The number of possible applications of NMR spectroscopy has rapidly increased during the past years. However, measurements can only be made with certainty when the signals are resolved from one another. But, often in the spectra of organic molecules, the signals are bunched together in the featureless clusters from which little definitive structural information can be obtained. One of possible means of simplifying spectra is using Lanthanide shift reagents (LSR). Following the discovery by Hinckley1 that large isotropic shifts ∆iso , are produced for the proton resonances of cholesterol when this molecule is placed in solutions of Eu(dpm)3(py)2, considerable interest has been shown2 in LSRs. While the action of shift reagents, ∆iso, is generally attributed to a through-space dipolar interaction, a through-bond Fermi contact interaction has been considered to contribute in some cases3. Dipolar shifts are proportional to magnetic susceptibility anisotropy, and for axially symmetric systems, to the geometric factor (3cos2Ө - 1) / r3, where r is the length of a radius vector from the metal atom to the resonating nucleus. Ө is the angle made by this vector with the principal axis. A number of workers [4] have chosen to neglect the angular dependence and have attempted to correlate the shifts with r-3 on the basis of assumed models. In this research, the effect of Pr(dbm)3 as LSR on chemical shifts, in 1HNMR spectra of some alcohols such as ethnol, n-propanol, n- butanol, n-pentanol, n-hexanol, n-heptanol has been investigated. We have found the induced shifts decrease rapidly by increasing the distance of the protons from the hydroxyl group. The LSRs are the coordination compounds which are formed a metal atom as Lewis acid and a β-diketone like as DBM acting as a Lewis base. The vacant sites on lanthanides could accommodate electrons of the substrate. The magnitude of the induced shift depends on the complex forming strength of the substrate with LSRs. i.e. their ability to act as a Lewis base. In the study on the same protons, it has been observed that the induced shifts of same protons on homolog alcohols increase along increasing of methylen groups, because of increasing Lewis base strength of hydroxyl groups.

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