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A 59 Co NMR chemical shift and relaxation study of preferential solvation toward tris(acetylacetonato)cobalt(III)
Author(s) -
Grahn Hans,
Edlund Ulf,
Holak Tadeusz A.
Publication year - 1987
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260250608
Subject(s) - chemistry , solvation , cobalt , tris , cyclohexane , relaxation (psychology) , hydrogen bond , chemical shift , inorganic chemistry , analytical chemistry (journal) , molecule , organic chemistry , social psychology , psychology , biochemistry
A 59 Co NMR chemical shift and relaxation study of the preferential solvation of tris(acetylacetonato)cobalt(III) was undertaken by varying the solute concentration in cyclohexane. As expected, the preferred solvation is most pronounced for hydrogen‐bond donating solutes, such as chloroform and methanol. However, the expected levelling of the 59 Co chemical shift curve on increasing the alcohol molar fraction is not observed because of competing solute‐solute interactions in bulk solution. The order of preference is close to that proposed using paramagnetically induced relaxation times or shifts in solutions doped with tris(acetylacetonato)chromium(III). The 59 Co line‐width measurements correlate with Co(acac) 3 rotational correlation times. Contrary to earlier proposals, the 59 Co relaxation is claimed to be controlled by modulation of the static quadrupolar tensor of Co(acac) 3 .