Spektrophotometrische Untersuchung der Komplexbildung von Eisen(III) mit Ethylendiamintetraessigsäure und einigen Thioliganden

Spectrophotometric Investigation of the Complexation of Iron(III)with Ethylene Diamine Tetraacetic Acid and Some Thioligands . In the system Fe^III/EDTE/R? SH (Thiophenol, Toluen-3,4-dithiol, Thioethanol bzw. Thioglycollic acid) ternary complexes could be detected in solution. By means of spectrophotometric measurements the ratio of components in the species Fe:L:L′=1:1:1 was determined. The optical properties of the complexes are discussed.     

Über Ternäre Chelate des Eisen(III)-Ions mit Nitrilotriessigsäure und Phenolderivaten

On Ternary Chelates of the Iron(III) Ion formed with Nitrilo-Triacetic Acid and Derivatives of Phenol Ternary chelates of iron(III) ions are produced with nitrilo-triacetic acid and some derivatives of phenol in aqueous solution. Their reactions of formation have been controlled by spectro-photometric methods. The ratio of components in the compounds Fe: X: L is 1: 1: 1 without any exception. The measured optical properties (λ_max, ε_max) of the ternary chelates are discussed and compared with the corresponding binary iron(III) phenol chelate.     

Die Reaktion von Eisen(III) mit Brenzkatechin-3,5-disulfonsäure (Tiron) und Äthylendiamintetraessigsäure

The Reaction of Iron(III) with Catechol-3,5-Disulphonic Acid (Tiron) and Ethylene Diamine-Tetracetic Acid In the system iron(III)-Tiron-EDTA a ternary chelate could be detected besides the well known complexes in a weak acid solution. By means of spectro-photometric measurements under various conditions (concentration of ligands) we found [FeHYL]^4? with λ_max = 555 nm und ε₅₅₅ = 2500 l · mol^?1 · cm^?1. The formation of the ternary chelate is an inner-complex reaction of displacing, in which donor atoms of the EDTA in FeY^? are replaced by Tiron. By graphic methods the equilibrium constants could be calculated from the measurements.     

Ternäre Phasen des Lithiums mit Kupfer und Phosphor

1. The system Li? Cu? P was investigated by phase analysis. The samples were prepared at 500–600°C. The resulting ternary phases were characterized mainly by x-ray investigation. 2. At 560°C the range of homogeneity of Cu ₃ P lies between 25.6–26.7 atomic % P. Cu₃P forms a high-temperature (HT) modifikation, which crystallizes in a hexagonal subcell of the low-temperature (TT) modification (Z = 6): a = 4.09, c = 7.19 Å, c/a = 1.76; Z = 2 at 560°C. The intensities of the HT-powder pattern could be explained by a model in the space group P3 ml—D³_3d, which was deduced from TT-Cu₃P. 3. Li ₂ CuP , which can be derived from Li₃P, crystallizes hexagonally with a = 16.18, c = 7.724 Å; c/a = 0.477; Z = 32. In the structure, copper occupies the Li position with lowest number and coordination. 4. LiCu ₂ P also crystallizes hexagonally with a = 12.08, c = 7.39 Å; c/a = 0.71; Z = 18. In the direction [001] there is a disordered superlattice. The lattice constants of the high-temperature modification of LiCu₂P, which are related to those of HT-Cu₃P, at 520°C are: a = 4.08, c = 7.44 Å; c/a = 1.82; Z = 2. The interpretation of the intensities of the powder patterns did not result in a plain model related to HT-Cu₃P when calculated for the space group P3 m1—D³_3d. 5. LiCu ₂ P ₂ crystallizes tetragonally with a = 3.887, c = 9.554 Å; c/a = 2.46; Z = 2. The structure determination gave the D1₃-type lattice. The space group is No. 139 I4/mmm—D¹⁷_4h, the atoms occupy the following positions: 2 Li in (2a), 4 Cu in (4d) and 4 P in (4e) with z = 0.388. The compound shows P₂ groups parallel to [001] with a P? P distance of 2.14 Å. 6. Li _1,75 Cu _1,25 P ₂ crystallizes orthorhombically with a = 3.874, b = 12.668, c = 8.743 Å; Z = 6. The crystal structure has been determined. The atoms occupy the following positions within the space group No. 71 Immm—D¹⁵_2h: 2 Li in (2a), 4 Li in (4g) with y = 0.27, 4 Li in (4j) with z = 0.33, 7.5 Cu in (8l) with y = 0.127 and z = 0.267, 8 P in (8l) with y = 0.352 and z = 0.377, and 4 P in (4h) with y = 0.085. This structure, too, is dominated by the occurence of P₂ groups, which are oriented as well parallel [001] as parallel [010].     

Ternäre Nickelphosphide und -arsenide mit einem Metall: Nichtmetall-Verhältnis von 2:1

Ternary Phosphides and Arsenides of Nickel with a Metal: Non-Metal Ratio of 2:1 Several new ternary phosphides and arsenides of nickel were prepared by reaction of the elements. SrNi₅P₃, SrNi₅As₃, and EuNi₅As₃ crystallize in the LaCo₅P₃ structure with the following lattice constants [Å]: BaNi₉P₅ (a = 6.534(1) Å, c = 10.847(2) Å) and BaNi₉As₅ (a = 6.760(1) Å, c = 11.226(2) Å) crystallize in a new type of structure (P6₃/mmc, Z = 2). The characteristic polyhedra are trigonal Ni-antiprisms centered by P or As atoms and trigonal Ni-prisms with vacant centres and sides capped by non-metal atoms. U₂Ni₁₂P₇ (a = 9.077(2) Å, c = 3.694(1) Å) has a Zr₂Fe₁₂P₇ structure (P6 , Z = 1).     

Spektralphotometrische Bestimmung von Eisen(III) und Chrom(VI) mit Helasolviolett 4R

Ohne Zusammenfassung

---

Spectrophotometric determination of iron(III) and chromium(VI) by means of helasol violet 4R

     

Gemischt-Ligand-Komplexe von Eisen(III) mit Brenzkatechin-3,5- disulfonsäure (Tiron) und Thiocyanat in wäßriger Lösung

Mixed-Ligand complexes of Iron(III) with Pyrocatechol-3,5- disulfonie Acid (Tiron) and Thiocyanate in Aqueous Solution In the system iron(III), tiron, thiocyanate two ternary complexes could be detected in acid solution. By spectrophotometric measurements we found the species [Fe(Tiron)(SCN)(H₂O)₃]^2? and [Fe(Tiron)₂(SCN)(H₂O)]^6?. The formation and the optical properties (^λmax,^? max) are discussed.     

Elektrophoretische Untersuchung der Komplexbildung von FeY− (H4Y = Ethylendiamintetraessigsäure) mit Aminopolycarbonsäuren

Electrophoretic Investigation of the Complexation of FeY^? (H₄Y = Ethylene Diamine Tetraacetic Acid) with Aminopolycarboxylic Acids In the system FeY/APC (iminodiacetic acid, nitrilotriacetic acid ethylenediaminetetraacetic acid, respectively) ternary complexes could be detected in aqueous solution. By means of electrophoretic measurements the ratio of the components in the species is FeY:APC = 1:1 without any exception. The stability constants K₁ = [FeYL]/[FeY][L] of the complexes are discussed.     

Hexakoordinierte Komplexe von Mangan(III) mit Hydrazonen

A few complexes of Mn(III) have been prepared by reacting manganese acetate with aroyl hydrazones in methanolic medium. The elemental analyses indicate 12 or 13 stoichiometry depending on the ligands. On the basis of the physicochemical investigations, coordination number six has been suggested for all these complexes.     

Ternäre Verbindungen des Natriums und Kaliums mit CaCu4P2-Struktur

Ternary Compounds of Sodium and Potassium with CaCu₄P₂-type Structure NaCu₄As₂, NaCu₄Sb₂, KCu₄As₂, and KCu₄Sb₂ were prepared and investigated by single crystal methods. They crystallize rhombohedrally and are isotypic to CaCu₄P₂ (space group R3 m). The (hexagonal) lattice constants are By reaction of the same element compositions but alterated conditions six further compounds could be synthesized in the systems Na(K)/Cu(Ag)/P(As, Sb). They crystallize hexagonally, their structure which has not been determined seems to be related to the structure of CaCu₄P₂.     

Über Eisen(III)-Komplexe mit Phenolen. V. Komplexbildung mit 4,5-Dibrombrenzcatechin-disulfonsäure(3,6)

The chelate formation between Fe³⁺ and 4.5-dibromopyrocatechol-3.6-disulfonic acid in aqueous solution has been investigated spectrophotometrically. The stability constants and the light absorption properties of the chelates are communicated. Compared with the bromine-free tiron, the ? values increase and the λ_max positions are shifted bathochromically on halogenation. However, due to the changed position of the sulfo groups, the bond-weakening effect of the halogen substituents is covered, leading to a distinct increase of pK_S1, but to only slight alterations of all the other constants. Poor solubility and accessability of the chelating reagent hinder its application in analysis.     

Die Komplexe von Dioxocyan (OCN)2 mit TiCl4 und ZrCl4

Complexes of Dioxocyanogen (OCN)₂ with TiCl₄ and ZrCl₄ A solution of (OCN)₂ was obtained by reaction of AgOCN with Br₂ in H₂CCl₂ at ?70°C. From this the complexes TiCl₄(NCO)₂ and ZrCl₄(NCO)₂ were obtained by addition of equimolar amounts of TiCl₄ and ZrCl₄, respectively. According to the i.r. and Raman spectra, the (NCO)₂ ligand is bonded via its N atoms to the metal.     

Extraktion von Eisen(III)-rhodanid mit Tributylphosphat

Ohne Zusammenfassung     

Die Reaktion der 2,7-Dichlorchromotrops?ure mit Eisen(III)

Ohne Zusammenfassung     

Titration von Eisen(III)-salz mit Versenat

Zusammentassung Die Abhangigkeit der Ergebnisse einer Titration von Eisen(III)-salz. mit Versenat (Äthylendiamintetraacetat) von der Konzentration des als Indicator zugesetzten Rhodanids wird besprochen. Die Abhangigkeit des Reagensverbrauch.es vom Logarithmus der Indicatorkonzentration weist ein Minimum auf, bei dem der Versenatverbrauch um einen Betrag zu klein ist, der den Eisen(III)-Ionen des Indicatorkomplexes äquivalent ist.Da die Konzentration dieses Komplexes mit Vorteil sehr klein gewählt werden kann (Farbe gerade unsichtbar), kann dieses Minimum der Versenatverbraueh — log — Indicatorkonzentrationskúrve zur Bestimmung der für die Titration einer vorgegebenen Eisen(III)-1ösung geeigneten Indicatorkonzentration dienen. Dies gilt auch, wenn der gefarbte Komplex durch Ausschutteln in einer Schicht eines organischen Losungsmittels besser sichtbar gemacht wird.Das Verfahren versagt dann, wenn sich das endliche Gleichgewicht in der Losung erst langsam einstellt. Dieser Übelstand ist aber bei einer unbekannten Lösung durch einen langsamen oder unstabilen Indicatorumschlag erkennbar; die Titration in der vorliegenden Lösung ist dann zu verwerfen.Es werden Titrationsbeispiele gezeigt. Als Beispiele solcher Stoffe, die eine langsame. Einstellung des Reaktionsgleichgewichtes verursachen, werden Aluminium-Ionen und Zink-Ionen angeführt. Eisen(III)-salz läßt sich aber auch in Anwesenheit dieser Ionen nach dem vorgeschlagenen Verfahren titrieren, wenn Citrat zur Vorlage hinzugesetzt wird.     

Zur quantitativen Trennung von Eisen(II) und Eisen(III)

Ohne Zusammenfassung     

Die Mitf?llung von Tracermengen Eisen(III) und Zink mit Aluminium

Ohne Zusammenfassung     

Anionenaustausch-Trennungen von Eisen (II) und Eisen (III) in Tartratmedium

Ohne Zusammenfassung