Toward the Understanding of Modulation in Molecular Materials: Barluenga’s Reagent and its Analogues.

Investigations into the phase transition of Barluenga’s reagent revealed a transient incommensurately modulated phase; the structures are presented herein. To understand the origin of the modulated phase and the chemistry that can affect it, analogues of Barluenga’s reagent were synthesized and studied. In this context, the halogen and anion can easily be exchanged. Studying different analogues led to the development of the Ratchet Model to describe the behavior in the solid state leading to a better understanding of modulation in this class of molecular crystal structure.