Coordination polymers of silver with piperazine and uncoordinated anions: Syntheses and crystal structures of [Ag(C4H10N2)]CH3SO3 and [Ag(C4H10N2)]PO2F2

The coordination polymers Ag(C₄H₁₀N₂)]CH₃SO₃ (I) and Ag(C₄H₁₀N₂)]PO₂F₂ (II) (C₄H₁₀N₂ is piperazine (Ppz)) are synthesized, and their structures are determined. The crystals of I are monoclinic, space group P2₁/c, a = 6.280(1) Å, b = 11.781(1) Å, c = 12.112(1) Å, β = 97.21(1)°, V = 889.0(2) ų, ρ_calcd = 2.160 g/cm³, and Z = 4. The crystals of II are orthorhombic, space group Cmca, a = 13.039(1) Å, b = 10.450(1) Å, c = 12.837(1) Å, V = 1749.1(3) ų, ρ_calcd = 2.240 g/cm³, and Z = 8. Structure I contains cationic polymer chains Ag(Ppz)] _∞ ⁺ . The silver atom bound to two nitrogen atoms of two Ppz ligands has an almost linear coordination mode (Ag-N_average 2.197 Å, angle NAgN 161.2(1)°). The structure includes supramolecular layers due to weak interactions Ag…O(CH₃SO₃). Structure II is built of zigzag polymer chains Ag(Ppz)]⁺ and tetrahedral cations PO₂F ₂ ^? . The Ag⁺ ion has a linear coordination mode (Ag-N 2.220(3) Å, and the NAgN angle is 164.3(2)°). The tetrahedral anions PO₂F ₂ ^? having weak contacts with the silver ions (Ag…O 2.630(3)Å) join the Ag(Ppz)] _∞ ⁺ chains into wavy layers.