A series of perylene tetracarboxylic acid bisimides 3a-e bearing 3,4,5-tridodecyloxyphenyl substituents on the imide N atoms and zero, two, or four phenoxy-type substituents in the bay positions of the perylene core were synthesized. From investigations of their spectroscopic properties and aggregation behavior in low-polarity solvents by absorption and fluorescence optical spectroscopy, not only were these compounds found to form fluorescent J-type aggregates, but also binding constants for aggregation could be derived which reflect the number and steric demand of the phenoxy substituents for bisimides 3a-d. In the pristine state, 3a-d form thermotropic hexagonal columnar mesophases which exist over a broad temperature range from below -30 degrees C to over 300 degrees C. For the tetraphenoxy-substituted compound 3e, however, a layered crystalline structure was found. This difference in behavior can be explained by the concept of microphase segregation of the aromatic cores of the molecules and the alkyl chains at the periphery. The high stability and bright fluorescence of the mesophase of several of the compounds make them promising for applications as polarizers or components in (opto)electronic devices.

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2,6-Dichloronaphthalene dianhydride has been synthesized by a modified procedure. The imidization of this dichlorinated anhydride with amines and subsequent stepwise nucleophilic exchange of the chlorine atoms by alkyl- or arylamines afforded a series of hitherto unknown monoamino- and diamino-substituted naphthalene diimides. An alternative route for the synthesis of diamino-substituted naphthalene diimides is also reported. Optical and electrochemical properties of the newly synthesized amino-functionalized naphthalene diimides were studied in detail. The absorption maxima (530-620 nm) of these dyes are appreciably bathochromically shifted compared to those of the corresponding core-unsubstituted compounds. At the naphthalene core alkylamino-substituted diimides exhibit fluorescence quantum yields up to 60%.

OMBD is due to the combination of shape and bonding features of the molecules, together with kinetic factors such as directional hydrogen bonding, and the self-shadowing and self-correcting effects. Not all organic molecules having shapes similar to 1 and 2 can be used to obtain in-plane ordering by oblique OMBD. Long-range ordering was not observed in films of several other stilbene-type dipolar chromophores without sticky ends. [19] This suggests that the bonding feature of 1 and 2 is necessary to achieve the alignment. We believe that our preliminary results [10] and the mechanism proposed here for the growth and alignment will stimulate interests in using supramolecular assemblies based on hydrogen bonding [18,20] for OMBD growth of ordered thin films. Further experimental and theoretical studies, including computer simulation, are necessary to fully understand the origin of the in-plane ordering, and the role of the materials and deposition conditions on the ordering. Such understanding will rationalize material design and processing conditions for the fabrication of oriented organic thin films for advanced applications, such as nonlinear optics and electro-optics.Nature is abundant with functional structures that are organized hierarchically through non-covalent interactions. Introducing functionality is also a main goal in supramolecular chemistry [1] to make use of molecular recognition events for sensor applications, [2] control of transport processes, [3] or electrical and optical devices. [4] Especially for the latter, spontaneous self-assembly could provide a powerful tool to achieve architectural control and functional specificity. The major challenge confronting such a bottom-up approach is how to position predefined functional building blocks in space to optimize complex processes such as energy or charge transport.As electrical and optical functionalities rely on extended conjugated systems, a lot of work has been devoted to p stacking as the major driving force for one-dimensional columnar superstructures. [5] However, the concomitant electronic interactions are not always desired because of substantial and hardly predictable changes of the molecular properties of the chromophores. Moreover, progress toward long-range three-dimensional structures is difficult to realize for these systems because additional non-covalent forces, such as hydrogen bonding or metal±ligand coordination, often cause the formation of insoluble pigments. [6,7] In this paper we report our initial results toward well-defined mesoscopic structures based on a multifunctional perylene chromophore of high photostability, high fluorescence quantum yield, [8] and distinct redox activity. [9] The process of superstructure formation is shown to involve multiple orthogonal intermolecular interactions, appropriate solubilizing substituents, and a solvent of low polarity (Scheme 1).

The cover picture shows mesoscopic strands of highly fluorenscent perylene bisimide ± melamine assemblies as visualized by confocal fluorenscence microscopy. This technique does not only provide topological information such as related AFM or STM images, but truly shows the functionality of fluorescent optical networks of the present supramolecular system. The synthesis and structural investigations of the fluorescent mesoscopic superstructures is presented by F. Würthner et al. on p. 3871 ff. The author wishes to thank the BASF AG for kindly covering the costs for the cover picture

Self‐aggregation and hydrogen bond‐directed superstructure formation with a perylene bisimide dye were investigated for melamines bearing two or four alkyl chains. For a melamine with two n‐octadecyl substituents, large micellar aggregates of several hundred nanometers were observed in methylcyclohexane solution by dynamic light scattering. By means of hydrogen bonding these micelles were loaded with various contents of perylene bisimide dyes up to an equimolar amount. Even at low dye contents, islands of strongly aggregated perylene bisimides were formed according to UV‐vis absorption spectroscopy. In a series of melamines functionalized with n‐octadecyl esters of chiral amino acids, no self‐aggregation of the melamines was observed, and the stability of the assemblies with the perylene bisimide dyes showed strong dependence on the melamine substituents. For four melamine–perylene bisimide combinations stable assemblies formed, which exhibited exciton‐coupled circular dichroism (CD) effects for the perylene bisimide absorption bands whose sign is controlled by the stereoisomerism of the respective melamine. While for (S,S)‐melamines a negative Cotton effect was observed, indicating an M‐helical arrangement of the chromophores within the assembly, the (R,R)‐enantiomer induced P‐helicity, and no CD effect was found for the achiral (R,S)‐diastereomer.

The photo‐ and redox‐active diaza ligand 1 and its doubly alkylated derivative 2 were obtained from perylene bisimides. The suitability of 1 for obtaining supramolecular architectures was confirmed by binding studies with carboxylic acids, zinc porphyrins, and metal ions.

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