Zum Einfluß der Alkylkette auf Protolyse,Komplexbildung und Extraktionseigenschaften N-substituierter 2-(o-Hydroxyphenyl)-Δ2-imidazoline

Influence of the Alkyl Chain on Protolysis, Complex Formation, and Extraction Properties of N-Substituted 2-(Δ²-Imidazolin-2-yl)-phenols N-substituted 2-(Δ²-imidazolin-2-yl)-phenols RNNOH may be used as extractants of copper(II) from acidic solutions. In an aqueous phase they are existent as betains \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R}\mathop {\rm N}\limits^ \oplus {\rm HNO}^ \ominus $\end{document} ( IIa ). Solvents with lower dielectricity constants (dioxane-water-mixtures) favour the neutral acid RNNOH ( IIb ) a tautomer of IIa . The protonation of IIa or IIb proceeds in a weakly acidic solution. Therefore, at 3 ≤ pH ≤ 4 which is favourable for copper(II) extraction, the extractants exist as the cations [RNHNOH]⁺. The octyl compound OcNNOH from such a solution is extracted by chloroform, less effective by toluene, as an ion pair \documentclass{article}\pagestyle{empty}\begin{document}$ [{\rm Oc}\mathop {\rm N}\limits^ \oplus {\rm HNOH]X} $\end{document}. The distribution coefficient increases in the order HSO₄^? < NO₃^? < ClO₄^? which is well-known for quaternary ammonium salts. The affinity of the ion pairs, which are derived from the butyl compound BuNNOH, to organic solvents is very weak independently of the anion. For solubility reasons a study of the formation of the trans-planar copper(II) chelates Cu(RNNO)₂ is possible only in dioxane-water mixtures. Because of lg K₁ ≥ lg k₂ + 2 the stability regions of Cu(RNNO)⁺ and CU(RNNO)₂ are clearly separated. The distribution coefficients of Cu(RNNO)₂ increase with the length of R exceeding that of the free ligand by one power of ten and more.     

Katalytischer Effekt der Kupfer(II)-ionen auf die Reaktionen mit Kaliumhexacyanoferrat (III)

Ohne Zusammenfassung     

Zum Einfluß der Zusammensetzung gemischter Lösungsmittel auf die Stabilitäts- und Bildungskonstanten von Kupfer(II)- und Nickel(II)-Komplexen substituierter 1,2-Dioxime

Influence of the Composition of Mixed Solvents on the Stability and Formation Constants of Copper (II) and Nickel(II) Complexes of Substituted 1,2-Dioximes The stability constants ^cK₁, ^cK₂, and _cβ₂ of the complexes which are formed in the systems M²⁺/DH₂, M²⁺/Ac? DH₂, and M²⁺/Et, Me\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm N}\limits^ \oplus $\end{document}? DH₂ (M²⁺ ? Cu²⁺, Ni²⁺; DH₂, Ac? DH₂, Et₂Me\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm N}\limits^ \oplus $\end{document}? DH₂ = 1,2-dioximes) are determined in water and in water-dioxane mixtures (25, 50 and 75 per cent). Because of the stabilisation of the l,2-complexes by intramolecular hydrogen bonds ^cK₂, is always higher than ^cK₁. On account of the decrease of the dielectricity constant the constants ^cK₁, ^cK₂, and ^cβ₂, rise with increasing contents of dioxane in the mixtures. The influence of the dielectricity constant may be eliminated by considering the formation constants ^cK_1(B), ^cK_2(B), and ^cβ_2(B). The individual formation constants ^cK_1(B) of the 1,l-complexes investigated are independent of the composition of the solvent, but among the overall formation constants ^cβ_2(B) this comes true only for the complexes Ni(Ac? DH)₂, Ni(Et₂Me\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm N}\limits^ \oplus $\end{document}? DH)₂, and Cu(Et₂Me\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm N}\limits^ \oplus $\end{document}? DH)₂. With Cu(DH₂) and Cu(Ac? DH)₂ a linear relation between log ^cβ_2(B) and the molar fraction of water is stated. This effect is attributed to a specific solvatation of the chelates Cu(DH)₂ and Cu(Ac? DH)₂ by water.     

Zum Einfluß der Gasphase auf die thermische Zersetzung von K2[SiF6]

Effect of the Gas Phase on the Thermal Decomposition of K₂[SiF₆] K₂SiF₆ produced in usual ways is contaminated by traces of oxygen and protons. These and traces of water fed by gas atmosphere influence the thermal decomposition reaction. To study the influence of the gas phase definite amounts of H₂O and HF were added. The formation of SiF₄ was determined. The development of a SiO₂ phase in presence of H₂O and other experimental results suggest the construction of a layer on the K₂SiF₆ surface, which hinders further SiF₄ being developped. Temperature and linear velocity of the gas influence the length of a zone of decomposition migrating through the solid. This is explained by sorption and reaction behavior of intermediately formed fluorosiloxanes.     

Zum Einfluß von Substitutionen durch Ionen gleicher Ladung auf die Lumineszenz des Europium(II)-aktivierten Pentastrontiumchloridphosphats

On the Influence of Substitutions by Ions of the Same Charge on Luminescence of Pentastrontium Chloridephosphate Activated by Divalent Europium Powder materials of pentastrontium chloridephosphate activated by divalent europium and of substituted luminophors have been prepared by solid state reaction. Strontium was substituted partially by calcium, barium or cadmium. These luminophors crystallize in the hexagonal apatite structure. There are two crystallographical different sites for the cations. In addition to X-ray diffractograms, emission and excitation spectra and spectra of the diffuse reflection of the luminophors have been studied at room temperature and moreover the emission of the samples above 25°C. The cations affect size of the elementary cell and therefore the luminescence properties of the chloridephosphates activated by divalent europium. The luminescence arises from transitions between 4f⁶5d and 4f⁷ configurations of the Eu¹¹ ion.     

ESR-Untersuchungen an Kupfer(II)-bis(diäthyl-diselenocarbamat) in Zn(II)-und Pd(II)-bis-(diäthyldiselenocarbamat): Zum Einfluß verschiedener Symmetrien der Se4-Koordinationssphäre auf die Parameter des Spin-Hamilton-Operators und die Bindungsverhältnisse

EPR Investigations on Copper(II)-bis(diethyl-diselenocarbamate) in Zn(II) and Pd(II)bis(diethyl-diselenocarbamate): The Influence of Different Symmetries of the Se₄-Coordination Sphere on the Parameters of the Spin-Hamilton ian and on the Bonding Properties EPR investigations on polycrystalline samples of Cu(desc)₂ in Pd- and Zn(desc)₂ and on single crystals of Cu(desc)₂/Zn(desc)₂ are reported (desc = diethyldiselenocarbamate). In the EPR spectra the rare case of noncoinciding principal axes of the g- and the Cu-hyperfine structure tensor is observed. The influence of the different coordination geometries in Pd(desc)₂ (planar) and Zn(desc)₂ (distorted tetrahedron) on the spin-Hamiltonian parameters and the bonding situation is investigated and compared with the parameters obtained from Cu(desc)₂/Ni(desc)₂. In Cu/Zn(desc)₂ a general shift of the g-tensor components to higher g-values is observed indicating a descrease of the covalency in the in-plane- and out-of-plane-π-bonds. The degree of covalency of the ground state-σ-bond remains unchanged neglecting small differences. The x-, y-components of the g-tensor and the angle between the noncoinciding principal axes in the Cu(dsc)₂ are found to be very sensitive indicators with respect to direct changes (caused by changes in the ligand field symmetry in the different host lattices) and to indirect changes (caused by variation of the N-alkyl groups in the ligand) in the bonding situation of the 1^st coordination sphere.     

Einfluß der Alkylgruppen auf die Struktureigenschaften der Cyanato-Kupfer(II)-Komplexe mit Alkylpyridinen

New cyanato-copper(II) complexes of the type Cu(NCO)₂ L ₂ (L=2,3-, 2,5-, 3,4- or 3,5-lutidine, 3- or 4-ethylpyridine) and Cu(NCO)₂ L (L=2,3- or 2,5-lutidine, 2-ethylpyridine) were prepared. Solid state electronic, ESR and IR spectral results show, that Cu(NCO)₂ L ₂ complexes have tetragonal structures varying from pseudooctahedral to practically planar forms, also involving a square-pyramidal arrangement. The -form of Cu(NCO)₂(2-picoline)₂ was isolated and found to be a distortion isomer of the known -form. According to physical results, Cu(NCO)₂ L complexes exhibit highly distorted five-coordinate structures. Further knowledge about the influence of type, number and position ofL ligand alkyl groups on the structure-bonding properties of cyanato-copper(II) complexes was obtained.

18. Mitt.:Valach, F., Dunaj-Juro, M., Handlovi, M., J. Cryst. Mol. Struct.10, 61 (1980).     

Zum Einfluß der Ringgröße auf die Struktur von Metallchelaten. IV. Palladium(II)- und Platin(II)-Komplexe pyridylsubstituierter Dialkylsulfide und -amine

The Influence of Ring Size on the Structure of Metal Chelates with Tridentate Ligands. IV. Palladium(II) and Platinum(II) Complexes of Pyridyl Substituted Dialkyl Sulfides and Amines [β-(Pyridyl-2)-ethyl]-[(pyridyl-2)-methyl]-amine(2,3-py₂tri) forms planar palladium(II) complexes [Pd(2,3-py₂tri)X]X (X = Cl, Br) occupying trans-positions as a tridentate ligand. An analogous behaviour is observed with bis[β-(pyridyl-2)-ethyl]-sulfide(3,3-py₂Stri) in the chelate compounds [Me^II(3,3-py₂Stri)X]X (Me^II = Pd, Pt; X = Cl, Br, J, SCN). On the other hand the rigid ligand bis[(pyridyl-2)-methyl]-sulfide(2,2-py₂Stri) is only bidentate in the complexes Me^II(2,2-py₂Stri)X₂ (Me^II = Pd, Pt; X = Cl, Br, J, SCN), one pyridine group does not interact with the central atom. The reasons are the angular relations within the thioether group of 2,2-py₂Stri which allow a tridentate coordination in a facial conformation (octahedral and trigonal-bipyramidal nickel(II) and copper(II) complexes), but not in a meridional one (planar palladium(II) and platinum(II) complexes). In Pt(2,2-py₂Stri)(SCN)(NCS) one thiocyanato ligand is linked by sulfur, the other one by nitrogen.     

ESR-Untersuchungen zum Substituenteneinfluß an Kupfer(II)-β-Thioxoketonaten

The ESR spectra of some copper chelates of β-thioxoketones are reported. Using a simple MO-model the MO-parameters are calculated. The influence of the substituents with respect to the degree of covalency of the metal ligand bonds is discussed.     

Zum Einfluß von Zusätzen auf die Hydratation von Tricalciumsilicat (Ca3SiO5)

On the Influence of Admixtures on the Hydration of Tricalcium Silicate (Ca₃SiO₅) The influence of several compounds (alcohols, ketones, organic acids and the ir salts, cation exchange resin) on the hydration of tricalcium silicate was investigated by means of differential calorimetric analysis (DCA). The acceleration and retardation of this reaction found in these experiments are discussed on the basis of Ca(OH)₂ solubility, the pH of the solution and the rate of conversion of a C? S? H rich in CaO into a C? S? H poor in CaO at the surface of the C₃S grains.     

Zum Einfluß der Ringgröße auf die Struktur von Metallchelaten dreizähliger Liganden. II.; Stabilitätsmessungen an Chelaten pyridylsubstituierter Dialkylsulfide mit 3d-Elementen

Inhaltsübersicht. Es wird über die Komplexbildung zwischen Ionen der 3d-Elemente und Bis[β-pyridyl(2)-äthyl]-sulfid (3, 3-py₂S-tri) und [Pyridyl(2)-methyl]-[β-pyridyl(2)-äthyl]-sulfid (2, 3-py₂S-tri) in wäßriger Lösung berichtet. 2, 3-py₂S-tri bildet mit Kupfer(ii)- und Nickel(ii) 1, 1- nnd 1,2-Komplexe, in denen es als dreizähliger Ligand fungiert. In den Komplexen M(2,3-py₂S-tri-H)³⁺ (M = Cu(II) oder Nickel(ii)) besetzen die Liganden 2,3-py₂S-tri-H⁺'zwei Koordinationsstellen und bilden Chelatfünfringe aus. Bei dem Liganden 3,3-py₂S-tri konnten normale und protonierte 1,1-Komplexe, im Falle des Kupfer(II) auch ein 1,2-Komplex nachgewiesen werden. Für eine Komplexbildung zwischen Kobalt(ii) oder Zink(ii) und 2,3-py₂S-tri oder 3,3-py₂S-tri ergaben sich keine Hinweise. Aus sterischen Gründen sind die Komplexe des stärker basischen Liganden 3,3-py₂S-tri instabiler als die des 2,3-py₂S-tri. The Influence of Ring Size on the Structure of Metal Chelates with Tridentate Ligands. II. Stability Measurements of 3d-Metal Chelates with Pyridyl Substituted Dialkyl Sulfides Abstract. The complex formation between ions of the 3d-elements and bis[β-pyridyl(2)-ethy)]-sulfide (3,3-py₂S-tri) and [pyridyl(2)-methyl]-[β-pyridyl(2)-ethyl]-sulfide (2,3-py₂S-tri) was investigated in aqueous solution. 2,3-py₂S-tri forms 1,1- und 1,2-complexes with copper(II) and nickel(ii) acting as a tridentate ligand. In the complexes M(2,3-py₂S-tri-H)³⁺ (M = Cu(ii) or Ni(ii)) the ligand 2,3-py₂S-tri-H⁺ is bidentate forming a five-membered chelate ring. With the ligand 3,3-py₂S-tri normal and protonated 1,1-complexes were detected, in the case of copper(ii) also a 1,2-complex. No complex formation was observed between cobalt(ii) or zinc(ii) and 2,3-py₂S-tri or 3,3-py₂S-tri. From steric reasons the complexes of the higher basic ligand 3,3-py₂S-tri are more instable than the those of the ligand 2,3-py₂S-tri.     

Komplexchemie P-reicher Phosphane und Silylphosphane. X [1] Zum Einfluß der Komplexierung auf die Reaktivität des [(Me3Si)2P]2PH

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. X. The Influence of the Formation of Complex Compounds on the Reactivity of [(Me₃Si)₂P]₂PH Whereas [(Me₃Si)₂P]₂PH 1 by BuLi is attacked at the PH group to give [(Me₃Si)₂P]₂PLi 2 , the related chromium carbonyl complex (Me₃Si)P^IV ? ²P^IV(H) ? ³P^III(Si? Me₃)₂ · Cr(CO)₄ 3 with BuLi yields Li(Me₃Si)¹P^IV ? ²P^IV(H) ? ³P^III(SiMe₃)₂ · Cr(CO)₄ 4 by cleaving a Si? P bond at the chromium substituted ¹P atom. Dissolved in ether, 4 is stable for a longer time, while under comparable conditions 2 forms Li₃P₇ which is not obtained from 4 . MeOH in 3 cleaves selectively the Me₃Si groups from the complex substituted P atom yielding (Me₃Si)(H)¹P^IV ? ²P^IV(H) ? ³P^III(SiMe₃)₂ · Cr(CO)₄ 5 and HP^IV ? ²P^IV(H) ? ³P^III(SiMe₃)₂Cr(CO)₄ 6. 5 and 6 seem to be stable in contrast to the uncoordinated triphosphanes which are not known.     

Einfluß der Chelatbildner dppe und dppp auf die Bildung und die Eigenschaften der Pt-Komplexe des tBu2P–P

Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XV. Influence of the Chelate Compounds dppe and dppp on Formation and Properties of the Pt Complexes of ^tBu₂P–P The chelating ligands dppe and dppp replace the PPh₃ groups in [η²-{^tBu₂P–P}Pt(PPh₃)₂] 1 yielding [η²-{^tBu₂P–P}Pt(dppe)] 2 and [η²-{^tBu₂P–P}Pt(dppp)] 8 . However, they don't replace the phosphinophosphinidene ligand ^tBu₂P–P. dppm does not react at all with 1 . [η²-{H₂C=CH₂}Pt(dppe)] 3 yields in the presence of ^tBu₂P–P=P(Me)^tBu₂ 4 exclusively Pt(dppe)₂ 5 and elemental Pt; no 2 could be detected. Similarly, [η²-{H₂C=CH₂}Pt(dppp)] 7 reacts with 4 to give mainly Pt(dppp)₂ 9 and Pt; [η²-{tBu₂PP}Pt(PPh₃)₂] 8 is present only as a minor product. [η²-{^tBu₂P–P}Pt(dppe)] 2 crystallizes in the monoclinic space group P2₁/c (no. 14) with a = 1834.40(10) pm, b = 1679.70(10) pm, c = 1125.79(6) pm, β = 103.963(5)°.     

Komplexbildung des Kupfer(II) mit Opioidpeptiden

Complex Formation of Copper(II) with Opioid Peptides Complex compounds of copper(II) with the neuropeptide enkephaline were detected as CuH_?(n?1)L + nLi⁺ ions by means of FAB mass spectrometry. Formation constants of proton and copper(II) complexes of four opioid peptides (L-I ? L-IV) were determined potentiometrically. Complexes with methionine-containing ligands show the highest stability. Under physiological pH values all brain-existent enkephaline may be bound by endogeneous copper provided that [Cu²⁺] > 10^?7 M.     

Komplexone XLIV. Die Komplexe der Anionen der Triäthylentetraminhexa-Essigsäure mit Calcium(II), Kupfer(II) und Zink(II)

Using pH-methods - direct titration according to Schwarzenbach, and ligand-ligand exchange - the stability constants of the complexes of divalent calcium, copper and zinc ions with the anions of triethylenetetramine hexaacetic acid have been determined. The complications arising by the interpretation of the experimental measurements of pH-values below 3.5 are discussed. These factors are normally not taken into account, and often wrong values of the equilibrium constants have been communicated.