Chinese Journal of Chemistry, 2006, 24, 862—866 Full Paper * E-mail: xwwei@mail.ahnu.edu.cn; weixianwen@yahoo.com Received October 17, 2005; revised December 18, 2005; accepted March 24, 2006. Project supported by the National Natural Science Foundation of China (Nos. 20271002, 20490217), Excellent Young Scholar Foundation (No. 04046065) and the Natural Science Foundation of Anhui Province (No. 00045122), the Scientific Research Foundation for the Returned Overseas Chinese Scholars and Excellent Young Teachers Program of the Ministry of Education of China, and the Education Department of Anhui Province (Nos. 2001KJ115ZD, 2006KJ006TD). © 2006 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Synthesis and Characterization of a Noncovalently Linked Porphyrin-[1,2-(1-acridin-10'-yl-2-aza-2-methylprop-1,3-ylene)- fullerene] Dyad XIANG, Yun a (项云) WEI, Xian-Wen* ,a (魏先文) ZHANG, Xin-Ming a (张新明) ZHA, Qing-Qing a (查庆庆) SUN, Jian a (孙健) YIN, Gui b (尹桂) XU, Zheng b (徐正) a College of Chemistry and Materials Science, Anhui Key Laboratory of Functional Molecular Solids, Anhui Normal University, Wuhu, Anhui 241000, China b State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, Nanjing University, Nanjing, Jiangsu 210093, China 1,2-(1-Acridin-10'-yl-2-aza-2-methylprop-1,3-ylene)fullerene was synthesized firstly and characterized by UV-Vis, 1 H NMR, 13 C NMR and electrospray ionization mass spectroscopy, which is capable of forming a stable complex with zinc tetraphenylporphyrin via the axial ligation. The steady state fluorescence studies show efficient quenching of the zinc tetraphenylporphyrin emission upon axial coordination of acridine attached to C 60 . Keywords fullerene, zinc tetraphenylporphyrin, complex, self-assembly Introduction Fullerenes are excellent electron acceptors with unique three-dimensional structure and low reduction potentials, in combination with their electronic absorp- tion characteristics over most of the visible region, which make such compounds particularly suitable building blocks for the construction of the artificial light harvesting systems. 1-3 In recent years, noncovalently linked donor-acceptor systems formed by coordination of functionalized fullerenes bearing pyridine units or imidazole to zinc tetrapyrrole macrocycles have been reported. 4-15 Supramolecular triads, composed of two porphyrins plus a single fullerene entity, 9,16 and zinc porphyrin-C 60 dyads to probe the distance and orienta- tion effects for the quenching of the donor emission, 17 have been elegantly designed and studied. The nitrogen in the fullerene attached pyrrolidine has good commu- nication with the fullerene core, 18 and one can employ a combination of these structural elements for the bridge between fullerene and the metal center. To gain further insights into the axial coordination governed self-assembly process, and evaluate the factors respon- sible for the stability, such as the steric hindrance, elec- tronic effect, etc., the acridine-substituted pyrrolidine attached to fullerene was firstly synthesized here and is capable of forming a self-assembled complex with zinc tetraphenylporphyrin Zn(TPP) via axial ligation method. 19,20 Zn(TPP) has strong absorption in the visi- ble and near-IR regions, to extend the absorption char- acteristics of the dyads, and the efficient emission quenching upon coordination with the acridine- functionalized fullerenes was observed. Experimental Synthesis Silica gel (HG/T2354-92) for column chromatogra- phy was purchased from Qingdao Haiyang Chemical Co. C 60 with purity of 99% was from Henan Tianan Corpo- ration, and Zn(TPP) was from Alfa Aesar. All the sol- vents were of A.R. grade and redistilled before use. 10-Formylacridine: According to the literature, 21 a mixture of 10-methyl acridine (499 mg, 2.58 mmol) and SeO 2 (288 mg, 2.59 mmol) in 32 mL of diglyme was heated at reflux under argon for 2 h, poured into 60 mL of hot water and filtered to remove selenium. After ex- traction with CH 2 Cl 2 for 2—3 times, a dark brown solu- tion was obtained. After removing the solvent under reduced pressure, the crude product was purified over a silica gel column using 10∶1 (V∶V) petroleum ether and ethyl acetate as eluent, affording 373 mg (70%) of 10-formylacridine. 1 H NMR (CDCl 3 , 300 MHz) δ: 11.53 (s, CHO), 8.74 (d, J＝8.82 Hz, 2H), 8.31 (d, J＝ 8.73 Hz, 2H), 7.81—7.86 (m, 2H), 7.68—7.73 (m, 2H). 1,2-(1-Acridin-10'-yl-2-aza-2-methylprop-1,3-yl- ene)-fullerene: The title compound was synthesized