Antipyrine and pyridine n-oxide complexes of iron(II)

Iron(II) complexes of 1-phenyl-2,3-dimethyl-5-pyrazolone (antipyrine, Apy) and pyridine N-oxide (PyO), having the formulae [Fe(Apy)6](ClO4)2, Fe(Apy)2Cl2, Fe(Apy)2Br2, Fe(Apy)4I2, [Fe(PyO)3Cl3]2 . 2H2O, [Fe(PyO)Cl2 . 2H2O]2, [Fe(PyO)3Br2]2 and [Fe(PyO)6]I2 have been prepared and characterized. [Fe(Apy)6](ClO4)2 in nitrobenzene and [Fe(PyO)6]I2 in acetonitrile behave as 1:2 electrolytes; Fe(Apy)4I2 shows considerable dissociation while Fe(Apy)2Cl2 and Fe(Apy)2Br2 are non-electrolytes and monomeric in nitrobenzene. [Fe(PyO)3Cl2]2 . 2H2O and [Fe(PyO)3Br2]2 in nitrobenzene and [Fe(PyO)Cl2 . 2H2O]2 in acetonitrile behave as non-electrolytes. All the complexes are spin-free. The i.r. spectra show that the oxygens of the CO and NO groups are the donors in the Apy and PyO complexes. A large decrease in the NO stretching frequency in [Fe(PyO)Cl2. 2H2O]2 suggests PyO acts as a bridge forming a binuclear complex. The chloro and the bromo complexes of Apy have been assigned pseudo tetrahedral structures while the rest of the complexes have octahedral or near octahedral configurations around the iron(II) on the basis of the magnetic moments and the electronic transitions.

Potentiometric and spectrophotometric investigations of nickel-triethanolamine complexes

A detailed study of nickel-triethanolamine complexes has been made employing potentiometric and spectrophotometric methods. The potentiometric method has been used to investigate the conditions for the formation of both mono- and polynuclear complexes. The formulae and the stability constants of the following complexes have been determined Ni(TEA)2+, Ni(TEA)22+, and Ni2(TEA)24+. Absorption spectra of pure mononuclear complexes have been computed by the combination of potentiometric and spectrophotometric methods. The results are discussed on the basis of ligand field theory. Comparison of the step constants of the nickel-ethanolamines (mono-, di- and tri-) shows a slight chelate effect in these complexes due to coordination through hydroxyl oxygen. In the case of polynuclear complexes it is likely that bridging occurs through hydroxyl oxygen.

Electroreduction of oxygen on some novel cobalt phthalocyanine complexes

The catalytic activity of cobalt phthalocyanine monomer and some of its polymeric derivatives towards the electroreduction of molecular oxygen in salt and alkaline solutions is examined. It is found that most of these complexes exhibit a higher catalytic activity than the cobalt phthalocyanine monomer.

Electronic structures of electron donor-acceptor complexes: results from ultraviolet photoelectron spectroscopy and molecular orbital calculations

HeI photoelectron spectra of 1:1 electron donor-acceptor complexes are discussed in the light of molecular orbital calculations. The complexes discussed include those formed by BH3, BF3 and SO2. Some systematics have been found in the ionization energy shifts of the complexes compared to the free components and these are related to the strength of the donor-acceptor bond. Hel spectra of hydrogen bonded complexes are discussed in comparison with results from MO calculations. Limitations of such studies as well as scope for further investigations are indicated.

Domännamnstvister och ond tro - En rättslig analys av UDRP, särskilt med tanke på begreppet ond tro i artikel 4.a.iii

Internets ökade betydelse gjorde att företagen började inse vilka problem som kan uppstå av att en webbsida med ett domännamn i form av deras varumärke olovligen handhas av en utomstående part. Konflikterna blev därför fler medan existerande tvistlösningsmekanismer ansågs dyra, tungrodda och ineffektiva. Ur detta behov föddes sedermera Uniform Domain Name Dispute Resolution Policy (UDRP). Detta internationella tvistlösningsförfarande skapades för att tillämpas på s.k. cybersquatting, dvs. situationer där domännamn, som inkräktar på andras varu- eller servicemärken, registreras i ond tro t.ex. för framtida försäljning. Jag granskar i denna avhandling huvudsakligen förutsättningarna för överföring eller upphävning av domännamnsregistreringar i enlighet med UDRP, varför jag fokuserar på artikel 4.a och då i synnerhet på innebörden av begreppet ”registrering och användning i ond tro”. Arbetet bygger huvudsakligen på en analys av de avgöranden som fattats inom ramen för UDRP. Syftet är att genom en systematisk undersökning av tillämpningen av begreppet ond tro beskriva och utvärdera rättstillämpningen inom UDRP. De granskade avgörandena är 396 st. till antalet och har meddelats under tidsperioden 14.1.2000-15.8.2001.

4,4′-Bipyridyl complexes of iron: Magnetic, Mössbauer and other spectroscopic studies

4,4prime-Bipyridyl (4,4prime-bipy) complexes of ferrous salts of the Fe(4,4prime-bipy)x(anion)y type (where x or y=1 or 2) and of ferric salts of the Fe(4,4prime-bipy)m(anion)n type (where m=1 or 2 and n=3) have been synthesised. Elemental analyses, i.r. and electronic spectra, magnetic and Mössbauer studies have been performed to characterize the complexes. 4,4prime-Bipy and some anions are inferred to act as bridging ligands. The magnetic moments, electronic and Mössbauer spectra suggest that the complexes are of high spin type with distorted octahedral structures. The value of the isomer shift and quadrupole splitting are discussed in terms of bonding of the ligand and anions.

Rare-earth chromium citrates as precursors for rare-earth chromites: lanthanum biscitrato chromium(III) dihydrate, La[Cr(C6H5O7)2]·2H

The thermal decomposition of lanthanum biscitrato chromium(III) dihydrate has been studied in static air and dynamic argon atmospheres. The complex decomposes in four steps: dehydration, decomposition of the citrate to an intermediate oxycarbonate, formation of LaCrO4(V) from oxycarbonate, and finally decomposition of LaCrO4(V) to LaCrO3. Formation of LaCrCrO4(V) requires the presence of oxygen The decomposition behaviour of a mechanical mixture of lanthanum citrate hydrate and chromium citrate hydrate was compared with that of the citrato complex. Both the starting material and the intermediates were characterized by X-ray diffraction, IR electronic and ESR spectroscopy, surface area and magnetic susceptibility measurements, as well as by chemical analysis. A scheme is proposed for the decomposition of lanthanum biscitrato chromium(III) dihydrate in air. LaCrO3 can be obtained at temperatures as low as 875 K by isothermal decomposition of the complex.