Search results

Sort By:

Limit search:

Optical Properties of Europium Compounds with L- and DL-α-Alanine-Hydroxamic Acids

100%

Legendziewicz J., Gawryszewska P., Gałdecka E., Gałdecki Z.

Acta Physica Polonica A

1996

vol. 90

issue 2

439-446

Two of europium complexes with L- and DL-α-alanine-hydroxamic acids were synthesized. To our knowledge they are the first examples of X-ray and spectral data of lanthanide single crystals with hydroxamic acid derivatives. Both compounds consist of dimers in their structures, formed by two OH bridging groups of amino-hydroxamic acid molecules. Besides, two metal ions are chelated by CO and OH groups, forming five-membered rings. In the complex with L-ligand, different than in the DL-one, two additional perchloric acid molecules are included in crystal cavities and form hydrogen bondings with nitrogen and oxygen atoms of the ligand. Absorption, emission and excitation spectra were measured and analyzed at room and low temperatures. Structural effect of ligand chirality was found and its spectroscopic consequences are reported. The effect of the dimeric structure on spectroscopic properties is discussed.

Optical Properties and Structure of Ln(NCS)(Hmpa)_{4}-(SCN)_{2}- HgCl(SCN)

88%

Gałdecka E., Gałdecki Z., Amirkhanov V., Kern K., Legendziewicz J.

Acta Physica Polonica A

1996

vol. 90

issue 2

469-476

Praseodymium, neodymium and europium complexes of the formula Ln(NCS)(Hmpa)_{4}-(SCN)_{2}-HgCl(SCN) were synthesised from non-aqueous solutions. The structure of neodymium complexes was determined by X-ray diffraction. The crystals of the title compounds crystallise in the space group Cc, where lanthanide ions are coordinated to seven ligand groups: four of Hmpa molecules and three SCN¯ ions. The compounds were characterised by IR, luminescence, excitation and absorption spectra at 6, 77, and 298 K. Probabilities of electronic transitions for Pr^{3+} ion were examined at 6 K and at room temperatures. Vibronic components were observed and analysed on the basis of IR and Raman data. Asymmetric arrangement of Ln ions was found from X-ray analysis and its influence on optical properties of active centre was discussed.

Refine search results

2 Acta Physica Polonica A

2 1996

2 Gałdecka E.

2 Gałdecki Z.

2 Legendziewicz J.

1 Amirkhanov V.

1 Gawryszewska P.

1 Kern K.

Search results

Optical Properties of Europium Compounds with L- and DL-α-Alanine-Hydroxamic Acids

Optical Properties and Structure of Ln(NCS)(Hmpa)_{4}-(SCN)_{2}- HgCl(SCN)