Phthalocyanines lanthanide complexes

Double-decker phthalocyanines are soluble in a narrow range of solvents and are insoluble in water, however, we have developed methods for preparing aqueous multicomponent systems based on lanthanide complexes phthalocyanines double-decker. Macromolecular stmctures (proteins, polymers), supiamolecular stmctures (micelles) and nanosized silica were used as solubilizers. 

Lanthanides form phthalocyanines PcMX, sandwich-like complexes of the type Pc2M, and triple-decker complexes of the type Pc3M2. 

The template methods have also been used for the synthesis of a number of substituted Ln di(naphthalocyanine) complexes, LnNc2 [82-88]. Apart from thermal fusion by conventional heating processes, complexation has been initiated by microwave radiation, although only a few publications are devoted to the template synthesis of lanthanide bis(phthalocyanine) complexes by this method [89, 90]. The use of microwave radiation (MW) reduces the reaction time from several hours to several minutes. Unsubstituted complexes LnPc2 (Ln = Tb, Dy, Lu) were prepared [90] by irradiation (650-700 W) of a mixture of phthalonitrile with an appropriate lanthanide salt for 6-10 min (yields >70%). 

As demonstrated above, lanthanide complexes containing phthalocyanines and various porphyrins as ligands have been studied in great detail. In contrast, the number of studies on analogous complexes containing phthalocyaninato and tetrapyrrole ligands like tetrabenzoporphyrinato-, tetraazaporphyrinato- or N-confused porphyrinato-, is rather limited [151-155], though such compounds also attract considerable interest. 

As a result of their low redox potentials [173], bis(phthalocyaninato) lanthanide complexes are often inadvertently reduced or oxidized, and they are also very sensitive to acids and bases. In order to solve these problems, Veciana et al. achieved certain success on designing a series of novel compounds with characteristics that would give them improved redox stability. Electroactive ligands based on phthalo-cyaninato tetra dicarboximide [175] or perfluorinated phthalocyanine [176] were used to assemble the double-decker lanthanide complexes, with the effect of stabilizing the negative charge of the anionic state of the compounds, which resulted in a strong shift of 0.7 V of their first oxidation potentials. 

The last category was concerned with miscellaneous subjects, while citing some chirogenic porphyrin-based systems. Representative reviews include chiral lanthanide complexes by Aspinall [41], coordination chemistry of tin porphyrins by Arnold and Blok [42], photoprocesses of copper complexes that bind to DNA by McMillin and McNett [43], nonplanar porphyrins and their significance in proteins by Shelnutt et al. [44], cytochrome P450 biomimetic systems by Feiters, Rowan, and Nolte [45] and phthalocyanines by Kobayashi [46,47]. 

Phthalocyanines are tetraaza tetrabenzo analogues of porphyrins. Lanthanide complexes with phthalocyanines are prepared by the condensation of phthalonitrile (4 moles) with a lanthanide salt. The monocomplexes were prepared by heating a 1 4 mixture of lanthanide saltiphthalonitrile at 275°C. The molten solution solidified after an hour and purification of the complex is done by removal of excess phthalonitrile and impurities with organic solvents. Final purification is done by chromatography [85]. The bis complexes are prepared in a similar fashion but with a large excess of phthalonitrile [86]. Mixed ligand... 

Lanthanide complexes of porphyrins and phthalocyanins as liquid crystals and surfactants 02CRV2303. 

A connectivity of 1 is given for side chain metal-containing polymers as 1 in which the metal complex is connected via one bond to the main chain [11]. Additional examples for other connectivities are (Fig. 1-8) connectivity 2 in metal(yne)s 2 [12] connectivity 3 in arsenic(III) sulfide 3 connectivity 4 in a polymeric methyl rhenium oxide of the formula Ho.5[(CH3)o.92Re03] co 4 [13] or polymeric phthalocyanines 5 [14] connectivity 8 in lanthanide complexes of bis(tetradendate) Schiff base bridging ligands 6 [15]. 

The lanthanide complexes of phthalocyanines, which have attracted intense interest owing to their electrical properties, are not included in this survey because they do not possess a true metal-macrocyclic structure. Even the smallest lanthanide, Lu(III), cannot be accommodated inside the four-N-donor cavity of the phlhalocyanine system. In these complexes, the metal ion is always considerably displaced from the plane of the ligand and sandwich-type structures are common. 

Double-decker phthalocyanine lanthanide complexes have a high stability [1], intense absorption and can be used in various technological [2] and biomedical applications [3]. Therefore, it is necessary to study the nature of the bands in the electronic absorption spectra, as well as the possibility of changing the spectral properties depending on the composition of multicomponent systems. 

The objects of study were double-decker phthalocyanine lanthanide complexes with the lutetium (Lu), ytteibium (Yb), holmium (Ho) and erbium (Er) as metal-... 

In solutions of polymers (PVP, PEG, PDDA) complete or partial neutralization of the negative charge of the anionic form of the initial metal complex was seem Similar behavior was observed for metal complexes comprising micelles (SDS). In the case of micellar system CTABr lanthanide bis-phthalocyanine predominantly existed in the anionic form. 

The emergence of a new band with = 660 nm was seen in albumin solution (Fig. 9.3). The presence of oxygen in aqueous solution led to the formation of a complex withbis-phthalocyanine [9, 10] and the transition from the initial form to a neutral anion. Albumin presented in the solution prevented the oxidation process of phthalocyanine. Due to the hydrophobic nature of the lanthanide complexes, which bind to a hydrophobic pocket presented in albumin and thereby altering the spectral properties [11]. 

Study of the spectral properties of double-decker phthalocyanine based on lanthanide complexes is one of the most promising area of research due to their attractiveness for applications primarily in the biomedical field [13] as a prototype sensitive model. 

It is important to keep the spectral properties of lanthanide complex in a thin layer. Because, specific interaction bis phthalocyanine with albumin plays an important role in the evaluation of protein. Band in the absorption spectram (Fig. 9.9) phthalocyanine ytterbium in formed a thin layer is characterized by 664 mu. Spectral shape and position of the absorption band corresponds to the neutral form [16]. 

The electrochromism of the phthalocyanine ring-based redox processes of vacuum-sublimed thin films of [Lu(Pc)2] was first reported in 1970,32 and since that time this complex has received most attention, although many other (mainly lanthanide) metallophthalocyanines have been investigated for their electrochromic properties.1 Lu(Pc)2 has been studied extensively by Collins and Schiffrin33,34 and by... 

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