Neue Lanthanoidmagnetoplumbite: LaFe11A1019, SmFe4Al8O19 und Eu0,83Fe2Al10O19

New compounds of magnetoplumbite structure with rare earth-ions were prepared by solid state reactions and determined by X-ray single crystal work. They crystallize in space group D _6h ⁴ -P6₃/mmc withA:a=582.6,c=2283;B:a=563.4,c=2208;C:a=565.8,c=2218 pm. The distribution of Fe and Al to the metal positions were determined and the thermal ellipsoids of the metal positions are discussed.

     

Synthese und Strukturaufklärung von SrBeLa2O5

A new compound of the formula SrBeLa₂O₅ was prepared by high temperature technique. Single crystal X-ray investigations led to orthorhombic symmetry (a=9.730,b=7.377,c=6.687 Å, space group: D _2h ¹⁶ -Pnma,Z=4). SrBeLa₂O₅ shows a typical tunnel structure of a three-dimensional connection of Sr, La/O-prisms, related to a distortedKgomé-network. The tunnels are occupied by La³⁺- and Be²⁺-ions. A detailed discussion of the polyhedra, their connection, and the statistical distribution of Sr²⁺ and La³⁺ within the trigonal O^2–-prisms are given.

     

Über das Kriechen kristallisierender Salze, 12. Mitt.: Die Verteilung mehrerer verunreinigender Salze bei der kriechenden Kristallisation

Zusammenfassung Es werden experimentelle Ergebnisse dargelegt, welche die Verteilung mehrerer verunreinigender Salze bei kriechender Kristallisation betreffen. Sie bestätigen die in einem früheren Beitrag¹ auf Grund des Verteilungskoeffizienten gemachten Schlußfolgerungen.

---

Experimental data are given treating the distribution of more than one impurities during creeping crystallization. They confirm the conclusions made in a previous contribution¹ on the basis of the distribution coefficient.

     

Influence of the matrix on the complexation of metal ions by chelating ion exchangers

Summary Chelating ion exchangers show distribution coefficients that are considerably lower than those expected from complexation equilibria with the corresponding free ligands in solution. Furthermore, dependence of distribution coefficients on the concentration of exchanging ions in solution is observed. Both effects are due to the influence of the surrounding matrix on the anchor groups. The distribution coefficients of Fe³⁺, Ni²⁺, Cu²⁺, Pb²⁺ and UO ₂₊ ² on two cellulose exchangers carrying different anchor groups are investigated as function of the concentration in solution. In case of the anchor group of high flexibility a strong increase of the distribution coefficients with decreasing concentration in solution is measured. This is explained by the fact that the anchor groups located at the surface are less affected by interactions with the matrix, with the result of higher distribution coefficients. The explanation is in agreement with the sorption isotherm.

---

Einfluß der Matrix auf die Komplexierung von Metallionen durch chelatbildende Ionenaustauscher

---

Dedicated to Prof. Dr. G. Tölg on the occasion of this 60th birthday     

Substituenteneinfluß auf die Bindung von Metallkationen an Amiden

The interactions of a series of cations with acetamide and its homologs is investigated using¹H-n.m.r. spectroscopy. The complexation of a cation by the amide induces changes in the electronic distribution of the ligands which lead to different chemical shifts in the n.m.r. spectra. The results are in agreement withab initio-calculations of the atomic population by the Mulliken Populations Analysis method using a minimal basis set.

     

Investigation of the homogeneity of the distribution of doped elements in oxide single crystals

Summary The homogeneity of the distributions of doped V and Ti in Al₂O₃:V³⁺, Y₃Al₅O₁₂:V³⁺, Al₂O₃:Ti³⁺, Y₃Al₅O₁₂:Ti³⁺ single crystals was studied by means of laser emission microanalysis. The applied statistical methods include one-way variance analysis, two-way variance analysis, regression models and the gradient method.     

On the chemistry of pyrrole pigments,LXXXIX: Vinylogous linear di- and tetrapyrroles

Summary A vinylogous dipyrrinone, its Ehrlich aldehyde condensate, and the vinylogous bilindione derived from the vinylogous dipyrrinone were prepared. Their structural aspects of tautomerism, configuration and conformation were derived by analysis of their¹H-NMR data. Selected physical properties were determined and are discussed.

---

Zur Chemie von Pyrrolpigmenten, 89. Mitt.: Vinyloge Lineare Di- und Tetrapyrrole

Zusammenfassung Ein vinyloges Dipyrrinon, sein Ehrlich-Aldehyd-Kondensat und ein vom vinylogen Dipyrrin abgeleitetes vinyloges Bilindion wurden dargestellt. Ihre strukturellen Aspekte der Tautomerie, Konfiguration und Konformation wurden durch Analyse ihrer¹H-NMR-Daten abgeleitet. Ausgewählte physikalische Eigenschaften wurden gemessen und diskutiert.

     

Ionenaustausch von Chlorid, Bromid und Iodid am Anionenaustauscher Amberlit IRA 458

Zusammenfassung Die Verteilungskoeffizienten von Cl^–-,Br^–- und I^–-Ionen an dem Polyacryl-Anionenaustauscher Amberlit IRA 458 wurden als Funktion des pH-Wertes bestimmt. In Schüttel- und Säulenversuchen wurde gezeigt, daß Iodidionen aus Salzwasser angereichert werden können.

---

Ion-exchange of chloride, bromide and iodide on the anion-exchanger amberlite IRA 458

Summary The distribution coefficients of Cl^–, Br^– and I^– on the polyacryl anion-exchanger Amberlite IRA 458 are determined as function of pH. It is shown by batch and column experiments that I^–-ions can be enriched from salt water.

     

The benzene ring as a dipolarophile: Reactions of monosubstituted benzenes with tetracyanoethylene oxide

Summary The reaction of tetracyanoethylene oxide on one hand and toluene, chlorobenzene, fluorobenzene, anisole, and nitrobenzene, on the other, has been studied. Toluene and the halogenobenzenes yield mixtures of monoadducts, anisole yieldp-methoxyphenylmalononitrile and its dimer and nitrobenzene does not react. These results are discussed with the help of a qualitative orbital model.¹H-NMR analysis of some monoadducts has been carried out.

---

Der Benzolring als Dipolarophil: Reaktionen monosubstituierter Benzole mit Tetracyanoethylenoxid

Zusammenfassung Es wurden die Reaktionen von Tetracyanoethylenoxid mit Toluol, Chlorbenzol, Fluorbenzol, Anisol und Nitrobenzol untersucht. Toluol und die Halogenbenzole ergaben Mischungen von Monoaddukten, Anisol ergabp-Methoxyphenylmalononitril und sein Dimer, Nitrobenzol zeigte keine Reaktion. Diese Resultate werden mit Hilfe eines qualitativen Orbitalmodells diskutiert. Die Analyse einiger Monoaddukte erfolgte mittels¹H-NMR-Analyse.

     

Synthese und Eigenschaften von 1,1,3,3-Tetrakis(pentafluorphenyl)-cyclo-di(silthian) und verwandten Verbindungen

Summary The synthesis of tetrakis(pentafluorophenyl)-cyclo-di(silthiane) and related compounds by reacting organosubstituted silanes with sulfur or hexamethyldisilthiane is reported The compounds are characterized by analysis, by relative molecular mass, by¹H,¹³C,¹⁹F, and²⁹Si NMR spectroscopy, and by mass and IR spectra, respectively. Two²⁹Si NMR signals of different intensity found for compounds with two different organic substituents on silicon are explained by the existence of diastereomers.

     

Aspects of characterizing the normal modes of a (PO4C2)− model by means of the potential energy distribution

Summary In the normal coordinate analysis, potential energy distribution is often used to assist in the assignment of infrared absorption bands to normal modes. Applying this method to a simplified (PO₄C₂)^– model simulating the vibrational behaviour of the phosphate group in DNA, it is shown that normal modes may alter in nature by the influence of external chemical effectors. It is to be emphasized that this circumstance should be taken into consideration whenever the molecules under study are influenced by external interactions.

---

Aspekte der Charakterisierung der Normalmoden eines (PO₄C₂)^–-Modells über die Energieverteilung

Zusammenfassung Im Rahmen der Normalkoordinatenanalyse wird die Verteilung der potentiellen Energie oft als Hilfsmittel zur Zuordnung von Infrarotabsorptionsbanden zu Normalmoden verwendet. Die Anwendung dieser Methode auf ein vereinfachtes (PO₄C₂)^–-Modell zur Simulierung des vibratorischen Verhaltens der Phosphatgruppe der DNA zeigt, daß die Art der Normalmoden durch externe chemische Effektoren beeinflußt werden kann. Es wird betont, daß dieser Umstand immer in Betracht gezogen werden sollte, wenn Moleküle unter dem Einfluß externer Effekte untersucht werden.

     

Schwingungsspektroskopische Untersuchungen an Sulfamid-Einkristallen

The infrared (300 K) andRaman (300 and 90 K) spectra of single crystals of sulfamide are recorded. In addition theRaman spectra of the deuterated and N¹⁵-substituted polycrystalline sulfamide are measured. A vibrational assignment based on these data and a normal coordinate analysis is proposed. Lattice bands and factor group splittings are discussed.

     

Ligandenaustausch in Alkoxo/Halogenostiban-Systemen

Summary In Sb(OR)₃/SbHal ₃ systems (R=Et, Pr, ⁱ Pr, Bu, ⁱ Bu, ^neo Pent; Hal=Cl, Br) a rapid exchange of ligands takes place. It is shown by ebullioscopic data that there is a random distribution in a system containing 7 different particles. The mixed alkoxohalogenostibanes are associated. The total association is estimated comparing the averaged experimental and statistical molecular masses. An ebullioscope of high precision is described.

     

Analyse von Anionen in Aerosolen der Luft

Zusammenfassung Die Anwendung der Ionen-Chromatographie bei der Bestimmung vertikaler und horizontaler Konzentrationsverteilungen und zeitlicher Konzentrations schwankungen von Anionen in troposphärischen Aerosolen wird beschrieben. Die Probenahme erfolgt mit Teflonfiltern. Nach einer Extraktion der Filter erfolgt die quantitative Bestimmung der Anionen mit Hilfe der Ionen-Chromatographie. Die Nachweisgrenzen des Gesamtverfahrens liegen bei 64 ng/m³ Chlorid, 54 ng/m³ Nitrat und 137 ng/m³ Sulfat (Probevolumen: 1,4 m³). Bei der gleichzeitigen gas-chromatographischen Bestimmung von gasförmigem Chlorwasserstoff in der Atmosphäre liegt die Nachweisgrenze bei 5 ng/m³ (Probevolumen: 61).

---

Determination of anions in atmospheric aerosols

Summary The application of ion-chromatography to the determination of vertical and horizontal distributions and temporal variations of the anion concentration in tropospheric aerosols is presented. Teflon filters are used for sampling. The quantitative anion determination in the extract solutions of the filters is done by ion-chromatography. The overall limits of detection are 64 ng/m³ chloride, 54 ng/m³ nitrate and 137 ng/m³sulfate (sample volume: 1.4 m³). A detection limit of 5 ng/m³ (sample volume: 61) is obtained for the simultaneous determination of gaseous hydrogen chloride in the atmosphere.

---

---

Vortrag anläßlich des Symposiums Anorganische Anionenanalytik, Regensburg, 19.–21. 9. 1984     

Distribution analysis for materials research

Summary The property related characterization of materials demands information about bulk composition, distribution of elements and phases, and structure. The requirements concerning information content of methods, their spatial resolution, detection power, precision and accuracy are constantly increasing. This led to a significant improvement of existing and development of new methods and techniques.This contribution which has been published already in two review papers [1, 2], discussed important trends of development and their significance for high technology:In situ microanalysis: stereometric phase characterization, nanoanalysis, distribution analysis of trace elements, speciation, structure analysis.Surface analysis: trace analysis at surfaces, high spatial resolution microanalysis of surfaces, speciation structure analysis with atomic resolution.

---

Verteilungsanalyse für die Werkstoff-Forschung

     

Spurenanalyse mit der flammenlosen AAS unter Verwendung fester Proben

Zusammenfassung Die direkte Bestimmung von Spurenelementen in metallischen und oxidischen Proben im Gehaltsbereich 0,1–10 g/g (entsprechend 10^–5-10^–3 Massen-%) wird beschrieben. Hierzu bietet sich die Verwendung einer speziellen Graphitofen-Boottechnik an, mit deren Hilfe die Proben direkt in fester Form eingebracht werden können. Zwei unterschiedliche Verfahren sind erforderlich: die mehrfache Aufschmelzung für metallische Proben und die zweifache Verdampfung von oxidischen Stoffen. Die Resultate beider Verfahren werden diskutiert.

---

Trace analysis by non-flame atomic absorption spectrometry using compact samples

Summary The direct determination of trace elements of metallic and oxidic samples in the range of 0.1–10 g/g (or 10^–3–10^–5 mass-%) is described by using a special graphite furnace boat-technique with direct sample input. Two different procedures are necessary: a multiple heating technique in case of metallic samples and a double vapourization technique in case of oxides. The results using both techniques are discussed.

Für die Durchführung der zahlreichen praktischen Versuche danken wir den Herren H. Topp und H. Loepp.     

Beiträge zur Chemie der Pyrrolpigmente, 79. Mitt. Zum strukturellen Einfluß stark raumerfüllender Reste bei 10-substituierten 1,19-Bilindionen

Summary 1,19-Bilindiones bearing a phenanthryl, mesityl,tert-butyl, and isopropyl substituent at the C-10 position were synthesized. Conformational analysis using¹³C- and¹H-NMR spectroscopic techniques and absorption spectroscopy together with semiempirical calculations revealed that the aryl derivatives adopt the common circular helical geometry, whereas thetert-butyl derivative is heavily distorted. The mean planes of the two dipyrrinone moieties are orthogonally positioned to each other. The 10-isopropyl-bilindione tautomerizes to the 10-isopropyliden-biladiene-ac.

     

Mehrdimensionale Varianz- und Diskriminanzanalyse spektrographischer Daten von Glasperlenfunden

Zusammenfassung Pattern-Recognition-Methoden gestatten durch multivariate Untersuchung vieldimensionaler Datensätze komplexe Zusammenhänge zwischen Eigenschaften und Meßvariablen aufzudecken und insbesondere Wechselwirkungen zwischen den Variablen einzubeziehen. Dabei besitzen statistische Methoden wie die mehrdimensionale Varianz- und Diskriminanzanalyse den Vorteil, durch statistische Wichtung der Meßvariablen deren stark unterschiedlichen Einfluß auf die Klassifizierungseigenschaften zu berücksichtigen. Am Beispiel der Klassifizierung historischer Glasfunde nach deren Gehalt an färbenden Elementen wird gezeigt, daß die mehrdimensionale Varianz- und Diskriminanzanalyse nach Eliminierung univariat erkennbarer Ausreißer sehr gute Ergebnisse liefert.

---

Multidimensional variance and discriminance analysis of spectrographical data of glass bead findings

Summary Pattern recognition methods as applied to multivariate investigations of multidimensional data sets permit the detection of complex connections between properties and the measured datas including the interaction of the variables.In this case, statistical methods like multidimensional variance and discriminance analysis are advantageous because of the possibility to weight the variables according to their influence on the classification. Application of multidimensional variance and discriminance analysis to a set of spectrographically determined concentrations of colouring elements in historical glass bead findings yields good classification results after eliminating univariate detectable outliers.