Crystal structures of [Ln(NO(3))(3)(μ(2)-bpydo)(2)], where Ln = Ce, Pr or Nd, and bpydo = 4,4′-bi­pyridine N,N′-dioxide: layered coordination networks containing 4(4) grids

Three isostructural coordination networks of Ce, Pr, and Nd nitrate with 4,4′-bi­pyridine N,N′-dioxide (bpydo) are reported, namely poly[[tris­(nitrato-κ(2) O,O′)cerium(III)]-bis­(μ(2)-4,4′-bi­pyridine N,N′-dioxide-κ(2) N:N′)], [Ce(NO(3))(3)(C(10)H(8)N(2)O(2))(2)], poly[[tris­(nitrato-κ(2) O,O′)praeseodymium(III)]-bis­(μ(2)-4,4′-bi­pyridine N,N′-dioxide-κ(2) N:N′)], [Pr(NO(3))(3)(C(10)H(8)N(2)O(2))(2)], and poly[[tris(nitrato-κ(2) O,O′)neodymium(III)]-bis­(μ(2)-4,4′-bi­pyridine N,N′-dioxide-κ(2) N:N′], [Nd(NO(3))(3)(C(10)H(8)N(2)O(2))(2)]. All three compounds are isostructural to the previously reported La analogue. The asymmetric unit of [Ln(NO(3))(3)(μ(2)-bpydo)(2)] contains one lanthanide cation, two bpydo ligands, and three nitrate anions. Both bpydo ligands act as end-to-end μ(2)-bridges and display nearly ideal cis and gauche conformations, respectively. The bpydo ligands link the ten-coordinate Ln (III) cations, forming inter­digitating 4(4) grid-like layers extending parallel to (-101), where inter­digitation of layers is promoted by C—H⋯O inter­actions between nitrate anions and bpydo ligands. The inter­digitated layers are linked to sets of neighboring layers via further C—H⋯O and π–π inter­actions.