Crystal structures of [<i>Ln</i>(NO<sub>3</sub>)<sub>3</sub>(μ<sub>2</sub>-bpydo)<sub>2</sub>], where<i>Ln</i>= Ce, Pr or Nd, and bpydo = 4,4′-bipyridine<i>N</i>,<i>N</i>′-dioxide: layered coordination networks containing 4<sup>4</sup>grids
Acta crystallographica. Section E, Crystallographic communications