Optical Properties Of Phthalocyanines Research Articles

New phthalocyanine-hybrid glass materials for optoelectronics – Photostability and temperature-dependent optical properties

The organically modified silicate matrix (ORMOSIL) is the most commonly used solution for immobilization of the optically active organic compounds. The materials are characterized by much higher thermal and chemical resistance. The aim of the study was to obtain the hybrid material (in the form of thin films and gels) using the sol-gel method with covalently bound newly synthesized d-block metal phthalocyanine. The hybrid layers were prepared using the dip-coating technique. A series of the sol-gel syntheses based on various types of silicate matrix modifiers (trialkoxysilanes) and their molar ratios were prepared to obtain a photostable and durable material. The optical properties of phthalocyanine (fluorescence) with different concentration in the hybrid glass matrix were studied. Thermoluminescence of the hybrid materials were analyzed. Finally, tests of material stability under the exposure of UV at room temperature and additional under high-energy radiation were carried out with emission measurement in the ultraviolet range and in the temperature range 298–573K.

Effect of the sol-gel condition on photostability and optical properties of alkoxy-substituted zinc phthalocyanine in the hybrid glass matrix

The series of sol-gel synthesis was prepared using different organic and inorganic acids and bases, and with different polarity of solvents, and with various concentration of the luminophore to immobilize zinc phthalocyanine to the matrix. Immobilization was achieved by coordination of zinc phthalocyanine in the axial position with isonicotinamide substituted by alkoxysilane. By using siloxane precursors, matrices of variable hydrophilicity were obtained by the sol-gel method in order to select the optimal environment for phthalocyanine immobilization. The optical properties of phthalocyanine (fluorescence and thermoluminescence) of hybrid materials were investigated. Finally, tests of material photostability under the influence of high-energy radiation were carried out with emission measurement in the ultraviolet and visible range. The aim of this study was to optimize the conditions for obtaining hybrid material containing phthalocyanine for potential application in optoelectronic systems, such as, photodiodes.

Different parameter influences of picosecond pulse trains on optical properties of aminophenoxy substituted phthalocyanines and covalent linkage conjugates to cadmium telluride quantum dots

We carried out the research into different parameter influences of picosecond pulse trains on optical properties of phthalocyanines with benzothiazole substitutes and the covalent attachments to cadmium telluride quantum dots (CdTe QDs). Total number of subpulses, time spacing between subpulses, width of each subpulse and propagation distance of the pulse trains were taken into account thoroughly. The covalent attachments of phthalocyanines to CdTe QDs showed more excellent optical limiting dynamics than phthalocyanines with picosecond pulse trains. Increasing the total number with broader width of subpulses is helpful to improve optical limiting properties, while the time spacing between subpulses has almost no influence.

The optical properties of a novel metal-free phthalocyanine

In the present work, 4-(4′-dodecyloxycarbonyl) phenoxy phthalonitrile was synthesized and then this phthalonitrile derivative was cyclotetramerized in dodecanol resulting a new metal-free phthalocyanine. The optical properties of this phthalocyanine were investigated. Novel metal-free phthalocyanine thin films were deposited on indium tin oxide-coated glass substrates by spinning method. Surface and microstructural properties of the films were characterized by atomic force microscopy and scanning electron microscopy. Both the transmittance and reflectance spectra of the deposited films were recorded using an NKD analyser. The optical band gap energy, the thickness of thin films, refractive index (n) and extinction coefficient (k) were calculated as 2.7 eV, 300 nm, 1.47 and 0.02, respectively.

Preparation and optical properties of phthalocyanine–carbon dot blends

To develop better light-capturing nanostructures, we plan to connect an excellent light-harvesting molecule with rich redox chemistry (phthalocyanine, Pc) to a fascinating luminescent material (carbon dots, CDs). Firstly, CDs with diameters of 3.0–5.5 nm were synthesized using a chemical oxidation, and were then blended with Pc phosphoric acid solution under ultrasonication. UV-vis and infrared spectroscopy were used to determine the interactions between CDs and phthalocyanine. The photoluminescent behavior of the blends depends on the proportion of CDs and phthalocyanine used. This can be attributed to the formation of two different structures; sandwich and plum pudding. The Pc–carbon dot blends exhibit broader UV-vis absorption and better visible light emission. Therefore, these findings pave the way for the development of new antenna systems that can capture solar light.

Electron structures and non-linear optical properties oftertbutyl-nitro-phthalocyanines

The electron structures and the non-linear optical properties of phthalocyanines and asymmetrically substituted phthalocyanines are studied with the AM1 method. The results show that thetertbutyl-nitro-phthalocyanines have much higher second order non-linear optical coefficients.

Theoretical determination of the molecular and solid-state electronic structures of phthalocyanine and largely extended phthalocyanine macrocycles

The molecular and solid-state electronic structures of metal-free phthalocyanine and a series of linearly benzoannulated phthalocyanines have been investigated using the valence effective Hamiltonian (VEH) quantum-chemical method. Geometry optimizations show that, from the molecular structure standpoint, phthalocyanine-based macrocycles are the result of joining four polyacenic units to the C8N8 central ring. The electronic structure calculated for the parent phthalocyanine is compared with that of porphyrin, and the consequences of benzoannulation and meso-tetraaza substitution on the optical properties of phthalocyanines are discussed. The VEH results obtained for extended phthalocyanines are in agreement with available photoemission, cyclic voltammetry and optical absorption data and help to rationalize the evolution of the electronic properties. The first ionization energy is predicted to decrease with linear benzoannulation and asymptotically converges to an extrapolated value of –5.7 eV. Strikingly, a non-convergent behaviour is obtained for the HOMO–LUMO energy gap and very low excitation energies are predicted for extended phthalocyanines. Band-structure calculations have been performed for one-dimensional stacks of the molecules investigated. The variation of the bandwidth with the staggering angle and the intermolecular separation provides a coherent picture of the electrical conductivities observed experimentally in crystals and polymers. Very small bandgaps lower than 0.5 eV are predicted for extended phthalocyanines.

Theoretical characterization of the electronic properties of unsymmetrical phthalocyanine analogues

The electronic structure of unsymmetrical phthalocyanine-based compounds is investigated using the nonempirical valence effective Hamiltonian (VEH) method. The VEH results predict a slight but continuous destabilization of the HOMO level and a monotonous narrowing of the HOMO-LUMO energy gap as the size of the system increases. The theoretical trends are found to agree with optical absorption experimental data and show that the optical properties of phthalocyanine can be monitored by adjusting the size of the π-conjugated macrocycle.

Third-Order Nonlinear Optical Properties of Phthalocyanines

ABSTRACTThis paper discusses the third-order nonlinear optical (NLO) properties of substituted phthalocyanines measured by time-resolved degenerate four-wave mixing at 1064 nm. The study explores optical pumping as a mechanism contributing to a large third-order optical nonlinearity in one member of this interesting class of NLO materials, PbPc(CP)4.