Self metallomacrocycles

Wang P, Mooiefield CN, Newkome GR. Nanofabrication teversible self-assembly of an imbedded hexameric metallomacrocycle within a macromolecular superstructure. Angew Chem Int Ed 2005 44 1679-1683. 

Numerous metallomacrocycles self-assemble from their components giving species possessing various structures, for instance triangular shape [9.30,9.31] containing a cavity [9.32], which may include a guest molecule [9.33] square [9.34,9.35] or star like [9.36-9.39] shapes wheel-shaped or toroidal hexameric [9.40], octameric [9.41] or decameric [9.42,9.43] structures square [9.44,9.45] rectangular [9.46,9.47] or bent [9.48] boxes into which substrate molecules may bind [9.49,9.50] adaman-tanoid shape [9.51,9.52] with cation inclusion [9.51c], formally related to that of the spheroidal macrotricycle 21 catenane type [9.53]. Coordination species of dendri-mer or arborol nature have been constructed [7.61, 8.27, 9.54]. 

Treatment of 2,9-dibromophenanthrene with Pt (Et3P)4 followed by bromine-nitrate exchange gave the desired 60° tecton, 2,9-6/i [/ra 5 -Pt(PEt3)2(N03)]phenanthrene, which with different linear connectors afforded a series of self-assembled supramolecular triangles <03JA5193>. A series of related binuclear metallomacrocycles [Cd(N03)2L]2, where L is an angular exo-bidentate, such as 4-(4 -pyridinyl)(2-pyridinylethynyl) benzene, have been reported... 

The self-assembly of ligands based on a pyrrole framework possessing dithiocarbamate end groups when treated with zinc(II), nickel(II) or copper(II) afforded a series of neutral, dinuclear metallomacrocycles or trinuclear metallocryptands 45 <03DT603>. 

Aromatic templates, in conjunction with coordinative bonds, have been employed by Sanders et al. [42] to self-assemble a [2]catenane incorporating a chiral metallomacro-cycle. The 1,5-dioxynaphthalene-based macrocyclic polyether 60 threads onto the r-elec-tron-deficient compound 61 in MeCN. Thus, when both compounds and Zn(OS02CF3)2 are mixed in this solvent, threading of 60 onto 61 is followed by the [2 + 2] assembly of a helical metallomacrocycle as a result of the tetrahedral coordination of two Zn centers by the bipyridine ligands appended to the r-electron-deficient recognition sites. The resulting [2]catenane 62 was characterized by a combination of H-NMR spectroscopy and electrospray mass spectrometry. 

Electrochemical Sensors Based on Self-Assembled Monolayers (SAMs) of Metallomacrocycles... 

As noted in Section 2, the self-assembly of an o-carborane-based, bister-pyridyl hgand 42, utihzing either Zn or Fe in a precise (1 1) metalrhgand ratio, generated metallomacrocycles that were studied via ESI-TWIM-MS,... 

MPs and MPcs show very similar physical and chemical properties and they are structurally related to biological catalysts like cytochrome c and hemoglobin. The basic difference between their structures is shown (Fig. 7.1). As it will be discussed in details later, the properties of these complexes are very dependent on the type of central metal (M) and on the nature of substituents on the ligand. It is important to remark that the choice of substituents for the macrocyclic ligands is inexhaustible which leaves plenty of room for tailoring their properties. For example, the properties of metaUoporphyrins may be varied widely by means of substitution groups at the p and meso-positions of the ring (Fig. 7.1a). Furthermore, the concepts of supramolecular chemistry and molecular self-assembly offer additional possibilities to vary the properties of metallomacrocyclic [22-24]. 

Thomas and coworkers have used the self-assembly of kinetically stable Ru(II) metallomacrocycles (74-76) to... 

P. Wang, C.N. Moorefield, G.R. Newkome - Nanofabrication Reversible Self-Assembly of an Imbedded Hexameric Metallomacrocycle within a Macromolecular Superstructure, Angew. Chem. Int. Ed. 44,1679,2005. 

DjA-symmetric coordination capsules 743-746 undergo slow self-rearrangement by Scheme 5.99 in their solutions leading to the corresponding polynuclear metallomacrocyclic complexes [98]. 

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