Koordinationsverhältnisse in basenfreien tricyclopentadienyl-lanthanoid(III)-komplexen: IV. Die röntgenstrukturen von tricyclopentadienyl-erbium(III) und -thulium(III)

The single crystal X-ray analyses of sublimated (C₅H₅)₃Er (6) and (C₅H₅)₃Tm (7) confirm, for the first time, the existence of coordinatively well-saturated molecules containing just three η⁵-C₅H₅ ligands per metal ion (formal coordination number: 9, space group: Pna2₁, lattice parameters: a 1972.1(3), b 1389.4(1), c 862.4(3) pm for 6, and a 1999.1(3), b 1379.8(4), c 1379.8(4), c 857.8(3) pm for 7; R = 0.076 and 0.047, respectively). Individual molecules align themselves into chains by Van der Waals interactions. The structures of 6 and 7 show a marked contrast to those of their La und Pr homologues on the one hand, and with the structure of (C₅H₅)₃Lu on the other.     

Tetraaquatetrakis(ɛ-caprolactam)lutetium(III) hexaisothiocyanatochromate(III) sesquihydrate

The ionic complex [Lu(?-C₆H₁₁NO)₄(H₂O)₄][Cr(NCS)₆] · 1.5H₂O, the first example of coordination of ?-caprolactam to the lutetium atom, was synthesized by the reaction of Lu(NO₃)₃, K₃[Cr(NCS)₆], and ?-caprolactam in an aqueous solution. The structure of the complex was established by IR spectroscopy and X-ray crystallography. The crystals are triclinic, space group P \(\bar 1\) T = 100 K, a = 11.9604(3) Å, b = 12.3640(3) Å, c = 18.3506(5) Å, α = 91.3200(10)°, β = 108.6640(10)°, γ = 112.4460(10)°, V = 2343.45(10) ų, Z = 2, ρ_calcd = 1.597 g/cm³, R = 0.0299 for 9839 reflections with F _hkl ≥4σ(F). The coordination polyhedron of the lutetium atom is a distorted square antiprism with broken square faces with the oxygen atoms of the organic ligands and water at the vertices. There are weak intramolecular hydrogen bonds N-H…O(H₂) in the cation. The coordination polyhedron of the chromium atom is a somewhat distorted octahedron. The thermal stability of the compound was studied in an inert atmosphere and in air.     

氯冉酸阴离子桥联的Nd(III)-Nd(III), Dy(III)-Dy(III)和 Ho(III)-Ho(III)双 核配合物的合成与磁性

本文合成了三个以氯冉酸阴离子为桥基的稀土双核配合物,Ln~2(Phen)~4(CA)(NCS)~4(Ln=Nd,Dy,Ho;Phen=菲咯啉;CA=氯冉酸二价阴离子)。通过元素分析,红外光谱,电导,电子吸收光谱及变温(4-300K)磁化率表征了配合物,并由变温磁化率观察到的数据和理论方程通过最小二乘法拟合,得出分子内稀土离子间的相互作用参数:Z'J'=-0.79(Nd),-0.67(Dy),-0.63cm^-^1(Ho);表明稀土离子间存在极弱的反铁磁性交换相互作用。零场分裂参数Δ=-0.16(Nd),-0.76(Dy),-2.55cm^-^1(Ho);g=0.618(Nd),1.739(Dy),1.601(Ho),拟合因子≈10^-^4。     

氯冉酸阴离子桥联的Nd(III)-Nd(III), Dy(III)-Dy(III)和 Ho(III)-Ho(III)双 核配合物的合成与磁性

本文合成了三个以氯冉酸阴离子为桥基的稀土双核配合物,Ln~2(Phen)~4(CA)(NCS)~4(Ln=Nd,Dy,Ho;Phen=菲咯啉;CA=氯冉酸二价阴离子)。通过元素分析,红外光谱,电导,电子吸收光谱及变温(4-300K)磁化率表征了配合物,并由变温磁化率观察到的数据和理论方程通过最小二乘法拟合,得出分子内稀土离子间的相互作用参数:Z'J'=-0.79(Nd),-0.67(Dy),-0.63cm^-^1(Ho);表明稀土离子间存在极弱的反铁磁性交换相互作用。零场分裂参数Δ=-0.16(Nd),-0.76(Dy),-2.55cm^-^1(Ho);g=0.618(Nd),1.739(Dy),1.601(Ho),拟合因子≈10^-^4。     

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.     

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...     

Complexation of Sc(III), Ga(III), In(III) and Ln(III) with Eriochrome Red B

Cyclic linear-sweep voltammetry was used to study the complexation of Sc(III), Ga(III), In(III) and Ln(III) with eriochrome red B (ERB). It was established that all metal ions investigated form complex compounds with azodye having a mole ratio, M(III):ERB = 1:2. The hydroxo forms of M(III) ions, which take part in interaction with ERB, were determined by the Nazarenko method. The stability constants for the formation of these chelates are nearly the same. It was shown that the reduction of the ligand in the complex does not only depend on the peculiarities of complexation, but the processes occurring in pre-electrode layer also influence it.     

Strongly decussated π-stacking in a Ag(I)–Co(III) complex containing a Ag2Co2 44 square tile motif

A mixed Co–Ag complex with 2,6-dicarboxypyridine (H₂PDC), AgCo(PDC)₂, was synthesized under hydrothermal conditions. The complex adopts a 2D layer structure formed by intramolecular π-stacking. Each Co(III) ion is chelated by two 2,6-dicarboxypyridine anions to give the [Co(PDC)₂]^? anion that is further extended by Ag⁺ to form 4⁴ square grids.     

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.     

Transport behaviour of the lanthanide 152Eu(III), 153Gd(III) and 170Tm(III) and transplutonium element 254Es(III), 244Cm(III), 241Am(III), 249Cf(III) and 249Bk(III) ions in aqueous solutions at 298 K

Ionic self-diffusion coefficients (D) for trivalent radiotracers, lanthanide and actinide ions have been determined in concentrated aqueous solutions of supporting electrolytes of Gd(NO₃)₃–HNO₃ or Nd(ClO₃)₄–HClO₄ up to 1.5 mol L^?1 at 298.15 K and pH 2.50 by the open-end capillary method. The data obtained in large range of concentrations, allow to derive the limiting value D°, the validity of the Onsager limiting law and a more extended law. This study contributes to demonstrate similarities in transport and structure properties between 4f and 5f trivalent ions explained by a similar electronic configuration, ionic radius and hydration number. An empirical equation is suggested for predicting ionic hydration number with a good precision.     

Leitfähigkeitsmessungen in Phosphoroxychlorid. 5. Mitt.: Eisen(III)-chlorid und Aluminiumchlorid

Zusammenfassung Das Komplexion FeCl₄-ist auch in Phosphoroxychlorid sehr stark, nicht wesentlich solvolysiert, solvatisiert oder zu Polyionen assoziiert. Dagegen zeigt ein Vergleich einiger physikalisch-chemischer Eigenschaften von Eisen(III)-chlorid und Aluminiumchlorid mit ihren POCl₃-Verbindungen in diesen das Vorliegen von O-Koordination. In Lösung liegt FeCl₃ auch im verd. Zustand noch als Polyion vor; das Verhältnis Ladung: Fe ist kleiner als 13. AlCl₃ besitzt als in POCl₃ amphoteres Chlorid eine um Größenordnungen zu hohe Leitfähigkeit; das geht vermutlich auf Koordinationsformen des Typs [AlCl₄]^– [AlCl₂(POCl₃)₂]⁺ zurück.Mit 7 AbbildungenZugleich 16. Mitt. der Reihe: Das Solvosystem Phosphoroxychlorid.4. Mitt.:M. Baaz undV. Gutmann, Mh. Chem.90, 426 (1959).     

Beiträge zur Ringofenmethodik. II. Komplexometrische Ultra Mikro-Bestimmung von Eisen(III)

Zusammenfassung Die quantitative Bestimmung von Ultramikromengen Eisen(III) durch Titration des Thiocyanatkomplexes mit 0,001-m ÄDTA wird vorgeschlagen. Etwa anwesende Fremdionen werden mit Hilfe der Ringofentechnik vorher abgetrennt.

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Summary The quantitative determination of iron(III) in ultramicro quantities by titration of the thiocyanate complex with 0.001M EDTA is proposed. Any foreign ions may be removed beforehand with the aid of the ring furnace technique.

     

X-ray structures of trans-dichloro(4-methylpyrimidine) (η1-phenyl)bis(pyridine)rhodium(III) hydrate and trans-dichloro(phenyl)tris(triphenylstibine)rhodium(III) ethylacetate solvate. Molecular orbital analysis of trans-dichloro (4-methylpyrimidine)(η1-phenyl)bis(pyridine)rhodium(III)

The crystal and molecular structure of trans-dichloro(4-methylpyrimidine)(η ¹ -phenyl)cis-bis(pyridine)rhodium(III) water solvate, 1x 0.17H₂ O, and trans-dichloro(η ¹ -phenyl)tris(triphenylstibine)rhodium(III) ethylacetate solvate, 2x CH₃ CO₂ CH₂ CH₃ have been studied via X-ray diffraction from a single crystal at room temperature. The final refinement converged to R1 conventional index of 0.0350 and 0.0361 for the structural analysis of 1x 0.17H₂ O [space group R(-3) and 2x CH₃ CO₂ CH₂ CH₃ P(-1) , respectively. The 4-methylpyrimidine ligand (Pym) is only weakly bound to Rh in 1, as shown by the long Rh-N distance (2.251(4) Å), compared to the Rh N(pyridine) lengths average, 2.066(4) . N-C bond distances involving the N donor average 1.329(6) and 1.345(6) for Pym and pyridine (Py) ligands, respectively. The C N C bond angle on the donor is 114.1(5)° for Pym and average 117.4(4)^° for Py.The structure of the complex molecule of 2x CH₃ CO₂ CH₂ CH₃ has some differences when compared to that of the corresponding acetone solvate previously studied in this laboratory (Cini, R., Giorgi, G. and Pasquini, L., Inor`. Chim. Acta, 1992, 196, 7). The two structures differ mainly by the orientation of the phenyl donor with respect to the Cl-Rh-Cl axis (which is more eclipsed for the ethylacetate solvate) and by the conformation of the SbPh₃ ligands.Density functional calculations at the B3LYP/LANL2DZ level with full geometry optimization were carried out on the free Pym molecule and on some Sc(N ¹ Pym) ^{3 +}and Sc(N ² Pym) ^{3 +} model molecules. The effect of metal coordination consists mainly in enlarging the (Sc)N-C bond distances up to 0.150Å, whereas the C-N(Sc)-C bond angle decreases of 1.9°. Significant changes on other bond lengths and angles relevant to ring atoms of Pym occur upon metal coordination to the nitrogen atom. The metal coordination to N(2) is less favorable than to N(1) of 7.5 kcal for 1:1 species of Sc^{3 +}Extended Hückel calculations showed that HOMO consists mostly of metal-d orbitals with some character of chloride and phenyl and pyrimidine ligands, whereas LUMO is composed of phenyl, pyridine and pyrimidine orbitals. The method well reproduces the Rh-N and Rh-C bonding distances and gives Rh-C dissociation energy 2.38 and 5.48 times that for the Rh-N(Py) and Rh-N(Pym) bonds, respectively.     

Syntheses of (imidazole)pentaamminemetal(III) and μ-imidazolatodecaamminedimetal(III) complexes from trifluoromethanesulfonato precursors

The [M(NH₃)₅(imidH)]³⁺ complex ions (M = Co, Rh or Ir; imidH = imidazole) can be readily prepared by reaction of [M(NH₃)₅(OSO₂CF₃)]²⁺ ions with imidazole in sulfolane. Subsequent reaction of [M′(NH₃)₅(OSO₂CF₃)]²⁺ with [M(NH₃)₅(imidH)]³⁺ in sulfolane in the presence of a non-coordinating base permits synthesis of the binuclear imidazolate-bridged complexes [(NH₃)₅M(imid)M′(NH₃)₅]⁵⁺ (M = M′= Co or Rh; M = Co, M′ = Rh), characterized by spectroscopic, chromatographic and voltammetric methods, and by reactivity.     

Octa(ɛ-caprolactam)erbium(III) hex(isothiocyanato)chromate(III): Synthesis and crystal structure

The ionic mixed-ligand bimetallic complex [Er(?-C₆H₁₁NO)₈][Cr(NCS)₆] has been synthesized and studied by X-ray diffraction analysis. The crystals are monoclinic, space group C2/c, a = 39.627(2) Å, b = 22.3406(11) Å, c = 23.7155(10) Å, β = 107.687(2)°, V = 20 002.9(16) ų, Z = 12, ρ_calcd = 1.467 g/cm³. The coordination polyhedron of the erbium atom is a distorted square antiprism formed by the oxygen atoms of the organic ligands. The Er-O bond lengths vary within 2.29–2.44 Å. The coordination polyhedron of the chromium atom is a slightly distorted octahedron, and the Cr-N bond lengths range from 1.99 to 2.01 Å.     

Polynuclear Heteroligand Yb(III)–Er(III) Complexes as Potential Upconversion Materials

Russian Journal of Coordination Chemistry - The synthesis of complexes LnI(C6F5O)2 and LnCp(L)2 (Ln = Er, Yb; L = C6F5O, SONF), which are convenient precursors for the preparation of heteroligand...     

Mit Cer(III)-Sulfatl?sungen lassen sich Hexacyanoferrat(III) und Permanganat

Ohne Zusammenfassung     

Thermal analysis of rare-earth metal(III) hexa(isothiocyanato)chromate(III) complexes with ɛ-caprolactam

Thermal decomposition of the complexes [LnL₈][Cr(NCS)₆] (Ln = La³⁺, Ce³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺, Tm³⁺, Yb³⁺, Lu³⁺; L = ɛ-C₆H₁₁NO) in air and in inert atmosphere was studied by thermogravimetry, X-ray phase analysis, IR spectroscopy, and mass spectrometry. The compositions of gaseous and solid thermolysis products were established. A reversible thermochromic effect was found on heating to 200–210°C.     

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.     

σ-Bonded organometallic derivatives of yttrium(III) and thulium(III): An unusual ligand coupling reaction mediated by thulium(III)

The reaction between LnI₃(THF)_3.5 and 2 equiv. of {(Me₃Si)₂(Me₂MeOSi)C}K (1) in THF at room temperature yields only the mono-substituted products {(Me₃Si)₂(Me₂MeOSi)C}LnI₂(THF)₂ [Ln = Y (5), Tm (6)]; under more forcing conditions decomposition occurs. In contrast, the metathesis reaction between TmI₃(THF)_3.5 and 2 equiv. of the lithium iodide-containing salt {(Me₃Si)₂(Me₂MeOSi)C}K(LiI)_x yields the highly unusual separated ion pair complex [[{(Me₃Si)₂C(SiMe₂)}₂O]TmI₂{Li(THF)₃}₂][[{(Me₃Si)₂C(SiMe₂)}₂O]TmI₂] (8). The dianionic ligand in 8 is derived from the coupling of 2 equiv. of (Me₃Si)₂(Me₂MeOSi)C⁻, accompanied by the formal elimination of Me₂O. The structures of compounds 5, 6, and 8 have been determined by X-ray crystallography; compound 8 crystallizes as an unusual ion pair, the cation and anion of which differ only in the inclusion of 2 equiv. of Li(THF)₃ in the former, bridged to thulium by iodide ions.