Reactions of 3-(2-(pyridin-4-yl)ethyl)pentane-2,4-dione (HacacPyen) with AgPF
6 and AgBF
4 afforded cationic silver complexes [Ag(HacacPyen)
2]
+ with essentially linear coordination of the Ag
I cation by two pyridine N atoms. Rather unexpectedly, the HacacPyen ligands in the PF
6− salt
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Reactions of 3-(2-(pyridin-4-yl)ethyl)pentane-2,4-dione (HacacPyen) with AgPF
6 and AgBF
4 afforded cationic silver complexes [Ag(HacacPyen)
2]
+ with essentially linear coordination of the Ag
I cation by two pyridine N atoms. Rather unexpectedly, the HacacPyen ligands in the PF
6− salt
1 adopt the diketo form, in contrast to the uncoordinated HacacPyen molecule, whereas the corresponding BF
4− salt
2 and the majority of 3-substituted acetylacetones crystallizes as the enol tautomer. In both compounds
1 and
2, complex cations aggregate
via short Ag···Ag interactions to pairs. These contacts amount to 3.21 Å in
1 and 3.26 Å or 3.31 Å in
2. As they are unsupported by any additional bridging ligands and correspond to the closest interionic interactions between neighbouring complex cations, they may be addressed as argentophilic interactions. The PF
6− anions in
1 and the BF
4− counter ions in
2 are involved in long and presumably electrostatic Ag···F contacts of ca. 2.9 Å. Additional coordination between Ag
I and keto O atoms of symmetry-equivalent ligands occurs in
1 and leads to an extended two-periodic supramolecular structure.
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