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Detection and Measurement of Noncoincidence between the Principal Axes of the g-Matrix and Zero-Field Splitting Tensor Using Multifrequency Powder EPR Spectroscopy: Application to cis-[(NH3)2Pt(1-MeU)2Cu(H2O)2](SO4).4.5H2O (1-MeU = Monoanion of 1-Methyluracil)

Citation

Collison, DC and Goodgame, DML and Hitchman, MA and Lippert, B and Mabbs, FE and McInnes, EJL, Detection and Measurement of Noncoincidence between the Principal Axes of the g-Matrix and Zero-Field Splitting Tensor Using Multifrequency Powder EPR Spectroscopy: Application to cis-[(NH3)2Pt(1-MeU)2Cu(H2O)2](SO4).4.5H2O (1-MeU = Monoanion of 1-Methyluracil), Inorganic Chemistry, 41, (11) pp. 2826-2833. ISSN 0020-1669 (2002) [Refereed Article]

DOI: doi:10.1021/ic011283e

Abstract

Multifrequency continuous wave EPR spectra (4-34 GHz) on a powder of the title compound are consistent with a spin-triplet state. This arises from interaction between centrosymmetrically related pairs of copper(II) ions in the solid. The spectra at all frequencies have been simulated with a single set of spin-Hamiltonian parameters. The results show that there is noncoincidence between the principal axes of the g-matrices on each copper center and those of the zero-field splitting (D) tensor. This noncoincidence is a single rotation of 33° ± 2°. The parameters from the powder spectra have been verified by a subsequent single-crystal EPR study which yielded the spinHamiltonian parameters g XX = 2.074, g YY = 2.093, g ZZ = 2.385, D XX = ±0.0228 cm -1, D YY = ±0.0211 cm -1, D ZZ = 0.0439 cm -1 with Euler angles of α = 179°, X = 33.4°, and γ = 328°. Analysis of the zero-field splitting tensor in terms of exchange indicates that the interaction between the pairs of copper(II) ions is almost entirely dipolar in origin. This study shows that multifrequency EPR spectroscopy on powders, coupled with spectrum simulation, can detect and measure noncoincidence between the principal axes of the g-matrix and zero-field splitting tensor, and does not necessarily require the presence of metal hyperfine interactions.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Inorganic Chemistry
Research Field:Inorganic Chemistry not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Chemical Sciences
Author:Hitchman, MA (Dr Michael Hitchman)
ID Code:25295
Year Published:2002
Web of Science® Times Cited:4
Deposited By:Chemistry
Deposited On:2002-08-01
Last Modified:2003-05-20
Downloads:0

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