Komplexe von Kupfer(I) mit Glyoxal-bis-N-t.-butylimin

Formation of strongly colored complexes of Cu⁺ with glyoxal-bis-(N-t-butylimin) (GLI) is observed in acetonitrile. Optical measurements reveal two complexes, Cu(GLI)⁺ (?_max = 26.0 kK, δ = 2800) and Cu(GLI) (?_max = 19.3 kK, ε = 8530). The equilibrium constants (0.1M tetraethylammoniumperchlorate) are logK₁ = 3.9 and logK₂ = 2.5. The equilibrium data are confirmed by potentiometric measurements with a copper electrode. In O-donor solvents, only the 1:2 complex is observed. Cu(GLI)₂CIO₄ can be crystallized as a dark red solid which is stable towards atmospheric oxygen.     

Eine Methode zur Bestimmung von Kupfer, Kupfer(I)-oxyd und Kupfer(II)-oxyd nebeneinander

Ohne Zusammenfassung     

Mischungsenthalpien von geschmolzenen Kupfer(I)-halogenid-Chalkogen Systemen

Enthalpies of Mixing of Liquid Copper(I)-Halide-Chalkogen Systems The integral enthalpies of mixing of liquid CuCl(Br)–Se(Te) mixtures were determined in an isoperibolic calorimeter at temperatures of 766 and 818 K for tellurium and 818 K for selenium mixtures. The selenium systems are endothermic, the tellurium systems exothermic. The absolute value of the enthalpy of mixing of the tellurium systems decreases with increasing temperatures. The endothermic resp. exothermic behaviour of these systems is interpreted in terms of the structure of these melts.     

Darstellung und Struktur von Tetraethylcyclotetraarsoxan-Komplexen von Kupfer(I)-Halogeniden

Preparation and Structure of Tetraethylcyclotetraarsoxane Complexes of Copper(I) Halides The polymeric complexes [Cu₄Cl₄{cyclo-(C₂H₅AsO)₄}₃]_n ( 1 ), [Cu₃Br₃{cyclo-(C₂H₅AsO)₄}₂]_n ( 2 ) and [Cu₆I₆{cyclo-(C₂H₅AsO)₄}₃]_n ( 3 ) were prepared by the reaction of (C₂H₅AsO)_n and CuX (X = Cl, Br, I) in acetonitrile and characterised by X-ray analysis. All three complexes contain only tetramers (C₂H₅AsO)₄ as ligands, in which the As₄O₄ ring systems coordinate between two and four Cu-atoms. In each case one As₄O₄ ring with a crown-shaped conformation is observed, which coordinates either four (in 1 ) or three (in 2 and 3 ) axially sited Cu-atoms. In addition there are further (C₂H₅AsO)₄ ligands, which display either a boat-chair- (in 1 ) or a twist-chair-conformation (in 1–3 ). The individual building units are connected to one another via Cu? X? Cu bridges (in 2 and 3 ) and/or centrosymmetric As₄O₄ ring systems (in 1–3 ) into chain ( 1 ) or layer structures ( 2 und 3 ).     

Die arsenometrische Bestimmung von Kupfer(I)- und Kupfer(II)-ionen nebeneinander

Ohne Zusammenfassung     

Darstellung und Fluoreszenzeigenschaften von Kupfer(I)-Carboxylaten

Preparation and Fluorescence Properties of Copper (I) Carboxylates By reduction of copper(II) carboxylates with ascorbic acid in aqueous solutions some aromatic copper(I) compounds can easily be obtained by precipitation. Powder x-ray photographs of copper(I) propionate and copper(I) monochloroacetate have similar characteristic interferences as copper(I) acetate, from which a layer structure is known. All the here described copper(I) carboxylates are fluorescent, indicating that oxygen atoms behave as sufficently strong donors, but most of them and especially those with tetragonal structure, do not change their fluorescence colour by cooling in liquid nitrogen like many copper(I) complexes with nitrogen bases do (fluorescence thermochromism). Fluorescence thermochromism occurs however at copper(I) 3-hydroxybenzoate. This presumably results from a lower symmetry.     

Kathodische Chronopotentiometrie 1 von Kupfer(I) und Kupfer(II) in bromidhaltigen L?sungen

Ohne Zusammenfassung     

Darstellung und einige Eigenschaften von Kupfer(I)-Kupfer(II)-Selenocyanaten

Preparation and Some Characteristics of Copper(I)-Copper(II) Selenocyanates From the system Cu²⁺-H₂O-en-SeCN-in dependence on the conditions two new complexes have been prepared: Cu₃en₂(SeCN)(CN)₃· H₂O(I) and Cu₃en₂(SeCN)₂(CN)₂· H₂O(II). They were studied by the methods of infra-red and EPR spectra as well as by those of X-ray diffraction. It has been found that Cu₂₊ is coordinated in these complexes with two molecules of ethylene diamine and one molecule water. The anion ligands have a bridging function and coordinate the copper(I). The EPR spectra show that the two complexes exhibit around the atom Cu²⁺ have different ligand field symmetry. For complex (I) it is a typically axial spectrum with two values of the gfactor g⊥? 2.18 and g⊥? 2.05 while complex (II) has an asymmetrical isotropic spectrum with one g-factor value only g⊥? 2.07.     

Die photometrische Bestimmung von Kupfer als Kupfer (II)-aminoacetat

Ohne ZusammenfassungHerrn Prof. Dr. O. Glemser, Direktor des anorgan.-chemischen Instituts, danke ich für die Förderung der Arbeit durch Institutsmittel.     

Ascorbinometrische Bestimmung von Kupfer(II)-ionen

Zusammenfassung Es wurden mehrere Titrationsverfahren zur direkten reduktometrischen Bestimmung der Kupfer(II)-ionen mit Hilfe von Ascorbinsäuremaßlösung ausgearbeitet. Von den in verschiedenen Medien wie Mohrschem Salz + Kaliumrhodanid, Kaliumbromid + Natriumacetat, Natriumchlorid + Natriumacetat und schließlich Ammoniumchlorid + Natriumacetat durchführbaren Titrationen eignet sich die zuletzterwähnte am besten für praktische Analysenzwecke. Das Verfahren steht in bezug auf Genauigkeit und Reproduzierbarkeit der jodometrischen Bestimmung nicht nach, wird nur durch wenige Ionen gestört, und die zur Anwendung kommenden Reagentien sind alle sehr billig. Die ascorbinometrische Titration läßt sich visuell und unter Anwendung potentiometrischer Endpunktsanzeige im Makro- oder Mikromaße gut durchführen.Für die Ausführung einiger Versuche sagen wir Frau I. Buzás und Herrn Gy. Liptay verbindlichen Dank.     

Über fluoreszierende Verbindungen von Kupfer(I)-jodid mit aromatischen Stickstoffbasen

On Fluorescent Compounds of Copper(I) Iodide with Aromatic Nitrogenous Bases The easily obtainable compounds of copper(I) iodide with esters of nicotinic acid, with nicotinic acid amide and nitrile, as well as with quinoline, isoquinoline and quinaldine are strongly fluorescent in ultraviolet light. They are remarkably stable against water and air, compared with analogous picoline and lutidine compounds. Only in one case (nicotinic acid hexyl ester-copper(I) iodide) the phenomenon of fluorescence thermochromism has been observed.     

Kupfer(I)-jodid-Reagenspapier und Fluorescenz-Thermochromie

Zusammenfassung Zahlreiche aromatische und aliphatische Stickstoffbasen bilden mit Kupfer(I)-jodid fluorescierende Verbindungen, die bei Abkühlung in flüssigem Stickstoff ihre Fluorescenzfärbung ändern. Zur analytischen Auswertung dieses Phänomens wurde ein Reagenspapier entwickelt.Verff. sind der Deutschen Forschungsgemeinschaft, dem Fonds der chem. Industrie und der Wiss. Gesellschaft Saar e.V. für die Förderung dieser Untersuchungen zu Dank verpflichtet.     

Kupfer(I)-jodid-Reagenspapier und Fluorescenz-Thermochromie

The usual methods that are presently used for evaluation of potentiometric titrations make only partial use of the intrinsic information. Here is described a new method that processes all the data points that are generated in order to calculate concentration of the sample, pK-values and normal potential. Using the example of the titration of a single protonic acid we demonstrate that exact and reproducible results can be obtained in the range of pK-values from 4 to 11. In addition the time of measurement can be reduced by up to 80% without any loss in precision.     

Über Chalkogenolate. 179. Kupfer(I)-thioxanthate und Thioxanthatocuprate(I)

On Chalcogenolates. 179. Copper(I) Thioxanthates and Thioxanthatocuprates(I) Copper(I) thioxanthates Cu[S₂C? SR], where R = C₂H₅, ⁿC₄H₉, and CH₂? C₆H₅, have been prepared by two procedures and studied by means of diverse methods. They are soluble in ethanolic and acetonic solutions containing the corresponding [S₂C? SR]^? ions in excess to yield thioxanthatocuprates(I) [Cu_n(S₂C? SR)_n+1]^?. The compounds [(C₆H₅)₄P][Cu_n(S₂C? SC₂H₅)_n+1] with n = 1, 4, 6 have been isolated. The existence of [(C₆H₅)₄P][Cu₄(S₂C? SC₄H₉)₅] and [(C₆H₅)₄P][Cu₆(S₂C? SCH₂? C₆H₅)₇] has been ascertained.     

Über Chalkogenolate. LXVIII. Kupfer(I)-trithiocarbonate

On Chalkogenolates. LXVIII. Copper(I) Trithiocarbonates The prepared copper(I) trithiocarbonates MCuCS₃ with M = NH₄, K, α-Rb, α-Cs M = β-Rb, β-CS, [(C₆H₅),As] CU₂CS₃ · 2 KCN · 2H₂O are investigated by different methods.     

Über Kupfer(I)-carboxylate und Chlorocuprate(I)

In mixtures of 7 vol. acetonitrile and 3 vol. acetic acid, solutions or suspensions of copper(II) acetate can be reduced with hydrazine hydrate to solutions of copper(I) acetate. In this way, purely white copper(I) acetate can be isolated. Other copper(I) carboxylates can be prepared by reduction of copper(II) carboxylates or by reaction of solid carboxylic acids with copper(I) acetate. By adding acetyl chloride to solutions of copper(I) acetate in acetonitrile/acetic acid mixtures, solutions of chlorocuprates(I) are formed. From these, highly pure copper(I) chloride can be obtained. By adding alkali acetate or tetramethyl ammonium chloride to solutions of chlorocuprates(I), the pure compounds Cs₃[Cu₂Cl₅], Rb₂[CuCl₃] and NMe₄[Cu₂Cl₃] were obtained.