Abstract

The long-range spin–spin coupling constants between hydroxyl protons and ring protons or fluorine nuclei are used to establish the conformer populations in iodine and brornine derivatives of 2-trifluoromethylphenol in C6H12, CCl4, and C6D6 solutions. The sequence Cl, [Formula: see text] is established for the so-called hydrogen bonding preferences of the hydroxyl group in 2,4,6-trisubstituted phenols, the corresponding free energy sequence being −ΔG = 1690, 1690 > 1300 > 1230 > 0 ± 200 cal/mol at 32 °C in CCl4 solution. An indirect estimate of the free energy differences in the vapor phase suggests the sequence −ΔG = 2800, 2800 > 2400 > 2300 > 1100 ± 300 cal/mol; the latter value meaning that the hydroxyl group in 4-bromo-2-trifluoromethylphenol prefers the CF3 group by this amount in the vapor phase. Benzene interacts preferentially with the OH group in this compound to the extent of 1300 cal/mol (ΔG), referenced to the vapor phase.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.