Related Experiment Video
Updated: Sep 7, 2025

Quantitative Structure-Activity Relationship, Activity Prediction, and Molecular Dynamics of Non-nucleotide Reverse Transcriptase Inhibitors
Published on: May 9, 2025
Electronic insights into aminoquinoline-based PNHN ligands: protonation state dictates geometry while coordination
Matthew V Gradiski1, Benjamin E Rennie1, Alan J Lough1
1Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario, M5S 3H6, Canada. rmorris@chem.utoronto.ca.
Abstract:
A variety of transition metal complexes bearing aminoquinoline PNHH'-R ligands R = Ph (L1H), Cy (L2H) and their amido analogues are reported for rhodium(I) ([Rh(L1H)(PPh3)]+1 and Rh(L1)(PPh3) 2), cobalt(II) (Co(L2)(Cl) 3), and iron(II) ([Fe(L1H)2]2+5, Fe(L1)26, and [Fe(C5Me5)(L1H)]PF67). The acid-base and redox properties of the amido complexes 2, 6, and their protio parent complexes 1, and 5 permit the determination of the pKa and bond dissociation free energy (BDFE) of their N-H bonds while the ligand scaffold is coordinated to metal centres of square planar and octahedral geometry, respectively. From relative concentrations obtained by the use of 31P{1H} NMR spectroscopy, a pKaTHF value of 14 is calculated for rhodium complex 1, 6.4 for iron complex 5, and 24 for iron complex 7. These data, when combined with elecrochemical potentials obtained via cyclic voltammetry, allow the calculations of BDFE values for the N-H bond of 69 kcal mol-1 for 1, and of 55 kcal mol-1 for 5.
More Related Videos
Related Concept Videos
Structure of Amines
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Basicity of Heterocyclic Aromatic Amines
Valence Bond Theory
Coordination Number and Geometry
EDTA: Chemistry and Properties

