Showing papers by "Heinz Gornitzka published in 2001"
TL;DR: In this article, the synthesis of a tetrapyridyl ligand, bis[di-1,1-(2-pyridine)ethyl]amine (BDPEA), with manganese(II), iron(III) or copper(II) chlorides was described.
Abstract: The synthesis of a new tetrapyridyl ligand, bis[di-1,1-(2-pyridyl)ethyl]amine (BDPEA), is described. Complexation of this ligand with manganese(II), iron(III) or copper(II) chlorides afforded mononuclear complexes: Mn(BDPEA)Cl2 (1) [Fe (BDPEA)Cl2]Cl (2) and [Cu(BDPEA)Cl]Cl (3). In all cases, BDPEA is coordinated to the metal center by three pyridine nitrogen atoms and the secondary amine. The geometrical environments around the metals in Mn(BDPEA)Cl2 and [Fe(BDPEA)Cl2]Cl are best described as distorted octahedrals and in [Cu (BDPEA)Cl]Cl as a slightly distorted square pyramid. The DNA cleavage activities of manganese(II), iron (III) or copper(II) complexes of both BDPEA and another tetrapyridyl ligand, bis[di(2-pyridyl) methyl]amine (BDPMA), in the presence of an oxidant (H2O2) or a reducing agent (ascorbate) with air, are reported. The iron(III) complexes exhibited significantly enhanced efficiencies, compared to copper(II) complexes. [Fe(BDPEA)Cl2]Cl is found to be the most active DNA cleaver, in agreement with a better stability of BDPEA in oxidizing conditions.
105 citations
TL;DR: In this article, the crystal structures of BETS molecules were determined by X-ray diffraction methods, and the structures of 1, 2, and 3 were characterized by strong disorder of their respective anions.
Abstract: κ-(BETS) 8 (Cu 2 Cl 6 )(CuCl 4 ) ( 1 ), θ-(BETS) 2 (CuCl 2 ) ( 2 ), (BETS) 2 (CuCl 4 ) ( 3 ) (BETS = bis(ethylenedithio)tetraselenafulvalene) have been prepared by diffusion-electrocrystallisation of BETS and (AsPh 4 ) 2 (Cu 2 Cl 6 ) solutions in chlorobenzene–ethanol. 2 has also been obtained by simple diffusion of BETS and (AsPh 4 ) 2 (Cu 2 Cl 6 ) solutions. 1 and 2 exhibit metal-like behaviour, down to 40 K for 1 and 4 K for 2 . 3 behaves as an insulator. The crystal structures of 1 , 2 , and 3 are determined by X-ray diffraction methods. The structures of 1 (at 140 and 25 K) and 2 are characterised by a strong disorder of their respective anions. The crystal structure of 3 shows an unusual packing of the BETS molecules, consisting of slipped stacked (BETS) 2 dimers, leading to insulating properties. Based on the structures of 1 (at 140 and 25 K), 2 and 3 , molecular and band structure calculations are carried out for the interpretation of the physical behaviours of these phases.
1 citations