Conformational dynamics of Cu(I) complexes of tripodal ligands: Steric control of molecular motion

Jing Zhang, Kam Siu, Chin H. Lin, James Canary

Research output: Contribution to journalArticle

Abstract

The dynamics of molecular conformational changes for Cu(I) complexes of two tripodal ligands were studied. Variable-temperature NMR and circular dichroism in combination with two-dimensional NMR experiments were employed to determine the structural and energetic details of a dynamic process in which one of three arms dissociates from coordination to Cu(I). Dissociation was triggered by addition of a strongly coordinating anion (SCN-). One-electron oxidation to the Cu(II) complex returned coordination of all three ligand arms. The observed phenomena were dependent upon steric crowding; addition of a single methyl group to one arm resulted in marked differences in behavior. The CuSCN and CuPF6 complexes of tris(2-quinolylmethyl)amine (TQA) and the CuPF6 complex of 1-(quinolin-2-yl)-N,N-bis(quinolin-2-ylmethyl) ethanamine (MeTQA) did not give any evidence for differences in coordination over the temperature range 0-35 °C, while CuI(MeTQA)NCS demonstrated marked differences in NMR but not CD spectra over this temperature range. In the latter complex, two diastereotopic arms displace each other with a transition energy of 14.0 kcal mol-1. The structure of the arm-dissociated complex contains a higher degree of stereochemical complexity than the tetradentate complexes.

Original languageEnglish (US)
Pages (from-to)1147-1151
Number of pages5
JournalNew Journal of Chemistry
Volume29
Issue number9
DOIs
StatePublished - Sep 2005

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Ligands
Nuclear magnetic resonance
Coordination Complexes
Dichroism
Temperature
Amines
Anions
Negative ions
Oxidation
Electrons
Experiments
cuprous thiocyanate

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  • Chemistry(all)

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Conformational dynamics of Cu(I) complexes of tripodal ligands : Steric control of molecular motion. / Zhang, Jing; Siu, Kam; Lin, Chin H.; Canary, James.

In: New Journal of Chemistry, Vol. 29, No. 9, 09.2005, p. 1147-1151.

Research output: Contribution to journalArticle

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