ABSTRACT
Optoelectronically active organic molecules or polymers composed of π-conjugated backbones have extremely rich and tailorable optoelectronic properties such as light harvesting, photoluminescence, and photosensitization. To achieve suitability for the practical applications, flexible, deformable, or fluidic molecular/polymeric materials are required. A new generation of solvent-free fluid materials, termed functional molecular liquids (FML), has emerged. The chapter discusses the design, synthesis, and application of various FML. To soften the intrinsically rigid and crystalline p-conjugated optoelectronic functional materials, disturbing intra- or intermolecular π-π stackings is the most essential methodology. Aliphatic side chains in FMLs can be classified into linear and branched chains. Linear alkyl chains have been used to soften and improve the solubility of π-conjugated molecules for a long time. Aromatic hydrocarbons, namely arenes, are a class of π-conjugated molecules composed of one or more fused aromatic rings. π-Conjugated polymers have attracted considerable interests for organic optoelectronic applications owing to their distinguishing mechanical properties, processability, and electronic conductivity.
