10.1021/ol402582p r XXXX American Chemical Society ORGANIC LETTERS XXXX Vol. XX, No. XX 000–000 Synthesis of P‑Triazole Dithienophospholes and a Cyclodextrin- Based Sensor via Click Chemistry Xiaoming He, Ping Zhang, Jian-Bin Lin, Huy V. Huynh, Sandra E. Navarro Mu ~ noz, Chang-Chun Ling, and Thomas Baumgartner* Department of Chemistry and Centre for Advanced Solar Materials, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada thomas.baumgartner@ucalgary.ca Received September 6, 2013 ABSTRACT The synthesis of a series of highly luminescent, functional dithienophospholes via a click reaction is reported. Slight modification of the lateral aromatic substituents leads to a significant difference in their solid-state organization. In addition, a novel water-soluble β-cyclodextrin hybrid is demonstrated to be an effective sensor for picric acid. By virtue of their unique bonding and electronic proper- ties, the incorporation of main-group elements (e.g., B, Si, P) offers great opportunities for efficiently tuning the optoelectronic properties of π-conjugated materials at the molecular level. 13 Phosphole-based π-conjugated compounds, in particular, have attracted significant atten- tion because of the versatile reactivity of the P center that endows these materials with tunable photophysical and redox properties, as well as interesting molecular organiza- tion and self-assembly. 3 Systematic studies by others and our group have revealed that the LUMO energies of the phosphole derivatives are stabilized through σ*π* orbi- tal coupling, which also makes phosphole-based materials very promising electron-acceptor materials. 3 Over the past decade, we have established the dithieno- [3,2-b:2 0 ,3 0 -d]phosphole (Figure 1) as a unique building block for the development of highly emissive materials. 4 To date, most efforts have invested on the P-phenyl species (I) for tuning the optoelectronic and self-assembly proper- ties of the system via introduction of different aromatic groups on the conjugated backbone (at R 1 and R 2 ), or simple modification of the phosphorus center (E = lone pair, O, S, Me þ , BH 3 , and metals). 4e In doing so, we were able to successfully utilize this intriguing building block in a variety of different functional materials such as white-light emitting species, 5 sensors, 6 liquid crystals, and (1) (a) J€akle, F. Chem. Rev. 2010, 110, 3985–4022. (b) Wade, C. R.; Broomsgrove, A. E. J.; Aldrige, S.; Gabbaı¨, F. P. Chem. Rev. 2010, 110, 3958–3984. (c) Hudson, Z. M.; Wang, S. Acc. Chem. Res. 2009, 42, 1584– 1596. (2) (a) Yamaguchi, S.; Tamao, K. J. Chem. Soc., Dalton Trans. 1998, 3693–3702. (b) Chen, J.; Cao, Y. Macromol. Rapid Commun. 2007, 28, 1714–1742. (3) (a) Baumgartner, T.; Reau, R. Chem. Rev. 2006, 106, 4681–4727. Correction: 2007, 107, 303. (b) Crassous, J.; Reau, R. Dalton Trans. 2008, 6865–6876. (c) Matano, Y.; Imahori, H. Org. Biomol. Chem. 2009, 7, 1258–1271. (d) Ren, Y.; Baumgartner, T. Dalton Trans. 2012, 41, 7792–7800. (e) Fukazawa, A.; Yamaguchi, S. Chem. Asian J. 2009, 4, 1386–1400. (4) (a) Baumgartner, T.; Neumann, T.; Wirges, B. Angew. Chem., Int. Ed. 2004, 43, 6197–6201. (b) Baumgartner, T.; Bergmans, W.; Karpati, T.; Neumann, T.; Nieger, M.; Nyulaszi, L. Chem.;Eur. J. 2005, 11, 4687–4699. (c) Dienes, Y.; Durben, S.; Karpati, T.; Neumann, T.; Englert, U.; Nyulaszi, L.; Baumgartner, T. Chem.;Eur. J. 2007, 13, 7487–7500. (e) Romero-Nieto, C.; Baumgartner, T. Synlett 2013, 24, 920–937. (5) (a) Romero-Nieto, C.; Durben, S.; Kormos, I. M.; Baumgartner, T. Adv. Funct. Mater. 2009, 19, 3625–3631. (b) Huynh, H. V.; He, X. M.; Baumgartner, T. Chem. Commun. 2013, 49, 4899–4901. (6) Neumann, T.; Dienes, Y.; Baumgartner, T. Org. Lett. 2006, 8, 495–497. (7) (a) Ren, Y.; Kan, W. H.; Henderson, M. A.; Bomben, P. G.; Berlinguette, C. P.; Thangadurai, V.; Baumgartner, T. J. Am. Chem. Soc. 2011, 133, 17014–17026. (b) Ren, Y.; Kan, W. H.; Thangadurai, V.; Baumgartner, T. Angew. Chem., Int. Ed. 2012, 51, 3964–3968.