Diarylethenes (DAEs) have rarely been used in the design of photoresponsive supramolecular assemblies with a well-defined morphology transition owing to rather small structural changes upon photoisomerization. A supramolecular design based on the parallel conformation of DAEs enables the construction of photoresponsive dye assemblies that undergo remarkable nanomorphology transitions. The cooperative stacking of perylene bisimide (PBI) dyes was used to stabilize the parallel conformer of DAE through complementary hydrogen bonds. Atomic force microscopy, UV/Vis spectroscopy, and molecular modeling revealed that our DAE and PBI building blocks coassembled in nonpolar solvent to form well-defined helical nanofibers featuring J-type dimers of PBI dyes. Upon irradiating the coassembly solution with UV and visible light in turn, a reversible morphology change between nanofibers and nanoparticles was observed. This system involves the generation of a new self-assembly pathway by means of photocontrol.

Supramolecular rosettes of oligothiophenes that do not bear long aliphatic tails have been designed as semiconducting nanomaterials for solution-processable bulk heterojunction solar cells. The rosettes consist of six barbiturated thienyl[oligo(hexylthiophene)] units (Bar-T-hTn ; n=3,4,5) aggregated by multiple hydrogen bonds, which have been directly visualized by scanning tunneling microscopy (STM) at a solid-liquid interface. (1) H NMR spectroscopy in [D8 ]toluene showed that Bar-T-hTn exists as a mixture of monomers and small hydrogen-bonded aggregates. Hierarchical organization of the hydrogen-bonded aggregates took place through π-π stacking interactions upon casting their toluene solutions, resulting in the growth of highly ordered nanorods whose widths are consistent with the diameters of the rosettes. The nanorods could be generated in the presence of soluble fullerene derivatives via solution casting or the annealing of the resulting thin films. The solar cells fabricated based on these bulk heterojunction films showed power conversion efficiencies of 1-3 %, which are far higher than those of the non-hydrogen-bonded reference oligothiophene and the derivative that possesses long aliphatic tails.

π-Conjugated compounds that exhibit tunable luminescence in the solid state under external mechanical stimuli have potential applications in sensors and imaging devices. However, no rational designs have been proposed that impart these mechano-responsive luminescent properties to π-conjugated compounds. Here we demonstrate a strategy for mechano-responsive luminescent materials by imparting amphiphilic and dipolar characteristics to a luminescent π-conjugated system. The oligo(p-phenylenevinylene) luminophore with a didodecylamino group at one end and a tri(ethylene glycol) ester group at the other end yields segregated solid structures by separately aggregating its hydrophobic and hydrophilic moieties. The segregated structures force the molecules to align in the same direction, thereby generating a conflict between the side-chain aggregation and dipolar stabilization of the π-system. Consequently, these metastable solid structures can be transformed through mechanical stimulation to a more stable structure, from a π–π stacked aggregate to a liquid crystal and further to a crystalline phase with variable luminescence. Some π-conjugated molecules exhibit tunable luminescence—a property that is useful for the next generation of optical devices. Yagai et al. propose a strategy to design these materials on a molecular level, which tailors the emission colour via structural changes in response to mechanical stimuli.

Azobenzene dimer 1 has been previously shown to form chiral nanorings in nonpolar solvents. In this study, azobenzene chromophores are replaced with oligo(p-phenylenevinylene) (OPV). The resulting OPV dimer 2 was shown to form a small number of nanorings, and other assemblies were extended fibrils due to stronger pi-pi stacking interaction.

Bismelamines end-functionalized with oligo(p-phenylenevinylene) self-aggregate in nonpolar solvent to form short nanorods by helical π-π stacking. This inherent self-aggregation can be guided to a supramolecular polymerization pathway by complexing with a cyanurate, leading to gel-forming elongated nanotapes lacking the helical sense of the π-conjugated moieties.

A cholesterol-functionalized gold(i)-isocyanide complex exhibiting mechanochromic luminescence properties was self-organized into distinct microscopic structures with different photoluminescence properties through vapor-diffusion of a poor solvent into its dichloromethane solution. The structure-optical property relationship of these microstructures could be related to the mechanically induced phase transition.

Three series of alkyl methacrylate based copolymers having photo-reactive side chains (C=C double bond) were synthesized and examined their performances as photopolymer in the presence of suitable oxime ester or triazine type radical photo-initiators for 365 nm light. Along to our previous report showed that correlation was observed between photochemical reactivity and chain length of the side chain/density of reactive side chain in the cyclohexyl methacrylate main chain. Our proposed mechanism is that sterically stacked nonpolar cyclohexyl groups may push out the polar reactive side chains, and length and density of the side chain controls cross linking between two reactive sites in the single main chain or two different main chains. Now we have examined structural effect of the alkyl groups on the efficiency of photocrosslinking. We have examined 5 series and totally 15 polymers. As a result, cyclohexyl methacrylate based copolymer showed excellent performance for polymerization.

Photochromism: Functionalization of a diarylethene derivative with π-conjugated oligomers resulted in a higher aggregation capability in the open rather than the closed form due to tunable steric hindrance of methyl groups of the diarylethene core (see scheme). Distinct aggregation abilities of the open and the closed isomers in nonpolar solvent and phototunable energy transfer between the two functional units enabled visible-light-triggered formation of fluorescent organogels. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

The intramolecular photochemical processes excimer formation and charge-transfer (CT) complex formation were investigated by comparing the behavior of α,ω-di(1-naphthyl)permethyloligosilanes ((1-naphthyl)-(SiMe2) n -(1-naphthyl); NS n N, n = 1, 3, and 6) and 1-(1-naphthyl)permethyloligosilanes ((1-naphthyl)-(SiMe2) n -Me; NS n, n = 1, 3, and 6) by use of stationary and time-resolved fluorescence (TR-FL) measurements. Formation of excimer and CT complexes is highly dependent on the silicon chain length and polarity of the medium.

Iridium complexes are one of the most important materials for fabrication of organic light emitting diodes (OLEDs). There are difficulties in the preparation of blue phosphorescent complexes with respect to chromaticity, emission efficiency, and stability of the material, compared with green and red phosphorescent complexes. Control of the frontier orbital energy level (HOMO-LUMO) is the sole method to achieve better blue phosphorescent iridium complexes by appropriate ligand selection and the introduction of adequate substituents. Homoleptic and heteroleptic iridium(III) tris(phenylimidazolinate) complexes were synthesized, and the effect of the substituents on their nature in the excited state was examined. Density functional theory calculation showed that the imidazolinato complexes have the HOMO localized at the iridium d- and phenyl π-orbitals. The LUMO is also localized on the phenyl moiety with a much higher population than HOMO. This LUMO is quite different from other complexes, such as iridium(III) tris(phenylpyridinate) and tris(phenylpyrazolinate) complexes. Therefore, substitution with π-electron donating groups and electron withdrawing groups induces blue and red spectral shifts, respectively, which is the reverse shift exhibited by other complexes. The ancillary ligand (acetylacetone) acts as a path for nonradiative deactivation in the blue phosphorescent complexes.

Organogels: Dimerization of perylene bisimide dyes through an oligomethylene linker enabled the facile control over columnar and lamellar self-organized architectures by an odd/even effect with respect to the number of methylene groups. The difference in the self-organized architectures was shown to have an impact on their material morphologies, as well as charge-carrier mobilities (see scheme).

Two soluble phosphorescent host materials, 1,4-bis(3,6-di([1,1′:3′,1″:3″,1‴:3‴,1⁗-quinquephenyl]-5″-yl)-9H-carbazol-9-yl)benzene (P-mPCCP) and 1,4-bis(3,6-bis(4,4″-di-tert-butyl-[1,1′:3′,1″-terphenyl]-5′-yl)-9H-carbazol-9-yl) benzene (T-mPCCP) derived form carbazole and m-terphenyl derivatives were designed and synthesized. These two hosts exhibit good solubility in common organic solvents and possess high glass transition temperature (Tg>160°C) and thermal stability. P-mPCCP and T-mPCCP as the host materials doped with the guest of fac-Ir(ppy)3, we fabricated phosphorescent organic light emitting diodes (PHOLED) by spin coating process. The turn-on voltage of P-mPCCP and T-mPCCP composing device was 4.0 and 7.0eV and showed a maximum luminance of 21,100 and 3290cd/m2 and a maximum luminance efficiency of 15.0 and 7.6cd/A, respectively.

Diarylethene 1 equipped with two monotopic melamine hydrogen-bonding sites and oligothiophene-functionalized ditopic cyanurate (OTCA) were mixed in a nonpolar solvent to form AA-BB-type supramolecular co-polymers (SCPs) bearing photoswitchable moieties in their main chains and extended π systems as side chains. UV/Vis, fluorescence, dynamic light scattering (DLS), TEM, and AFM studies revealed that the two functional co-monomers formed flexible quasi-one-dimensional SCPs in solution that hierarchically self-organized into helical nanofibers through H-aggregation of the oligothiophene side chains. Upon irradiating the SCPs with UV light, a transition occurred from the H-aggregated state to non-aggregated monomeric oligothiophene side chains, as shown by spectroscopic studies, which indicates the formation of small oligomeric species held together only by hydrogen-bonding interactions. TEM and AFM visualized unfolded fibrils corresponding to elongated single SCP chains formed upon removal of solvent. The helical nanofibers were regenerated upon irradiating the UV-irradiated solution with visible light. These results demonstrated that the supramolecular polymerisation followed by hierarchical organization can be effectively controlled by proper supramolecular designs using diarylethenes and π-conjugated oligomers.

Perylene 3,4:9,10-tetracarboxylic acid bisimide (PBI) was functionalized with ditopic cyanuric acid to organize it into complex columnar architectures through the formation of hydrogen-bonded supermacrocycles (rosette) by complexing with ditopic melamines possessing solubilizing alkoxyphenyl substituents. The aggregation study in solution using UV-vis and NMR spectroscopies showed the formation of extended aggregates through hydrogen-bonding and π-π stacking interactions. The cylindrical fibrillar nanostructures were visualized by microscopic techniques (AFM, TEM), and the formation of lyotropic mesophase was confirmed by polarized optical microscopy and SEM. X-ray diffraction study revealed that a well-defined hexagonal columnar (Col(h)) structure was formed by solution-casting of fibrillar assemblies. All of these results are consistent with the formation of hydrogen-bonded PBI rosettes that spontaneously organize into the Col(h) structure. Upon heating the Col(h) structure in the bulk state, a structural transition to a highly ordered lamellar (Lam) structure was observed by variable-temperature X-ray diffraction, differential scanning calorimetry, and AFM studies. IR study showed that the rearrangement of the hydrogen-bonding motifs occurs during the structural transition. These results suggest that such a striking structural transition is aided by the reorganization in the lowest level of self-organization, i.e., the rearrangement of hydrogen-bonded motifs from rosette to linear tape. A remarkable increase in the transient photoconductivity was observed by the flash-photolysis time-resolved microwave conductivity (FP-TRMC) measurements upon converting the Col(h) structure to the Lam structure. Transient absorption spectroscopy revealed that electron transfer from electron-donating alkoxyphenyl groups of melamine components to electron-deficient PBI moieties takes place, resulting in a higher probability of charge carrier generation in the Lam structure compared to the Col(h) structure.

Nature has evolved complex self-organized architectures of pigment assemblages with rational nanoscale topologies and chromophore orientation. Circular architectures of the chlorophyll–protein complexes found in the light-harvesting systems of purple photosynthetic bacteria could be regarded as perfect supramolecular assemblies of pigments in view of not only their topological features but also a functional standpoint. 2] Sunlight is absorbed uniformly by circularly organized chlorophyll pigments, and the resulting exciton states are delocalized over the closed arrays of chlorophylls. Such exciton delocalization is achieved by partially overlapped arrays of chlorophyll p systems, which could be referred to as J-type (offset) stacking. In contrast, onedimensional stacks of largely overlapped p systems, which can be referred to as H-type (face-to-face) stacking, are promising as quasi one-dimensional pathways of mobile charge carriers for organic electronics. Thus, these natural and artificial assemblies of p systems show the importance of simultaneous control over dimensionality of nanostructures and local stacking arrangements to optimize the functionality in the systems. Herein we report that a regioisomerism in specifically designed self-assembling small molecules can offer the aforementioned two extreme nanoarchitectures with favorable stacking arrangements of their p systems. We have recently reported the self-assembly of p-conjugated molecules substituted asymmetrically with barbituric acid (BAR) and a wedge-shaped aliphatic tail (“minidendron”). An unique feature of these BAR–p-wedge molecules in nonpolar media is that their ability to form dramatically different nanostructures, namely nanorings and nanorods, depending on the structure of the p moiety. X-ray diffraction analysis in the mesomorphic state suggested that the BAR–p-wedge molecules form columnar stacks of hydrogen-bonded hexamers (rosettes), which are in nonpolar media solvated to form curved (for nanorings) or straight nanostructures (for nanorods). Although this molecular design is attractive for the construction of well-defined nanostructures consisting of functional p systems, it remains difficult to clarify the structural relationship between monomers and assemblies. We now report a striking impact of the regioisomerism of BAR–naphthalene-wedge molecules (Figure 1) on their self-assembled nanostructures, which

Ditopic melamines possessing one (1) or two (2) perylene bisimide (PBI) chromophores were synthesized and their self-aggregation and coaggregation with dodecyl cyanurate (dCA) or barbital (Bar) were investigated. Optically transparent organogels were formed through self-aggregation of 1 and coaggregation of 1 or 2 with dCA or Bar in nonpolar solvents. X-ray diffraction of the xerogels exhibited typical diffraction patterns assignable to lamellar structures, suggesting the formation of tapelike hydrogen-bonded motifs. Remarkably low critical gelation concentrations (cgc) of 8.0 × 10−4 M were revealed for all organogels, thus they can be classified as supergelators. Comparison of the thermal stabilities of the gels revealed that the gels containing 2 have higher melting temperatures (Tm) than those containing 1. Scanning electron microscopy and atomic force microscopy showed that the gels containing 1 are composed of sheetlike microstructures, whereas those containing 2 are composed of fibrous nanostructures, consistent with the difference in their thermal stabilities. The different self-assembled structures of our PBI aggregates can be related to whether extended stacks of PBI dyes along the hydrogen-bonded strands are possible or not. Ditopic hydrogen bonding melamines possessing perylene bisimide chromophores were synthesized and their self-aggregation and coaggregation with complementary guest molecules were investigated. In this system, 2-D lamellar structures of perylene bisimides were constructed through hierarchical organization of hydrogen-bonded tapes, which can gelate aliphatic and aromatic solvents. The resulting gels are highly transparent and exhibit remarkably low critical gelation concentrations of 8.0 × 10−4 M. The thermal stabilities and the mesoscopic morphologies of these organogels could be reasonably explained by the number of perylene bisimide chromophores introduced in the melamine components.

We report a precise control over the hierarchy levels in the outstanding self-organization process shown by chiral azobenzene dimer 1. This compound forms uniform toroidal nanostructures that can hierarchically organize into chiral nanotubes under the control by temperature, concentration, or light. The nanotubes further organized into supercoiled fibrils, which finally intertwined to form double helices with one-handed helical sense.

Angewandte Chemie International EditionVolume 51, Issue 38 p. 9679-9683 Communication Photoswitchable Exciton Coupling in Merocyanine–Diarylethene Multi-Chromophore Hydrogen-Bonded Complexes Prof. Dr. Shiki Yagai, Corresponding Author Prof. Dr. Shiki Yagai [email protected] Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan) CREST, JST, Chiyoda-ku 102-0075 (Japan)Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)Search for more papers by this authorKazunori Iwai, Kazunori Iwai Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)Search for more papers by this authorProf. Dr. Takashi Karatsu, Prof. Dr. Takashi Karatsu Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)Search for more papers by this authorProf. Dr. Akihide Kitamura, Prof. Dr. Akihide Kitamura Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)Search for more papers by this author Prof. Dr. Shiki Yagai, Corresponding Author Prof. Dr. Shiki Yagai [email protected] Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan) CREST, JST, Chiyoda-ku 102-0075 (Japan)Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)Search for more papers by this authorKazunori Iwai, Kazunori Iwai Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)Search for more papers by this authorProf. Dr. Takashi Karatsu, Prof. Dr. Takashi Karatsu Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)Search for more papers by this authorProf. Dr. Akihide Kitamura, Prof. Dr. Akihide Kitamura Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)Search for more papers by this author First published: 29 August 2012 https://doi.org/10.1002/anie.201205504Citations: 50Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Graphical Abstract Light on: Photocontrol of J-type exciton interactions by using chromophores is reported (see picture). Hydrogen-bonded merocyanine dyes could be switched reversibly through photoinduced ring-closure/ring-opening reactions of diarylethene receptors. Addition of H-aggregation-inducing bismelamine receptors enabled the partial interconversion between J- and H-type exciton coupling. Supporting Information Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Filename Description anie_201205504_sm_miscellaneous_information.pdf440.9 KB miscellaneous_information Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. References 1 1aS. Shinkai, T. Minami, Y. Kusano, O. Manabe, J. Am. Chem. Soc. 1983, 105, 1851–1856; 1bV. Balzani, M. Venturi, A. Credi, Molecular Devices and Machines. A Journey into the Nanoworld, Wiley-VCH, Weinheim, 2003; 1cS. Yagai, T. Karatsu, A. Kitamura, Chem. Eur. J. 2005, 11, 4054–4063; 1dC.-H. Huang, D. M. Bassani, Eur. J. Org. Chem. 2005, 4041–4050; 1eS. Yagai, A. Kitamura, Chem. Soc. Rev. 2008, 37, 1520–1529; 1fT. Muraoka, K. Kinbara, J. Photochem. Photobiol. C 2012, 13, 136–147. 2 2aH. Nakamichi, T. Okada, Angew. Chem. 2006, 118, 4376–4379; Angew. Chem. Int. Ed. 2006, 45, 4270–4273; 2bK. D. Ridge, K. Palczewski, J. Biol. Chem. 2007, 282, 9297–9301. 3 3aH. Kai, S. Nara, K. Kinbara, T. Aida, J. Am. Chem. Soc. 2008, 130, 6725–6727; 3bT. Muraoka, K. Kinbara, T. Aida, Nature 2006, 440, 512–515. 4J. Kärnbratt, M. Hammarson, S. Li, H. L. Anderson, B. Albinsson, J. Andréasson, Angew. Chem. 2010, 122, 1898–1901; Angew. Chem. Int. Ed. 2010, 49, 1854–1857. 5 5a"Chlorins Programmed for Self-assembly in Supramolecular Dye Chemistry": T. S. Balaban, H. Tamiaki, A. R. Holzwarth, Topics Current Chemistry, Vol. 258 (Ed.: ), Springer, Berlin, 2005, pp. 1–38; 5bT. Kondo, K. Yoshida, A. Nakagawa, T. Kawai, H. Tamura, T. Goto, Nature 1992, 358, 515–518. 6For covalently-tethered multichromophoric systems, see: 6aJ. Wang, A. Kulago, W. R. Browne, B. L. Feringa, J. Am. Chem. Soc. 2010, 132, 4191–4196; 6bT. Fukaminato, M. Irie, Adv. Mater. 2006, 18, 3225–3228. 7R. Ahuja, P. L. Caruso, D. Moebius, W. Paulus, H. Ringsdorf, G. Wildburg, Angew. Chem. 1993, 105, 1082–1085; Angew. Chem. Int. Ed. Engl. 1993, 32, 1033–1036. 8 8aL. J. Prins, C. Thalacker, F. Würthner, P. Timmerman, D. N. Reinhoudt, Proc. Natl. Acad. Sci. USA 2001, 98, 10042–10045; 8bF. Würthner, S. Yao, B. Heise, C. Tschierske, Chem. Commun. 2001, 2260–2261. 9 9aS. Yagai, M. Higashi, T. Karatsu, A. Kitamura, Chem. Mater. 2005, 17, 4392–4398; 9bS. Yagai, M. Higashi, T. Karatsu, A. Kitamura, Chem. Commun. 2006, 1500–1502; 9cS. Yagai, T. Kinoshita, M. Higashi, K. Kishikawa, T. Nakanishi, T. Karatsu, A. Kitamura, J. Am. Chem. Soc. 2007, 129, 13277–13287. 10S. Yagai, K. Ohta, M. Gushiken, K. Iwai, A. Asano, S. Seki, Y. Kikkawa, M. Morimoto, A. Kitamura, T. Karatsu, Chem. Eur. J. 2012, 18, 2244–2253. 11T. Seki, A. Asano, S. Seki, Y. Kikkawa, H. Murayama, T. Karatsu, A. Kitamura, S. Yagai, Chem. Eur. J. 2011, 17, 3598–3608. 12For examples of supramolecular control of exciton interaction between merocyanine chromophores, see: 12aF. Würthner, S. Yao, U. Beginn, Angew. Chem. 2003, 115, 3368–3371; Angew. Chem. Int. Ed. 2003, 42, 3247–3250; 12bF. Würthner, J. Schmidt, M. Stolte, R. Wortmann, Angew. Chem. 2006, 118, 3926–3930; Angew. Chem. Int. Ed. 2006, 45, 3842–3846; 12cS. Yagai, M. Ishii, T. Karatsu, A. Kitamura, Angew. Chem. 2007, 119, 8151–8155; Angew. Chem. Int. Ed. 2007, 46, 8005–8009; 12dS. Yagai, Y. Nakano, S. Seki, A. Asano, T. Okubo, T. Isoshima, T. Karatsu, A. Kitamura, Y. Kikkawa, Angew. Chem. 2010, 122, 10186–10190; Angew. Chem. Int. Ed. 2010, 49, 9990–9994; 12eS. Yagai, Y. Goto, L. Xu, T. Karatsu, A. Kitamura, D. Kuzuhara, H. Yamada, Y. Kikkawa, A. Saeki, S. Seki, Angew. Chem. 2012, 124, 6747–6751; Angew. Chem. Int. Ed. 2012, 51, 6643–6647. 13 13aM. Irie, Chem. Rev. 2000, 100, 1685–1716; 13bH. Tian, S. Yang, Chem. Soc. Rev. 2004, 33, 85–97; 13cM. Morimoto, S. Kobatake, M. Irie, Chem. Rec. 2004, 4, 23–38; 13dM. Irie, Photochem. Photobiol. Sci. 2010, 9, 1535–1542. 14 14aM. Kasha, H. R. Rawls, M. A. El-Bayoumi, Pure Appl. Chem. 1965, 11, 371–392; 14bF. Würthner, T. E. Kaiser, C. R. Saha-Möller, Angew. Chem. 2011, 123, 3436–3473; Angew. Chem. Int. Ed. 2011, 50, 3376–3410. 15 15aT. A. Golovkova, D. V. Kozlov, D. C. Neckers, J. Org. Chem. 2005, 70, 5545–5549; 15bM. Berberich, A.-M. Krause, M. Orlandi, F. Scandola, F. Würthner, Angew. Chem. 2008, 120, 6718–6721; Angew. Chem. Int. Ed. 2008, 47, 6616–6619; 15cJ. W. Chung, S.-J. Yoon, S.-J. Lim, B.-K. An, S. Y. Park, Angew. Chem. 2009, 121, 7164–7168; Angew. Chem. Int. Ed. 2009, 48, 7030–7034. 16Langhals et al. reported an example of energy transfer from a nonfluorescent donor: H. Langhals, S. Saulich, Chem. Eur. J. 2002, 8, 5630–5643. 17 17aA. Lohr, S. Uemura, F. Würthner, Angew. Chem. 2009, 121, 6281–6284; Angew. Chem. Int. Ed. 2009, 48, 6165–6168; 17bT. Seki, S. Yagai, T. Karatsu, A. Kitamura, J. Org. Chem. 2008, 73, 3328–3335. 18L. J. Prins, R. Hulst, P. Timmerman, D. N. Reinhoudt, Chem. Eur. J. 2002, 8, 2288–2301. 19 19aM. Takeshita, M. Hayashi, S. Kadota, K. H. Mohammed, T. Yamato, Chem. Commun. 2005, 761–763; 19bS.-L. Li, T. Xiao, W. Xia, X. Ding, Y. Yu, J. Jiang, L. Wang, Chem. Eur. J. 2011, 17, 10716–10723. Citing Literature Volume51, Issue38September 17, 2012Pages 9679-9683 ReferencesRelatedInformation