Synthesis and electropolymerization studies of non-aggregated (4-{3-[3-(dimethylamino,diethylamino)phenoxy]propoxy}phenyl)propanoxy substituted silicon naphthalocyanines

In this study, 3-(4-{3-[3-(dimethylamino)phenoxy]propoxy}phenyl)propan-1-ol, 3-(4-{3-[3-(diethylamino)phenoxy]propoxy}phenyl)propan-1-ol and axially disubstituted silicon naphthalocyanines (SiNc) bearing electropolymerizable bis-[(4-{3-[3-(dimethylamino)phenoxy]propoxy}phenyl)propanoxy] and bis-[(4-{3-[3-(diethylamino)phenoxy]propoxy}phenyl)propanoxy] units were synthesized for the first time. Aggregation behavior of SiNcs was examined in different solvents and concentrations in DMSO. In all solvents and concentrations, SiNcs were non-aggregated. Also, electrochemical studies of SiNcs were investigated by cyclic and square wave voltammetry. While SiNcs gave only naphthalocyanine-based reduction process during the cathodic potential scans, they were electropolymerized on the working electrode during the anodic potential scan because of the oxidative electropolymerization of (4-{3-[3-(dimethylamino)phenoxy]propoxy}phenyl)propanoxy and (4-{3-[3-(diethylamino)phenoxy]propoxy}phenyl)propanoxy groups on the substituents of the complexes.     

Synthesis,characterization and electrochemical properties of new phthalocyanines

The chemical synthesis and characterization with spectroscopic and electrochemical properties of [bis(4-fluorophenyl)-methoxy]-substituted metallo-phthalocyanines were reported for the first time. The new phthalocyanines have been characterized by elemental analysis, UV-Vis, FT-IR, and mass spectroscopies. The aggregation behavior of the phthalocyanine compounds was investigated in different solvents and concentrations. It is found that the fluoro substituents of peripherally Co and Cu complexes are examined and induce a shift to the redox processes toward the negative potentials and formed more reversible processes. Metal-based reduction and oxidation reactions were obtained for the Co(II) complex, whereas Cu(II) complexes exhibited Pc-ring-based electron-transfer reactions. The voltammetric measurements supported the proposed structure of the complexes.     

Synthesis and electrochemical characterization of biphenyl-malonic ester substituted cobalt,copper, and palladium phthalocyanines

Phthalocyanines with four biphenyl-malonic ester groups on the periphery were synthesized by cyclotetramerization of 4-(1,1-dicarbethoxy-2-(4-biphenyl)-ethyl)-phthalonitrile. The new compounds were characterized by elemental analyses, FT-IR, ¹H NMR, ¹³C NMR, UV–Vis, and MASS spectral data. Electrochemical behaviors of novel Co(II), Cu(II), and Pd(II) phthalocyanines were investigated by cyclic voltammetry, potential differential pulse voltammetry, and applied potential chronocoulometry techniques. While Cu(II) and Pd(II) phthalocyanines give up to four common phthalocyanine ring reductions, Co(II) phthalocyanine gave two ligand-centered and two metal-centered redox processes. HOMO–LUMO gap of the complexes are comparable with the reported MPc papers.     

Synthesis,characterization, antioxidant and antibacterial properties of non-peripherally and peripherally tetra-substituted phthalocyanines

abstract

This study focuses on the synthesis, spectral, antioxidant and antibacterial properties of the metal-free, zinc and cobalt phthalocyanines (3–8) bearing 4-methoxy-phenoxy substituents on the nonperipheral [(1(4), 8(11), 15(18), 22(25)] or peripheral [2(3), 9(10), 16(17), 23(24)] positions. The new synthesized complexes 7 and 8 have been characterized by elemental analysis, FT-IR, MALDI-MS, and UV-vis spectral data. The antioxidant activities of all tested compounds were investigated by applying three different antioxidant methods such as radical scavenging ability of 1,1-diphenyl-2-picrylhydrazyl, chelating ability to ferrous ions and reducing power activity methods. In addition, the antibacterial activities of the compounds were screened by disc diffusion method against one gram-negative and four gram-positive bacteria. The tested phthalocyanine compounds showed very good antioxidant activity and promising antibacterial properties.     

Highly photostable silicon(IV) phthalocyanines containing adamantane moieties: synthesis, structure, and properties

Two new axially disubstituted silicon(IV) phthalocyanines 1 and 2 have been synthesized by treating silicon phthalocyanine dichloride with 1-adamantanemethanol or 1-adamamtaneethanol, respectively. The crystal structure of compound 2 has been characterized by X-ray diffraction analysis. Both compounds are efficient singlet-oxygen generator with a quantum yield of 0.40-0.43. With two rigid bulky adamantane moieties at the axial positions, these phthalocyanines not only are essentially non-aggregated in common solvents, but also exhibit a high photostability. They are about 100 times more stable than zinc phthalocyanine under the same irradiation conditions. With the goal of enhancing the biocompatibilities, interactions and conjugations of these two compounds with bovine serum albumin have also been investigated.     

Co(II) and Fe(II) phthalocyanines: synthesis,investigation of their catalytic activity towards phenolic compounds and electrochemical behaviour

4‐[(1‐Benzylpiperidin‐4‐yl)oxy]‐substituted cobalt(II) and iron(II) phthalocyanine complexes were synthesized and their catalytic activity towards various phenolic compounds was investigated. Converting from environmentally harmful phenolic compounds into less harmful oxidation products using phthalocyanines makes this study attractive. This catalysis is feasible and time‐saving in terms of procedure and the best oxidation conditions determined. Electrochemical studies were also carried out using cyclic voltammetry and square wave voltammetry techniques. Voltammetric analyses of the synthesized phthalocyanine complexes supported their proposed structures. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis,characterization and electrochemical properties of novel metal free and zinc(II) phthalocyanines of ball and clamshell types

The phthalodinitrile derivative 1 was prepared by the reaction of 4-nitrophthalonitrile and 1,3-dimethoxy-4-tert-butylcalix[4]arene in dry dimethylsulfoxide as the solvent, in the presence of the base K₂CO₃, by nucleophilic substitution of an activated nitro group in an aromatic ring. The tetramerization of compound 1 gave a binuclear zinc(II) phthalocyanine and a metal-free phthalocyanine of the ball type, 2 and 3, respectively. Its condensation with 4,5-bis(hexylthio)phthalonitrile results in a binuclear phthalocyanine of the clamshell type, 4. The newly synthesized compounds were characterized by elemental analysis, UV–Vis, IR, MS and ¹H NMR spectra. The electronic spectra exhibit an intense π → π^∗ transition with characteristic Q and B bands of the phthalocyanine core. The electrochemical properties of 2–4 were examined by cyclic voltammetry in non-aqueous media. The voltammetric results showed that while there is no considerable interaction between the two phthalocyanine rings in 4, the splitting of a molecular orbital occurs as a result of the strong interaction between the phthalocyanine rings in 2 and 3.     

Electrochemical characterization of Co(II) and Pd(II) phthalocyanines carrying diethoxymalonyl and carboxymethyl substituents

In this study, electrochemical behaviors of Co(II) and Pd(II) phthalocyanines carrying tetrakisdiethoxymalonyl and Pd(II) phthalocyanine carrying tetrakiscarboxymethyl substituents at the peripheral positions are investigated by cyclic voltammetry and applied potential chronocoulometry techniques. Cyclic voltammetric studies show that, while Pd(II) phthalocyanines carrying diethoxymalonyl and carboxymethyl substituents give up to three common phthalocyanine ring reductions, Co(II) phthalocyanine carrying diethoxymalonyl substituents gives a metal-centered oxidation and a metal-centered reduction and three ligand-centered reduction and a ligand-centered oxidation processes. First reduction processes of both the PdPc complexes have shoulders. This different voltammetric behaviors of Pd(II) phthalocyanines carrying carboxymethyl and diethoxymalonyl substituents results from interaction of this distinctive substituents with the phthalocyanine ring π electron system and interaction with the different solvent systems. Observation of the splitting of the first reduction process of Pd(II) phthalocyanines carrying diethoxymalonyl and carboxymethyl substituents suggests the aggregation of the complex. Very small diffusion coefficient of the complexes with respect to Co(II) phthalocyanine also confirms the existence of the aggregation of the complex during the electrochemical studies. Effects of the substituents and the solvent media are clearly observed from the differences of the voltammograms of Pd(II) phthalocyanines carrying diethoxymalonyl and carboxymethyl substituents in DMSO and THF solvent media, respectively. Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 1, pp. 36–43. The text was submitted by the authors in English.     

New amphiphilic silicon(IV) phthalocyanines as efficient photosensitizers for photodynamic therapy: synthesis, photophysical properties, and in vitro photodynamic activities

A novel series of silicon(IV) phthalocyanines substituted axially with one or two 1,3-bis(dimethylamino)-2-propoxy group(s) have been prepared by ligand substitution and alkoxy exchange reactions. Two dicationic and tetracationic phthalocyanines have also been prepared by methylation of two of these compounds. The nonionic phthalocyanines are essentially nonaggregated in common organic solvents and show a weak fluorescence emission, while the methylated derivatives are also nonaggregated, even in aqueous media, and exhibit a strong fluorescence emission. These new phthalocyanines, in particular the unsymmetrical and amphiphilic analogues, are highly potent against HepG2 human hepatocarcinoma cells and J774 mouse macrophage cells with IC50 values down to 0.02 microM. The photodynamic activities are related to the cellular uptake and the efficiency to generate singlet oxygen. A higher positive charge at the phthalocyanine hinders the uptake, reflected by the lower intracellular fluorescence intensity. Fluorescence microscopic studies have also revealed that the unsymmetrical phthalocyanine SiPc[C3H5(NMe2)2O](OMe) (4) has a high and selective affinity to the mitochondria of HepG2 cells.     

Synthesis, spectroscopic and electrochemical properties of manganese, nickel and iron octakis-(2-diethylaminoethanethiol)-phthalocyanine

The syntheses, spectroscopic and electrochemical properties of manganese (3), nickel (4) and iron (5) phthalocyanine complexes, octa-substituted at the peripheral positions with diethlyaminoethanethiol substituent, are reported. The electrochemistry of these complexes and the corresponding cobalt complex (6) are reported. Complex 3 showed two reversible reduction couples attributed to the Mn^IIIPc⁻²/Mn^IIPc⁻² (E_½ = −0.12 V versus Ag|AgCl) and Mn^IIPc⁻²/Mn^IIPc⁻³ (E_½ = −0.82 V versus Ag|AgCl) species. Two ring-based reduction couples were also observed for complex 4. Two reduction couples, assigned to the Fe^IIPc⁻²/Fe^IPc⁻² (E_½ = −0.35 V versus Ag|AgCl) and Fe^IPc⁻²/Fe^IPc⁻³ (E_½ = −0.96 V versus Ag|AgCl) species, and an oxidation couple, attributed to Fe^IIIPc⁻²/Fe^IIPc⁻² (E_½ = 0.26 V versus Ag|AgCl) species, were observed. For complex 6, two reductions and one oxidation were also observed with the potential range of 1.2 to −1.8 V versus Ag|AgCl Spectroelectrochemical studies were used to confirm some of the assigned processes.     

Synthesis, characterization, spectroscopic and electrochemical properties of phthalocyanines substituted with four 3-ferrocenyl-7-oxycoumarin moieties

The synthesis, spectroscopic and electrochemical properties of the tetra-(3-ferrocenyl-7-oxycoumarin)-substituted zinc (II) and cobalt (II) phthalocyanines (3 and 4) are reported for the first time. The synthesis of novel 3-ferrocenyl-7-hydroxycoumarin (1) was performed according to Perkin reaction, and the ligand, 7-(3,4-dicyanophenoxy)-3-ferrocenylcoumarin (2), was synthesized by the reaction of 3-ferrocenyl-7-hydroxycoumarin with 4-nitrophthalonitrile in the presence of K₂CO₃ as the base in dry dimethylformamide. The preparation of the corresponding zinc (II) and cobalt (II) metallo phthalocyanines (3 and 4) substituted with 3-ferrocenyl-7-oxycoumarin moieties at β-positions of the phthalocyanine ring was achieved by the cyclotetramerization of the coumarin ligand (2) with relevant metal(II) acetates in dry 2-dimethylaminoethanol. The new compounds have been characterized by elemental analyses, FT-IR, ¹H NMR, Mass and electronic spectroscopy. The fluorescence property of the zinc metallo phthalocyanine (3) is strongly affected by the presence of ferrocenyl moiety. The ferrocenyl moieties were very efficient in quenching the excited state of 3, which show very poor fluorescent intensity. The electrochemical properties of the complexes were also investigated by cyclic and differential pulse voltammetry techniques in non-aqueous medium. It was found that the redox-active ferrocene substituents are reduced concurrently at one potential.     

Synthesis and electrochemical properties of amphiphilic crown ether langmuir-blodgett films [1]

4-Octadecanoylbenzo-15-crown-5 (I) and four 4-alkylbenzo-15-crown-5 ligands [4-XB15C5 where X =n-C₁₈H₃₇ (II), X =n-C₁₆H₃₃ (III), X =n-C₁₄H₂₉ (IV), and X =n-C₁₂H₂₅ (V)] have been synthesized. The -A isotherms ofI andII were systematically investigated. The results indicated that the Langmuir-Blodgett (LB) films have high stability where the ratios ofI/SA andII/SA were 1 : 1 and 1 : 10, respectively, with a 6.2 pH subphase. The LB films of the crown ethers were deposited onto graphite electrodes pretreated by immersing them in liquid wax. The peak current reached the maximum value when the electrode surface was modified with five layers of the amphiphilic crown ethers.     

Synthesis,characterization, conduction,and dielectric properties of tetra tert-butylsulfanyl substituted phthalocyanines

The tert-butylsulfanylphthalonitrile has been prepared with optimized synthetic procedure. Metal free (H₂Pc) and metallo phthalocyanines (Pcs) (ZnPc, CoPc, CuPc, PbPc) have been synthesized by cyclotetramerization of tert-butylsulfanylphthalonitrile in the presence of DBU and metal salts. Thus, tert-butylsulfanyl groups enhance the solubility, shift the Q band absorption to the red visible region, and inhibit efficient cofacial interaction of the Pcs (2–6) as evaluated by UV–vis spectra. The electrical conduction and dielectric properties of the synthesized Pc thin films sandwiched between indium tin oxide and aluminum electrodes (ITO–Pc–Al) were investigated from 300 to 500 K. At low bias voltage the conduction is ohmic while at high bias voltage the conduction becomes space charge limited with an exponential distribution of traps. The measured ac conductivity data are discussed in terms of classical models based on pair approximation. It was found that the ac conductivity obeys the power law given by σ_ac = σ₀ω^s, in which the frequency exponent s decreases with temperature. The real and imaginary parts of the impedance are found to be dependent on both frequency and temperature.     

Synthesis and characterization of new mesomorphic octakis(alkylthio)-substituted lead phthalocyanines and their films

The syntheses of new octakis (alkylthio)-substituted phthalocyanines of Pb(II) (1a and 2a) are described. These compounds are very soluble in most common organic solvents. They have been fully characterized using elemental analysis, NMR, infrared and UV–Vis spectroscopy. The mesogenic properties of these new materials were studied by differential scanning calorimetry and optical microscopy. These phthalocyanine derivatives are liquid at room temperature and form columnar-hexagonal (Col_h) mesophases below −10 °C. It has been indicated that the addition of methylene bridges to the phthalocyanine (Pc) core increases the clearing point temperatures. Also, the coordination of Pb²⁺ with the phthalocyanine core decreases the clearing point temperatures and the liquid crystal phase transition temperatures. Thin films of octakis(alkylthio)-substituted Pb(II) phthalocyanines 1a and 2a were prepared by the method of spin-coating. To obtain films with an ordered structure the film of 1a was slowly cooled from room temperature down to −10 °C. Sandwich structures of the form Au/PbPc(1a)/Au were prepared for the investigation of their electrical properties. It was shown that a slowly cooled Au/PbPc(1a)/Au structure demonstrates repeatable and stable electrical switching behaviour for applied bias voltages between −1 V and +1 V.     

Synthesis,characterization, and optical studies of pentoxy-substituted tetrakis(pentafluorobenzyloxy)phthalocyanines

Abstract

The synthesis and characterization of peripherally 2′,3′,5′,6′-tetrafluoro-4′-pentoxy-benzyloxy-substituted metal-free and metallo (Zn(II) and Co(II)) phthalocyanines are described in this study. Aggregation properties of these phthalocyanines were studied in the concentration range of 1 × 10^?5?1 × 10^?6 M in tetrahydrofuran. Thin films of phthalocyanines were prepared by spin-coating technique. The spectrophotometric measurements of transmittance spectra were carried out in the wavelength range of 200–1000 nm. Optical band gaps of phthalocyanine thin films were also calculated. Surface morphologies and thickness of the films were examined by Scanning Electron Microscopy. Results show that film thickness can be changed significantly depending on the type of metal in the phthalocyanine.     

Synthesis,characterization, and electrochemical studies of Co(II,III) dithiocarbamate complexes

Cobalt(II) complexes of N-methyl phenyl, 1-phenylpiperazyl, and morpholinyl dithiocarbamates have been synthesized and characterized by UV–Visible, FTIR, ¹H-, ¹³C-NMR, and mass spectrometry. The spectroscopic data indicated that two ligands coordinated in bidentate chelating to the metal ion to form four-coordinate cobalt(II) complexes (1–3), which was confirmed by mass analysis (TOF MS ES⁺) of the complexes with m/z [M]⁺ = 450.98, 382.94, and 382.94 for 1, 2, and 3, respectively. Single crystal analysis of 2A and 3A show centrosymmetric mononuclear cobalt(III) bonded to three dithiocarbamate ligands forming a distorted octahedral geometry, indicating the cobalt(II) undergoes aerial oxidation to cobalt(III) during recrystallization. In addition, 2A crystallized with one solvated molecule of toluene. The redox behaviors of the complexes were studied by cyclic and square wave voltammetry in dichloromethane; the result revealed a metal centered redox process consisting of a one-electron quasi-reversible process assigned to Co(III)/Co(IV) oxidation and a corresponding Co(IV)/Co(III) reduction. Randles–Sevcik plots (anodic peak current versus the square root of the scan rate (I_p,a versus ν^1/2)) for the redox couples revealed diffusion-controlled behavior.     

Synthesis and electrochemical behavior of linear oligo(ferrocenylsilane) and hyperbranched poly(ferrocenylsilane)

Linear oligo(ferrocenylsilane) and hyperbranched poly(ferrocenylsilane) (LOFS and HPFS) were synthesized by polycondensation of 1,1′‐dilithioferrocene (FcLi₂) with dimethyldichlorosilane (Me₂SiCl₂) and FcLi₂ with methyltrichlorosilane (MeSiCl₃) in THF under different conditions, respectively. The electrochemical behaviors of LOFS and HPFS in different solvents, such as THF, CH₂Cl₂, and CHCl₃, were investigated systematically by means of cyclic voltammetry (CV). The influences of the solvent, structure of polymer, and scan rate on electrochemical behavior of poly(ferrocenylsilane) solutions are discussed. It is found that ΔE_1/2 decreases with the fall of solvent polarity apart from the solvent donor effect and increases with the increase of the acceptor number (AN) of the solvent. More interestingly, the structure of polymer imposes greatly on the interaction between ferrocene units. According to the result, the mechanism of stepwise oxidation of the ferrocene units was proposed, that is, the different conformations of polymers, attaching to electrode surface, before and after oxidized resulted in the stepwise oxidation of ferrocene groups along a chain. Kinetic parameters from CVs indicate that the electrode processes are controlled by both the electrode reaction and mass diffusion and the electrochemical irreversibility of poly(ferrocenylsilane) solutions may be ascribed to the lower electron exchange efficiency on the electrode surface. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2880–2889, 2007     

Copper-cysteamine nanoparticles encapsulating fluorocoumarin silicon(IV) phthalocyanines: synthesis,characterization, and photophysical properties

Abstract

Three nanohybrid materials (FCSiPc@PEG-Cu-Cy) using poly (ethylene glycol) copper-cysteamine (PEG-Cu-Cy) nanoparticles as a carrier to load three fluorocoumarin silicon(IV) phthalocyanines (FCSiPcs) were prepared. The morphologies of these nanohybrids were characterized by transmission electron microscopy (TEM). The interactions between PEG-Cu-Cy nanoparticles and three FCSiPcs were studied by UV/Vis and fluorescence spectroscopic methods. The photophysical and photochemical properties of these FCSiPcs were influenced by PEG-Cu-Cy nanoparticles and exhibited substituents dependent of phthalocyanines in nanohybrids. The fluorescence resonance energy transfer (FRET) occurred from FCSiPcs (donors) to PEG-Cu-Cy nanoparticles (acceptors). These nanohybrids may be potential photosensitizers for photodynamic therapy.     

Synthesis,characterization, and thermal properties of silicon(IV) compounds containing amidinate ligands as CVD precursors

The title compounds of the type R-C(=NⁱPr) (-N′ ⁱPrSiMe₃) (with R = Me or ⁿBu) as potential chemical vapor deposition (CVD) precursors have been synthesized and characterized by ¹H, ¹³C, and ²⁹Si NMR spectroscopy as well as by EI-MS and elemental analysis where necessary. Thermal properties, including stability, volatility, transport behavior, and vapor pressure, were evaluated by thermogravimetric analysis to confirm that they are suitable for the CVD procedure. Deposition was accomplished in a hot wall CVD reactor system, which qualitatively verified the ability of these compounds as CVD precursors.