DOI: 10.1021/la104276y 1513 Langmuir 2011, 27(4), 1513–1523 Published on Web 01/21/2011 pubs.acs.org/Langmuir © 2011 American Chemical Society Thermosolutal Self-Organization of Supramolecular Polymers into Nanocraters † Tomas Marangoni, ‡ Stefano A. Mezzasalma,* ,‡ Anna Llanes-Pallas, ‡ K. Yoosaf, § Nicola Armaroli,* ,§ and Davide Bonifazi* ,‡, ) ‡ Dipartimento di Scienze Farmaceutiche and UdR INSTM, Universit  a di Trieste, Piazzale Europa 1, 34127 Trieste, Italy, § Molecular Photoscience Group, Istituto per la Sintesi Organica e la Fotoreattivit  a, Consiglio Nazionale delle Ricerche (CNR-ISOF) Via Gobetti 101, 40129 Bologna, Italy, and ) Department of Chemistry, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium Received October 29, 2010. Revised Manuscript Received December 21, 2010 The ability of two complementary molecular modules bearing H-bonding uracilic and 2,6-(diacetylamino)pyridyl moieties to self-assemble and self-organize into submicrometer morphologies has been investigated by means of spectroscopic, thermogravimetric, and microscopic methods. Using uracilic 3 N-BOC-protected modules, it has been possible to thermally trigger the self-assembly/self-organization process of the two molecular modules, inducing the formation of objects on a mica surface that exhibit crater-like morphology and a very homogeneous size distribution. Confirmation of the presence of the hydrogen-bonding-driven self-assembly/self-organization process in solution was obtained by variable-temperature (VT) steady-state UV-vis absorption and emission measurements. The variation of the geometric and spatial features of the morphologies was monitored at different T by means of atomic force microscopy (AFM) and was interpreted by a nonequilibrium diffusion model for two chemical species in solution. The formation of nanostructures turned out to be affected by the solid substrate (molecular interactions at a solid-liquid interface), by the matter-momentum transport in solution (solute diffusivity D 0 and solvent kinematic viscosity ν), and the thermally dependent cleavage reaction of the BOC functions (T-dependent differential weight loss, θ = θ(Τ)) in a T interval extrapolated to ∼60 K. A scaling function, f=f (νD 0 , ν/D 0 , θ), relying on the onset condition of a concentration-driven thermosolutal instability has been established to simulate the T-dependent behavior of the structural dimension (i.e., height and radius) of the self-organized nanostructures as Æhæ ≈ f (T) and Æræ ≈ 1/f (T). Introduction In the last few decades, materials possessing well-defined structural properties on the nanoscale and microscale have shown to be extremely promising for applications in several fields such as microelectronics, 1-3 biology, 4 and solar cells fabrication. 5 This is due to the fact that the manufacture of organic-based devices, for any kind of application, requires the development of reproducible protocols to engineer materials featuring precise structural properties. To improve control on the nanoscale level, both bottom-up and top-down approaches have been intensively exploited to date. 6,7 Although nowadays the second is still predominant at applicative levels, Moore’s law foresees its final limit in a few years. 8 Among the various bottom-up approaches, the exploitation of non-covalent interactions, 9-11 capable of inducing the selective and controlled association of molecular components leading to aggregates of defined structural proper- ties, has turned out to be extremely promising. In this field, the key concepts of molecular recognition through noncovalent interac- tions (i.e., supramolecular chemistry) have been very effective tools for the preparation of nanostructured organic materials. 12-27 The exploitation of highly directional noncovalent interac- tions such as hydrogen bonds has been employed to induce † Part of the Supramolecular Chemistry at Interfaces special issue. *Corresponding authors. E-mail: smezzasalma@units.it, armaroli@isof. cnr.it, davide.bonifazi@fundp.ac.be. (1) Coropceanu, V.; Cornil, J.; da Silva Filho, D. A.; Olivier, Y.; Silbey, R.; Br edas, J. L. Chem. Rev. 2007, 107, 926. (2) Kim, D. H.; Lee, B.-L.; Moon, H.; Kang, H. M.; Jeong, E. J; Park, J.; Han, K.-M.; Lee, S.; Yoo, B. W.; Koo, B. W.; Kim, J. Y.; Lee, W. H.; Cho, K.; Becerril, H. A.; Bao, Z. J. Am. Chem. Soc. 2009, 131, 6124. (3) Forrest, S. R. Nature 2004, 428, 911. (4) Sarikaya, M.; Tamerler, C.; Jen, A. K. Y.; Schulten, K.; Baneyx, F. Nat. Mater. 2003, 2, 577. (5) G€ unes, S.; Neugebauer, H.; Sariciftci, N. S. Chem. Rev. 2007, 107, 1324. (6) Balzani, V.; Credi, A.; Venturi, M. Chem.;Eur. J. 2002, 8, 5524. (7) Smay, J. E.; Gratson, G.; Shepperd, R. Adv. Mater. 2002, 14, 1279. (8) Moore, G. Electronics 1965, 38, 114. (9) Bl eger, D.; Kreher, D.; Mathevet, F.; Attias, A. J.; Schull, G.; Huard, A.; Douillard, L.; Fiorini-Debuischert, C.; Charra, F. Angew. Chem., Int. Ed. 2007, 46, 7404. (10) Kudernac, T.; Lei, S.; Elemans, J. A. A. W.; De Feyter, S. Chem. Soc. Rev. 2009, 38, 402. (11) Puigmartı´-Luis, J.; Minoia, A.; Ujii, H.; Rovira, C.; Cornil, J.; De Feyter, S.; Lazzaroni, R.; Amabilino, D. B. J. Am. Chem. Soc. 2006, 128, 12602. (12) Lehn, J. M. Supramolecular Chemistry: Concepts and Perspectives; Wiley- VCH: Weinheim, Germany, 1995. (13) Hoeben, F. J. M.; Jonkheijm, P.; Meijer, E. W.; Schenning, A. Chem. Rev. 2005, 105, 1491. (14) Davis, J.; Spada, G. Chem. Soc. Rev. 2007, 36, 296. (15) Ajayaghosh, A.; Praveen, V. K. Acc. Chem. Res. 2007, 40, 644. (16) Ajayaghosh, A.; Praveen, V. K.; Vijayakumar, C. Chem. Soc. Rev. 2008, 37, 109. (17) Palermo, V.; Samor  i, P. Angew. Chem., Int. Ed. 2007, 46, 4428. (18) Palermo, V.; Schwartz, E.; Finlayson, C. E.; Liscio, A.; Otten, M. B. J.; Trapani, S.; Mullen, K.; Beljonne, D.; Friend, R. H.; Nolte, R. J. M.; Rowan, A. E.; Samor  i, P. Adv. Mater. 2010, E81. (19) Elemans, J. A. A. W.; Hameren, R. v.; Nolte, R. J. M.; Rowan, A. E. Adv. Mater. 2006, 1251. (20) Elemans, J. A. A. W.; Rowan, A. E.; Nolte, R. J. M. J. Mater. Chem. 2003, 2661. (21) Nakanishi, T. Chem. Commun. 2010, 20, 3425. (22) Asanuma, T.; Li, H.; Nakanishi, T.; Moehwald, H. Chem.;Eur. J. 2010, 16, 9330. (23) Guldi, D. M.; Zerbetto, F.; Georgakilas, V.; Prato, M. Acc. Chem. Res. 2005, 38, 871. (24) Bonifazi, D.; Mohnani, S.; Llanes-Pallas, A. Chem.;Eur. J. 2009, 15, 7004. (25) Mohnani, S.; Llanes-Pallas, A.; Bonifazi, D. Pure Appl. Chem. 2010, 10, 917.