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Conductance Study of Ion-Pairing of Alkali Picrate and Tetraphenylborate Complexes with Some Macrocyclic Polyethers in Methanol

Ljerka Tušek-Božić ; Department of Physical Chem'istry, Rugjer Boskovic Institute, Zagreb
Božidar Božić ; Research Institute PLIVA, Zagreb, Yugoslavia

Sažetak

The conductance of dibenzo-18-cmwn-6 (DB18C6), bis
(3,5-di-,tert-butylbenzo)-18-crown-6 (dtbDB18C6) and dibenzo-
24-crown-8 (DB24C8) complexes with sodium and potassium
picrates and tetr-a;phenylborates was investigated in methanol
at 25 •c. Shedlovsky plots gave straight lines from which the
limiting conductances, .Ao, and ion-pai.r dissociation constants,
Kv, were calculated. Generally, tetraphenylbora:te complexes are
slightly more dissociated than the corrnsponding picrate complexes,
as are also the potassium complexes compared to those
of the sodium salts. The results obtained are compared with
!those obtaillled for the conductance of sodium and po.tassium
picrates and tetraphenylborates in methanol, and are discussed
in terms of the polyether interactions with al•kali cation which
are controlled by their size, solvent interactions with the polyether-
cation complexes, size and charge density of the counterion,
and the steric factors caused by the presence of the
bulky tert-butyl substituents in the polyether molecule.

Ključne riječi

Hrčak ID:

194176

URI

https://hrcak.srce.hr/194176

Datum izdavanja:

15.2.1984.

Posjeta: 829 *