Porphyrin guest molecules

Lindsey s group used the same methodology for the synthesis of a hexameric wheel of porphyrins that shows in the presence of appropriate guest molecules interesting light-harvesting properties [29]. Its synthesis starting from 67 and... 

The metastable, 2-D packing motif presented by some Pcs adsorbed on Ag(l 11) has also prompted the utilization of such ensembles as templates for the organization of complementary guest molecules such as fullerenes [193] or corannulenes [194], giving rise to the formation of two-component, 2-D architectures. More recently, a similar approach has been used to prepare a surface-supported, three-component system. In fact, the immersion of an Au substrate into a solution containing both a ZnPc and a Zn porphyrin led to the formation of a highly ordered, 2-D arrangement of both Pc and porphyrin which can act as a bimolecular chessboard toward the supramolecular assembly of a third component (i.e., C6o fullerene) which is selectively trapped in the open spaces (Fig. 25) [195],... 

The open-isomer of DTE having two zinc porphyrin moieties could form coordination complex with 4,4-bipyridyl like a tweezer (see Scheme 4), but the closed isomer could not bind cooperatively because of its structural rigidity. The different binding behavior of ZnP-DTE-ZnP with 4,4-bipyridyl was though to make the photo-control of affinity to guest molecules possible. 

Phthalocyanines and porphyrins are often used as model compounds for the manipulation (guest molecule) of surface-supported supramolecular two-dimensional arrays both in UHV and in solution. Spillmann et al. reported that zinc(II) 5,15-bis(3-cyanophcnyl)-10,20-bis 3,5-di(/c/7-bu(yl )phcnylj porphyrin, 2, molecules predominantly formed a hexagonal pattern by trimer formation, when 0.5-0.7 MLs of 2 was deposited on Ag(l 11) especially, 2 forms a characteristic nanostructure on Ag(l 11) at low coverage [163], As reported by Yokoyama et al., it is suggested that the molecular assembly is driven by both van der Waals and dipole-dipole interactions involving the polar 3-cyanophenyl residues [79], After further deposition of C60... 

Fully substituted porphyrin 97 has been prepared by Aida and co-workers. Porphyrin 97 does not adopt an achiral planar conformation, but rather adopts a chiral saddle-shaped conformation. A rapid saddle-to-saddle inversion, that is, racemization, readily takes place at room temperature. In the presence of a chiral guest molecule such as mandelic acid, 97 retains an enantiomeric saddle-shaped conformation by the formation of a hydrogen-bonded complex with two molecules of mandelic acid. When mandelic acid is replaced by achiral acetic acid, 97 still retains the enantiomeric saddle-shaped conformation. Thus the... 

MgTPP has also been examined as a substrate for constructing porphyrin sponges, i.e., lattice clathrates that can reversibly absorb and release guest molecules. Such guests as methyl benzoate, propanol and (R)-phenethylamine) have been structurally authenticated other examples are known. " ... 

Qualitative studies of both types of complexation reactions were performed injecting solutions of host and guest molecules in a 1 2 and 1 1 ratio, resulting upon mixing on-chip in a final concentration of 2 x 10 4 M Zn porphyrin (1) and 2 x 10-5 M (S-CD (7), respectively. 

In Zn-porphyrin 1 the metal center has one binding site available for coordination of a guest molecule such as pyridine (2), 4-ethylpyridine (3), 4-phenylpyridine (4), A-methylimidazole (5) and A-butylimidazole (6), to yield... 

The more versatile and stable modular interface was successfully used to investigate supramolecular complexations based on the metal-ligand interaction between Zn-porphyrin 1 and the nitrogen-containing guest molecules 2, 3, 4, 5 and 6 or the encapsulation of guests 8 and 9 in the cavity of p-CD (7). 

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