| Autor: |
Atkinson, Ian M., Chartres, Jy D., Everett, Grover W., Ji, Xue-Kui, Lindoy, Leonard F., Matthews, Owen A., Meehan, George V., Skelton, Brian W., Wei, Gang, White, Allan H. |
| Zdroj: |
Journal of the Chemical Society, Dalton Transactions; April 7, 2000, Vol. 2000 Issue: 7 p1191-1198, 8p |
| Abstrakt: |
A pyridylmethyl derivative of a 14-membered, N2O2-donor macrocycle (L) and its complexes with cobalt(II), copper(II), zinc(II), silver(I), cadmium(II) and lead(II) have been prepared. Thermodynamic stabilities of the 1∶1 (metal∶ligand) complexes in 95% methanol (I = 0.1 mol dm−3, NEt4ClO4; 25 °C) and crystal structures of the 1∶1 complexes of copper(II), silver(I) and lead(II) with L were determined. The structure of the copper complex shows the presence of a cation of type [CuL(NO3)]+; it has a distorted octahedral geometry in which one co-ordination site is occupied by a unidentate nitrate ligand. In contrast, the cationic silver complex is of type [AgL]+ with the two pyridine ring nitrogen atoms of L dominating the co-ordination environment, which may be regarded as essentially two-co-ordinate. On the other hand, the lead complex, [PbL(NO3)(ClO4)], is eight-co-ordinate and incorporates bidentate nitrate and unidentate perchlorate ligands. A competitive mixed-metal transport experiment across a bulk chloroform membrane incorporating L as ionophore was performed. The aqueous source phase contained equimolar concentrations of cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), silver(I), and lead(II) as their nitrate salts. Under the influence of a back proton gradient, silver and copper were preferentially transported to the aqueous receiving phase. |
| Databáze: |
Supplemental Index |
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