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

Abstract

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) A, b = 11.781(1) A, c = 12.112(1) A, β = 97.21(1)°, V = 889.0(2) A3, ρcalcd = 2.160 g/cm3, and Z = 4. The crystals of II are orthorhombic, space group Cmca, a = 13.039(1) A, b = 10.450(1) A, c = 12.837(1) A, V = 1749.1(3) A3, ρcalcd = 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-Naverage 2.197 A, 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 PO2F2−. The Ag+ ion has a linear coordination mode (Ag-N 2.220(3) A, and the NAgN angle is 164.3(2)°). The tetrahedral anions PO2F2− having weak contacts with the silver ions (Ag…O 2.630(3)A) join the [Ag(Ppz)]∞+ chains into wavy layers.