Crystal structures of [Ln(NO3)3(μ2-bpydo)2], where Ln = Ce, Pr or Nd, and bpydo = 4,4'-bipyridine N,N'-dioxide: Layered coordination networks containing 44 grids

Abstract

Three isostructural coordination networks of Ce, Pr, and Nd nitrate with 4,4'-bipyridine N,N'-dioxide (bpydo) are reported, namely poly[[tris(nitrato-κ2 O,O')cerium(III)]-bis(μ2-4,4'-bipyridine N,N'-dioxide-κ2 N:N')], [Ce(NO3)3(C10H8N2O2)2], poly[[tris(nitrato-κ2 O,O')praeseodymium(III)]-bis(μ2-4,4'-bipyridine N,N'-dioxide-κ2 N:N')], [Pr(NO3)3(C10H8N2O2)2], and poly[[tris(nitrato-κ2 O,O')neodymium(III)]-bis(μ2-4,4'-bipyridine N,N'-dioxide-κ2 N:N'], [Nd(NO3)3(C10H8N2O2)2]. All three compounds are isostructural to the previously reported La analogue. The asymmetric unit of [Ln(NO3)3(μ2-bpydo)2] contains one lanthanide cation, two bpydo ligands, and three nitrate anions. Both bpydo ligands act as end-to-end μ2-bridges and display nearly ideal cis and gauche conformations, respectively. The bpydo ligands link the ten-coordinate Ln III cations, forming interdigitating 44 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.