DOI: 10.1002/asia.200600205 Metallomacrocycles That Incorporate Cofacially Aligned Diimide Units Meisa S. Khoshbin, [a] MaximV. Ovchinnikov, [a] Khalid S. Salaita, [a] Chad A. Mirkin,* [a] Charlotte L. Stern, [a] Lev N. Zakharov, [b] and Arnold L. Rheingold [b] Introduction Coordination-chemistry-driven assembly processes are now commonly used to prepare a wide variety of supramolecular complexes. Several general synthetic approaches have emerged that rely on metal–ligand interactions, including the directional-bonding, symmetry-interaction, and weak- link approaches (WLA). [1–5] An attractive feature of these methods is that through careful ligand design and choice of transition-metal precursor, one can rapidly put together complex architectures such as squares, rectangles, cubes, cyl- inders, and other two- and three-dimensional struc- tures. [1–3,6–8] Moreover, in certain cases, one can position chiral moieties, fluorophores, and redox-active centers within such structures in a deliberate and high-yielding fash- ion. [6,9–15] This capability has allowed researchers to design large functional structures with tailored recognition and cataACHTUNGTRENNUNGlytic properties that have formed the basis for a series of new chemical sensors and several novel classes of cata- lysts. [9,10,16–19] Most recently, our group showed how one can use the WLA to prepare a new type of allosteric catalyst that mimics the properties of allosteric enzymes and can be used in the context of amplified chemical detection. [20] Redox-active ligands are attractive because, once incorpo- rated into a supramolecular architecture, they can be used either as probes to follow recognition or as modulators of chemical reactivity. Indeed, we and others have developed routes to use ferrocenyl moieties, Wurster crowns, and por- phyrins to build macrocyclic structures that, in some cases, retain the reversible redox activity of the ligand from which they derive. [21–26] One class of metallomacrocyclic structures that have not been fully explored are those that derive from pyromellitic diimide and naphthalene diimide, two mole- cules in the rylene family of dyes. Some initial work has uti- lized the symmetry-interaction and directional-bonding ap- proaches to assemble rigid macrocycles. [6,14,27–31] Of the few existing examples, most had to combat problems with insta- bility of the resulting metallomacrocycles or the formation of mixtures of products. [14,27–29] Despite limited success with attempts to make metallomacrocycles with these ligand building blocks, organic chemists have used it as a motif in the preparation of a wide variety of donor/acceptor com- plexes, host/guest complexes, and electron-transfer sys- tems. [32–43] Abstract: Pyromellitic diimide and naphthalene diimide moieties were in- corporated into hemilabile phosphanyl- alkyl thioether ligands. These ligands reacted with [CuACHTUNGTRENNUNG(CH 3 CN) 4 ]PF 6 and [RhACHTUNGTRENNUNG(NBD)Cl] 2 (NBD = norbornadiene) by the weak-link approach to form condensed intermediates. Upon reac- tion of each diimide ligand with these transition-metal precursors, the two di- ACHTUNGTRENNUNGimide units became cofacially aligned within a supramolecular macrocyclic architecture. The introduction of ancil- lary ligands to each of these condensed intermediates caused the weak thioeth- er–metal bonds to break, thus generat- ing a large macrocycle in which the dis- tance between diimide units is signifi- cantly larger than for the condensed in- termediates. The two Rh I cationic con- densed intermediates were characterized by single-crystal X-ray diffraction studies, and the electro- chemical activity of these macrocycles was demonstrated with the naphtha- lene diimide–Cu I macrocycles. Keywords: electron-deficient compounds · hemilabile ligands · macrocycles · metallacycles · supra- molecular chemistry [a] M. S. Khoshbin, M. V. Ovchinnikov, K. S. Salaita, Prof. C.A. Mirkin, C. L. Stern Department of Chemistry and Institute for Nanotechnology Northwestern University 2145 Sheridan Road, Evanston, Illinois 60208-3113 (USA) Fax:(+ 1)847-467-5123 E-mail: chadnano@northwestern.edu [b] L. N. Zakharov, Prof. A. L. Rheingold Department of Chemistry and Biochemistry University of California, San Diego 9500 Gilman Drive, MC 0358, La Jolla, California 92093-0358 (USA) 686 # 2006 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim Chem. Asian J. 2006, 1,686–692 FULL PAPERS