Metal Phthalocyanine Complexes Research Articles

Optical Power Limiters Based on Colorless Di‐, Oligo‐, and Polymetallaynes: Highly Transparent Materials for Eye Protection Devices

AbstractThe synthesis, characterization, and photophysics of a series of solution‐processable and tractable di‐, oligo‐, and polymetallaynes of some group 10–12 transition metals are presented. Most of these materials are colorless with very good optical transparencies in the visible spectral region and exhibit excellent optical power limiting (OPL) for nanosecond laser pulse. Their OPL responses outweigh those of the state‐of‐the‐art reverse saturable absorption dyes such as C60, metalloporphyrins, and metallophthalocyanines that are all associated with very poor optical transparencies. On the basis of the results from photophysical studies and theoretical calculations, both the absorption of triplet and intramolecular charge‐transfer states can contribute to the enhancement of the OPL properties for these materials. Electronic influence of the type, spatial arrangement, and geometry of metal groups on the optical transparency/nonlinearity optimization is evaluated and discussed in detail. The positive contribution of transition metal ions to the OPL of these compounds generally follows the order: Pt > Au > Hg > Pd. The optical‐limiting thresholds for these polymetallaynes can be as low as 0.07 J cm–2 at 92 % linear transmittance and these highly transparent materials manifest very impressive figure of merit σex/σo values (up to 22.48), which are remarkably higher than those of the benchmark C60 and metal phthalocyanine complexes. The present work demonstrates an attractive approach to developing materials offering superior OPL/optical transparency trade‐offs and these metallopolyynes are thus very promising candidates for use in practical OPL devices for the protection of human eyes and other delicate optical sensors.

Synthesis and characterization of novel phthalocyanines with nitrone substituents

A novel series of nitrone-substituted, metal phthalocyanine complexes (the central metal ion being Co , Ni and Cu , respectively) were synthesized for the first time in pure state with quantitative yield. These complexes were characterized using elemental analysis, UV-visible, IR-spectroscopy, magnetic susceptibility, X-ray crystallography, and thermogravimetry. All three complexes had a monoclinic structure with different crystal lattice constants. Horowitz-Metzger, Coats-Redfern and Broido's relations were employed to calculate the kinetic and activation parameters associated with the thermal decomposition of the above complexes. Electrical conductivity studies were undertaken for all three complexes using a two-probe technique in the temperature range 30-200°C. They showed an improvement of 103-105 times the electrical conductivity at room temperature, compared to the corresponding unsubstituted metal phthalocyanines.

Use of various activated forms of elemental nickel and copper for the synthesis of phthalocyanine at low temperature

The synthesis of non-substituted metal phthalocyaninates, starting from phthalonitrile in various non-aqueous solvents, by using chemically activated nickel in two forms (commercial pyrophoric metal and synthesized Rieke nickel) and copper (Rieke copper) at low temperatures (0–50°C), is described. The presence of activated metal causes the rapid formation of phthalocyanine metal complexes (PcM) in low-weight alcohols. A reaction mechanism is proposed which includes the participation of small metallic aggregates as matrices for phthalonitrile cyclization.

Correlation dependences in infrared spectra of metal phthalocyanines

Metal-phthalocyanine (MPc) complexes CoPc, CuPc, CuPcCl15–16, CuPc(4-NO2-5-OPh)4, CuPc(4-CH2-phthalimide)4, CuPc(4-NO2-5-NHPhBr)4, PdPc, MgPc, PbPc, EuOAcPc, SmOAcPc, SmPc2, and YOAcPc were obtained and studied using IR spectroscopy. The correlation between the shift of the absorption band maximum in the range of 1100–1600 cm−1 and the atomic radius of template metal is found. It is shown that the planarity of the macrocycle of peripherally substituted CuPc can be estimated from the characteristics of the IR spectra.

White Metallopolyynes for Optical Limiting/Transparency Trade‐off Optimization

High-transparency optical limiters: A series of solution-processable white metallopolyynes are shown to be excellent optical power limiters (see picture) with optimized optical transparency/nonlinearity trade-off. They exhibit an optical-limiting performance superior to those of the common reverse saturable absorption dyes, such as C60 and metal phthalocyanine complexes. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z601651_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Functional alcohol-soluble double-decker phthalocyanines: synthesis, characterization, electrochemistry and peripheral metal ion binding

In this study we report the preparation, physical characterization and electrochemistry of peripherally functionalized substituted ionophore double-decker lanthanide phthalocyanines, lanthanide bis-[(4,4″,4″,4‴)-tetrakis-(6-hydroxyhexylthio)phthalocyaninates], { M [ Pc ( S - C 6 H 13 OH )4]2} ( M = Pr III, Yb III, and Lu III). All benzenes on the double-decker phthalocyanines are functionalized with hydroxyhexylsulfanyl moieties for potential use as metal ion binding and surface anchors. The double-decker phthalocyanines synthesized from the anhydrous metal salts { Ln ( acac )3} and the corresponding 4-(6-hydroxyhexylthio)-1,2-dicyanobenzene exhibit ion-specific optical changes in the presence of Ag + and Pd 2+. Thio donors of the complexes coordinate to Ag + and Pd 2+ to give 4:1 metal-phthalocyanine complexes. Newly synthesized lanthanide double-decker phthalocyanines are soluble in methanol ( MeOH ), ethanol ( EtOH ), tetrahydrofuran ( THF ), dimethylformamide ( DMF ), dimethylsulfoxide ( DMSO ), chloronapthalene, quinoline and less soluble in i- PrOH and acetonitrile. Electrochemical studies reveal that all lanthanide-base complexes undergo ligand-based redox processes. The smaller HOMO-LUMO gaps of the complexes indicate the existence of strong π-orbital interactions between the rings of the sandwich. The newly synthesized compounds have been characterized by elemental analysis, FTIR, 1H and 13 C NMR, MS (ESI and Maldi-TOF), UV-vis and EPR spectral data.

Synthesis of New Monoporphyrinato Lanthanide Complexes for Potential Use in Optical Limiting

Abstract Three monoporphyrinato lanthanide complexes based on 5,10,15,20-tetrakis(p-diphenylaminophenyl)-21H,23H-porphine (H2TDPAPP) were synthesized, and experimental investigations of the nonlinear optical transmittance characteristics at 532 nm show that they are excellent optical limiters with performance comparable or superior to those of the reverse saturable absorption dyes such as fullerene C60 and metal phthalocyanine complexes.

Metal Complexes of Phthalocyanines in Polymers as Suitable Materials for Optical Limiting

AbstractSummary: Germanium and tin phthalocyanines containing peripheral and axial different substituents were synthesized. Thin multi‐layer films of PMMA and PVC containing monomolecular phthalocyanines were obtained by spin‐coating on glass substrates. The phthalocyanines were characterized by their absorption spectra. Optical limiting properties of the phthalocyanines in solution and in polymer films were investigated.

Large Optical-Limiting Response in Some Solution-Processable Polyplatinaynes

Experimental investigations of the nonlinear optical transmittance characteristics of a series of solution-processable platinum polyyne polymers at 532 nm show that they are excellent optical limiters with performance comparable or superior to those of the state-of-the-art reverse saturable absorption dyes such as fullerene C60 and metal phthalocyanine complexes. On the basis of results from photophysical studies, both the inclusion of a platinum chromophore for increasing the intersystem crossing rate and the formation of an intramolecular charge-transfer state between the electron-withdrawing and electron-donating moieties along the polymer chain are very effective approaches for the enhancement of the optical-limiting properties of these metal polyynes. The structural influence of the aryl linker units on the optical-limiting action has been evaluated in detail. The optical-limiting thresholds for these polymetallaynes range from 0.06 to 0.15 J/cm2 at 82% linear transmittance, and these polymeric materials are very promising candidates for use in practical optical-limiting devices.

Carboxy-substituted Phthalocyanine Metal Complexes

Metal complexes of carboxy-substituted phthalocyanines differing in the number of carboxy groups and their positions and those having carboxy groups together with other substituents were synthesized, and their spectral and some other properties were studied.

Selective synthesis and spectroscopic properties of alkyl-substituted lanthanide(III) mono-, di-, and triphthalocyanines

Methods for the selective synthesis of mono-(RPcLnOAc), di-(RPc2Ln), and triphthalocyanines (RPc3Ln2) of rare-earth metals (Ln = Lu, Er, Eu) from symmetrically substituted 2,3,9,10,16,17,23,24-octaalkylphthalocyanines RPcH2 (R = Et, Bu) were developed. The synthesized complexes were characterized by NMR spectroscopy, mass spectrometry, and electronic absorption spectra. The conditions for 1H NMR spectra recording were optimized. Regularities in changing the spectral properties of the synthesized compounds, depending on the lanthanide nature and the planarity of metal phthalocyanine complexes, were found.

Synthesis, spectral and magnetic susceptibility studies on tetrachloro metal(II)phthalocyanines

The present paper describes a simple method for the synthesis of symmetrically substituted 1,8,15,22-tetrachloro phthalocyanines of copper, cobalt, nickel and zinc. The title complexes are synthesized from the corresponding tetraamino metal phthalocyanines by modified Sandmeyers method and in turn the tetraamino metal phthalocyanines are prepared from 3-nitrophthalic acid. The bluish-green coloured tetrachloro metal phthalocyanine complexes are characterized by elemental, electronic, IR, magnetic susceptibility and X-ray powder diffraction studies to check the purity and the structural integrity. The magnetic susceptibility studies revealed that, the experimental values are higher than that of the spin only value magnetic moment, and the presence of intermolecular co-operative effects.

Preparation, characterization and gas sensing properties of high soluble metal (II) phthalocyanine thin films by spin-coating method

Three novel metal (II) phthalocyanine complexes were synthesized by cyclic tetramerisation reaction of a dicyano benzene component and different metal ions (Pd2+, Co2+, Zn2+). The structure of complexes was confirmed by elemental analysis, mass and IR spectrum. The excellent solubility of the complexes in benzene enabled us to obtain films by a spin-coating method. The films were characterized by IR, electronic spectral and AFM. The gas sensing properties to NO2 of the metal (II) phthalocyanine complex films were studied. In addition, the effects of different metal ions and the gas sensing temperature on the sensing properties were studied.

Optical Limiting of Transition Metal-Phthalocyanine Complexes: A Photochromic Effect involving the Excited State of the Conjugated Molecule

ABSTRACT The nonlinear optical effect of optical limiting which is produced upon high intensity irradiation in the visible spectrum of an optical system containing phthalocyanines is a photochromic event. The photoswitching process at the basis of the optical limiting effect in phthalocyanines is the increase of the optical absorption of the conjugated complex at the wavelength of irradiation following the formation of a highly absorbing excited electronic state of phthalocyanines. The intensity of the optical fields that provoke optical limiting effect in phthalocyanines can be as high as several megawatts per square centimeter. In the present contribution the optical limiting effect generated by phthalocyanines against nanosecond laser pulses in the visible range is reported and analyzed in terms of the structural features of the photoactive molecule. Phthalocyanines with varied structural elements, e.g., different ring-substituents, coordinating central atoms and axial ligands, could be prepared through various synthetic strategies. The analysis of the optical limiting properties of the various phthalocyanines has been carried out under conditions which could allow a meaningful comparison of their actual effectiveness.

Zeeman Effect on Holes in the Q Bands in the Absorption Spectra of Molecules of Phthalocyanine Metal Complexes in Amorphous Polymer Glasses

The effect of magnetic fields up to 140 kOe on holes in inhomogeneously broadened absorption spectra of molecules of phthalocyanine complexes with aluminum and zinc in disordered polymer matrices of polyvinyl butyral was investigated experimentally. The effective values of the projections of the orbital angular momentum on the symmetry axis of the molecules studied are obtained in the S1 excited state, and the parameters characterizing the specific features of the manifestation of the Jahn–Teller dynamic effect and the crystal field effect in the systems under consideration are determined.

Oxidation of ascorbic acid in the presence of phthalocyanine metal complexes. Chemical aspects of catalytic therapy of cancer 2. Catalysis by cobalt octacarboxyphthalocyanine. Reaction products

The products of ascorbic acid oxidation in the presence of cobalt octa-4,5-carboxy-phthalocyanine sodium salt (TPH) were identified. These include the ascorbate radical (A·), hydroxyl radical (OH·), and hydrogen peroxide (H2O2). The kinetics of accumulation and consumption of the reaction products was studied. For the concentration ranges of ascorbic acid $$C_{AH_2 }$$ = 0–2.5 ⋅ 10−3 mol L−1 and the catalyst C TPH = 0–3.5 ⋅ 10−5 mol L−1, the the highest possible concentration of the ascorbate radical is ∼10−7 mol L−1, the concentration of H2O2 is 7 ⋅ 10−4 (30% of the starting concentration of ascorbic acid) and the concentration of the hydroxyl radical is at most 10−6 mol L−1.

Phosgene-Free Synthesis of Carbamates over Zeolite-Based Catalysts

Alkyl and aryl carbamates are synthesized in high yields (≥80%) at mild reaction conditions by reaction of the corresponding amine, CO2 and alkyl halides over either titanosilicate molecular sieves or metal phthalocyanine complexes encapsulated in zeolite-Y. The catalysts could be reused with little or no loss in activity. In contrast to hitherto known catalysts for carbamate synthesis, the zeolite-based catalysts of the present study do not require additional onium salts as co-catalysts.

Synthesis and Properties of Sulfophenyl-Substituted Metal Phthalocyanine Complexes

Sulfonation of 4-phenylphthalic acid gave 4-(p-sulfophenyl)phthalic acid triammonium salt which was used in the synthesis of tetra[4-(p-sulfophenyl)]phthalocyanine copper and cobalt complexes by the urea method. The products were characterized by elemental analyses and 13C NMR, IR, and electronic spectra. Some specific features of the electronic spectra of sulfophenyl-substituted metal phthalocyanines were revealed, depending on the central metal atom, solvent nature, and concentration.

Mesomorphism and Glass Formation of Phthalocyanine Metal Complexes with Bulky Substituents

This paper deals with the synthesis of phthalocyanine complexes, containing four oligo(oxyethylene)-, oxybenzene-, esther of p-oxybenzoic acid or p-oxyazobenzene side chains terminated by a bulky trityl substituent. Their purity was established by column chromatography and by satisfactory elemental analysis. The structures of resultant phthalocyanines were characterized by nuclear magnetic resonance (NMR), fast atom bombardment mass spectroscopy (FAB-MS), ultraviolet-visible (UV-VIS) and infrared (IR) spectroscopy and their phase transitions were studied by polarizing optical microscopy. Some of these complexes exhibit enantiotropic mesomorphic properties and transition into glass state on cooling. The glass appearance is influenced not only by side chains’ structure, but also by the nature of metal.

Sulfonated phthalocyanines: aggregation and singlet oxygen quantum yield in aqueous solutions

The influence of sulfonation degree (n) and central atom nature on singlet oxygen quantum yield (ΦΔ) were studied for a series of sulfonated phthalocyanine metal complexes MPcS n mix . It was found that in DMSO, where the studied dyes exist as monomers, ΦΔ values are independent of number and position of the sulfogroups and are equal to 0.11 ± 0.02, 0.19 ± 0.03, 0.37 ± 0.05, 0.38 ± 0.05 and 0.68 ± 0.10 for the metal-free and Mg , Gd , Al and Zn complexes, correspondingly. However, in aqueous solutions, aggregation of the dyes determines their photochemical activity. Substitution in adjacent to macrocycle 3 and 6 benzene positions interferes with aggregation compared to 4 and 5 positions, presumably due to enhanced steric hindrances in the former case. In the ZnPcS n mix series (n varied from 2 to 4), as an example, the linear relationship between degree of aggregation and ΦΔ indicates that only the monomer fraction of the dye is responsible for singlet oxygen production. For less sulfonated samples the order of activity of the dyes in water is as follows: H 2 PcS n mix < M II PcS n mix < M III PcS n mix which is in contrast to their tendencies to form aggregates.