Structural studies of Hg(II) self-assembly with bidentate pyridyl ligands and various ketonylate bridging anions

Self-assembly of HgX₂ (X⁻ = NO₃⁻, ClO₄⁻, CF₃SO₃⁻) with naphthalene-2,6-diyldipicolinate (L) in ketone media affords seven mercury complexes (1–7) via in situ formation of monoanionic ketonylates. Single-crystal X-ray diffraction shows that the ketonylates act as bridging anions in the keto form, generating dimensional diversity across the series: 1D chains, 2D layers (including orthogonally interpenetrated pseudo-3D architectures), and genuine 3D frameworks. Topological analysis (metal-centered simplification) assigns hcb layers, cem nets (interpenetrated), and sqp frameworks, with coordination numbers governed by Hg–O cutoff criteria. Spectroscopy corroborates keto-form coordination in the solid state and persistence in solution. These results demonstrate solvent-guided ketonylate generation as a handle to steer framework dimensionality, informing the design of Hg-based coordination architectures and related functional materials.