Building Blocks for Self-Assembled Porphyrinic Photonic Wires

Self-organized porphyrinic materials

The self-assembly and self-organization of porphyrins and related macrocycles enables the bottom-up fabrication of photonic materials for fundamental studies of the photophysics of these materials and for diverse applications. This rapidly developing field encompasses a broad range of disciplines including molecular design and synthesis, materials formation and characterization, and the design and evaluation of devices. Since the self-assembly of porphyrins by electrostatic interactions in the late 1980s to the present, there has been an ever increasing degree of sophistication in the design of porphyrins that self-assemble into discrete arrays or self-organize into polymeric systems. These strategies exploit ionic interactions, hydrogen bonding, coordination chemistry, and dispersion forces to form supramolecular systems with varying degrees of hierarchical order. This review concentrates on the methods to form supramolecular porphyrinic systems by intermolecular interactions other than coordination chemistry, the characterization and properties of these photonic materials, and the prospects for using these in devices. The review is heuristically organized by the predominant intermolecular interactions used and emphasizes how the organization affects properties and potential performance in devices.

Synthesis and Characterization of Donor−Acceptor Chromophores for Unidirectional Electron Transfer

[reaction: see text] A series of electron-transfer chromophores containing a donor and acceptor linked by an alkyl spacer were synthesized, and their electronic spectra were investigated. By inclusion with amylose, the supramolecularly encapsulated chromophores exhibit enhanced fluorescence quenching with discrete distance dependence and acquire the ability to sustain self-assemblies of a densely packed supramolecular array on a SiOH/Si substrate.