Related Experiment Video
Updated: Sep 8, 2026
Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
DAPhen vs BLPhen: Transposition of Coordination Centers Redirects the Metal Binding Affinity
Pavel S Lemport1, Alexei D Averin1, Javokhirmirzo K Isomiddinov1
1Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1 bld. 3, 119991Moscow, Russia.
Abstract:
A series of 5-7-membered bis-lactam-derived phenanthroline ligands was synthesized. The structure of all of the obtained ligands was investigated by spectral methods, including 2D NMR spectroscopy and X-ray for all three ligands. The coordination chemistry of the synthesized ligands with d- and f-elements was studied. NMR titration of the ligands L1-L3 with lanthanides trinitrates and aluminum, zinc, and lead perchlorates was performed. It was shown that in the case of f-elements, the LM complex is often in equilibrium with the free ligand L. With d-elements, a clear formation of L2M complexes is observed. X-ray diffraction analysis of the single crystals obtained from solutions upon NMR titration showed that in the course of titration of L1 with Al(ClO4)3, no complexation occurred, but rather the asymmetrically protonated form of the ligand was formed with perchlorate as a counterion due to the higher Brønsted basicity of these ligands. The new ligands demonstrated moderate extraction ability toward Pb(II) and Pd(II), while the extraction of lanthanides and most other tested metal cations remained insignificant.
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