STRUCTURES OF CHARGE-PERTURBED AND STERICALLY OVERCROWDED MOLECULES .19. TETRACYANOHYDROQUINONE AND ITS DIMORPHOLINIUM SALT - HYDROGEN-BONDS O-H...N OR O-CIRCLE-MINUS...H-CIRCLE-PLUS-N TO NITROGEN BASES OF DIFFERENT STRENGTHS

How a network of hydrogen bonds is influenced by the basicity of a proton acceptor center is demonstrated partiCularly clearly by the title compounds: tetracyanohydroquinone. a relatively acidic phenol. forms linear molecular strings by self-association through hydrogen bonds between QH and CN groupS--provided that addition of a stronger base SuCh IS morpholine does not cause hydrogen bonds to be formed preferentially between different molecules. with concomitant hydrogen transfer (see below). [GRAPHICS]