Supramolecular Nanoarchitectures DOI: 10.1002/anie.201004127 Controlling the Transformation of Primary into Quaternary Structures: Towards Hierarchically Built-Up Twisted Fibers** Juan Luis López, Carmen Atienza, Wolfgang Seitz, Dirk M. Guldi,* and Nazario Martín* Dedicated to Professor Antonio García Martinez on the occasion of his 70th birthday The construction of self-assembling and replicating structures that bear photonic and/or electronic active units at the nanometric scale constitutes one of the biggest challenges in contemporary science. [1] In the bottom-up approach, control over the self-organizing constituents of unprecedented one-, two-, and three-dimensional nanostructured materials at different length scales is of primary interest for the fine- tuning of electronic and optical properties. Leading examples of truly sophisticated architectures contain photo- and redoxactive constituents, such as porphyrins, [2] hexabenzacor- onenes, [3] oligo(p-phenylene)vinylenes, [4] tetrathiafulvalene, [5] perylene bisimides, [6] and fullerenes, [7] all of which—with the exception of the spherical fullerenes—have planarity in common as a templating motif. Notably, concave curved polycyclic aromatic hydrocarbons (PAHs; e.g., corannulenes) support supramolecular ensembles that are based on face-to- face interactions between complementary p surfaces; how- ever, only a few examples have been reported to date. [8] Our research group has pioneered the use of 2-[9-(1,3- dithiol-2-ylidene)anthracen-10(9 H)-ylidene]-1,3-dithiole (p- extended tetrathiafulvalene, p-exTTF) derivatives, which have concave curved anthracene cores, as topographic templates for fullerenes. [9] In these system, fullerene recog- nition, which is thermodynamically driven by concave– convex complementarity combined with electronic interac- tions and charge transfer, induces the self-association of the constituents into a variety of supramolecular ensembles, such as oligomers/polymers and dendrimers. However, to the best of our knowledge, the 3D ordering of p-quinoid p-exTTF units into nanometric arrays in solution is unprecedented. Inspired by the manifold possibilities of “curved” scaffolding p-exTTF species, we have now explored the creation of novel photo- and electroactive 3D nanoarchitectures. We focused on the use of 1, a well-known and versatile hydrogen-bonding building block, [10, 11] and 2, which consists of a hydrogen- bonding diamino-s-triazine, a p-conjugated p-phenyleneviny- lene spacer, and p-exTTF (Figure 1). Brought together, for example in solution, 1 and 2 self-assemble into 1·2. Compound 2 was synthesized from 2-(p-cyanophenyl)- vinyl-p-exTTF and dicyanamide and characterized by stan- dard spectroscopic techniques (see the Supporting Informa- tion). Compound 1 was prepared in accordance with pre- viously reported experimental procedures. [12] 1 H NMR spectroscopic studies in CDCl 3 confirmed the hydrogen-bonding interactions of the constituents to afford complex 1·2, for which 1:1 or 2:1 stoichiometries are possible. In particular, in the 1 H NMR spectrum of 1 (8  10 À4 m), the N À H proton resonances were observed as a singlet at d = 7.75 ppm, whereas the NH 2 proton resonances of 2 (8  10 À4 m) appeared as a single, broad signal at d = 5.14 ppm. Throughout the titration assays, a significant downfield shift was discernable for the imide hydrogen atoms of 1 (8  10 À4 m), from d = 7.75 to 7.96 ppm. This downfield shift implies that, at room temper- ature, the N À H imide hydrogen atoms form hydrogen bonds in CDCl 3 with 2 (see Figure S1 in the Supporting Information). [13] In contrast, no appreciable shifts were observed for assays in either CD 3 CN or [D 8 ]THF in similar concentration ranges (see Figure S2 in the Supporting Information). Hydrogen-bonding interactions in 1·2 were also deduced from FTIR spectra in methylcyclohexane (MCH) and CHCl 3 (see Figure S4 in the Supporting Information). In the absence of 2, the imide carbonyl stretching bands of 1 appeared at around 1774–1685 cm À1 , whereas in 1·2 the stretching was observed at frequencies of 1724, 1607, 1458, and 1406 cm À1 . Likewise, the N À H stretching of 2 at 3199 and 3340 cm À1 was invisible in an equimolar mixture of 1 and 2 in both MCH and CHCl 3 . Corresponding experiments in CH 3 CN are best described as the simple superimposition of the individual IR spectra and thus indicated noninteracting constituents (see Figure S5 in the Supporting Information). [*] Dr. J. L. López, Dr. C. Atienza, Prof. N. Martín Departamento de Química Orgµnica, Facultad de C. C. Químicas Universidad Complutense de Madrid, 28040 Madrid (Spain) Fax: (+ 34) 91-394-4332 and IMDEA-nanociencia 28049 Madrid (Spain) Fax: (+ 34) 91-394-4103 Dr. W. Seitz, Prof. D. M. Guldi Department Chemie und Pharmazie and Interdisciplinary Center for Molecular Materials Universität Erlangen-Nürnberg Egerlandstrasse 3, 91058 Erlangen (Germany) Fax: (+ 49) 9131-85-28307 E-mail: nazmar@quim.ucm.es guldi@chemie.uni-erlangen.de Homepage: http://www.ucm.es/info/fullerene [**] Financial support by the Ministerio de Ciencia e Innovación (MICINN) of Spain (projects CTQ2008-00795/BQU and Consolider- Ingenio CSD2007-00010), the EU (FUNMOLS FP7-212942-1), and the CAM (MADRISOLAR-2 project S2009/PPQ-1533) is acknowl- edged. We also thank the Deutsche Forschungsgemeinschaft (SFB583) and the Office of Basic Energy Sciences of the US. We thank Prof. E. Ortí (ICMol) for the preliminary theoretical calcu- lations. J.L.L. thanks the Fundación SØneca, CARM of Spain, for a postdoctoral fellowship. Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/anie.201004127. Communications 9876  2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Angew. Chem. Int. Ed. 2010, 49, 9876 –9880