Steric complementarity in carboxylate anion recognition.
A 2,6 pyridino-linked aminocryptand acts as a good host for carboxylate anions, oxalate, malonate, acetate and lactate at low protonation levels as shown by aqueous complexation constants. With oxalate, at the hexaprotonated level of the host, the crystal structure shows formation of a dimeric unit linked by an oxalate/semioxalate short (2.474 A) H-bond. The protonated cryptand uses a cleft-binding mode in preference to the cavity-binding mode used by other aminocryptand hosts.
Nelson
Jane
J
School of Biomedical Sciences, University of Ulster Coleraine, BT52 1SA, UK. j.nelson@ulster.ac.uk
Nieuwenhuyzen
Mark
M
Pál
Ibolya
I
Town
Raewyn M
RM