F···HO intramolecular hydrogen bond as the main transmission mechanism for (1h)J(F,H(O)) coupling constant in 2'-fluoroflavonol.
Flavonoids are useful compounds in medicinal chemistry and exhibit conformational isomerism, which is ruled by intramolecular interactions. One of the main intramolecular forces governing the stability of conformations is the hydrogen bond. Hydrogen bond involving fluorine covalently bonded to carbon has been found to be rare, but it appears in 2'-fluoroflavonol, although the F···HO hydrogen bond cannot be considered the main effect governing the conformational stability of this compound. Because (19)F is magnetically active and suitable for NMR studies, the (1h)J(F,H(O)) coupling constant can be used as a probe for such an interaction in 2'-fluoroflavonol. In fact, the (1h)J(F,H(O)) coupling was computationally analyzed in this work, and the F···HO hydrogen bond was found to be its main transmission mechanism, which modulates this coupling in 2'-fluoroflavonol, rather than overlap of proximate electronic clouds, such as in 2-fluorophenol.
Department of Chemistry, Federal University of Lavras, Lavras, Minas Gerais, Brazil.
Tânia A O
TA
Fonseca
Teodorico C
TC
Ramalho
Matheus P
MP
Freitas
D044948:Flavonols / Q000737:chemistry*; D005461:Fluorine / Q000737:chemistry*; D006860:Hydrogen Bonding; D006878:Hydroxides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D015394:Molecular Structure; D012015:Reference Standards
C579294:2'-fluoroflavonol; D044948:Flavonols; D006878:Hydroxides; D005461:Fluorine; C031356:hydroxide ion