Interaction Dependence and Similarity in Thermal Expansion of a Dimorphic 1D Hydrogen-Bonded Organic Complex

The thermal expansion trends for the two one-dimensional hydrogen-bonded 1:2 cocrystal polymorphs of 1,2,3,4-cyclobutanetetracarboxylic acid and trans-1,2-bis­(4-pyridyl)­ethylene have been studied. The expansion modes were found to be highly anisotropic but similar in these two forms. The mode of expansions along different directions is found to depend on the nature of the interactions and contacts that are present along those directions.