The study presents a comprehensive computational investigation into the formation and nature of Au(I)–E(II) covalent bonds, with a particular focus on the elusive Au(I)–Pb(II) interaction. Using a series of model systems [(PH₃)₃Au–(ECl₃)] where E = Ge (4), Sn (5), or Pb (6), the research employs high-level quantum chemical methods including MP2/def2TZVPP theory for geometry optimization and counterpoise-corrected bond energy calculations to eliminate basis set superposition error (BSSE). Natural Energy Decomposition Analysis (NEDA) is applied to dissect the energetic components of the bonding, revealing that electrostatic attraction and charge transfer are dominant stabilizing factors, while core repulsion plays a significant role in weakening the interaction. The inert pair effect becomes evident as the charge transfer contribution decreases from Au–Ge to Au–Pb, reflecting reduced participation of the 6s/6p lone pair in bonding due to its increased stability.WIF1 Antibody Technical Information
A topological analysis using Quantum Theory of Atoms in Molecules (QTAIM), Electron Localization Function (ELF), and Density Overlap Region Indicator (DORI) provides qualitative insight into the bonding character. QTAIM results show positive Laplacian values at bond critical points, indicating a closed-shell interaction with partial covalency, consistent with dative bonding. ELF plots confirm the presence of localized lone pairs on E(II), particularly showing a more diffuse and less reactive 6s/6p lone pair on Pb(II) compared to Ge(II) and Sn(II), supporting the idea of decreased donor ability.CD239 Antibody custom synthesis DORI analysis further reveals covalent interactions between Au and E atoms, along with weak non-covalent contacts such as H⋯Cl or F⋯Cl, which contribute to stabilization—especially in systems with electron-withdrawing ligands.PMID:34789344
To explore the possibility of enhancing Au(I)–Pb(II) bonding, three additional models [(PR₃)₃Au–(PbCl₃)] were studied with varying phosphine donors: PMe₃ (7), PH₃ (8), and P(CF₃)₃ (9). DFT-D3/PBE calculations with dispersion corrections revealed that stronger electron-withdrawing ligands lead to shorter Au–Pb distances and higher dissociation energies. Model 9 exhibits the strongest interaction (406 kJ/mol), attributed to enhanced electrostatic attraction and greater charge transfer facilitated by the P(CF₃)₃ ligand. NBO analysis confirms a larger charge transfer from Pb(II) to Au(I) in this case, while the fluorine atoms acquire positive charges, promoting favorable F⋯Cl weak interactions. These findings suggest that both electronic effects from ligands and intermolecular stabilization via weak interactions can significantly influence the feasibility of Au(I)–Pb(II) complex formation.
In conclusion, although the intrinsic Au(I)–Pb(II) bond is weaker than Au(I)–Ge(II) or Au(I)–Sn(II) due to the inertness of the Pb(II) 6s/6p lone pair, it remains a viable target for synthetic design. By employing electron-deficient phosphine ligands and leveraging stabilizing weak interactions between ligands, the formation of stable Au(I)–Pb(II) coordination complexes may be achievable, opening new avenues in heavy group 14 metal chemistry.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com