Issue 18, 2003

Structure and dynamics of copper complexes with 2,2′:6′,2″-terpyridines in glassy matrices

Abstract

Continuous-wave and pulse electron paramagnetic resonance (EPR) as well as electron-nuclear double resonance (ENDOR) techniques are applied for determination of the electronic and geometric structure of copper(II) complexes with terpyridine and related ligands that are relevant in the context of supramolecular chemistry. The results are analysed in conjunction with density functional theory computations and are compared to the crystal structure of the bis(terpyridyl) copper(II) complex in the limit of static Jahn–Teller distortion (R. Allmann, W. Henke and D. Reinen, Inorg. Chem. 1978, 17, 378, ). The static structure in disordered environments is subject to some strain in both the g-values and copper–ligand distances, but otherwise is rather similar to the structure in crystals. The formation of coordination oligomers is indicated by broadening of the lineshape and a decrease in the transverse relaxation time at low fields which are both related to exchange coupling between copper centres. At high fields of approximately 3 T and a temperature of 15 K, the transverse relaxation rate is governed by modulation of the g-values induced by small-amplitude libration along the Jahn–Teller active mode. A study of the dynamics in a temperature range from below the glass transition temperature to above the melting point of ethanol by CW EPR reveals that the complex is a sensitive probe for matrix dynamics, which detects dynamic heterogeneities and the transition from the structural glass to the crystalline phase. Jahn–Teller dynamics is completely unfrozen only on melting of the matrix.

Supplementary files

Article information

Article type
Paper
Submitted
22 May 2003
Accepted
23 Jul 2003
First published
06 Aug 2003

Phys. Chem. Chem. Phys., 2003,5, 3959-3967

Structure and dynamics of copper complexes with 2,2′:6′,2″-terpyridines in glassy matrices

E. Narr, H. Zimmermann, A. Godt, D. Goldfarb and G. Jeschke, Phys. Chem. Chem. Phys., 2003, 5, 3959 DOI: 10.1039/B305764J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements