We have synthesized new pentametallic macrocyclic complexes based on the polynucleating ligand, porphyrazine- 2,3,7,8,12,13,17,18-octathiolate, (pzot)8-. This ligand can be thought of as a porphyrazine (tetraazaporphyrin) bearing four dithiolene moieties peripherally at the /3-pyrrole positions, and we show that a transition-metal ion can be chelated to each of the four peripheral dithiolene moieties. The complexes [(P-P)Ni]4[Ni(pzot)] (2a, P-P = dppe; 2b, P-P = dppy; 2c, P-P = dppb; 2d, P-P = dope) have been synthesized and characterized. Complex 2a crystallizes in the orthorhombic space group Cmc2i (No. 36) with 4 macrocycles and 16 solvent molecules (Ñ,/V-dimethylformamide) in a unit cell of dimensions a = 24.630(5) Á, b = 20.607(4) Á, c = 30.675(6) Á. The [Ni(pzot)]8ligand in 2a coordinates four Ni(P-P) moieties around its periphery with the two thiolate sulfur atoms of each pyrrole binding a nickel ion in a bidentate (S-S) coordination mode. This is in contrast to the reaction of [Ni(pzot)]8-with SnR^Xi, which yielded Ni(pzot)(SnR.2)4 (1), where each tin is coordinated in the tridentate (S-N-S) mode, with the thiolate sulfur atoms from two pyrroles and one w-nitrogen atom as ligands from the macrocycle (Velázquez, C. S.; Fox, G.
The derivatization of metal-tris(2,2′-bipyridine) complexes with oligo(ethylene glycol) tails produces ionicallyconductive room-temperature melts in which appreciable concentrations of lithium electrolytes dissolve. Charge transport rates in these redox polyether hybrids, in the undiluted state, have been investigated using microelectrode solid state voltammetry. In the ligand bpy(CO 2 MPEG350) 2 , MPEG350 is -(CH 2 CH 2 O) 7 -CH 3 . The apparent diffusion coefficient, D APP , for the oxidation of [Fe(bpy(CO 2 MPEG350) 2 ) 3 ](ClO 4 ) 2 is ca. 10 3 larger than that for [Co(bpy(CO 2 MPEG350) 2 ) 3 ](ClO 4 ) 2 . This difference is ascribed to transport dominated in the former by electron self-exchange reactions between adjacent Fe(II) and Fe(III) complexes. The very slow physical self-diffusivity in these metal complex melts, measured by the Co(III/II) reaction, provides an opportunity to assess the effect of electron donor/acceptor concentration on electron self-exchange dynamics in a semisolid matrix. Various models have been described for the site concentration dependency of charge transport in redox polymers, including ion association, electron migration, and percolation. This study examines the effects of changing redox site concentration on D APP by diluting [Fe(bpy(CO 2 MPEG350) 2 ) 3 ](ClO 4 ) 2 isostructurally with the analogous Co and Ni complexes, and interprets the results in the context of the previous models.
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