The chemical shift of protons in intramolecular hydrogen bonds has been measured in 41 ortho substituted phenol type compounds. The change in chemical shift " ΔσOH " on formation of these hydrogen bonds is taken as the difference between the infinite dilution chemical shift of the parent phenol compound in CCl₄ solution and the chemical shift measured for the proton in the intramolecular
hydrogen bond. This change in chemical shift is correlated with the corresponding frequency shift " ΔνOH " in the -OH stretching region of the infra-red spectrum.
The dilution chemical shift for the -OH proton in the o-halophenols has been investigated over a concentration range 1-5 mole % in CS₂ and a temperature region -53 to 107°C Using the infinite dilution shift values, the equilibrium constants of the cis-trans conversion were obtained. Values for δCIS, the chemical shift of the completely hydrogen bonded form; δ TRANS, the chemical shift of the unbonded form, and ΔH , the enthalpy of formation of the hydrogen bond, were also calculated. From these results a value for ΔH, the enthalpy of formation for the dimer was calculated, assuming that the major dimer species in solution was formed from the combination of a cis and trans bonded form.
Temperature studies of the change in chemical shift of the -OH proton for 2,1,6-trihalosubstituted phenols is also reported. The temperature range in this case was 0°C to 111°0. / Science, Faculty of / Chemistry, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/38352 |
| Date | January 1963 |
| Creators | Allan, Ernest Albert |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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