Reversibly Shape-Shifting Organic Optical Waveguides: Formation of Organic Nanorings, Nanotubes, and Nanosheets

This Account is focused on the self-assembly of p-phenylenevinylenes, a linear pi-system, which has been extensively studied over the years due to both fundamental and technological importance. A serendipitous observation of the gelation of an oligo( p-phenylenevinylene) (OPV) derivative in nonpolar hydrocarbon solvents that led to a new class of functional materials, namely, pi-organogels, is described. Strategies to control the size, shape, and functions of the supramolecular architectures of OPV self-assemblies are highlighted. Formation of nano- to microsized helical architectures, control on chromophore packing, self-assembly induced modulation of optical properties, and application as light-harvesting assemblies are the important features of this novel class of photonically and electronically active soft materials.

The possibility to graft nano-objects directly on its surface makes graphene particularly appealing for device and sensing applications. Here we report the design and the realization of a novel device made by a graphene nanoconstriction decorated with TbPc(2) magnetic molecules (Pc = phthalocyananine), to electrically detect the magnetization reversal of the molecules in proximity with graphene. A magnetoconductivity signal as high as 20% is found for the spin reversal, revealing the uniaxial magnetic anisotropy of the TbPc(2) quantum magnets. These results depict the behavior of multiple-field-effect nanotransistors with sensitivity at the single-molecule level.