Unsymmetrical Calix[4]arene Bisporphyrin Pacman Gre ´ gory Pognon, Jennifer A. Wytko, and Jean Weiss* CLAC, Institut de Chimie, UMR 7177 CNRS-ULP, BP 1032, 4 rue Blaise Pascal, 67070 Strasbourg, France jweiss@chimie.u-strasbg.fr Received December 5, 2006 ABSTRACT The synthesis of a Pacman heterobisporphyrin associating an octaethyl porphyrinatozinc (ZnOEP) energy donor and a triaryl porphyrinatozinc (ZntPP) energy acceptor around a calix[4]arene spacer is described. Contrary to previous symmetrical architectures, correlations between the chromophores in the unsymmetrical calixarene bisporphyrin Pacman scaffold can now be observed in ROESY experiments. Independent of the excitation wavelength, only the luminescence of the ZntPP moiety was observed corresponding to quenching of the OEP moiety’s emission. Over the last 25 years, many structures in which two porphyrins are preorganized in a cofacial geometry have been reported. 1 Although rigid spacers were initially chosen to control the distance separating the tetrapyrrolic macrocycles in the scaffolds, we have recently introduced the concept of flexible Pacman structures by using the upper rim of calix- [4]arene spacers as a preorganization platform. 2 Literature reports have shown that the attachment of porphyrins onto the lower rim of calixarenes via ether linkages at the phenol oxygens affords rather flexible hosts whose geometries are controlled by the binding of guests. 3 By functionalizing these calixarene spacers with a rigid and linear acetylenic linker on the upper rim, the cofacial geometry can be controlled, even in the absence of a guest. (1) (a) Collman, J. P.; Wagenknecht, P. S.; Hutchison, J. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 1337. (b) Deng, Y.; Chang, C. J.; Nocera, D. G. J. Am. Chem. Soc. 2000, 122, 410. (c) Chang, C. J.; Deng, Y.; Heyduk, A. F.; Chang, C. K.; Nocera, D. G. Inorg. Chem. 2000, 39, 959. (d) Chang, C. J.; Baker, E. A.; Pistorio, B. J.; Deng, Y.; Loh, Z.-H.; Miller, S. E.; Carpenter, S. D.; Nocera, D. G. Inorg. Chem. 2002, 41, 3102. (e) Chang, C. J.; Deng, Y.; Peng, S.-M.; Lee, G.-H.; Yeh, C.-Y.; Nocera, D. G. Inorg. Chem. 2002, 41, 3008. (f) Chang, C. J.; Yeh, C.-Y.; Nocera, D. G. J. Org. Chem. 2002, 67, 1203. (g) Flamigni, L.; Johnston, M. R. Chem.-Eur. J. 2002, 8, 3938. (h) Harvey, P. D. In The Porphyrin Handbook II; Kadish, K. M., Smith, K. M., Guilard, R., Eds.; Academic Press: San Diego, 2003; Vol. 18, Chapter 113. (i) Chang, L. L.; Chang, C. J.; Nocera, D. G. J. Org. Chem. 2003, 68, 4075. (j) Jiao, L.; Courtney, B. H.; Fronczek, F. R.; Smith, K. M. Tetrahedron Lett. 2006, 47, 501. (k) Flamigni, L.; Talarico, A. M.; Ventura, B.; Rein, R.; Solladie ´, N. Chem.-Eur. J. 2006, 12, 701. (l) Wytko, J. A.; Weiss, J. In N-4 Macrocyclic Metal Complexes; Zagal, J. H., Bedioui, F., Dodelet, J. P., Eds.; Springer: Heidelberg, 2006; pp 603-724. (2) (a) Jokic, D.; Asfari, Z.; Weiss, J. Org. Lett. 2002, 4, 2129. (b) Jokic, D.; Boudon, C.; Pognon, G.; Bonin, M.; Schenk, K.; Gross, M.; Weiss, J. Chem.-Eur. J. 2005, 11, 4199. (c) Tremblay-Morin, J.-P.; Faure, S.; Samar, D.; Stern, C.; Guilard, R.; Harvey, P. D. Inorg. Chem. 2005, 44, 2836. (d) Pognon, G.; Boudon, C.; Schenk, K. J.; Bonin, M.; Bach, B.; Weiss, J. J. Am. Chem. Soc. 2006, 128, 3488. (3) (a) Baldini, L.; Ballester, P.; Casnati, A.; Gomila, R. M.; Hunter, C. A.; Sansone, F.; Ungaro, R. J. Am. Chem. Soc. 2003, 125, 12181. (b) Dudic, M.; Lhotak, P.; Stibor, I.; Petrickova, H.; Lang, K. New. J. Chem. 2004, 28, 85. (c) Ballester, P.; Costa, A.; Castilla, A. M.; Deya, P. M.; Frontera, A.; Gomila, R. M.; Hunter, C. A. Chem.-Eur. J. 2005, 11, 2196. ORGANIC LETTERS 2007 Vol. 9, No. 5 785-788 10.1021/ol062945c CCC: $37.00 © 2007 American Chemical Society Published on Web 02/02/2007