作者:Cameron Peebles、Paul M. Alvey、Vincent Lynch、Brent L. Iverson
DOI:10.1021/cg401522v
日期:2014.1.2
In order to exploit the use of favorable electrostatic interactions between aromatic units in directing the assembly of donor acceptor (D-A) dyads, the present work examines the ability of conjugated aromatic D-A dyads with symmetric side chains to exhibit solid-state polymorphism as a function of time during the solid formation process. Four such dyads were synthesized, and their packing in the solid state from either slower (10-20 days) or faster (1-2 days) evaporation from solvent was investigated using single crystal X-ray analysis and powder X-ray diffraction. Two of the dyads exhibited tail-to-tail (A-A)packing upon slower evaporation from solvent and head-to-tail (D-A) packing upon faster evaporation from solvent. A combination of single-crystal analysis and XRD patterns were used to create models, wherein a packing model for the other two dyads is proposed. Ourfindings suggest that while side chain interactions in asymmetric aromatic dyads can play an important role in enforcing segregated D-A dyad assembly, slowly evaporating symmetrically substituted aromatic dyads allows for favorable electrostatic interactions between the aromatic moieties to facilitate the organization of the dyads in the solid state.