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A novel class of copolyesters containing the metallophthalocyanine ring [M-Pc, M=Fe(III), Co(II)] in the chain was synthesized by polycondensation of (dicarboxyphthalocyaninato) metal [M-Dapc, M=Fe(III), Co(II)] diacid chloride, terephthalic acid chloride and aliphatic diols. The structures of the copolyesters were characterized by infrared, electronic as well as ESR spectra, and viscosity measurement. The thermal stabilities of the polymers were evaluated by dynamic thermogravimetric analyses. The polymers obtained thus were easily soluble in chloroform, dichloromethane, etc. The green or blue colored fiber was formed by melt spinning of the copolyesters containing below 1 mol % M-Pc component. The copolyester containing Co(II)-Pc in the chain obtained from 1,2-ethanediol as a diol component catalysed the autoxidation of 2-mercaptoethanol in the presence of oxygen.

The iron complex of 2(3),9(10),16(17),23(24)-tetra[1,5-di(3-triethoxysilyl-propyl)biuryl]phthalocyanine (1) was prepared by reacting iron tetraaminophthalocyanine with 3-(triethoxysilyl)propyl isocyanate. This complex was directly grafted onto silica to give a supported catalyst without preliminary modification of silica support. This supported catalyst was successfully applied in clean catalytic oxidations by using molecular oxygen in combination with isobutyraldehyde. Cyclooctene, cyclohexene and styrene were oxidized to corresponding epoxides with 90, 78 and 74% yields, respectively. 2,3,6-Trimethylphenol was selectively oxidized to 2,2',3,3',5,5'-hexamethyl-4,4'-biphenol.

Iron–phthalocyanine (FePc) organic photoconductive detector was fabricated using pulsed laser deposition (PLD) technique to work in ultraviolet (UV) and visible regions. The organic semiconductor material (iron phthalocyanine) was deposited on n-type silicon wafer (Si) substrates at different thicknesses (100, 200 and 300) nm. FePc organic photoconductive detector has been improved by two methods: the first is to manufacture the detector on PSi substrates, and the second is by coating the detector with polyamide–nylon polymer to enhance the photoconductivity of the FePc detector. The current–voltage (I–V) characteristics, responsivity, photocurrent gain, response time and the quantum efficiency of the fabricated photoconductive detector were measured. The performance of the fabricated detector was taken under dark and illumination using two types of light sources: UV LED with wavelength (365nm), power of (10W) and Tungsten lamp with wavelength range between (500–800) nm and the optical power of (250W). The photoresponse enhancement was improved by coating the FePc films with 200nm of polyamide nylon polymer. This type of coating, which can be considered as a surface treatment, highly increased the photoresponse of the fabricated FePc UV detector. The results show that the responsivity increased four orders of magnitudes more than the responsivity of the uncoated FePc film. The effects of the coated polymers on the responsivity and the response time of the detector were investigated.

Cobalt (4) and iron (5) phenylthio-substituted phthalocyanines (MPc(SR)₈) have been synthesized and characterized. Cyclic square wave voltammetry in dimethylformamide containing tetrabutylammonium perchlorate revealed five and six redox processes, respectively, for complexes 4 and 5. The complexes are easier to reduce compared to the corresponding unsubstituted MPc and to butylthio substituted derivatives. The first oxidation and reduction occurs on the metal for both complexes. Spectroelectrochemistry (in dimethylformamide containing tetrabutylammonium perchlorate) was employed to assign the cyclic voltammetry peaks, and gave spectra characteristic of Fe^IPc for reduction of 5 and Co^IPc for the reduction of 4. The spectrum of the former is particularly of importance since such species have not received much attention in the literature.

The synthesis of the iron phthalocyanine bearing four fused tetraazamacrocycles starting from N,N',N″,N‴-tetrakis(p-tolylsulfonyl)triethylenetetraamine and 1,2-dibromo-4,5-bis(bromomethyl)benzene is reported. The exchange of protecting tosyl groups by acetyl groups was necessary to obtain iron phthalocyanine. The efficiency of iron phthalocyanine as oxidation catalyst was tested for the practically important oxidation of 2,3,6-trimethylphenol (TMP) at different reaction conditions.

The QCA paradigm is one of the approaches to decrease the size scale of computing devices. When molecules are used as QCA cells, they may be able to perform computing at room temperature. This paper describes a novel molecular QCA cell candidate which is a side-by-side iron phthalocyanine dimer, and an investigation of its optical and redox properties. The new dodeca(pentyloxy) substituted side-by-side iron phthalocyanine dimer, along with the octa(pentyloxy) iron phthalocyanine monomer, are soluble in non-polar organic solvents. These compounds were isolated by gel permeation chromatography (GPC) and high-performance liquid chromatography (HPLC) to final purities of 98% and 99%, respectively. The NMR spectra of both compounds in CDCl₃ are broad due to aggregation, but become well resolved after the addition of the coordinating solvent pyridine-d₅. Addition of pyridine also gives changes in the UV-vis spectra and electrochemical peaks of both monomer and dimer in dichloromethane indicative of axial iron coordination. The electrochemical data indicates the loss of pyridine ligands from the oxidized products of both monomer and dimer. The comproportionation constant of side-by-side phthalocyanine dimer shows that its oxidized and reduced mixed-valence complexes are fairly stable. The dimer is thus a candidate for molecular QCA systems.

The syntheses and spectroscopic properties of new μ-nitrido-[2,3,9,10,16,17,23,24-octa(n-pentoxy)phthalocyaninato]diiron complexes in Fe(IV)Fe(IV) and Fe(+3.5)Fe(+3.5) oxidation states are reported. UV-vis spectra of both dimers demonstrate a strong solvatochromic behavior. UV-vis and ¹H NMR data reveal the presence of two different forms for both oxidation states in apolar and polar solvents. Fe K-edge X-ray absorption near-edge structures (XANES) spectra of two Fe(IV)Fe(IV) forms also show a significant difference: pre-edge feature in toluene is shifted to higher energy compared to that in tetrahydrofuran. The difference of properties between two forms is explained by solvent-dependent mutual orientation of two phthalocyanine rings. A strong sharp Q-band in UV-vis spectrum at 642 nm and small splitting of aromatic protons (0.18 ppm) in ¹H NMR spectrum observed in apolar solvents (toluene, benzene, cyclohexane) imply that the green form is in more symmetric D_4d configuration. In turn, a broad multipreaked Q-band and relatively high splitting of aromatic protons (0.56 ppm) observed in THF and CH₂Cl₂ for the blue form are in agreement with less symmetric D₄ conformation. The Fe(μ-N)Fe structure is relatively rigid showing no free rotation at room temperature in NMR time scale. Tuning of the structure of N-bridged diiron macrocyclic complexes by introduction of substituents and modification of electronic properties of the complexes via conformation changes might be useful for optimization of their catalytic properties as well as for their potential application in sensors.

Pioneering work by Nyokong and others have highlighted the potential benefits for improved electron transfer processes and catalysis of hybrid configurations of metallophthalocyanines with carbon nanotubes. Here we examine the practical application of such hybrid configurations in an Enterobacter cloacae microbial fuel cell. Electrochemical investigations at glassy carbon electrodes (GCEs) showed that FePc and FePc:multiwalled carbon nanotube (MWCNT) hybrid surface modifications display significant oxygen reduction reaction electrocatalytic properties compared to either MWCNT-modified or bare GCE surfaces throughout acidic- to moderately-alkaline pHs. Significant stabilization of the current response at FePc:MWCNT surfaces are notable throughout the pH range, compared to GCE surfaces modified with FePc alone. Corresponding results were obtained for surface modifications of bare carbon paper (BCP) cathodes in a microbial fuel cell where power density increases were observed in the order: Pt > FePc:MWCNT > FePc > MWCNT > BCP. A synergistic combination of simple treatments such as increased ionic strength (300 mM NaCl), temperature (35 °C), and agitation of the anode chamber in this MFC configuration increased the power density to 2.5 times greater than that achieved at platinised cathode configurations under non-optimised conditions, achieving peak power densities of 212 mW.m^-2. The long-term stability of the MFC was assessed over 55 days. Surprisingly, the majority of signal loss over extended MFC operation was attributed, in this study, to fouling of the Nafion® PEM membrane rather than either leaching/fouling of the catalysts from the electrodes or nutrient depletion in the anode over the time periods examined.

Iron(II) 2,3- and 3,4-tetrapyridinoporphyrazine complexes (2,3-PyD and 3,4-PyD) were synthesized and characterized as to their electrochemistry, UV-visible spectroelectrochemistry and catalytic properties towards the reductive dechlorination of 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (p,p′-DDT) in pyridine, dimethyl sulfoxide (DMSO), N,N′-dimethylacetamide (DMA) and N,N′-dimethylformamide (DMF). These properties were compared with those of the unsubstituted iron(II) phthalocyanine ((Pc)Fe). Electrochemistry indicates that there are up to three reductions and one oxidation in the three investigated derivatives. The easiest reduction takes place for 3,4-PyD while the most difficult one occurs for (Pc)Fe in all of the solvents investigated. The first reduction is metal-centered corresponding to the formation of [P(-2)Fe(I)]^- while the second and third reductions are ring-centered leading stepwise to the generation of [P(-3)Fe(I)]^2- · and [P(-4)Fe(I)]^3-, where P = phthalocyanine or tetrapyridinoporphyrazine rings. Aggregation exists in the solutions of all three iron complexes and its extent depends upon the nature and concentration of the iron compounds and the binding property of each solvent. The order of the extent of aggregation for the three iron derivatives is 3,4-PyD > 2,3-PyD > (Pc)Fe. Stronger binding solvents such as pyridine and DMSO do not favor the aggregation. The singly and doubly reduced species of investigated complexes, [P(-2)Fe(I)]^- and [P(-3)Fe(I)]^2- ·, are active in DDT reductive dechlorination, the latter of which has better catalytic performance. As a result, three products, 1,1-bis(4-chlorophenyl)-2,2-dichloroethane (p,p′-DDD), 1,1-bis(4-chlorophenyl)-2,2-dichloroethylene (p,p′-DDE), and 1,1-bis(4-chlorophenyl)-2-chloroethylene (p,p′-DDMU), were obtained after the dechlorination of DDT catalyzed by each iron complex. The increasing order of catalytic performance is 3,4-PyD < 2,3-PyD < (Pc)Fe in pyridine, which is superior to DMSO and DMA for the DDT dechlorination reaction. An overall electrocatalytic mechanism is proposed for DDT reductive degradation based on the electrochemical and UV-visible spectroelectrochemical results.

Bis(tert-butyl isocyanide) iron(II) phthalocyanine complex in the crystalline form was obtained by a direct reaction of β-FePc with tert-butyl isocyanide. This complex crystallizes in the centrosymmetric space group P 2₁/c of the monoclinic system. The Fe(II) cation is equatorially ligated by the four N-isoindole atoms of Pc^2- macrocycle and axially by the C atom of tert-butyl isocyanide on both sides of a planar FePc molecule. Gas-phase conformation of the bis(tert-butyl isocyanide) iron(II) phthalocyanine molecule obtained by molecular orbital calculations shows a similar conformation as in the crystal. In both phases (solid and gas) a similar correlation between the equatorial Fe–N and axial Fe–C bonds are observed. Steric hindrance of the tert-butyl isocyanide molecules ligated to Fe in axial positions of planar FePc leads to the lowering of the π–π interaction between the π-clouds of Pc macrorings and makes the crystals of the bis(tert-butyl isocyanide) iron(II) phthalocyanine complex better soluble in the most organic solvents than the parent FePc compound. EPR and magnetic susceptibility measurements clearly show that ligation of the intermediate spin FePc by tert-butyl isocyanide leads to the change of the ground state from S = 1 (for FePc, e_g³b_2g²a_1g¹) to S = 0 yielding the low-spin complex ((CH₃)₃C-N≡C)₂FePc, e_g⁴b_2g²). The calculated three-dimensional MESP maps are helpful for understanding of the interaction between the FePc and tert-butyl isocyanide molecules forming bis(tert-butyl isocyanide) iron(II) phthalocyanine complex.

The catalytic reaction of crystal violet leucobase oxidation by dioxygen in o-dichlorobenzene into corresponding dye was studied as a model of hydrocarbons C–H group oxidation. Substituted iron phthalocyanines in acidic form HPcFeX were used as the catalysts. It was shown that the oxidation process was accompanied in all cases by autocatalytic destruction of catalyst with induction period depending on concentrations of reactants. The kinetics of dye formation and catalyst degradation, as well as the effect of radical reaction inhibitors were studied. The nature of the process main stages was proposed.

A presence of bulky 2,6-di-iso-propylphenoxy groups in bis-tert-butylisocyano adduct of 2(3),9(10),16(17),23(24)-tetrachloro-3(2),10(9),17(16),24(23)-tetra(2,6-di-iso-propylphenoxy)-phthalocyaninato iron(II) complex allows separation of two individual positional isomers and a mixture of the remaining two isomers using conventional chromatography. X-ray structures of “$D_{2h}$” and “$C_{4h}$” isomers were confimed by X-ray crystallography. Density functional theory (DFT) and time-dependent DFT (TDDFT) calculations of each individual positional isomer allowed insight into their electronic structures and vertical excitation energies, which were correlated with the experimental UV-vis and MCD spectra.

The electronic structures of a set of PcFe(azole)₂ complexes (azole = imidazole, $N$-methylimidazole, pyrazole, isoxazole, thiazole, 1,2,4-triazole, 3-amino-1,2,4,-triazole, and 5-amino-1,2,3,4-tetrazole) were examined by Mössbauer spectroscopy and Density Functional Theory (DFT) calculations. In addition, the geometric distortions in these compounds were elucidated by X-ray crystallography for imidazole, pyrazole, and thiazole-containing compounds. Predicted by DFT calculations, Mössbauer hyperfine parameters for all compounds are in reasonable agreement with experimental results, and the influence of the $\sigma$-donor and $\pi$-acceptor properties of the axial azoles on the electronic structure of the PcFe(azole)₂ complexes is demonstrated by comparison with the reference PcFePy₂ compound.

The elusive PcFe(DABCO)₂ (Pc = phthalocyaninato(2-) ligand; DABCO = 1,4-diazabicyclo[2.2.2]octane) complex was prepared and characterized by UV-Vis, MCD, ¹H NMR, and Mössbauer spectroscopies. The X-ray crystal structure of this complex indicates the longest Fe-N(DABCO) bond distance among all known PcFeL₂ complexes with nitrogen donors as the axial ligands. The target compound is only stable in the presence of large access of the axial ligand and rapidly converts into the (PcFe)₂O $\mu$-oxo dimer even at a modest temperature. The electronic structure of the PcFe(DABCO)₂ complex was elucidated by DFT and TDDFT methods. The DFT calculations predicted a very small singlet-triplet gap in this compound. The femtosecond transient absorption spectroscopy is indicative of extremely fast ($\sim$200 fs) deactivation of the first excited state in PcFe(DABCO)₂ with a lack of formation of the long-lived low-energy triplet state.

Two μ-nitrido phthalocyanine complexes tetra non-peripherally substituted with either electron-withdrawing hexylsulfonyl chains ([FePc(SO₂Hex)₄]₂N) or electron-donating hexyloxy chains ([FePc(OHex)₄]₂N) were prepared and fully characterized by FT-IR, MALDI-MS and UV-vis spectroscopic techniques, to investigate the effect of the substitution pattern on their catalytic properties. Iron atoms in both μ-nitrido complexes are in the Fe^IV–N=Fe^IV oxidation state, hence under their cationic form, as evidenced by the N₃ peak in FT-IR and the fact that they are EPR silent. Both [FePc(SO₂Hex)₄]₂N and [FePc(OHex)₄]₂N complexes were tested as catalysts for the oxidation of different benzyl alcohols by ^tBuOOH and gave the corresponding benzoic acids with excellent selectivity and complete conversion. The electron-withdrawing hexylsulfonyl-substituted μ-nitrido complex [FePc(SO₂Hex)₄]₂N exhibited slightly better catalytic activities and selectivity towards the benzoic acid products than the electron-donating hexyloxy substituted μ-nitrido complex [FePc(OHex)₄]₂N.

A novel heterogeneous Fenton catalyst was prepared by immobilizing iron(II) phthalocyanine (FePc) onto the amidoximated Polyacrylonitrile (PAN) fiber through axial coordination bonds. The obtained catalyst was characterized using XRD and DRS technique, and then used for the degradation of Rhodamine B under visible irradiation. The results indicated that optimum FePc concentration in the dispersion solution is 7.5 g/L, and the amidoxime groups having great coordination ability significantly facilitate anchoring FePc onto the catalyst. FePc immobilization led to the catalyst with decreased crystallinity region and obvious absorption feature in the visible region. In addition, the catalyst was found to be an efficient catalyst for oxidation elimination of RhB by activating H₂O₂ under visible irradiation.