Bisphthalocyanines

Unsubstituted bisphthalocyanines 2 are formed in the presence of several elements which exist in a stable oxidation state of + III or +IV such as titanium, zirconium, hafnium, indium and most of the lanthanide and actinide elements. 

Although direct reaction of lanthanide mono-porphyrins with free phthalo-cyanine or its lithium derivatives is generally more efficient than the template synthesis, and gives rise to mixed-ligand complexes, the template strategy can also be applied for synthesis of phthalocyanine-porphyrin complexes, as in the case of unsymmetric bisphthalocyanine complexes (Scheme 8.2, B(b)) [106, 136, 145, 146]. Thus, metallation of free porphyrins with lanthanide salts in TCB or n-octanol leads to single-decker complexes, which then react with phthalonitriles under the action of DBU in alcoholic media to give the desired compounds. 

The metallophthalocyanines which have found application as elecfiochromes are mainly the rare earth derivatives, especially lutetium, and second row fiansition metals such as zirconium and molybdenum. Synthesis of these molecules follows the fiaditional routes, e.g. condensation of 1,2-dicyanobenzene with a metal acetate in a high boiling solvent (see Chapter 2). These compounds have structures in which the rare earth element is sandwiched between two phthalocyanine rings, e.g. zirconium bisphthalocyanine (1.92 M = Zr) and lutetium bisphthalocyanine (192 M = Lu), the latter protonated on one of the meso N atoms to balance the charge. 

Parra, V., Hernando, T., Rodriguez-Mendez, M. L., and de Saja, J. A. (2004). Electrochemical sensor array made from bisphthalocyanine modified carbon paste electrodes for discrimination of red wines. Electrochim. Acta 49(28), 5177-5185. 

Rare-earth bisphthalocyaninates, especially LuPc2, are one of the important objects of intense investigation because of their electrochemical (electrochromic effect), electrical, and optical properties. The ball-type four t-butyl-calix[4]arene bridged double decker lutetium(III) and indium(III) Pcs have also been prepared, Fig. 3 [42],... 

Bariain C, Matias IR, Fernandez-Valdivielso C, Arregui FJ, Rodriguez-Mendez ML, de Saja JA. Optical fiber sensor based on luthetium bisphthalocyanine for the detection of gases using standard telecommunication wavelengths. Sens Actuators 2003 B93 153-8. 

Bisphthalocyanines based on rare earth metals lutenium (45j) and thulium (45k) were studied as early as 1990.[267] These compounds had a field-effect mobility of 10 cm V- s- under vacuum, but the electronic properties degraded rapidly upon exposure to ambient conditions. 

Rodriguez Mendez and coworkers did a series of researches in the development of new sensors able to detect the odors and aromas [32,58,75-78], They first used lutetium bisphthalocyanine (LuPc ) LB and evaporated films for the detection of the aroma of olive oil or wine (hexanol, hexanal, -buthyl acetate, and acetic acid) based on the changes in their conductivity [76], The kinetics and the intensity of the response of the films depend not only on the morphology and the thickness of the films but also on the nature of the reactant gas. They detected acetic acid down to 88 mmol/L, based on the refractive index changes in combination with an optical fiber... 

LB films of octa-(15-crown-5)-lutetium bisphthalocyanine (CR-PcjLu) were sensitive to electron donor and electron acceptor gases as well as tobacco smoke [75]. The... 

Rodriguez-Mendez M. L., Aroca R., and De Saja J. A., Electrochromic and gas adsorption properties of Langmuir-Blodgett films of lutetium bisphthalocyanine complexes, Chem. Mater, 5, 933-937, 1993. 

Rodriguez-Mendez M. L., Souto 1., J. Gonzalez J., and de Saja J. A., Crown-ether lutetium bisphthalocyanine Langmuir-Blodgett films as gas sensors, Sens. Actuators B, B31, 51-55, 1996. 

Rodriguez, M.L., R. Aroca, and J.A. DeSaja (1992). Electrochromic properties of Langmuir-Blodgett films of bisphthalocyanine complexes of rare earth elements. Chem. Matter 4,1017. 

Aroca, R., A.H. Bolourchi, D. Battisti, and K.Najafi (1993). Gas adsorption and electrical properties of two Langmuir-Blodgett layers of cerium bisphthalocyanine. Langmuir 9, 3138. 

Gaffo, L., C.J.L. Constantino, W.C. Moreira, R.F. Aroca, and O.N. oliveira (2002). Atomic force microscopy and micro-Raman imaging of mixed Langmuir-Blodgett films of ytterbium bisphthalocyanine and stearic acid. Langmuir 18, 3561. 

Kilmc, N., Atilla, D., Gurek, A. G. Ozturk, Z. (2009). Tetrakis(aIkylthio)-substituted lutetium bisphthalocyanines for sensing NO and O Sensors and Actuators B142, 73-... 

Giuliani, E., Fernandes, R., Brazaca, L. C., Rodriguez-Mendez, M. L., Antonio de Saja, J. Zucolotto, V. (2011). Immobilization of lutetium bisphthalocyanine in nanostmc-tured biomimetic sensors using the LBL technique for phenol detection Biosensors and Bioelectronics 26, 4715—471. 

Vivas, M., Fernandes, R. Mendonca, R. (2012). Study of singlet excited state absorption spectrum of lutetium bisphthalocyanine using the femtosecond Z-scan technique Chemical Physics Letters 531, 173-176. 

Slota, R., Dyrda, G., Bloise, E. Sole, R. (2012). Novel Lipophilic Lanthanide Bisphthalocyanines Functionalized by Pentadecylphenoxy Groups Synthesis, Characterization and UV-PhotostabiUty Afo/ecii/es, 17,10738-10753. 

Murdey, R., Bouvet, Sumimoto, M., M., Sakaki, S. Sato, N. (2009). Direct observation of the energy gap in lutetium bisphthalocyanine thin films Synthetic Metals 159, 1677-1681... 

Bai, R., Shi, M., Ouyang, M., Cheng, Y, Zhou, H., Yang, L., Wang, M. Chen, H. (2009). Erbium bisphthalocyanine nanowires by electrophoretic deposition Morphology control and optical properties Thin Solid Films 517, 2099-2105. 

Figure 4 Bisphthalocyanine 5 (a) and transmission electron microscopy smdies showing ID nanoaggregates. (Reproduced from Ref. 20. American Chemical Society, 2003.)...

Electrochromic effects have been observed for LB films of rare-earth-substituted phthalocyanines (2), with X = Yb, Pt [82]. In general, the compressed monolayers are only found to be sufficiently stable when dimers of the type YbPc2 are used. However, electrochromic switching is only observed when alternative Y-type layers of the dimer are deposited with fatty acids. It has been established that a self-reorganization mechanism of the bisphthalocyanines operates, and that the alkyl-chain length of the acid can significantly affect the switching mechanism. For example, if the chain contains fewer than 20 carbon atoms, the electrochromic process is not impeded if 20 or 21 carbon atoms are involved, the... 

Apetrei C, Alessio P, Constantino CJL, de Saja JA, Rodriguez-Mendez ML, Pavinatto FJ, Ramos-Femandez EG, Zucolotto V, Oliveira ON Jr (2011) Biomimetic biosensor based on lipidic layers containing t5Uosinase and lutetium bisphthalocyanine for the detection of antioxidants. Biosens Bioelectron 26 2513-2519... 

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