Hydrogen bonding of molecules containing two equivalent proton donor centers

A study has been made of hydrogen bonding in two pairs of proton donors: 2,7-dihydroxynaphthalene and 2-hydroxynaphthalene, and malononitrile and methylmalononitrile. In each pair one of the proton donors contains one reactive center, and the other two. It is shown by NMR and quantum-chemical methods that molecules possessing two equivalent proton donor centers form hydrogen bonds involving both protons, the formation of one hydrogen bond having practically no effect on the other.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 3, pp. 340–344, May–June, 1990.