Triple-decker porphyrin complex

More recently, polythiophenes, some of which were substituted with porphyrin moieties as light harvesters, had been investigated for their performances in photovoltaic devices. In an original work, Shinkai et al. succeeded in the electropolymerization of a Ce(III) triple decker porphyrin complex bearing bithienyl substituents at an ITO electrode surface. ... 

Yamashita, K., M. Ikeda, M. Takeuchi, and S. Shinkai (2003). Electropolymerization of bithienyl-appended cerium(III) triple decker porphyrin complex. Chem. Lett. 32(3), 264-265. 

Yamashita K, Ikeda M, Takeuchi M, Shinkai S (2003) Electropolymerization of bithienyl-appended Cerium(in) triple decker porphyrin complex. Chem Lett 32 264-265... 

Interestingly, in the case of lanthanide ions as metal centers, triple decker porphyrin sandwich complexes were also synthesized and studied (Wittmer. Holten, 19%). 

Selective complexation of di- and tetra-substituted porphyrins with cerium(III) ion led to novel double- and triple-decker sandwich complexes. In such complexes, the two or three porphyrin macrocyles were rotated by ca. 20-45. The various complexes were prepared by reaction of the parent porphyrins with cerium acetate. 

Ishikawa, N. (2001). Electronic structures and spectral properties of double- and triple-decker phthalocyanine complexes in a localized molecular orbital view J. Porphyrins Phthalocyanines, 5, 87-101. 

A triple-decker porphyrin-based monomer 87 (Chart 5.27) has been prepared and electropolymerized [98]. Cyclic voltammetry and the UV-Vis absorption spectra of the films showed clear evidence that the lanthanide complex is intact and present in the film. 

Recently, the use of pthalocyanines and porphyrins by Ishikawa and coworkers enabled tiie synthesis of several so-called double-decker or triple-decker lanthanide complexes, described as stacked Ji-conjugate molecules. The photophysical properties of lantiianide ious depeud markedly on their coordination environments. Since a multidecker framework can effectively keep solvent molecules away from Ln centers, it is assumed that enhanced luminescent properties can be achieved witii these types of architectures. We discovered that the use of two conjugated Schiff-base ligands H2Lh can stabihze novel multidecker framewoiks (Scheme 1). 

Bocian, Lindsey and co-workers studied sandwich complex nanocapacitors comprised of porphyrin and phthalocyanine ligands separated by lanthanide metals [133]. A triple-decker sandwich of phthalocyanine-Eu-phthalocyanine-Eu-porphy-rin, with two phenylethynyl linker wires from the porphyrin, potentially has up to nine accessible oxidation states (—4 to +4). SAMs of monomers, dimers, trimers, and oligomers of this sandwich, anchored at one or both ends by thioacetyl groups, gave charge densities up to 10 10 mol cm-2, electron-transfer rates up to 105 electrons s-1, and charge-dissipation half-lives in the 10-50 s range. 

Most devices based on Pc are fabricated by vacuum deposition, i.e. thermal evaporation. However, recent solution-based Langmuir-Blodgett (LB) techniques have also been used. LB-films of 25h-251 gave poor (10 cm V s for 25j) to moderate (1.7 x 10 cm V s for 251) mobilities (Figure 3.1.9).[162-164] More recently, high mobilities of 0.24-0.60 cm V s have been observed for LB films of amphiphilic tris(phthalocyaninato) rare earth triple-decker complexes, 25m-25o.[165] OFET characteristics have also been reported for porphyrin derivatives, 25p-q with mobilities of 2.2 x 10 cm V s and 0.012 cm V s, respec-tively.[166-168] LB-prepared thin films of Cyclo[8]pyrrole (25r), an extended porphyrin-like molecule, also exhibited a high mobility of 0.68 cm V s, but with a low on/off ratio.[169]... 

The dimer formation of anionic metalloporphyrins [677], cationic porphyrins [678], heterodimer formation [679-682], an aggregate between porphyrin and cytochrome c [683], and dimer formation through metal-metal interaction [684] has been reported. The 1 2 complex formation between the metal ions such as Th ° and Ce and porphyrins afforded an interesting double-decker sandwich complex [685-687] and a triple-decker one [688]. 

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