Abstract
The Isotropic paramagnetic shifts in the H1 and P31 NMR spectra of triphenylphosphine, forming labile complexes in chloroform with the acetylacetonato compound of nickel(II), have been measured. The concentration dependence of the shifts has been used to calculate the hyperfine interaction constants and the spin densities in an individual complex, on the assumption that the complex has the composition [Ni(AA)2] (PPh3)2. It has been found that the spin density in the sp3 hybrid orbital of the phosphorus atom is positive and amounts to not less than 10%, indicating a σ-mechanism of transfer of spin density from the nickel to the phosphorus. The spin densities on the carbon atoms of the phenyl rings are smaller fay about two orders of magnitude than those on the phosphorus atom, and this is attributed to the orientation of these rings, which is unsuitable for conjugation with the unshared pair. The contributions of the different mechanisms to the delocalization of the spin density from the phosphorus atom to the π-system of the rings have been estimated.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
D. R. Eaton and W. D. Phillips, Adv. in Magnetic Resonance, vol. 1, 103, 1965.
A. Loewenstein, M. Shporer, and G. Navon, J. Am. Chem. Soc.,85, 2855, 1963.
J. Swift and R. E. Connik, J. Chem. Phys.,37, 307, 1962;41, 2553, 1964.
E. E. Zaev, Yu. N. Molin, G. M. Zhidomirov, and V. V. Voevodskii, DAN SSSR,173, 1370, 1967.
W. D. Horrocks, R. G. Taylor, and G. N. La Mar, J. Am. Chem. Soc.,86, 3031, 1964.
E. A. La Lancette and D. R. Eaton, J. Am. Chem. Soc.,86, 5145, 1964.
G. N. La Mar and W. D. Horrocks, J. Chem. Phys.,41, 2126, 1964.
R. W. Kluiber and W. D. Horrocks, Inorg. Chem.,6, 430, 1967.
R. G. Charles and M. A. Pawlikowski, J. Phys. Chem.,62, 440, 1958.
G. Shaw, Chem. Comm., 425, 1966.
H. G. Dehmelt, Phys. Rev.,99, 527, 1955.
J. J. Daly, J. Chem. Soc., 3799, 1964.
J. R. Morton, Chem. Rev.,64, 4531, 1964.
A. D. McLachlan, Mol. Phys.,3, 233, 1960.
N. M. Atherton and A. Hinchiffe, Mol. Phys.,12, 349, 1967.
Author information
Authors and Affiliations
Additional information
The authors wish to express their gratitude to the late Academician V. V. Voevodskii, whose initiative and constant support made this joint work possible. The authors thank A. Nesmei, for assistance in the construction of the phosphorus resonance measurement apparatus, and G. M. Zhidomirov, for discussion of the results.
Rights and permissions
About this article
Cite this article
Skubnevskaya, G.I., Radicz, L., Molin, Y.N. et al. Isotropic paramagnetic shifts of the phosphorus and proton magnetic resonance and the spin density distribution in paramagnetic complexes of triphenylphosphine with nickel acetylacetonate. Theor Exp Chem 5, 244–249 (1969). https://doi.org/10.1007/BF01109672
Issue Date:
DOI: https://doi.org/10.1007/BF01109672