ISSN:
1573-1111
Keywords:
Calix[4]arene
;
polyether
;
crystal structure
;
alkali metal ion binding
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The ligand 5,11,17,23-tetra-t-butyl-25,27-di(phenylmethoxy)-26,28-di(2-methoxy-ethoxy)calix[4]arene,designed as an analogue of some calixcrown speciesin order to evaluate possible origins of their selectivity in alkali metal ion binding, has been synthesised and structurally characterised by X-ray crystallography. The crystals are monoclinic, P21/n, a = 15.940(6), b = 19.388(5), c = 20.020(5) Å,β = 109.10(2) deg., Z = 4, conventional R on |F| being 0.073 for 3454 independent, ’observed‘ (I 〉 3σ(I)) reflections. 1H-NMR studies in 1:1 CD3CN/CDCl3solvent have shown that the ligand exerts a strong preference for the lighteralkali metal ions (Li+ and Na+) contrary to the binding behaviour of knowncalixcrowns. This may reflect interactions restricted to the lower rim donor atoms without concomitant interaction with the calixarene π-electrons, perhaps because the latter interactions are substituted by those with the benzyl group π-electrons.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007981710765
Permalink