68066-60-4Relevant articles and documents
ELECTRONIC EFFECT OF THE CYCLOPENTADIENYL ANION AS A SUBSTITUENT. THE EFFECT OF THE ALKALI METAL CATION, SOLVENT AND COMPLEXING AGENTS ON 19F CHEMICAL SHIFTS OF m- AND p-FLUOROPHENYLCYCLOPENTADIENYL ANIONS
Ogorodnikova, N. A.,Koridze, A. A.,Gubin, S. P.
, p. 293 - 301 (1981)
Salts of the carbanions M+-, where M = Li, Na, and K, have been investigated by 19F NMR spectroscopy.The effect of the alkali metal cation, the coordinating ability of the solvent, complexing agents (TMEDA, crown-ethers), and concentration on the 19F chemical shifts has been studied.The results are discussed in terms of an equilibrium between tight and solvent-separated ion pairs.On the basis of 19F chemical shift data for Li+- in HMPA solution, the electronic effect of the C5H4- substituent as a "free ion" has been determined.