Porphyrins analogues

Despite a smaller hole size in the pz, the zirconium is displaced from the mean plane of the coordinated nitrogens by the same distance as in the porphyrin analogue (33). The distance between the zirconium and the mean... 

Selected Average Bond Lengths (A), Angles (deg), and Metrical Parameters Involving Non-Hydrogen Atoms in Crystalline Zirconium Bis(octaethylporphyrazine) (29), Mixed Sandwich (heteroleptic Pz/porphyrin) (30), and Bis(octaethylporphyrin) (Porphyrin Analogue)... 

The modification of the physical properties of some molecules as consequence of complexation with CDs is well known. Kongo et al.126 studied the TB-p-CD/porphyrine complex and observed a drastic change in the photochemical and photophysical properties of porphyrine. The conformational analysis by NMR revealed strong NOE interactions between the ligand and the internal part of the CD, in agreement with a deep insertion of the porphyrine analogue into the CD s cavity. The NOE data provided structural information to propose the 3D model of 1 2 inclusion complexes. 

Phthalocyanines 392 are porphyrin analogues embellishing Nature with exciting colours. Their pentamer 393 obtained in a one-step reaction has a cavity, thus it can play the role of host [12]. 

Several porphyrin analogues with the pyrrolic nitrogens substituted by heteroatoms have been synthesized, but only the oxa analogues (23 X = O, Y = NH) are reported to form stable metal complexes (Figure 8). 60 Formation of a Zn complex of the thia analogue (23 X = S, Y = NH) requires the presence of a large excess of Zn" ion. An iron complex of dithiaporphyrin (23 X = Y = S) is also known. 

The axial coordination chemistry of metallohydroporphyrins parallels that of their porphyrin analogues. 

Like its porphyrin analogue, [Rh(CO)2]2(Tap) reacts with alkyl halides, aldehydes, alkoxy formates and ketones to give R—RhH1(Tap) or RCO—Rhm(Tap) (Scheme 55).134... 

We have compiled synthetic chemistry and properties of porphyrin analogues containing only furan, imidazole, or thiophene subunits in place of pyrrole subunit(s). Expanded porphyrinoids have been excluded. This write-up is not intended to give a comprehensive treatment, but is aimed to complement earlier reviews (06CCR468, 08CSR215). In the following two sections, the chemistry of core-modified porphycenes and porphyrins is presented. 

Figure 5.56 Schematic illustrating the self-assembled multilayers of sodium 3-mercaptoethane-sulfonate (layer 1 ), hexacationic homooxacalix[3]arene-fullerene (2 1) complex (layer 2 ), with either the anionic porphyrin polymer ( 3 ) or its zinc porphyrin analogue ( 4 ) forming the third layer. Reprinted with permission from A. Ikeda, T. Hatano, S. Shinkai, T. Akiyama and S. Yamada, /. Am. Chem. Soc., 123,4855 (2001). Copyright (2001) American Chemical Society...

The complexes [Ru(Pc)(CO)L] and [Ru(Pc)L2] (L = py, 4-methylpyridine, 4-tert-butylpyridine, imid, MeCN, DMF, DMSO) each show a reversible one electron oxidation in CH2C12 El — + 0.91 V and + 0.77 vs. SCE for [Ru(Pc)COpy] and [Ru(Pc)py2] respectively.2635 Quantitative oxidation gives the it radical cation products [Ru(Pc+)(CO)L] and [Ru(Pc+)L2] which have been characterized by electronic and ESR spectroscopy 26 the redox activity of ruthenium phthalocyani-nes have been compared to the corresponding porphyrin analogues.2635... 

It is the opinion of the authors that the chemistry of porphyrin analogues, porphyrin-like systems that are expanded, contracted, or isomeric , as compared to their well-studied tetrapyrrolic parents , now deserves a life of its own. Over the last decades, particularly in the last few years, so much has been accomplished that, on the one hand, the sheer mass of information precludes writing an all-encompassing journal-type review. On the other hand, this same progress has served to make clear that the chemistry of porphyrin analogues is prescient in terms of a number of current applications and future research possibilities. Thus, a synopsis of all that is known appears fully warranted. 

Liu X, Mahammed A, Tripathy U, Gross Z, Steer RP (2008) Photophysics of soret-excited tetrapyrroles in solution III porphyrin analogues aluminum and gallium corroles. Chem Phys Lett 459 113-118... 

Porphyrinoids (porphyrin analogues, porphyrin homologues and porphyrin vinylogues [31]), like porphyrins, are of interest as sensitizers in photodynamic tumour therapy [32]. Some of these systems, e.g. 41 - 43 have been synthesized (Franck, Vogel 1990) [33]. Their nomenclature takes into account the cyclic conjugation of the annulene perimeter and the number of methine groups between the four pyrrole units, e.g. porphyrin 1 is described as [18]porphyrin(l.l.l.l) porphycin 43, which is isomeric with porphyrin, is known as [18]porphyrin(2.0.2.0). 

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