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Updated: Jan 6, 2026
Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
Stability of metal-metal interactions in dinuclear Pt-Au complexes as a function of bridging Pt-arene ring
Katelynn M Farmer-Mason1, Jeffrey W Bacon1, Eric S Cueny1
1Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA. ecueny@bu.edu.
Abstract:
A series of dinuclear Pt-Au complexes [(bhq-PhR)(PPh3)Pt-Au(PPh3)]+ (R = -H (5), -OMe (5-OMe), -F (5-F), and -CF3 (5-CF3)), derived from novel Pt complexes (4, 4-OMe, 4-F, and 4-CF3), were prepared and analyzed using solution-state NMR spectroscopy and X-ray crystallography. The persistence of three-center Pt-Au-Cipso bonding interaction in solution and the migration of [Au(PPh3)]+ across electronically distinct arenes of 5, 5-OMe, 5-F, and 5-CF3 offers a unique opportunity to probe the intermediates of transmetallation as a function of bridging arene ring electronic properties. Analysis of the solid-state X-ray structures of these dinuclear complexes reveal that the degree of arene ring transfer is dictated by whether the [Au(PPh3)]+ bridges the Pt-benzoquinoline or the comparably more flexible Pt-PhR ring. Relative thermodynamic stability, evaluated via pyridine titrations, correlates with the electronic donating or withdrawing ability of the R group. A Hammett analysis of the Keq derived from pyridine titrations reveal a linear relationship between the log(KR/KH) and σp values. Together, these studies demonstrate how arene ring electronic properties influence the structure and stability of transmetallation intermediates, important progress towards a deeper understanding of transmetallation between transition metal organometallic complexes.
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