Toggle Main Menu Toggle Search

Open Access padlockePrints

The Newcastle University research output collection, currently available on ePrints, will shortly be moving to a new open repository platform, Figshare. To prepare for the data migration we have paused adding new content to ePrints, and will resume once the new repository is launched. During this time you will continue to have access to ePrints (but no new content will appear). We will share updates here when available.

Further investigations into tetrahedral M4L6 cage complexes containing guest anions: new structures and NMR spectroscopic studies

Lookup NU author(s): Dr Luca Russo, Professor William Clegg

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.

Abstract

A series of ligands L-Ph, L-naph and L-anth, which contain two bidentate pyrazolyl-pyridine termini separated by an aromatic (1,2-phenyl,2,3-naphthyl or 2,3-anthracenyl, respectively) spacer have been used to prepare tetrahedral cage complexes of the form [M4L6]X-n, in which a bis-bidentate bridging ligand spans each of the six edges of the M-4 tetrahedron and one anion is bound in the central cavity. Several new examples have been structurally characterised, including an example with a new ligand (L-anth), the first example with a second-row transition metal ion [Cd(II)], and the first example of a cage containing a dianionic guest (hexafluorosilicate). The series of structurally similar Co(II) complexes [Co4L6(BF4)](BF4)(7) (L = L-Ph, L-naph and L-anth) have been examined in detail by NMR spectroscopy. The H-1 NMR spectra are highly shifted between -110 and +90 ppm, but the spectra can be completely assigned by correlation of measured T-1 relaxation times with distances of the protons in the complexes from the paramagnetic Co(II) centres. H-1 DOSY measurements have been used to estimate diffusion constants which confirm the structural integrity of the cages in solution, and F-19 DOSY measurements on the anions show that (i) the trapped [BF4](-) anion diffuses at the same rate as the cage superstructure surrounding it, indicating that it is trapped inside the cage cavity; and (ii) the 'free' [BF4](-) anions have diffusion rates consistent with substantial retardation due to ion-pairing with the 7+ complex cation.

Publication metadata

Author(s): Tidmarsh IS, Taylor BF, Hardie MJ, Russo L, Clegg W, Ward MD

Publication type: Article

Publication status: Published

Journal: New Journal of Chemistry

Year: 2009

Volume: 33

Issue: 2

Pages: 366-375

Print publication date: 01/01/2009

ISSN (print): 1144-0546

ISSN (electronic): 1369-9261

Publisher: Royal Society of Chemistry

URL: http://dx.doi.org/10.1039/b816864d

DOI: 10.1039/b816864d

Altmetrics

Altmetrics provided by Altmetric

Share