Naphthalocyanine derivatives

Fig. 6. Dyes for WORM media phthalocyanine derivatives. The basic stmcture (12) of naphthalocyanine derivatives. Y = Si, Ge, Sn, Al, Ga, In, or a transition metal = ORj, OSiR R R, polymer. and represent substituents on the tings of the naphthalene system.

Two naphthalocyanine derivatives (Scheme 9) were mixed together to improve read-out stability in a write-once optical storage system.220 The Ge derivative has a bulky structure with large side chains on the central atom, whilst the Cu derivative has a flat structure. The stability of the medium under 1 mW laser irradiation for read-out was improved 100-fold compared to that of a single-component system.220... 

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. ... 

Naphthalocyanine Derivatives. These dyes, which contain a naphthalocyanine skeleton as chromophore, show high absorption in the area around 830 nm, possess low melting points, and small heat conductivity. A disadvantage of the unsubstituated naphthalocyanine is its low solubility in organic solvents which do not attack the polymeric substrate material (generally polycarbonate) substituents improve solubility (see PHTHALOCYANINE compounds). 

At the first stage of the research, several zinc(II) tetrapyrroles (porphyrin, phthalocyanine and naphthalocyanine derivatives) were investigated [27] in the systems containing sacrificed compounds. The results obtained contributed to the development of the theory of redox reactions and energy-transfer processes, they were, however, of little practical significance. 

Schlettwein, D., Wohrle, D., and Armstrong, N.R. (1994) Photochemical investigations on naphthalocyanine derivatives in thin films. J. Phys. Chem., 98, 4760-4766. 

The first crystal structure analysis of a 1,2-naphthalocyanine derivative shows it to be the symmetrical isomer (see Fig. 11) [11],... 

Given stringent requirements for effective sensitizers and the desire to use wavelengths further to the red for therapeutic appHcations, definition of newer sensitizers has been a principal area of research since about 1987. Expanded theoretical and experimental understanding of photophysics has been a key element in identifying new classes of potential sensitizers (93—98). Research has focused on cationic derivatives of Nile Blue (93), metaHo-phthalocyanines (94), naphthalocyanines (95), chlorin-type compounds (96), expanded ring porphyrinoids (97), as well as porphyrins other than hematoporphyrin and its derivatives (98). This work has also been reviewed (10,91). Instmmentation for photodynamic therapy has been reviewed (99). 

Some additional derivatives containing extended 7t-systems in place of the benzene nucleus are naphthalene, anthracene (2,3-Ac) and phenanthrene (9,10-Phc). They also belong to the phthalocyanine family. For the naphthalene system two types of macrocyclcs, the 1,2-naph-thalocyanine (1,2-Nc) and the 2,3-naphthalocyanine (2,3-Nc), are known. 

Naphthalene-2,3-dicarbonitrile itself or mono- or aisubstitutea derivatives can be used in the cyclization reaction to afford naphthalocyanines, e.g. formation of 27 from naphthalene-2,3-dicarbonitrile. 

A series of aluminum(III) naphthalocyanines of potential value as PDT sensitizers has been synthesized. Thus, treatment of 2,3-dicyanonaphthalene with aluminum(III) chloride in refluxing quinoline for 2h gave 48% of ClAl(NPc).353,354 Hydrolysis gave HOAl(NPc), from which tri-alkylsiloxy derivatives could be made.354 Although nonenveloped viruses were resistant, various enveloped viruses were inactivated with aluminum(III) complexes of benzonaphthoporphyrazine sulphonic acids as sensitizers.355... 

The absorption spectra of the silicon(IV) naphthalocyanines follows the pattern already seen with the analogous zinc(II) (Section 9.22.12.1.4) and aluminum(III) (Section 9.22.13.2) derivatives 354 the red band is shifted about 100 nm further to the red, with intensification. Bis(trihex-ylsiloxy)silicon(IV) naphthalocyanine has Amax(PhH) = 776 nm (e = 650,000 M-1 cm-1) and <1>A 0.35 (oxygen-saturated benzene).389 The solution is fluorescent (main emission at 780 nm, Tf 2.85 ns) the triplet energy (ca. 22 k cal mol-1) is a little less than the energy of the first singlet state of dioxygen, and the process (Equation (9)) is reversible (cf. compounds (40) and (41), Section 9.22.10.2). 

The phthalocyanines, naphthalocyanines, and certain of their metal derivatives (Figure 6.17) are infrared fluorophores. 61"64 As a class, they are exceptionally stable compounds, with copper (Cu) phthalocyanine (not a fluorophore) remaining intact above 300 °C in air. First used for textile dyeing in the last century and still widely used, there is a rich chemistry of phthalocyanines. Most derivatives can be made by prolonged heating of a phthalimide or phthalic acid derivative with a metal in powder or salt form at elevated temperature. Several derivatives absorb in the near-IR, and either fluoresce or phosphoresce. The electronic transitions of phthalocyanines are complex and have been extensively studied, at least in part because the symmetry of the molecule makes theoretical calculations of its spectroscopic behavior more tractable. Unsubstituted phthalocyanines and naphthalocyanines are, as a class, very insoluble in solvents other than, for instance, nitrobenzene. Sulfonated phthalocyanines are water soluble and exhibit spectra comparable to the parent derivative. Photolumines-cent phthalocyanines (Pcs) include SiPc, ZnPc, and PC itself. These compounds have been little used for practical infrared fluorometry to date however, Diatron Corpora-... 

The synthesis of [RuL] where H2L = 2,3-naphthalocyanine has been reported. Reactions with suitable bridging ligands lead to oligomers, electrical conductivity data for which have been compared with those of related compounds. The tetrakis(tert-butyl) derivative [Ru ( BU4L)] has been prepared by the thermal decomposition of the [Ru( Bu4L)(Lax)2] (Lax = NH3, 3-Clpy). ... 

Naphthalocyanines (Nc) are of interest for applications involving near-infrared sensitivity. Nikles et al. (1992) used an w-butanol soluble derivative, [RO(CH3)2SiO]2 SiNc, and prepared the generation layers by solution coating. Hayashi et al. (1992) made generation layers from -SiO SiNc as dispersions and as vapor-deposited layers. The best results were obtained with a vapor-deposited generation layer and a transport layer containing bis(p-diethyl-aminophenyl-4,4-diphenyl)-l,3-butadiene. 

Krasnovsky et al. reported the first visible luminescence derived from singlet oxygen produced by protoporphyrin photosensitization in solution. Along with the "monomol" luminescence at 1270 nm, visible luminescence with intensity proportional to the square of the excitation power was observed. Certain compounds such as naphthalocyanines and phthalocyanines give luminescence with extremely high efficiency one of the most effective is tetra-r rr-butyl phthalocyanine (Pc). The spectrum of the... 

Phthalocyanine and naphthalocyanine are guest dye dopants suitable for the near infrared (IR) region. PVK is used as usual, as the hole transport polymer, Alqs, or a sulforamide derivative (Al(qs)3) is used as the host dye. The absorbance spectra of the guest dyes are significantly different from the emission spectra of the host dyes. However, the high molar absorption of the host dye dopants result in such efficiencies of energy transfer that are comparable to quinacridone or rubrene dopants. 

A class of compounds with a comparatively high thermal stability are unsaturated, sometimes aromatic metallomacrocycles, e.g. derivatives of tetraazaporphyrin (TAPHj) of which the most thoroughly investigated are the phthalocyaninatometal (PcM), the tetrabenzoporphyrinatometal (TBPM) complexes, the metal complexes of 1,2- and 2,3-naphthalocyanines (1,2- and 2,3-NcM), and the tetra(2,3-naphtho)porphyrins (2,3-TNPM) (Fig. 1). 

The relatively low energy porphyrins (5.1, 5.2), phthalocyanines (5.3, 5.5), naphthalocyanines, and their metallated derivatives, some of which are phosphorescent at room temperature, but many of which are not phosphorescent at either room temperature or 77 K. Lifetimes are typically 100 ps to a few ms. 

The functionalization of fullerenes with nitrogenated groups such as pyridine and imidazole allows such fullerene derivatives to coordinate with metallated porphyrines, phthalocyanines (Pc), and naphthalocyanines (Nc) (Figure 2.15). The structure of a noncovalently linked ZnTPP to a Cso derivative has been studied with x-ray diffraction, bringing more information regarding conformation and atom distances of the complex. ... 

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