Redox non-innocence of thioether macrocycles: elucidation of the electronic structures of mononuclear complexes of gold(ii) and silver(ii)

Shaw, J. L., Wolowska, J., Collison, D., Howard, J. A.K., McInnes, E. J.L., McMaster, J., Blake, A. J., Wilson, C. and Schroder, M. (2006) Redox non-innocence of thioether macrocycles: elucidation of the electronic structures of mononuclear complexes of gold(ii) and silver(ii). Journal of the American Chemical Society, 128(42), pp. 13827-13839. (doi:10.1021/ja0636439) (PMID:17044711)

Full text not currently available from Enlighten.

Abstract

The mononuclear +2 oxidation state metal complexes [Au([9]aneS3)2]2+ and [Ag([18]aneS6)]2+ have been synthesized and characterized crystallographically. The crystal structure of the Au(II) species [Au([9]aneS3)2](BF4)2 shows a Jahn−Teller tetragonally distorted geometry with Au−S(1) = 2.839(5), Au−S(2) = 2.462(5), and Au−S(3) = 2.452(5) Å. The related Ag(II) complex [Ag([18]aneS6)](ClO4)2 has been structurally characterized at both 150 and 30 K and is the first structurally characterized complex of Ag(II) with homoleptic thioether S-coordination. The single-crystal X-ray structure of [Ag([18]aneS6)](ClO4)2 confirms octahedral homoleptic S6-thioether coordination. At 150 K, the structure contains two independent Ag(II)−S distances of 2.569(7) and 2.720(6) Å. At 30 K, the structure retains two independent Ag(II)−S distances of 2.615(6) and 2.620(6) Å, with the complex cation retaining 3-fold symmetry. The electronic structures of [Au([9]aneS3)2]2+ and [Ag([18]aneS6)]2+ have been probed in depth using multifrequency EPR spectroscopy coupled with DFT calculations. For [Au([9]aneS3)2]2+, the spectra are complex due to large quadrupole coupling to 197Au. Simulation of the multifrequency spectra gives the principal g values, hyperfine (A) and quadrupole (P) couplings, and furthermore reveals non-co-incidence of the principal axes of the P tensor with respect to the A and g matrices. These results are rationalized in terms of the electronic and geometric structure and reveal that the SOMO has ca. 30% Au 5dxy character, consistent with DFT calculations (27% Au character). For [Ag([18]aneS6)]2+, detailed EPR spectroscopic analysis confirms that the SOMO has ca. 26% Ag 4dxy character and DFT calculations are consistent with this result (22% Ag character).

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Wilson, Dr Claire
Authors: Shaw, J. L., Wolowska, J., Collison, D., Howard, J. A.K., McInnes, E. J.L., McMaster, J., Blake, A. J., Wilson, C., and Schroder, M.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:Journal of the American Chemical Society
Publisher:American Chemical Society
ISSN:0002-7863
ISSN (Online):1520-5126

University Staff: Request a correction | Enlighten Editors: Update this record