Hydrogen-bonded three-dimensional networks encapsulating one-dimensional covalent chains: [Cu(3-ampy)(H₂O)₄](SO₄) ·(H₂O) (3-ampy = 3-aminopyridine)

A three-dimensional complex [Cu(3-ampy)(H₂O)₄] (SO₄)-(H₂O) (3-ampy = 3-aminopyridine) has been synthesized. Crystallographic data: C₅H₁₆CuN ₂O₉S, M_r = 343.80, triclinic, space group P1̄, a = 7.675(2), b = 8.225(3), c = 10.845(3) Å, α= 86.996(4), β= 76.292(4), γ= 68.890(4)°, V = 620.0(3) ų, Z =2, D_c= 1.841 g/cm³, F(000) = 354 and μ = 1.971 mm^-1. The structure was refined to R = 0.0269 and wR= 0.0659 for 1838 observed reflections (I > 2σ(I)). The structure consists of [Cu(3-ampy)(H₂O)₄]²⁺ cations, SO ₄^2- anions and lattice water molecules. 3-Ampy acting as a bidentate bridging ligand generates a ID covalent chain. A supramolecular 2D framework is formed through π-π stacking of pyridine rings. The lattice water molecules and SO₄^2- anions are located between the adjacent 2D frameworks. The hydrogen bonding interactions from lattice water molecules and SO₄^2- anions to coordinate water extend the 2D framework into a 3D network.