Silver(I)−Polynitrile Network Solids for Anion Exchange: Anion-Induced Transformation of Supramolecular Structure in the Crystalline State

Novel supramolecular solids whose topologies depend on the counteranion, [Ag(C14H20N6)(NO3)]
(1), [Ag(C14H20N6)]CF3SO3 (2), and [Ag(C14H20N6)]ClO4 (3), have been prepared by the self-assembly of
AgX (X = NO3-, CF3SO3-, and ClO4-) with ethylenediaminetetrapropionitrile (EDTPN, C14H20N6). X-ray
crystal structures indicate that compounds 1−3 are a 1-D coordination polymer, a 2-D layer, and a boxlike
2-D network, respectively. In 1, 2, and 3, the EDTPN ligand undergoes anion-dependent ligation to bind two,
three, and five Ag(I) ions per EDTPN, respectively, by using the cyano groups in addition to two tertiary
nitrogen atoms. The coordination numbers of Ag(I) ion in 1, 2, and 3, are five, four, and six, respectively.
Interestingly, the CF3SO3- anion of 2 is exchanged with NO3- and ClO4- quantitatively in the crystalline
state when the crystal of 2 is immersed in the aqueous solutions of NaNO3 and NaClO4, respectively. The
anion-exchange process is reversible between 1 and 2 but irreversible from 1 or 2 into 3. The supramolecular
structural transformations among 1−3 are observed in the crystalline state, concomitant with the anion-exchange.