Metallophthalocyanines structure

Since the electrochemical behaviour of metallophthalocyanines has been reviewed,103 we will simply demonstrate the ligand based nature of their redox processes. As a typical example, Figure 57 shows the redox aptitude of zinc-phthalocyanine [Zn(Pc)] CH2C12 in solution,96 together with its molecular structure.104... 

Figure 1. Molecular structures of metallophthalocyanine (MPc) complex. MPc complexes may be substituted at the peripheral or non-peripheral positions as shown. M = metal ion, and R = substituent containing terminal functional groups such as -NH2 and -OH.

Metal phthalocyanines are extremely important materials in a variety of fields ont-side their traditional nse as dyes and pigments (Chapter 2, sections 2.3.1.6 and 2.4.1.4), inclnding electrochromism. The properties of metallophthalocyanines make them attractive as potential electrochromic materials, e.g. high light stability, high molar absorption coefficients, stable and sublimable at high temperatures, and the possibility of multi-colours within one structure. 

The metallophthalocyanines which have found application as elecfiochromes are mainly the rare earth derivatives, especially lutetium, and second row fiansition metals such as zirconium and molybdenum. Synthesis of these molecules follows the fiaditional routes, e.g. condensation of 1,2-dicyanobenzene with a metal acetate in a high boiling solvent (see Chapter 2). These compounds have structures in which the rare earth element is sandwiched between two phthalocyanine rings, e.g. zirconium bisphthalocyanine (1.92 M = Zr) and lutetium bisphthalocyanine (192 M = Lu), the latter protonated on one of the meso N atoms to balance the charge. 

Fig. 2 (a) Kobayashi ting opening reaction of subphthalocyanines. (b) Schematic structure of a metallophthalocyanine with ligands in axial positions... 

This conformational mobility is exemplified in the structures of Ni(oep) (Fig. 26). In the triclinic form of Ni(oep)194-1 the molecules are planar and centrosymmetric (Fig. 26 a) and are stacked inclined relative to the stacking axis in a herringbone pattern similar to that adopted by most of the metallophthalocyanines. By change of solvent, Ni(oep) can be made to crystallize in a tetragonal form195) in which the molecule has crystallographi-... 

In the template method the zeolite is allowed to crystallize around the metal complex which is assumed to act as a structure directing agent, i.e. the bottle is built around the ship. This allows for the encapsulation of well-defined complexes without contamination by the fi-ee ligand or uncomplexed metal ions (see above). The method is restricted to metal complexes that are stable under the relatively harsh conditions of temperature and pH involved in hydrothermal synthesis. Balkus and coworkers [14,40,41] used this approach for the encapsulation of metallophthalocyanines in faujasite. However, in order to fit into the faujasite supercages the phthalocyanine ligands are strongly deformed and Jacobs has... 

Figure 10.15). Catalytic stability was enhanced by the encapsulation within the dendritic structure due to the catalytic activity of metallophthalocyanines being influenced by phthalo-cyanine aggregation resulting from strong intermolecular stacking. 

Fig. 7.33 Strategy for the co-facial assembly of structure-enforced group 4 metallophthalocyanine assemblies. [From Marks 1990.]...

Figure 2.3. Structures of different MN4 macrocycles. 1 metallophthalocyanine, 2 metal tetraphenylporphyrin, 3 metal tetraazaanuulene, and 4 metal tetramethoxyphenyl porphyrine.

Figure 7.1. Molecular structures of (a) metallophthalocyanine (MPC), (b) metallopor-phyrin (MP), and (c) ring substituted MPc where R = (CH2)2N b(R)xI -...

Structures and photoinduced electron transfer of protonated complexes of porphyrins and metallophthalocyanines 12CCR2488. 

The stability of metalloporphyrins and metallophthalocyanines alike is far from satisfactory for any practical application. Whereas there is irrefutable evidence for improved activity upon heat treatment of the N4-metallomacrocyclic complexes, the loss of their structural merit is obvious. The fact that the performance of nonprecious metal catalysts synthesized by heat treatment of inexpensive nitrogen, carbon, and metal precursors rivals that of heat-treated N4-metallomacrocyclic complexes, which... 

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