Silicon phthalocyanines

Although these methods were applied for the synthesis of a number of various phthalocyanines with different central atoms (e.g., H2, Cu, Zn, Ni, Pt, Pd, Lu, etc.) not all metal phthalocyanines can be prepared by one of these methods. For example, the synthesis of silicon phthalocyanine, rhenium phthalocyanine and boron subphthalocyanine need more drastic conditions. In the following, an overview of the synthesis of phthalocyanines containing all central metals which have hitherto been inserted into the ring is given. 

Germanium phthalocyanine (PcGeCl2), similar to silicon phthalocyanine, is prepared from isoindolinediimine and germanium(IV) chloride in quinoline.105,1 10,1 53 Besides this common procedure, it can also be prepared by metal insertion into PcH2 starting from germanium(IV) chloride in dimcthylformamidc.141 The diol can be obtained by reprecipitation from concentrated sulfuric acid. 

Silicon phthalocyanine-based dyes have also been studied for use in ODS. The synthesis, structural and conformational analysis, and chemical properties of some silicon phthalocyanine-based dyes (Scheme 8) were recently reported.218... 

An important area of research in silicon phthalocyanine chemistry has been the preparation of conducting polymers through Si—O—Si links.In one recent example, silicon phthalocyanine complexes have been appended to a den-drimer framework through Si—O—C(triazine) bonds formed by reaction of the salt Na [Si(Pc)(Ph)0 ] with a dichlorotriazine derivative. 

PTD has been evaluated in the treatment of transfused blood going into blood banks, the objective being to inactivate viruses, such as HIV, without affecting erythrocytes. Use of silicon phthalocyanine or naphthalocyanine derivatives allows irradiation at wavelengths where the erythrocytes do not absorb, and the process is reported to be very effective. The use of Photofrin in inactivating HIV-1 in blood has also been described, whilst BPD (see Figure 4.23) has been used to inactivate feline leukaemia retrovirus in both spiked human blood and infected cat s blood. ... 

Li, Z, Lieberman M, Hill W (2001) XPS and SERS study of silicon phthalocyanine mono-layers Umbrella vs octopus design strategies for formation of oriented SAMs. Langmuir 17( 16) 4887—4894... 

A series of axially-disubstituted silicon-phthalocyanines 353 (silicon-Pcs, Figure 23) was obtained by the nucleophilic displacement of one or two chlorine leaving groups from either PhSi(Pc)Cl or Si(Pc)Cl2, respectively, by reaction with the acid or alkoxide derivative of the ligand. Structure of these compounds was confirmed by H and 13C NMR, UV-vis absorption and emission spectra, electrospray or MALDI-ToF mass spectrometry as well as X-ray crystallography <2006T9433>. 

Here we wish to report that this model was further confirmed by changing the crystalline structure in such a way that the phthalocyanine molecules could be expected to be oriented parallel. This can be done in two ways. First a silicon phthalocyanine is prepared (216). The optical molecules are now kept together by a (Si-0-Si-0) chain (see Fig. 46). As is to be expected the migration in this crystalline phase is very fast and even at 4.2 K the luminescence intensity is very low. 

The synthesis, by Professor Malcolm Kenny at Case Western Reserve University, of a series of silicon phthalocyanine polymers (SiPc) (aggregates of the monomer of this series, m-SiPc, are discussed here) and of a series of aluminum and gallium, fluoro and chloro phthalocyanines (AIPc-Cl, GaPc-Cl, AIPc-Cl, GaPc-F) allowed us to study several oriented systems (16). 

Figure la. Silicon phthalocyanine polymer shown attached to SnO, surface. 

Axial dendritic substituents are an alternative way to functionalize these hyper-branched macromolecules and to avoid stacking. McKeown s group synthesized dendritic silicon phthalocyanines based on Frechet s poly(aryl ether) dendrons, and used them to create emissive thin films by spin-coating. The disappearance of stacking rearrangement was clearly seen in the UV-vis spectra [45],... 

Fig. 6. The chemistry of silicon phthalocyanines. Reaction pathway (1) Py/NH4OH ...

Thus (XX) reacts with phenol in pyridine to form diphenoxysilicon phthalocyanine (XXII), with benzyl alcohol to form (XXIII), and with triphenylsilanol to form (XXIV) (168,170, 200). These complexes sublime readily without decomposition (cf. corresponding aluminum derivatives). Bis(diphenylmethylsiloxy)silicon phthalocyanine, which melts before subliming, is one of the very few metal phthalocyanines which actually melt (873). The siloxy complex (XXIV) may also be prepared in benzyl alcohol, thus implying that the Si—O—Si(Pc)—0—Si backbone is more stable than C—O—Si(Pc)—O—C. The dibenzyloxy derivative (XXIII) reacts with diphenylsilanediol to form bis(benzyloxydiphenylsiloxy)silicon phthalocyanine (XXV). 

The condensation of hydroxyaluminum phthalocyanine with dihydroxy-silicon phthalocyanine has been studied (268a). The reaction proceeds in refluxing 1-chloronaphthalene ... 

J. B. Davison, K. J. Wynne, Silicon-Phthalocyanine Sitoxane Polymers Synthesis and Proton Nuclear Magnetic Resonance Study, USNTIS, AD A036 274, 1977. 

E. Ben-Hur, J. Oetjen, B. Horowitz (1997). Silicon phthalocyanine Pc 4 and red light causes apoptosis in HIV-infected cells. Photochem. PhotobioL, 65, 456-460. 

C.Y. Anderson, K. Freye, K.A. Tubesing, Y.S. Li, M.E. Kenney, H. Mukhtar, C.A. Elmets (1998). A comparative analysis of silicon phthalocyanine photosensitizers for in vivo photodynamic therapy of RIF-1 tumors in C3H mice. Photochem. PhotobioL, 67, 332-336. 

R. Decreau, M.J. Richard, P. Verrando, M. Chanon, M. Julliard (1999). Photodynamic activities of silicon phthalocyanines against achromic M6 melanoma cells and healthy human melanocytes and keratinocytes. J. Photochem. PhotobioL B. Biol., 48, 48-56. 

It should be pointed out that a specific modification of Ti(0)Pc 1 (R = -H) in organic polymers is the most widely used photoconductor in bilayer photoreceptor copiers and laser printers [19]. A thin film containing ethylene-bridged silicon phthalocyanine polymer dispersed in poly(vinylidene fluoride) (1 4 by weight) obtained by casting from a DMF slurry on quartz was orientated in an electrical field [20], A double-layered receptor device for measuring the... 

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