Ring structures metal coordination complexes, phthalocyanines

The cavity in faujasite contains four tetrahedrally disposed windows. Molecular mechanics calculations [46,47] show that if the phthalocyanine ring system undergoes a saddle deformation then the four phenyl rings can poke through the tetrahedral holes and the host-guest complex exhibits no close van der Waals contacts. The resulting minimised structure is shown in Figure 5 [47]. This saddle distortion is compatible with the shift in the electronic spectra which indicates a distortion in the metal coordination sphere. 

Other phthalocyaninatometal complexes can adopt a square pyramidal geometry having the metal positioned above the plane of the ring. Phthalocyanines can adopt a sandwich like structure when the central metals are lanthanoids and actinoids. In these complexes the coordination number of the metal atoms is 8 [4],... 

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