Calculation of Normal Vibrations for a Chromium Complex with Tris(malonodialdehyde)

Direct and inverse spectral problems were solved. A three-ligand model was used to assign the bands in an IR spectrum of a molecular chromium complex with tris(malonodialdehyde), Cr(Mal)₃. In CCl₄solution, the - and -hydrogen atoms of the ligands in this complex were shown to be involved in intermolecular interactions with solvent molecules. The symmetry of the coordination entity of the complex in the solid state was found to be below D ₃.     

Cycloheptatriene-rhodium(I) acetylacetonate

Cycloheptatriene-rhodium(I) acetylacetonate has been prepared; the d₇ analogue undergoes deuterium scrambling at 60°.     

Über Tris(siloxymethyl)-, Tris(silylmercaptomethyl)- und Tris(silylmethyl)amine

By the reaction of alkali salts of triorgano-silanols, -silanethiols and trimethylsilylmethanol as well as of triorganosilyllithium compounds with tris(chloromethyl)amine, silyl derivatives of tris(hydroxymethyl)-, tris(mercaptomethyl)- and tris(methyl)amine were prepared.     

Reaction of Tris(2-hydroxyethyl)amine with Iron(III) and Manganese(II) Salts

Russian Journal of General Chemistry - The reaction of tris(2-hydroxyethyl)amine with Fe(III) and Mn(II) carboxylates was studied for the first time. The complexes formation was confirmed by the IR...     

A semiempirical MO study of the electronic structure and excited states of the Tris(2,2′-bipyridyl)Iron(II) and Tris(glyoxal-Bis-N-methylimine)iron(II)Ions

A semi-empirical SCF-MO method, the PEEL method, has been applied in an investigation of the electronic structure and excited states of two iron compounds, [Fe(II)-(GMI)₃]⁺⁺ and [Fe(II)-(bipy)₃]⁺⁺.The electronic absorption spectra have been recorded. The calculations show that it is necessary to account for the trigonal distortion and the covalency in order to explain these spectra quantitatively. Mössbauer measurements have also been performed. The calculated electronic population of the iron is in accord with Mössbauer isomer shift data, indicating that a realistic electron distribution has been obtained by the PEEL method.

---

Zusammenfassung Eine semiempirische SCF-MO-Methode, die PEEL-Methode, wurde zur Untersuchung der Elektronenstruktur sowie von angeregten Zuständen der beiden Eisenverbindungen [Fe(II)-(GMI)₃]⁺⁺ und [Fe(II)-(bipy)₃]⁺⁺ angewendet.Die elektronischen Absorptionsspektren wurden aufgenommen. Die Berechnungen zeigen, daß die trigonale Verzerrung und die Kovalenz berücksichtigt werden müssen, um die Spektren quantitativ zu erklären. Mössbauer-Messungen wurden ebenfalls durchgeführt. Die berechnete Elektronenverteilung am Eisenatom ist in Übereinstimmung mit den Daten der Isomerenverschiebung der Mössbauer-Messungen, wodurch gezeigt wird, daß mit der PEEL-Methode eine realistische Elektronen-Verteilung erhalten wurde.

---

Résumé Une méthode SCF-MO semi-empirique, la méthode PEEL, a été appliquée à une étude de la structure électronique et des états excités de deux composés ferreux: [Fe(II)-(bipy)₃]⁺⁺ et [Fe(II)-(GMI)₃]⁺⁺. Les spectres d'absorption électronique ont été enregistrés. Les calculs montrent qu'il est nécessaire de rendre compte de la distorsion trigonale et de la covalence pour expliquer ces spectres quantitativement.Des mesures de l'effet Mössbauer ont aussi été effectuées. La population électronique calculée du fer est en bon accord avec les données sur le déplacement isomérique de Mössbauer, ce qui indique que la méthode PEEL fournit une distribution électronique réaliste.

     

Tris(triorganosilyl)borates

Summary Three new methods were developed for synthesis of tris(triorganosilyl) borates, based on reaction of triorganosilanols with boron trioxide or with boric acid, and on reaction of H₃BO₃ with triorganosilanes. These methods were employed for preparation of six compounds of this type, of which four were previously unknown.     

Tris(salicylhydroxamato)manganese(III)

Summary Hydroxamic acids show a degree of selectivity towards transition metal ions having symmetrical d-electron configuration, e.g. vanadium(V) (d⁰) and iron(III) (d⁶⁵). Hydroxamato complexes of metal ions having unsymmetrical d-electron distribution are rare. Thus for manganese(III) (d⁴) only some thiohydroxamato complexes⁽¹⁾ have been characterised so far. In this communication we report on the first synthesis of a salicylhydroxamato complex of manganese(III). Such investigations are of interest because these higher valent manganese complexes are potentially models for the water-splitting complex present in photosystem II⁽²).