Metal-controlled assembly and selectivity of a urea-based anion receptor.
1-(3-[1,10]phenanthrolin-2-yl-phenyl)-3-(4-trifluoromethyl-phenyl)-urea (1) forms a solution-stable 1:2 complex with copper(I), [CuI(1)2]+, which behaves as an anion receptor in aprotic media. The [CuI(1)2]+ receptor may adopt a geometrical arrangement in which the two facing urea subunits give tetrafurcate H-bond interaction with a spherical anion (halides and H2PO4-). In the presence of the Y-shaped acetate, the [CuI(1)2]+ receptor rearranges to interact with two CH3COO- ions, according to two stepwise equilibria. Thus, in the presence of substoichiometric amounts of the anions, [CuI(1)2]+ discriminates H2PO4- over CH3COO-, inverting the basicity trend.
Amendola
Valeria
V
Dipartimento di Chimica Generale and Sezione INSTM, viale Taramelli 12, Università di Pavia, 27100 Pavia, Italy.
Boiocchi
Massimo
M
Colasson
Benoît
B
Fabbrizzi
Luigi
L