Driving crystal construction via stoichiometry: π–π stacks in squaric acid organometallic salts

Abstract

Depending on the stoichiometric ratio, squaric acid (H2SQA) reacts with [Co(η5-C5H5)2][OH] to form crystalline materials based on anion–cation π–π stacks and/or squarate ion ribbons held together by O–H···O hydrogen bonds between squarate anions and by charge-assisted C–Hδ+···Oδ– hydrogen bonds between organometallic and organic components.