- Convenient method for preparation of aza-crown ethers
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A convenient method for the preparation of peraza crown ethers in a one-pot synthesis in the presence of KF/Al2O3 is presented. Copyright Taylor & Francis Group, LLC.
- Blǎni?ǎ, Gabriela,Buc?a, Monica,Vlassa, Mircea
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p. 1569 - 1573
(2007/10/03)
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- Derivative of cyclen with three methylene(phenyl)phosphinic acid pendant arms. Synthesis and crystal structures of its lanthanide complexes
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A new macrocyclic ligand 1,4,7,10-tetraazacyclododecane-1,4,7,10- tetraylmethyltrimethylenetris(phenylphosphinic acid) H3L1 was synthesised and its complexes with lanthanides were prepared. X-Ray analysis of seven Ln complexes (Ln = La, Ce, Nd, Eu, Tb, Er, Yb) shows a formation of dimers [LnL1]2 with phosphinic acid bridges in the solid state. All complexes are isostructural and the coordination polyhedra are formed by four N atoms and four O atoms of phosphinic acid groups. A water molecule is placed near the O4 base. The Ln-Ow distance is strongly dependent on Ln(III), it varies from 2.815(6) A in the La complex to 4.448(10) A in the Yb complex. The 31P NMR studies show formation of a rather complex mixture of isomers in solution. The dimer stability in solution is verified by reaction with triphenylphosphine oxide (tppo) and with pyridine N-oxide and by cyclic voltammetry. The Royal Society of Chemistry 2000.
- Rohovec, Jan,Vojtisek, Pavel,Hermann, Petr,Ludvik, Jiri,Lukes, Ivan
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p. 141 - 148
(2007/10/03)
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