The first coordination polymers with an [O]₂[N]P(S)-Hg segment: a combined experimental, theoretical and database...

Area of Science:

• Coordination Chemistry
• Materials Science
• Inorganic Chemistry

Background:

• The synthesis and structural characterization of mercury(II) coordination polymers are crucial for understanding their diverse applications.
• Ligands featuring thiophosphoramide moieties offer unique coordination possibilities with metal ions.
• Previous studies have not extensively explored mercury(II) coordination polymers incorporating (O)2(N)PS-based ligands.

Purpose of the Study:

• To synthesize and structurally characterize novel one-dimensional coordination polymers of mercury(II) using thiophosphoramide ligands.
• To investigate the coordination environment of mercury atoms and the resulting structural motifs.
• To evaluate the nature of mercury-ligand bonding and intermolecular interactions using theoretical methods.

Main Methods:

• Synthesis of mercury(II) coordination polymers: {Hg2Cl4L1}n (1), {HgBr2L1}n (2), and {Hg2Cl4L2}n (3).
• Single-crystal X-ray diffraction for structural determination.
• Quantum chemical calculations including Quantum Theory of Atoms in Molecules (QTAIM) and Natural Bond Orbital (NBO) analyses.
• Hirshfeld surface analysis and fingerprint plots for investigating intermolecular interactions.

Main Results:

• The study presents the first structural characterization of Hg(II) coordination polymers with (O)2(N)PS-based ligands.
• Mercury atoms exhibit distorted trigonal pyramidal coordination geometries (Hg(Cl)3(S) or Hg(Br)2(S)2).
• Theoretical calculations indicate that Hg-S and Hg-halide bonds possess a predominantly electrostatic nature with partial covalent character.
• Various intramolecular interactions (e.g., NH···Cl, CH···O) and supramolecular assemblies were identified and analyzed.

Conclusions:

• The synthesized mercury(II) coordination polymers exhibit unique one-dimensional structures dictated by the thiophosphoramide ligands.
• The bonding interactions are primarily electrostatic, with significant contributions from covalent forces.
• Hirshfeld analysis provides detailed insights into the structural features and intermolecular forces governing the crystal packing.