Komplexbildung des Hydroxycobalamins mit Kaliumhexacyanoferrat(II)

Zusammenfassung Das Hydroxycobalamin bildet mit Kaliumhexacyanoferrat(II) bei pH 2,5–2,7 ein wasserlösliches Derivat [B₁₂-Fe(CN)₆-B₁₂]^2–, das einen Komplex mit einer Bildungskonstante lgK=10,00±0,04 darstellt. Der Komplex ist reaktionsfähig und wird leicht in andere Derivate des Vitamins B₁₂ übergeführt.

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Complex Formation of hydroxycobalamin with potassium hexacyanoferrate(II)

Hydroxycobalamin forms with potassium hexacyanoferrate(II) at pH 2.5–2.7 a water soluble complex [B₁₂-Fe(CN)₆-B₁₂]^2– with a formation constant lgK=10.00±0.04. The complex has high reactivity and easily can be converted into other derivatives of vitamin B₁₂.

     

Komplexbildung des tert-Butyliminovanadium(V)-trichlorids mit O-Donor-Liganden

Coordination Compounds of tert-Butyliminovanadium(V) Trichloride with O-Donor-Ligands The reaction of tert-butyliminovanadium(V)trichloride ( 1 ) with cyclic and acyclic ethers, ethylene carbonate and thietane has been studied. The 1:1-complexes have a different stability; reversible and irreversible cleavage of ether in the coordination sphere of the vanadium atom rearranging in ω-chloroalkanolato ligands are observed. The reaction of 1 with 2-chloroethanol, 3-chloropropanol and 5-chloropentanol yields the complexes ^tC₄H₉N = V(OR)Cl₂ (R = CH₂CH₂CH₂CH₂CH₂Cl) and [^tC₄H₉N = V(OR)Cl₂ · ROH]; in the presence of triethylamine the disubstituted compounds ^tC₄H₉N = V(OR)₂Cl are formed. The ⁵¹V NMR spectra are discussed. The crystal structure of [^tC₄H₉N = VCl₃ · DME] ( 12 ) and [^tC₄H₉N = V(OCH₂CH₂Cl)Cl₂ · HOCH₂CH₂Cl] ( 13 ) has been determined. The vanadium atoms in 13 have a distorted octahedral coordination and are linked by the oxygen atoms of the 2-chloroethanolato ligands forming a binuclear complex. In solution molecular weight measurement and ⁵¹V NMR data indicate the equilibrium between a mononuclear complex 13 and its isomer [^tC₄H₉N = V(OCH₂CH₂Cl)₂Cl · HCl].     

Die Komplexbildung von 4-(2-Thiazolazo)-resorcin mit Kupfer(II), Blei(II), Zink(II), Cadmium(II) und Wismut(III)

Ohne Zusammenfassung     

Magnetisch anomale Kupfer(II)-Chelate mit Diaminliganden

Complexes of the formula Cu₂X₃ (OR)(N∩N)₂ [X = Cl, Br; R = H, CH₃; N∩N = bidentate amineligand] are described, their magnetic and spectrophotometric properties are discussed and the possible structures deduced.     

Reaktionen von Diaminosulfanen mit Kupfer(II)-Salzen

Reactions of bis(diethylamino) and dimorpholinosulfane with [Cu(H₂O)₆](ClO₄)₂ in acetonitrile and with CuCl₂·2H₂O in ethanol yield Cu(I) compounds and SO₂. The reaction product of dimorpholinosulfane and CuCl₂ in ethanol is OC₄H₈NSOC₂H₅. The reactions are discussed.     

Kupfer(II)-Komplexe mit 2,2′-Dihydroxychalkonen

Copper(II) complexes with 2,2-dihydroxychalkones have been prepared in aqueous alcohol medium and characterised by the elemental analysis. They have 11 stoichiometry and i.r spectra show the involvement of the OH and C=O groups in the bond formation. These copper(II) complexes show magnetic moments in the range of 1.53–1.98 _B and are insoluble in common organic solvents. In view of the magnetic data, solubility and electronic spectral evidences, an extended polymeric structure has been proposed for these complexes.     

Eine gravimetrische Kupfer(II)-bestimmung mit Diphenylcarbazid

Ohne Zusammenfassung     

Zur Oxydation von Nickel(0)-Komplexen mit Halogenverbindungen des Kobalt(II), Kupfer(II) und Zink(II)

Oxidation of Nickel(0) Complexes by Halogen Compounds of Cobalt(II), Copper(II), and Zine(II) In aceton as a solvent Ni(PPh₃)₄ is oxidized by; cobalt(II) complexes of the type (Ph₃P)₂CoX₂ to nickel(I) compounds. In the case of X = Cl (Ph₃P)₃NiCl and (Ph₃P)₃CoCl separately crystallize, while for X = Br the lattice compound CoNi(PPh₃)₆Br₂ and for X = I CoNi(PPh₃)₅I₂ are formed. CuBr₂ and Ni(PPh₃)₄ react to (Ph₃P)₂NiBr and (Ph₃P)_nCuBr. With (Ph₃P)₂ZnCl₂ also (Ph₃P)₃NiCl is formed But in this case the oxidant is hydrogen chloride originating from hydrolysis. The magnetic moments of the new compounds were measured and their vis and fir spectra compared with those of the simple compounds (Ph₃P)_nNiX (n = 2, 3) and (Ph₃P)₃CoX. The M–X stretching frequencies are assigned. The cobalt (I) complexes (Ph₃P)₃CoCl have identical (distorted tetrahedral) structures, but most probably the nickel (I) complexes have not.     

Die spektralphotometrische Bestimmung des Kupfer (II)-Ions

Ohne Zusammenfassung     

Coulometrische Titration von Kupfer(II) mit elektrolytisch erzeugtem Zinn(II)

Ohne Zusammenfassung     

Isomere Kupfer(II)-Chelate mit Liganden vom Cuprointyp

Two pairs of isomeric copper(II) chelates of the composition Cu(dm)(NO₃)₂ and Cu(dp)(NO₃)₂, resp., have been prepared (dm=6,7-dihydro-5,8-dimethyl-dibenzo[b,j][1,10]phenanthroline), anddp=6,7-dihydro-5,8-diphenyl-dibenzo[b,j][1, 10]-phenanthroline). By ESR, IR, and visible reflectance spectra the structures of the first coordination sphere of these chelates have been established, the two Cu(dm) (NO₃)₂ chelates and the brown -Cu(dp) (NO₃)₂, having coordination number six while the green -Cu(dp) (NO₃)₂ has coordination number seven. In comparison with the diamagnetically diluted complexes (solution, powder) the isomerism is found to be typical only for undiluted copper(II) complexes.

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Mit 2 Abbildungen

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19. Mitt.:D. Rehorek, H. Spindler undPh. Thomas, Z. Chem.15, 281 (1975).     

Kupfer(II)-Komplexe mit para- und diamagnetischen Semicarbazonliganden

A series of complexes formed between the copper(II) metal ion and the semicarbazone of the stable free radical 2-acetyl-2,5,5-trimethyl-4-phenyl-3-imidazoline-3-oxid-1-oxyl and the analogous hydroxylamine has been prepared. By analysis of the IR spectra of the complexes the coordination mode of the ligands was determined.

     

Eine selektive Kupfer (II)-bestimmung mit Hilfe von Pentandiamin

Ohne Zusammenfassung     

Die F?llungsbedingungen des Kupfer(I)-thiocyanats aus Kupfer(II)-salzl?sungen

Ohne Zusammenfassung     

Die Titrationsmethoden mit Kupfer (III) -perjodat oder Kupfer (III)

Ohne Zusammenfassung     

Zur Kenntnis der polymeren Achtringstruktur des Kupfer(II)-dichlorophosphats

Note on the polymeric 8-ring structure of copper(II) dichlorophosphate According to the vibrational spectrum, the Cu atoms in Cu(O₂PCl₂)₂ are linked to a polymeric 8-ring structure by O? P? O bridges resulting in a square planar coordination of Cu²⁺. From the EPR spectrum a canting angle 2γ? 104° between adjacent CuO₄ planes can be deduced as an additional information. The EPR powder data are discussed with respect to an alternative structural model: 2γ may be located either within each polymeric Cu(II) complex resulting in a strongly corrugated chain structure, or all CuO₄ planes of a chain may run parallel; 2γ then ought to be the angle between the CuO₄ planes of different chains.     

Reaktion von Phlorein mit Kupfer(II)-ionen und deren elektrophile Substitution mit Konkurrenzkationen

Zusammenfassung Die vorliegende Arbeit behandelt die Reaktion von Phlorein mit Kupfer(II). In äquimolaren Lösungen kommt es im p_H-Bereich 4,5 bis 8,2 zur Bildung eines Komplexes im Verhältnis der Komponenten 11. Die scheinbare Stabilitätskonstante entspricht beipH4,18 dem Wert logK _1,1= =5,1±0,1 und bei p_H 5,88 dem Wert log K_1,1=5,4±0,1. Bei einem mehr als zehnfachen Überschuß von Cu²⁺-Ionen ist es besonders in alkalischem Medium möglich, eine Komplexbildung mit erhöhter Anzahl koordinierter Metallionen anzunehmen.Mit Hilfe elektrophiler Substitution des Kupfers durch andere Kationen wurde Phlorein als analytisches Reagens für eine Reihe zwei- und einwertiger Kationen charakterisiert.

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Reaction of phlorein with copper(II) Ions and their electrophilic substitution with competing cations

Summary The present study deals with the reaction of phlorein with copper(II). In equimolar solutions and in the p_H range 4.5 to 8.2, there results a complex in which the components are in the ratio 11. The apparent stability constant at p_H 4.18 corresponds to the value log K_1,1=5.1±0.1 and at p_H 5.88 the value is log K_1,1=5.4±0.1. In the presence of a more than 10-fold excess of Cu²⁺ ions it is possible, especially in alkaline medium, to assume a complex formation with an increased number of coordinated metal ions.With the aid of electrophilic substitution of the copper by other cations, phlorein was characterized as an analytical reagent for a number of di- and monovalent cations.

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Symbolverzeichnis M Verdrängungskation - X Bezeichnung von Phlorein - [ ] Gleichgewichtskonzentrationen - analytische Gesamtkonzentrationen - g Anzahl koordinierter Metallionen - n Bjerrumsche komplexbildende Funktion - k _g stufenweise Stabilitätskonstante einesg-Komplexes - K _g totale Stabilitätskonstante einesg-Komplexes - K Gleichgewichtskonstante der Verdrängungsreaktion - Kd Dissoziationskonstante eines Cu²⁺-Komplexes - Proportionalitätskonstante der Ilkovi-Gleichung - Id polarographischer Grenzstromwert - E Potentialwert eines polarographischen Grenzstromes - R Variationsspannweite - (%) Variationskoeffizient in Prozent - (%) Relativfehler in Prozent - A C _X/C _Cu - B C _Cu/C _X