pH-Specific Crystalline Binary and Ternary Metal–Organic Framework Materials of Pb(II) with (Di)Tricarboxylate Ligands and <i>N</i>,<i>N</i>′‑Aromatic Chelators. Structure, Architecture-Lattice Dimensionality, and Electronic Spectroscopic Property Correlations

Efforts to probe and delineate intricate structure–property relationships key to the development of crystalline Pb­(II)-containing metal–organic framework materials led to the design and pH-specific hydrothermal synthetic investigation of binary/ternary Pb­(II)-(di)­tricarboxylate ligand (succinic, glutaric, tricarballylic acids) systems in the presence of variable-nature aromatic N,N′-chelators bipyridine (bpy)/phenanthroline (phen). The arisen crystalline materials [Pb­(phen)­(suc)]_<i>n</i> (<b>1</b>), [Pb₃(phen)₃­(glu)₃]_<i>n</i>­·7<i>n</i>H₂O (<b>2</b>), [Pb₃(tca)₂]<i>_n</i> (<b>3</b>), and [Pb₂(phen)₂­(tcaH)₂]_<i>n</i>­·<i>n</i>H₂O (<b>4</b>) provide evidence for structural correlations linking the nature of ligands with Pb­(II) chemistry and the emerging crystalline-polymeric assemblies. Detailed physicochemical characterization (Fourier transform infrared spectroscopy, ¹³C-,²⁰⁷Pb-cross polarization magic angle spinning NMR, thermogravimetric analysis, luminescence) reveals distinct architecture, lattice dimensionality (2D-3D), and luminescence property correlations and identifies structural and electronic factors interweaving into the design of functional materials