Octa phthalocyanine

Cu(OAc), H20 (0.75 g, 3.7 mmol) was added to a refluxing solution of metal-free 1,4,8,11.15,18,22,25-octa(propyloxy)phthalocyanine (0.1 g, 0.1 mmol) in BuOH (5 mL). The solution was maintained at reflux for 0.5 h, cooled, and chromatographed (silica gel, CH2C12 and Et20). The green-blue fraction eluted first was crystallized from a slowly evaporating solution in CH2Cl2/py yield 0.086 g (81 %). 

If lanthanide salts (e.g., Yb(OAc)3 H20) are used as the metal compound, hexadecasub-stituted bis(phthalocyanines) can be prepared starting from 2,3,9,10,16.17,23,24-octa-substituted metal-free phthalocyanines.201... 

Zinc(II) 2,3,9,10,16,17,23,24-Octa(oct-l-ynyl)phthalocyanine (12) Typical Procedure 129... 

The photophysical properties of magnesium(II) tetra-(i-butyl)phthalocyanine (27) have been studied in solution, in micelles and in liposomes cation radical formation (CBr4 as electron acceptor) has been detected with UV excitation, or by a two-photon excitation using a pulsed laser in the therapeutic window at 670 nm.118 The Mg11 complex of octa(tri-z -propylsilylethy-nyl)tetra[6,7]quinoxalinoporphyrazine (28) has been prepared as a potential PDT sensitizer. The synthesis is shown in Figure 8. Compound (28) has Amax 770 nm (e = 512,000 M-1 cm-1), d>f = 0.46 and d>A = 0.19 (all in THF, under air).119... 

Phthalocyanines (Pc) are attractive materials for their potential functions including the semiconductive behaviours in addition to the thermal and chemical stabilities. In particular, control of orientation of the Pc macrocycles in thin films is expected to provide novel molecular electronic devices. Previously, we have found that copper tetrakis(butoxycarbonyl) Pc is oriented nearly perpendicular to the surface and also the dipping direction in the LB films [46], while octa-alkyl Pc derivatives [H2Pc(R)8, CuPc(R)a R = CnH2n+i. n=7,9,11] take the orientation with Pc macrocycles nearly parallel to the plane of films deposited by the horizontal lifting method to form a non-alternating X-type film [47], as illustrated schematically in... 

Optical Spectra. The optical spectra of the unsymmetrical porphyrazines 65 and 66a-66d exhibit Soret bands between 330 and 375 nm and a split Q band, due to reduced symmetry between 650 and 700 nm. The peripherally metalated species 67d-67h do not have a split Q band, reflecting the extension of the pz n system into the five-membered chelate ring mediated by the bridging dithiolene. Table XVII compares the Q-band region of the optical spectra for 65, 66a-66c, 67b-67d to the symmetrical octa. V-bcnzyl porphyrazines 58, 59, 60a, 60b, 61a, and 61b to the analogous phthalocyanines (4). 

Palladium, platinum, and silver pthalocyaninates - 5,6-Di-substituted isoindoles were condensed in the presence of Pd(acac)2 or PtCl2 to obtain soluble octa-alkoxy-substituted phthalocyaninato palladium(II) and platinum(II) complexes [121]. Tetrakis-(neopentyloxy) phthalocyaninatosilver(II) was obtained in high yield from AgN03 and the respective metal free phthalocyanine in DMF at 75 °C [122],... 

Substitution. Copper phthalocyanine is preferred as starting material. Very little is known about the position of substitution. With the exception of hexadeca-chloro CuPc, all commercial Pc substitution products, as well as the tetrasubsti-tuted derivatives synthesized from monosubstituted phthalic acids, are mixtures of isomers. Despite the 16 hydrogen atoms that can be substituted, only two different monosubstituted Pc s are possible. The number of disubstituted isomers is higher. Mono- to heptasubstituted Pc derivatives have not yet been isolated in isomerically pure form. In addition, only a limited number of isomers are accessible in pure form by synthesis. Only symmetrically substituted phthalic acids, phthalimides, or phthalodinitriles (3,6-di-, 4,5-di-, or 3,4,5,6-tetrasubstituted derivatives) yield pure isomers of octa- or hexadecasubstituted phthalocyanine derivatives. All other substituted phthalic acids give mixtures of isomers. 

This scheme in principle is also conserved at present [318,319,328,332-334]. Thus, the structural isomers of octa-tert-butylphthalocyanines 712 (R — /-Hu) were obtained in 1997 according to a similar scheme (3.154) MX =Ni(OAc)2 f O, Solv — C dIK OII, / — 139 C] [334]. A more detailed description of phthalocyanine formation from various precursors is presented in Sec. 5.1. 

The spectra of octa phenyl phthalocyanines Pb4m, Ni4m, Zn4m, Sn4m, and H24m [59] were studied in toluene. Ni and Zn complexes showed only slight color... 

Mbambisa G, Tau P, Antunes E, Nyokong T (2007) Synthesis and electrochemical properties of purple manganese(III) and red titanium(IV) phthalocyanine complexes octa-substituted at non-peripheral positions with pentyl thio groups. Polyhedron 26(18) 5355-5364... 

Mbambisa G, Nyokong T (2008) Synthesis and electrochemical characterization of a near infrared absorbing oxo vanadium(IV) octa pentyl thio-phthalocyanine. Polyhedron 27(13) 2799-2804... 

Fox J P, Goldberg DP (2003) Octa alkoxy-substituted phosphorus(V) triazatetrabenzcorroles via ring contraction of phthalocyanine precursors. Inorg Chem 42(25) 8181-8191... 

Khene S, Cammidge AN, Cook MJ, Nyokong T (2007) Electrochemical and photophysical characterization of non-peripherally-octa alkyl substituted dichlorotin(IV) phthalocyanine and tetrabenzotriazaporphyrin compounds. J Porphyrins Phthalocyanines 11(10) 761-770... 

Khene S, Geraldo DA, Togo CA, Limson J, Nyokong T (2008) Synthesis, electrochemical characterization of tetra- and octa-substituted dodecyl-mercapto tin phthalocyanines in solution and as self-assembled monolayers. Electrochim Acta 54 183-191... 

Matemadombo F, Maree MD, Ozoemena K I, Westbroek P, Nyokong T (2005) Synthesis, electrochemical and spectroelectrochemical studies of octa phenyl thio-substituted phthalocyanines. J Porphyrins Phthalocyanines 9(7) 484-490... 

Phthalocyanine triple decker complexes have been used by N. Ishikawa et al. in 2002 to detect f-f interactions in a series of homodimetallic PcLnPcLnPc compounds, where Pc denotes a phthalocyanine octa-substituted by butoxy groups. The temperature dependence of the magnetic susceptibility of these triple deckers has been compared to the same data... 

Because of the fascination of synthetic organic chemists and molecular electronics device designers with ever-increasing charge mobilities, attention was focussed mainly on the magnitude of the end-of-pulse conductivity of PR-TRMC transients. Because of this, the after-pulse decay kinetics in discotic materials received only scant attention. The dramatic influence of the nature of the peripheral chains on the lifetime of the PR-TRMC conductivity transients, was in fact demonstrated early-on for octa-alkoxy phthalocyanine derivatives as mentioned previously in this section. This effect is illustrated with more recent data for some hexa-alkyl HBC derivatives in Fig. 7. 

Fig. 8. A semi-logarithmic plot of the /e decay time of the conductivity, T, versus the calculated disk diameter, Z), for hexa-alkyl derivatives of hexa-Z W-hexabenzo-coronene (filled circles) and octa-alkoxy derivatives of phthalocyanine (open squares). The straight line drawn through the points corresponds to an exponential dependence of on D. [Reprinted WPh permission from Ref. 98. Copyright 2005 American Chemical Society.]...

Warman JM, de Haas MP, van der Pol JF, Drenth W. (1989) Charge separation and recombination in pulse-irradiated columnar aggregates of peripherally octa- -alkoxy-substituted phthalocyanines. Chem Phys Lett 164 581-586. 

Synthesis of indium phthalocyanine complexes usually involves the assembly of a ring system in the presence of an indium source. For example, (t-Bu)4PcInCl(chloro(tetra-(tert-butyl)phthalo-cyaninato)indium(III)) or (w-CsHi i)8PcInCl(chloro(octa-( -pentyl)phthalocyaninato)indium(III))... 

Bai and co-workes reported a series of STM studies on various types of calixarenes on graphite and Au(lll) surfaces. Initially, they included p-tert-butylcalix[8]-arene in between domains of octa-alkoxyl-substituted phthalocyanine (PcOCg) monolayers on graphite [152]. The adsorption" of calix[4]arene (lower rim OH) on (111) facets of Au-beads lead to an "edge-on geometry of calixarene dimers with the lower rim pointing towards lower rim (Fig. 10.26a) [153]. 

Nakahara H, Fukuda K, Katahara Kand Nishi H 1989 Langmuir-Blodgett films of octa-alkyl phthalocyanines Thin Solid Films 7 361-6... 

M.S. Ismail, C. Dressier, P. Koeppe, R.G. Senz, B. Roder, H. Weitzel, H.P. Berlien (1997). Pharmacokinetic analysis of octa-alpha-butyloxy-zinc phthalocyanine in mice bearing Lewis lung carcinoma. J. Clin. Laser Med. Surgery, 15, 157-161. 

M.J. Cook, I. Chambrier, S.J. Cracknell, D.A. Mayes, D.A. Russell (1995). Octa-alkyl zinc phthalocyanines potential photosensitizers for use in the photodynamic therapy of cancer. Photochem. Photobiol., 62, 542-545. 

J.M. Warman, M.P. de Haas, J.F. van der Pol, and W. Drenth, Charge Separation and Recombination in Pulse Irradiated Columnar Aggregates of Peripherally Octa-n-alkoxy-Substituted Phthalocyanines, Chem. Phys. Lett., 164 (1989) 581. 

MPcRg Mesogenic octa-substituted phthalocyanine derivatives... 

---