My notes states that fluorine is too highly electronegative and hence clings on too tightly to its lone pair of electrons and so it cannot accept hydrogen bonds as well. However, it also stated that a hydrogen bond will be stronger if the electron density on the electron rich atom the stronger the hydrogen bond. These 2 statements seem to contradict though. I read online from this link http://www.quora.com/Why-can-chlorine-atoms-not-form-hydrogen-bonds-even-though-they-have-very-similar-electronegativity-to-nitrogen-which-can [Broken] that a hydrogen bond has an electrostatic component, but what differentiates it from a dipole-dipole interaction is that it also has a covalent component. And since the F clings onto its electrons too tightly it would not want to form a covalent bond which is why its a poor HBA and forms weak hydrogen bonds. So is the second statement wrong?