10144 Chem. Commun., 2012, 48, 10144–10146 This journal is c The Royal Society of Chemistry 2012 Cite this: Chem. Commun., 2012, 48, 10144–10146 Room-temperature synthesis of soluble, fluorescent carbon nanoparticles from organogel precursorsw Jules Rome´o Ne´abo, Ce´cile Vigier-Carrie`re, Simon Rondeau-Gagne´ and Jean-Franc¸ois Morin* Received 16th July 2012, Accepted 17th August 2012 DOI: 10.1039/c2cc35087d Carbon nanoparticles were obtained at room temperature by irradiating an organogel made from a 1,8-diaryloctatetrayne derivative in chloroform. During the topochemical polymerization, the morphology of the gel changes from fibers to soluble, yellow fluorescent nanoparticles in high yield. Analyses suggest that the resulting nanoparticles are made of amorphous graphitic carbon. Carbon-rich materials like fullerenes, carbon nanotubes and graphenes have attracted a lot of attention in the past 25 years because of their exceptional electronic and optical properties. 1 Although they are recognized as being very promising materials for several electronics- and optics-related applications, many drawbacks associated with their preparation such as the use of high temperatures (pyrolysis), vacuum and metal catalysts have slowed down their use in commercial devices. Thus, a wealth of efforts has been devoted to the development of preparative methods that allow the synthesis of well-defined, carbon-rich nanostructures under milder conditions, preferably below 100 1C and without the use of metal catalysts or complex setups. One emerging strategy to obtain carbon nanostructures at relatively low temperatures without a metal catalyst involved the use of oligoynes as highly reactive precursors. 2 In 2004, Ding and Olesik showed that an amphiphilic tetrayne derivative can be self-assembled in water to form ultrathin films that undergo a spontaneous polymerization reaction to form cross- linked polymer films. 3 These films can further be transformed into nanoparticles by heating the films suspension at 70 1C. More recently, Frauenrath et al. used a similar approach to prepare graphitic nanostructures from hexayne-based colloids. 4 Less ordered graphitic materials have also been prepared by Goroff et al. using poly(diiododiacetylene) as the carbon source and Lewis bases as a catalyst at room temperature. 5 However, to the best of our knowledge, none of the graphitic materials prepared thus far using room-temperature methods from reactive carbon-rich precursors are soluble in organic solvents. The good solubility of electro- and photoactive materials in common organic solvents represents a significant advantage for many electronics-related applications that rely on a film- forming process to cover large substrates such as light-emitting devices (LED) and organic solar cells. Herein, we report the synthesis of soluble, fluorescent carbon nanoparticles using a room-temperature, catalyst-free process. A 1,8-diaryloctatetrayne derivative (compound 1, Scheme 1), used as the carbon source, was self-assembled to form organogels and was irradiated under UV light at 254 nm at room-temperature. Our initial hypothesis was that by self- assembling the carbon source into a well-ordered array of molecules (organogel), the resulting graphitic materials would retain the gel morphology, namely nano- and microfibers, upon graphitization reaction at low temperatures. The possibility of morphology retention has recently been demonstrated for the graphitization of helical polyacetylene films. 6 In our case however, nanoparticles rather than the expected fibers were obtained. These nanoparticles, made of amorphous graphitic carbon, are soluble in common organic solvents and exhibit intense yellow fluorescence in solution. The first step toward the preparation of carbon nano- particles was the synthesis of a tetrayne derivative that bears amide groups with a long alkyl chain directly attached to the aryl groups at both ends of the molecule. We 7 and others 8 have Scheme 1 Synthesis of the reactive 1,8-diaryloctatetrayne derivative. De´partement de chimie and Centre de Recherche sur les Mate ´riaux Avance ´s (CERMA), Universite ´ Laval, 1045 Ave de la Me ´decine, Pavillon A.-Vachon, G1V 0A6, Canada. E-mail: jean-francois.morin@chm.ulaval.ca; Fax: +1-418-656-7916; Tel: +1-418-656-2812 w Electronic supplementary information (ESI) available: Experimental procedures and characterization data for all new compounds, XRD, FTIR, TEM and gelation properties. See DOI: 10.1039/c2cc35087d ChemComm Dynamic Article Links www.rsc.org/chemcomm COMMUNICATION Downloaded by Rice University on 09/04/2013 16:58:01. Published on 20 August 2012 on http://pubs.rsc.org | doi:10.1039/C2CC35087D View Article Online / Journal Homepage / Table of Contents for this issue