Topological Control of Columnar Stacking Made of Liquid-Crystalline Thiophene-Fused Metallonaphthalocyanines

Abstract

The spontaneous organization of two-dimensional polyaromatic molecules into well-defined nanostructures through noncovalent interactions is important in the development of organic-based electronic and optoelectronic devices. Two regioisomers of thiophene-fused zinc naphthalocyanines ZnTNcendo and ZnTNcexo have been designed and synthesized to obtain photo- and electroactive liquid crystalline materials. Both compounds exhibited liquid crystalline behavior over a wide temperature range through intermolecular π-π interactions and local phase segregation between the aromatic cores and peripheral side chains. The structural differences between ZnTNcendo and ZnTNcexo affected the stacking mode in self-assembled columns, as well as symmetry of the two-dimensional rectangular columnar lattice. The columnar structure in liquid crystalline phase exhibited an ambipolar charge-transport behavior. Liquid crystal stacks: Carrier mobility is enhanced by enlargement of π-conjugated core and control of self-organized nanostructures. Here, we designed two regioisomers of thiophene-fused zinc naphthalocyanines to obtain photo- and electroactive liquid crystalline materials. Both compounds exhibited liquid crystalline behavior over a wide temperature range through intermolecular π-π interactions and local phase segregation between the aromatic cores and peripheral side chains.