Macrocycles copper

M(iii) and Cn(m) complexes. In early classic studies the redox chemistry of tetraaza macrocyclic complexes of Ni(n) and Cu(n) (of the Curtis and reduced Curtis type) was investigated in acetonitrile (Olson Vasilevskis, 1969 1971). These authors were the first to report the electrochemical generation of Ni(m) and Cu(m) complexes of such N4-cyclic ligands. Since this time, a considerable number of related studies, involving both nickel and copper macrocyclic species, have been reported. 

DR. RALPH WILKINS (New Mexico State University) What is the rate of the reaction of trien with your copper macrocyclic tetrapeptide complex Based on your mechanism it should be... 

Transfer the diphenol-DMF solution to the copper-macrocycle solution via a double-tipped steel cannula the solution turns dark-red immediately. 

Figure 6 Complex fonnation between a copper-macrocyclic host and a redox-active bisp3nidyl-tetrazine guest . The set of CVs (20Vs ) on the right correspond to the titration of up to 1.05 equivalents of the host to the guest (l.OmM). (Reproduced with permission from Ref. 6. Wiley-VCH, 2010.)...

Although the substitution of a preformed phthalocyanine always leads to a complex mixture of more- or less-substituted products, the reaction is of major industrial importance. Besides the chloro- and bromocopper phthalocyanines, also polysulfonated phthalocyanines, which are used as water-soluble dyes, are produced by the reaction of copper phthalocyanine with the respective reactant. While typical aromatic reactions of the Friedel-Crafts type are also possible,333 direct nitration of the macrocycle commonly results in oxidation of the phthalocyanine. However, under mild conditions it is possible to introduce the nitro group directly into several phthalocyanines.334... 

In the Cambridge Structural Database [39] only two macrocyclic molecules with transition metals, in which the metal ions are joined only by imidazolyl units, have been reported. One structure is trimetallic and contains plati-num(II) [40a] and the second one is tetrametallic with copper(II) ions [40b]. 

As already mentioned, the macrocyclic ring can be further enhanced if the propylene moiety is substituted by a butylene group. Visible spectral data of a series of related compounds [Cu(L BF2)D]X 132 and the structural study of the derivative with D = H2O show that the seven-membered chelate ring influences the structure and other properties like electronic absorption of the copper(II) complex [193]. 

A dinuclear iron(ll/Ill) complex bearing a hexadentate phenol ligand displayed moderate activity toward aziridination of alkenes with PhlNTs a large excess of alkene (2,000 equiv. vs PhlNTs) was required for good product yields (Scheme 22) [76]. It is noteworthy that complex 4 is active in the aziridination of aliphatic alkenes, affording higher product yields than copper (11) catalysts with tetradentate macrocyclic ligands [77]. 

It is to be mentioned here that the coordination chemistry of macrocyclic ligands is covered in Volume 7. Therefore only selected systems having some direct relevance to the bioinorganic chemistry of copper will be discussed. Readers are recommended to consult review articles/ 3... 

To gain insight into electron-transfer kinetics of copper(II/I) complexes of macrocyclic thioethers,446,447 Rorabacher and co-workers reported448,4 7 structures of five complexes (complexes (548)-(552)). 

From this perspective they reported the structure (complex (791) Cu-Cu 10.061 A) of a m-xylyl-based TACN ligand.583 Structures of four mononuclear copper(I) complexes ((792)-(795)), supported by tridentate macrocycle, were also reported by this group. They investigated their oxygenation behavior and in each case clean formation of side-on peroxo-dicopper(II) species was demonstrated.416... 

Using 1,4,8,11-tetraazacyclotetradecane, the structure of complex (800) (distorted trigonal planar Cu-Cu 6.739 A) was determined. Reactivity with 02 was investigated to demonstrate the formation of trans-l,2-peroxo species.585 As part of their work with copper(I) complexes with 02, the structure of a dicopper(I) complex ((801) distorted tetrahedral 7.04 A), supported by macrocyclic ligand environment, was reported by Comba and co-workers. Tolman and co-workers structurally characterized a three-coordinate copper(I)-phenoxide complex (802) (planar T-shaped) that models the reduced form of GO.587 The copper(I) analogue [Cu(L)][CF3-SO3]-0.43MeOI I (803) of a copper(II) complex (534) was also reported to demonstrate the role of ligand framework conformability in CV /Cu1 redox potentials.434 Wilson and co-workers... 

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