Studies of tungsten-183 magnetic shielding by heteronuclear magnetic double and triple resonance

McFarlane, H. C. E., McFarlane, W. and Rycroft, D. S. (1976) Studies of tungsten-183 magnetic shielding by heteronuclear magnetic double and triple resonance. Journal of the Chemical Society: Dalton Transactions, 1976(16), pp. 1616-1622. (doi: 10.1039/DT9760001616)

Abstract

¹H-{¹⁸³W}, ¹H-{³¹P}, and ¹H-{¹⁸³W, ³¹P} nuclear magnetic double- and triple-resonance experiments have been used to determine tungsten-183 chemical shifts and other parameters in 35 tungsten(0) complexes with tertiary phosphine, η-cyclopentadienyl, and other ligands. The observed chemical shifts are several thousand p.p.m. to high field of those for derivatives of WF₆, and this is attributed to the occupancy of the d_xy, d_yz and d_xz valence orbitals in addition to the d_x²–y², and d_z², which reduces the d-electron imbalance and gives a smaller paramagnetic term. π-Back bonding with ligands produces a high-field shift and the marked sensitivity of the shielding to temperature and isotopic substitution is attributed to changes in electronic excitation energies.

• Item Type: Articles
• Keywords: Tungsten chemistry, NMR spectroscopy, multiple resonance.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Rycroft, Dr David
• Authors: McFarlane, H. C. E., McFarlane, W., and Rycroft, D. S.
• Subjects: Q Science > QD Chemistry
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of the Chemical Society: Dalton Transactions
• Publisher: The Chemical Society
• ISSN: 0300-9246