Pacman porphyrin complexes

II. SYNTHESIS AND PHYSICAL PROPERTIES OF PACMAN PORPHYRIN COMPLEXES... 

Figure 2. Cofacial Pacman porphyrin complexes of interest.

In most cases, the nature of the spacer is the governing factor as far as optical properties are concerned. Pacman porphyrins, with rigid spacers such as anthracene and biphenylene, have received much attention due to the electro-catalytic properties of their cobalt complexes. Variations of both the dihedral angle and the distance between the porphyrm rings in these architectures have afforded examples of cofacial porphyrins linked by xanthene and dibenzofurane derivatives. Recent examples are detailed hereafter. 

A systematic structural study of the DPX Pacman framework has been provided by a homologous series of dinuclear zinc, copper, and nickel derivatives. The molecular structures of the homobimetallic zincfll), copper(II), and nickel(II) complexes of the DPX construct (5-7) are shown in Fig. 3. Trends in bond lengths and angles of macrocyclic core structures and side chains agree well with those observed in related systems including H4(DPA), H4(DPB), and l,2-bis[5-(2,3,7,8-12,13,17,18-octaethyIporphyrinato)]-cw-ethene porphyrins (80-83). 

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