphonic acid (ferron)

The complex formation of gallium(III) with 8-hydroxy-7-iodoquinoline-5-sulphonic acid (ferron) (L) was studied by potentiometry; and the dissociation constants of the ligand were redetermined. A new computer program made it possible to make allowance for a considerable number of equilibria. In the pH range 2–10, the main species were as follows (the logarithm of the absolute stability constants at 25.0 ±0.1° for ionic strength 0.1 M are given in parentheses): GaHL (11.3), GaL (14.7), Ga(OH)₂L (32.3), GaL₂ (23.9), GaOHL₂ (31.0) and GaL₃ (29.6). For 1:1, 1:2 and 1:3 mixtures of metal with ferron, the mole fractions of the various complexes as a function of pH were calculated; the effect of pH on the conditional constants of the species GaL, GaL₂ and GaL₃ was also established.     

Heterovalent trinuclear Co(III)-Co(II)-Co(III) complexes with N-(2-Carboxyethyl)salicylaldimines

The heterovalent trinuclear cobalt complexes [Co₂^IIIL₄ ⁱ · Co^II(H₂O)₄] · nXmY (L ⁱ are deprotonated Schiff bases derived from substituted salicylaldehydes and β-alanine; i = 1–3) were obtained and characterized. An X-ray diffraction study of the trinuclear cobalt complex with N-(2-carboxyethyl)salicylaldimine showed that the central Co(II) ion and the terminal Co(III) ions are linked by bridging carboxylate groups. Either terminal Co(III) atom is coordinated to two ligand molecules. They form an octahedral environment consisting of two azomethine N atoms, two phenolate O atoms, and two O atoms of two carboxylate groups. The central Co(II) atom is coordinated to four water molecules and to two O atoms of two bridging carboxylate ligands involved in the coordination sphere of the terminal Co(III) atoms.     

Mixed halide dialkyldithiophosphate derivatives of arsenic(III) and antimony(III)

Mixed chloride dialkyldithiophosphates of arsenic(III) and antimony(III), [(RO)₂PSS]_nMCl_3?n (M = As, Sb; n = 1, 2; R = C₂H₅, n-C₃H₇, i-C₃H₇ and i-C₄H₉) have been synthesized for the first time by the reac metal chlorides with sodium dialkyldithiophosphates or alternatively by co-disproportionation reactions of metal chlorides with metal tris(dialkyldithiophosphates) in different stoichiometric ratios. Mixed halide dialkyl-dithiophosphates of antimony(III) have also been prepared by the cleavage reactions of antimony tris(diisopropyldithiophosphate) with bromine or iodine. Hydrolysis reactions of a few of these compounds have also been studied. The new compounds have been characterized by elemental analyses, molecular weight determinations (cryoscopic) as well as IR and NMR (¹H, ³¹P) data; chelated structures with bidentate dialkyldithiophosphate groups are proposed.     

Synthesis of intermediate sitting-atop complexes (i-SAT) from the reaction between free base meso-tetraarylporphyrins and phosphorus(III) chloride in solvent free media

The reaction of meso-tetraarylporphyrins (H₂tap) with phosphorus(III) chloride has been studied in the solid state. The reaction products are intermediate sitting-atop (i-SAT) complexes in which two pyrrolenine nitrogen atoms of the porphyrins act as electron donors to the phosphorus(III) atoms and two protons on the pyrrole nitrogen atoms remain. These new complexes have been characterized by (¹H, ³¹P, ¹³C) NMR, FT-IR and UV–Vis spectroscopy, elemental analysis and electrical conductometry.     

Hyperfine Shifts of the 13C-NMR. in Protoporphyrin IX Iron (III) Dicyanide and Deuteroporphyrin IX Iron (III) Dicyanide

The ¹³C-NMR. in Zn(II) (Protoporphyrin IX), Fe(III) (Protoporphrin IX) (CN)₂, Zn(II) (Deuteroporphyrin IX dimethylester), and Fe(III) (Deuteroporphyrin IX) (CN)₂ have been identified, and the ¹³C hyperfine shifts in the iron complexes evaluated. In a partial analysis of these data the parameters Q^H, Q_CCH^H, and Q_C′CH^C, which characterize the isotropic coupling through hyperconjugation between the ¹H and ¹³C nuclei of the porphyrin side chains and the unpaired electron spin density on the aromatic ring carbon atoms, have been re-examined. This paper is part of an investigation of the electronic states in low spin ferric hemes and hemoproteins, and the relations between the electronic structures and the biological roles of these molecules.     

A new binucleating ligand incorporating four oxime groups and its copper(II), manganese(II) and cobalt(III) complexes

A new binucleating ligand incorporating four oxime groups, butane-2,3-dione O-[4-aminooxy-2,3-bis-(2-hydroxyimino-1-methyl-propylideneaminooxymethyl)-but-2-enyl]-dioxime, (H₄mto), has been synthesized and its dinuclear cobalt(III), copper(II), and homo- and hetero-tetranuclear copper(II)–manganese(II) complexes have been prepared and characterized by ¹H- and ¹³C-n.m.r., i.r., magnetic moments and mass spectral studies. Elemental analyses, stoichiometric and spectroscopic data indicate that the metal ions in the complexes are coordinated to the oxime nitrogen atoms (C=N) and the data support the proposed structure for H₄mto and its complexes. Moreover, dinuclear cobalt(III) and copper(II) complexes of H₄mto have a 2:1 metal:ligand ratio.     

Lanthanum(III) and prasedymium(III) complexes with piperazine dithiosemicarbazones

Lanthanum(III) and praseodymium(III) complexes of the type [Ln(L)Cl(H₂O)]₂ (Ln = La(III) or Pr(III); LH₂ = dithiosemicarbazone ligands derived from piperazine dithiosemicarbazide and benzaldehyde, 4-nitrobenzaldehyde, and 2-methoxybenzaldehyde) have been synthesized in methanol in the presence of sodium hydroxide. The complexes have been characterized by elemental analyses, molecular weight, molar conductance, electronic absorption, IR, and ¹H and ¹³C NMR spectral studies. Nephelauxetic ratio, covalency parameter, and bonding parameter for these complexes have also been calculated. Thermal studies of the complexes have been carried out using TG, DTG, and DSC techniques. Kinetic parameters, such as apparent activation energy and order of reaction, were determined by the Coats-Redfern graphical method. The heats of reaction for different reaction steps were calculated from DSC curves. The article was submitted by the authors in English.     

Matrix effects in fast atom bombardment mass spectrometry of cationic iridium(III) and rhodium(III) coordination complexes

Fast atom bombardment mass spectra of cationic iridium(III) and rhodium(III) coordination complexes (M⁺Cl₂L₂, X^?; where the ligand L is a dinitrogenous aromatic system) have been obtained with thioglycerol, glycerol or tetraglyme as a matrix. Two kinds of reactions, initiated by particle bombardment, have been discovered between these complexes and the matrix. First, with thioglycerol one or two chlorine atoms are substituted by a thioglycerol radical, more rapidly for rhodium compounds; secondly, when the ligand L possesses a diazo function, this function is hydrogenated depending on the ability of the matrix to generate hydrogen radicals by bombardment.     

Thermal and spectroscopic studies of terbium(III) and dysprosium(III) complexes with piperidin-4-ones

Terbium(III) and dysprosium(III) nitrate complexes with variously substituted 2,6-diphenylpiperidin-4-ones (L¹)-(L¹⁰) of general formula [Ln(L)(NO₃)₂(H₂O)₂]NO₃ have been synthesized. These complexes have been characterized by analytical, spectral and thermal studies. Molar conductance data show that these complexes are 1:1 electrolytes. The presence of two coordinated water molecules is confirmed by thermal and infrared spectral studies. IR spectral data indicate that piperidin-4-ones, in spite of having two coordinating sites, are monodentate, coordinating only through ring nitrogen. The IR and conductance data reveal the presence of two bidentate and one ionic nitrate groups. The nephelauxetic ratio (β), covalency factor (b^1/2) and Sinha’s parameter (δ) evaluated from electronic spectral data of dysprosium(III) complexes indicate a little covalency in metal-ligand bonding.     

Substitution of Fe(III) for Ga(III) in calcium gallate glass confirmed from the Debye temperature

A Debye temperature θ_D of 378 (±5K) has been obtained by applying a simplified Debye model to the⁵⁷Fe Mössbauer spectra of 60CaO·39Ga₂O₃·⁵⁷Fe₂O₃ glass. The θ_D value is comparable to those (280–580 K) obtained so far in several oxide glasses, glass-ceramics, and ceramics in which Mössbauer atoms are covalently bonded to oxygen atoms and play a role of network former. It proves that Fe(III) atoms occupy the substitutional sites of Ga(III) constituting distorted GaO₄ tetrahedra.     

Synthesis,Crystal Structure,and Magnetic Property of New Trispin Ln(III)‐Nitronyl Nitroxide Complexes

Four Ln(III) complexes based on a new nitronyl nitroxide radical have been synthesized and structurally characterized: {Ln(hfac)₃[NITPh(MeO)₂]₂} (Ln = Eu( 1 ), Gd( 2 ), Tb( 3 ), Dy( 4 ); NITPh(MeO)₂ = 2‐(3′,4′‐dimethoxyphenyl)‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide; hfac = hexafluoroacetylacetonate). The single‐crystal X‐ray diffraction analysis shows that these complexes have similar mononuclear trispin structures, in which central Ln(III) ion is eight‐coordinated by two O‐atoms from two nitroxide groups and six O‐atoms from three hfac anions. The variable temperature magnetic susceptibility study reveals that there exist ferromagnetic interactions between Gd(III) and the radicals, and antiferromagnetic interactions between two radicals (J_Gd‐Rad = 3.40 cm^?1, J_Rad‐Rad = ?9.99 cm^?1) in complex 2 . Meanwhile, antiferromagnetic interactions are estimated between Eu(III) (or Dy(III)) and radicals in complexes 1 and 4 , and ferromagnetic interaction between Tb(III) and radicals in complex 3 , respectively.     

Synthese und Eigenschaften von cis-Diacidophthalocyaninato(2–)thallaten(III); Kristallstruktur von Tetra(n-butyl)ammonium-cisdinitrito(O,O′)- und -cis-dichlorophthalocyaninato(2–)thallat(III)

Syntheses and Properties of cis -Diacidophthalocyaninato(2–)thallates(III); Crystal Structure of Tetra(n-butyl)ammonium cis -dinitrito(O,O ′)- and cis -dichlorophthalocyaninato(2–)thallate(III) Blue green cis-diacidophthalocyaninato(2–)thallate(III), ^cis[Tl(X)₂pc^2–]^– (X = Cl, ONO′, NCO) is prepared from iodophthalocyaninato(2–)thallium(III) and the corresponding tetra(n-butyl)ammonium salt, (ⁿBu₄N)X in dichloromethane, and isolated as (ⁿBu₄N)^cis[Tl(X)₂pc^2–]. (ⁿBu₄N)^cis[Tl(ONO′)₂pc^2–] ( 1 ) and (ⁿBu₄N)^cis[Tl(X)₂pc^2–] · 0,5 (C₂H₅)₂O ( 2 ) crystallize in the monoclinic space group P2₁/n with cell parameters for 1: a = 14.496(2) Å, b = 17.293(5) Å, c = 18.293(2) Å, β = 98.76(1)° resp. for 2 : a = 13.146(1) Å, b = 14.204(5) Å, c = 24.900(3) Å, β = 93.88(1)°; Z = 4. In 1 , the octa-coordinated Tl atom is surrounded by four isoindole-N atoms (N_iso) and four O atoms of the bidental nitrito(O,O′) ligands in a distorted antiprism. The Tl–N_iso distances vary between 2.257(3) and 2.312(3) Å, the Tl–O distances between 2.408(3) and 2.562(3) Å. In 2 , the hexa-coordinated Tl atom ligates four N_iso atoms and two Cl atoms in a typical cis-arrangement. The average Tl–N_iso distance is 2.276 Å, the average Tl–Cl distance is 2.550 Å. In 1 and 2 , the Tl atom is directed out of the centre of the (N_iso)₄ plane (Ct_N) towards the acido ligands (d(Tl–Ct_N) = 1.144(1) Å in 1 , 1.116(2) Å in 2 ), and the phthalocyaninato ligand is concavely distorted. The vertical displacements of the periphereal C atoms amounts up to 0.82 Å. The optical and vibrational spectra as well as the electrochemical properties are discussed.     

Structures and fluorescence of two new hetero-dinuclear lanthanide(III) complexes derived from a Schiff-base ligand

Two isostructural dinuclear lanthanide(III)/Schiff-base complexes [{Ce_1.5Eu_0.5(clapi)}₂]·2CH₃CN (1) and [{La_1.5Eu_0.5(clapi)}₂]·2CH₃CN (2) {H₃clapi = 2-(5-chloride-2-hydroxyphenyl)-1,3-bis[4-(5-chloride-2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine} have been prepared by template procedure and characterized by elemental analyses, ICP, IR, and single-crystal X-ray diffraction analyses. Lanthanide ions Ce(III) and Eu(III) in 1, and La(III) and Eu(III) in 2 are disordered with occupancies 0.75 for Ce and 0.25 for Eu in 1; 0.75 for La and 0.25 for Eu in 2. In the compounds, each lanthanide is coordinated to four N and four O atoms from two clapi^3? ligands, forming a distorted square antiprism. Two phenol oxygen atoms from the middle arms of the two heptadentate μ₂-bridging ligands connect the two Ce(Eu) atoms in 1, and La(Eu) in 2. The solution of the two complexes in CH₂Cl₂ exhibits red fluorescence from Eu³⁺ ions at 77 K, very weak at room temperature.     

Stabilities of Scandium(III)- and Yttrium(III)-Tiron Chelates and their hydrolytic behavior

The interactions of Sc³⁺ and Y³⁺ ions with disodium 1,2-dihydroxybenzene-3,5-disulfonate (Na₂H₂L, where H₂L_2- = Tiron) were investigated in aqueous solution by means of potentiometric and spectroscopic methods. The coordination of Tiron to Sc³⁺ and Y³⁺ takes place through two phenolic oxygen atoms of catecholate ion in different stoichiometries. Thus, the binding of Tiron to Sc³⁺ occurs either in 1 : 1 or 1 : 2 molar ratios; they have resulted by the formation of [ScL]^- and [ScL₂]^5- type complexes, respectively. On the other hand, Y³⁺ ion behaves like Th⁴⁺ and Ln³⁺ ions toward Tiron. It forms [YL]^-type complex in 1 : 1 molar ratio; but in 1 : 2 or in higher molar ratios, only unique [Y₂L₃]^6- type complex formation takes place. The formation constants of [ScL]^-, [ScL₂]^5-, [YL]^-, and [Y₂L₃]^6- complexes were determined by analysis of the potentiometric data in ionic medium of 0.1 M KNO₃ or NaClO₄ at 25°C. The hydrolytic reactions of Sc(III) and Y(III) complexes with Tiron were determined from potentiometric data and the formation constants of [ScL(OH)]^2- and [YL(OH)]^2- were also calculated.From Koordinatsionnaya Khimiya, Vol. 31, No. 1, 2005, pp. 62–68.Original English Text Copyright © 2005 by Aydin, Türkel, Özer.     

Synthese von N-phenolat-funktionalisierten Makrocyclen des 1,4,7-Trazacyclononans sowie des 1-Oxa-4,7-diazacyclononans und ihre Komplexchemie mit Eisen(III)

Synthesis of N-Phenolate-functionalized Macrocycles of 1,4,7-Triazacyclononane and of 1-Oxa-4,7-diazacyclononane and their Coordination Chemistry with Iron(III) Six new tetra- or pentadentate, N-phenolate functionalized, pendant, arm macrocyclic containing a 1,4,7-traizacyclononane or a 1-oxa-4,7-diazacyclononane backbone have been synthesized and their coordination chemistry with iron(III) has been investigated. Electronic spectra of these octahedral high-spin Fe^III complexes have been measured. The Phenolate-to-iron(III) charge transfer band has been studied as a function of the number of coordinated phenolate residues (1,2, or 3) and of the substituents at the phenolate arms. The dinuclear complex [LFe₂(μ-O₂CPh)](C1O)₄)₃ has been synthesized where the two Fe^III centres are connected via a symmetric μ-benzoato bridge and two phenolate oxygen atoms (L⁷ = N-(2-hydroxybenzyl)-1,4,7-triazacyclononane).     

Cationic complexes of Eu(III) and Sr(II) with diphosphine dioxides in organic extracts

IR spectroscopy was used to study the structure and composition of Eu(III) and Sr(II) complexes formed by cation-exchange extraction of these metals from their aqueous nitrate solutions with dichlorethane solutions of mixtures of chlorinated cobalt(III) dicarbollide (CCD) as a superacid with diphenyldiphosphine dioxides containing a methyl (Me-DPDO), ethyl (Et-DPDO), or polyoxyethylene bridge between two phosphorus atoms of phosphine oxide groups. At molar ratios DPDO/CCD ≤ 1, [Eu(H₂O)_nL₄]³⁺ complexes are formed in organic phases, whereas with an excess of DPDO relative to CCD, Eu(NO₃)L ₄ ²⁺ complexes are formed, where L = Me-or Et-DPDO. Polyoxyethylenediphosphine dioxide forms anhydrous complexes of composition Eu:L = 1:1 and 1:2 with Eu(III) and outer-spheric complexes of composition Sr:L = 1:1 and 1:2 with Sr(II), where the organic ligand molecules envelop the hydrated Sr(H₂O) _n ²⁺ cation. The peculiarities of extraction of the complexes are explained based on data about their composition and structure.     

Kinetics and mechanism of oxidation of the drug mephenesin by bis(hydrogenperiodato)argentate(III) complex anion

Mephenesin is being used as a central‐acting skeletal muscle relaxant. Oxidation of mephenesin by bis(hydrogenperiodato)argentate(III) complex anion, [Ag(HIO₆)₂]^5?, has been studied in aqueous alkaline medium. The major oxidation product of mephenesin has been identified as 3‐(2‐methylphenoxy)‐2‐ketone‐1‐propanol by mass spectrometry. An overall second‐order kinetics has been observed with first order in [Ag(III)] and [mephenesin]. The effects of [OH^?] and periodate concentration on the observed second‐order rate constants k′ have been analyzed, and accordingly an empirical expression has been deduced: k′ = (k_a + k_b[OH^?])K₁/{f([OH^?])[IO^?₄]_tot + K₁}, where [IO^?₄]_tot denotes the total concentration of periodate, k_a = (1.35 ± 0.14) × 10^?2M^?1s^?1 and k_b = 1.06 ± 0.01 M^?2s^?1 at 25.0°C, and ionic strength 0.30 M. Activation parameters associated with k_a and k_b have been calculated. A mechanism has been proposed to involve two pre‐equilibria, leading to formation of a periodato‐Ag(III)‐mephenesin complex. In the subsequent rate‐determining steps, this complex undergoes inner‐sphere electron transfer from the coordinated drug to the metal center by two paths: one path is independent of OH^? whereas the other is facilitated by a hydroxide ion. In the appendix, detailed discussion on the structure of the Ag(III) complex, reactive species, as well as pre‐equilibrium regarding the oxidant is provided. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 440–446, 2007     

Tetraphenylphosphonium-tetradecachlorotetraarsenat(III), (PPh4)2As4Cl14

Tetraphenylphosphonium Tetradecachlorotetraarsenate(III), (PPh₄)₂As₄Cl₁₄ The title compound was obtained by reaction of As₄S₄, PPh₄Cl and chlorine in dichloromethane. According to its X-ray crystal structure analysis, the As₄Cl ion can be described as an association product of two AsCl₄^? units and two AsCl₃ molecules. The As atoms and ten Cl atoms are approximately in a plane, the remaining four Cl atoms alternately take positions above and below this plane. The As atoms have distorted ψ octahedral coordination.     

Alkylenedithiophosphate derivatives of arsenic(III), antimony(III) and bismuth(III)

Tris(alkylenedithiophosphates) of arsenic(III), antimony(III) and bismuth(III),

have been synthesized by the reactions of alkylenedithiophosphoric acids with metal oxides and chlorides and of their ammonium salts with metal chlorides in suitable solvents. Mixed chloride alkylenedithiophosphates of arsenic(III) and antimony(III),

have been obtained by the reactions of metal chlorides with ammonium alkylenedithiophosphates at 1 : 1 and 1 : 2 molar ratios or alternatively by the co-disproportionations reactions of metal chlorides with metal tris(alkylenedithiophosphates) at different (2 : 1 and 1 : 2) molar ratios. These new compounds have been characterized by elemental analyses, molecular weight measurements and spectroscopic (IR, and ¹H and ³¹P NMR) data. Chelated structures with bidentate alkylenedithiophosphate groups have been proposed for all these derivatives.     

Darstellung und Eigenschaften von Phthalocyaninato(2–)indaten(III) mit einzähnigen Acido-Liganden; Kristallstruktur von Tetra(n-butyl)ammonium-cis-difluoro-Phthalocyaninato(2–)indat(III)-Hydrat

Preparation and Properties of Phthalocyaninato(2–)indates(III) with Monodentate Acido Ligands; Crystal Structure of Tetra(n-butyl)ammonium cis -Difluorophthalocyaninato(2–)indate(III) Hydrate Tetra(n-butyl)ammonium cis-diacidophthalocyaninato(2–)indates(III) with the monodentate acido ligands fluoride, chloride, cyanide and formiate are synthezised by the reaction of chlorophthalocyaninatoindium(III) or cis-dihydroxophthalocyaninatoindate(III) with the respective tetra(n-butyl)ammonium salt or ammonium formiate and are characterized by their UV/VIS spectra and their vibrational spectra. The difluoro-complex salt crystallizes as a hydrate ((ⁿBu₄N)^cis[In(F)₂pc^2–] · H₂O) in the monoclinic space group P2₁/n (no. 14) with cell parameters: a = 13.081(3) Å, b = 13.936(2) Å, c = 23.972(2) Å; β = 97.79(1)°, Z = 4. Hexa-coordinated indium is surrounded by four isoindole nitrogen atoms (N_iso) and two cis-positioned fluorine atoms. The average In–F and In–N_iso distance are 2.0685(4) and 2.2033(5) Å, respectively, and the F–In–F angle is 81.5(1)°. The In atom is displaced outside the centre (Ct) of the N_iso plane towards the fluoride ligands: d(In–Ct) = 0.953(1) Å. The phthalocyaninato(2–) core is nonplanar (unsymmetrical concave distortion).