C–H⋯H–C and C–H⋯π contacts aid transformation of dimeric to monomeric anthracene in the solid state

Abstract

We report the C-H center dot center dot center dot H-C and C-H center dot center dot center dot pi interaction assisted formation of thermodynamically stable blue emissive AP-I from the kinetically stable green emissive AP-II crystal polymorph of 1-(anthracen-9-yl)pyrene (AP). The rotational degree of freedom at the bond between the two constituent chromophores facilitates the formation of conformational polymorphs AP-I and AP-II that can be quantitatively crystallized from ethyl acetate and hexane, respectively.