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A stereodynamic tripodal ligand with three different coordinating arms: Synthesis and zinc(II), copper(I) complexation study
Author(s) -
Liang Jian,
Canary James W.
Publication year - 2011
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20833
Subject(s) - chemistry , chirality (physics) , circular dichroism , diastereomer , ligand (biochemistry) , crystallography , metal , chromophore , proton nmr , photochemistry , stereochemistry , organic chemistry , biochemistry , physics , chiral symmetry breaking , receptor , quantum mechanics , nambu–jona lasinio model , quark
A tetradentate tripodal ligand containing a chiral center and three different coordinating arms was designed and synthesized. Its complexation properties with Zn II and Cu I were studied by NMR and optical spectroscopy. NMR experiments demonstrated the formation of two diastereomers, indicating the stabilization of the central tertiary amine configuration by metal coordination. The inversion of pyramidalization of the central tertiary amine of the ligand was found to be highly dependent upon metal ion, solvent, and temperature. Dynamic NMR measurements were used to estimate the energy of activation required for nitrogen atom inversion. Finally, absorption and circular dichroism measurements confirmed the expectation that metal complexes of the ligand gave rise to circular dichroism but that such spectra were not characterized by exciton‐coupling, in contrast to previously described ligands containing two identical arms with strong chromophores. Chirality 2011. © 2010 Wiley‐Liss, Inc.