Ligand-Driven Coordination Sphere-Induced Engineering of Hybride Materials Constructed from PbCl₂ and Bis-Pyridyl Organic Linkers for Single-Component Light-Emitting Phosphors

We report design and structural characterization of six new coordination polymers fabricated from PbCl₂ and a series of closely related bis-pyridyl ligands <b>L</b>^<b>I</b> and <b>HL</b>^<b>II</b>–<b>HL</b>^<b>VI</b>, namely, <b>[Pb</b>_<b>2</b><b>(L</b>^<b>I</b><b>)­Cl</b>_<b>4</b><b>]</b>_{<i><b>n</b></i>}, <b>[Pb­(HL</b>^<b>II</b><b>)­Cl</b>_<b>2</b><b>]</b>_{<i><b>n</b></i>}<b>·<i>n</i>MeOH</b>, <b>[Pb­(HL</b>^<b>III</b><b>)­Cl</b>_<b>2</b><b>]</b>_{<i><b>n</b></i>}<b>·0.5 <i>n</i>MeOH</b>, <b>[Pb</b>_<b>2</b><b>(L</b>^<b>IV</b><b>)­Cl</b>_<b>3</b><b>]</b>_{<i><b>n</b></i>}, <b>[Pb­(HL</b>^<b>V</b><b>)­Cl</b>_<b>2</b><b>]</b>_{<i><b>n</b></i>}, and <b>[Pb</b>_<b>3</b><b>(L</b>^<b>VI</b><b>)</b>_<b>2</b><b>Cl</b>_<b>4</b><b>]</b>_{<i><b>n</b></i>}<b>·<i>n</i>MeOH</b>. The topology of the obtained networks is dictated by the geometry of the organic ligand. The structure of <b>[Pb</b>_<b>2</b><b>(L</b>^<b>I</b><b>)­Cl</b>_<b>4</b><b>]</b>_{<i><b>n</b></i>} is constructed from the [PbCl₂]_<i>n</i> two-dimensional (2D) sheets, linked through organic linkers into a three-dimensional framework, which exhibits a unique binodal 4,7-connected three-periodic topology named by us as <i><b>sda</b></i><b>1</b>. Topological analysis of the 2D metal–organic sheet in <b>[Pb­(HL</b>^<b>II</b><b>)­Cl</b>_<b>2</b><b>]</b>_{<i><b>n</b></i>}<b>·<i>n</i>MeOH</b> discloses a binodal 3,4-connected layer topology, regardless of the presence of tetrel bonds. A one-dimensional (1D) coordination polymer <b>[Pb­(HL</b>^<b>III</b><b>)­Cl</b>_<b>2</b><b>]</b>_{<i><b>n</b></i>}<b>·0.5 <i>n</i>MeOH</b> is considered as a uninodal 2-connected chain. The overall structure of <b>[Pb</b>_<b>2</b><b>(L</b>^<b>IV</b><b>)­Cl</b>_<b>3</b><b>]</b>_{<i><b>n</b></i>} is constructed from dimeric tetranuclear [Pb₄(μ³-L^IV-κ⁶<i>N</i>:<i>N</i>′:<i>N</i>″:μ³-<i>O</i>)₂­(μ⁴-Cl)­(μ²-Cl)₂]³⁺ cationic blocks linked in a zigzag manner through bridging μ²-Cl^– ligands, yielding a 1D polymeric chain. Topological analysis of this chain reveals a unique pentanodal 3,4,4,5,6-connected chain topology named by us as <i><b>sda</b></i><b>2</b>. The structure of <b>[Pb­(HL</b>^<b>V</b><b>)­Cl</b>_<b>2</b><b>]</b>_{<i><b>n</b></i>} exhibits a 1D zigzaglike polymeric chain. Two chains are further linked into a 1D gridlike ribbon through the dimeric [Pb₂(μ²-Cl)₂Cl₂] blocks as bridging nodes. With the bulkiest ligand <b>HL</b>^<b>VI</b>, a 2D layered coordination polymer <b>[Pb</b>_<b>3</b><b>(L</b>^<b>VI</b><b>)</b>_<b>2</b><b>Cl</b>_<b>4</b><b>]</b>_{<i><b>n</b></i>}<b>·<i>n</i>MeOH</b> is formed, which network, considering all tetrel bonds, reveals a unique heptanodal 3,3,3,3,4,5,5-connected layer topology named by us as <i><b>sda</b></i><b>3</b>. Compounds <b>[Pb</b>_<b>2</b><b>(L</b>^<b>I</b><b>)­Cl</b>_<b>4</b><b>]</b>_{<i><b>n</b></i>}, <b>[Pb</b>_<b>2</b><b>(L</b>^<b>IV</b><b>)­Cl</b>_<b>3</b><b>]</b>_{<i><b>n</b></i>}, and <b>[Pb­(HL</b>^<b>V</b><b>)­Cl</b>_<b>2</b><b>]</b>_{<i><b>n</b></i>} were found to be emissive in the solid state at ambient temperature. While blue emission of <b>[Pb</b>_<b>2</b><b>(L</b>^<b>I</b><b>)­Cl</b>_<b>4</b><b>]</b>_{<i><b>n</b></i>} is due to the ligand-centered transitions, bluish-green and white luminescence of <b>[Pb</b>_<b>2</b><b>(L</b>^<b>IV</b><b>)­Cl</b>_<b>3</b><b>]</b>_{<i><b>n</b></i>} and <b>[Pb­(HL</b>^<b>V</b><b>)­Cl</b>_<b>2</b><b>]</b>_{<i><b>n</b></i>}, respectively, was assigned to ligand-to-metal charge transfer mixed with metal-centered excited states. Molecular as well as periodic calculations were additionally applied to characterize the obtained polymers