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This work reports on the synthesis and characterization of a new complex of Eu(3+) with the 3-hydroxypicolinamide ligand (Hhpa). Here we present an approach for obtaining bis[2-carbamoyl(κO)pyridin-3-olato(κO')] lanthanide complexes, which were characterized through elemental analysis, thermal analysis, infrared and photoluminescence spectroscopies (emission, excitation, luminescence lifetimes, quantum efficiencies, Judd-Ofelt parameters and quantum yields). Although hpa can act as a bidentate ligand in different conformations, the results attest for the occurrence of a unique coordination site of low symmetry for the Eu(3+) ions, in which two anionic hpa ligands coordinate the cations through an O/O chelating system. The phosphorescence of the synthesized gadolinium complex provides the energy of the triplet state, which is determined to be at 20,830 cm(-1) over the ground state. This makes the Hhpa ligand very adequate for sensitizing the Eu(3+) luminescence, which leads to a very efficient antenna effect and opens a wide range of applications for the complex in light emitting organic-inorganic devices.

This work presents the synthesis and characterization of a series of substituted pyridylpentafluroporphyrins, including the separation of the cis- and trans-isomers, the latter being characterized by X-ray crystallography. The spectroscopic and electrochemical properties of the series are dependent on the number of electron withdrawing pentafluorophenyl substituent, but they do not depend on the symmetry of the molecule. Ongoing from the monosubstituted to the more substituted pentafluorophenyl porphyrin H2(MPyTFPP) derivative, the Soret bands are slightly red-shifted and their quantum fluorescence yields range from 0.035 to 0.046, consistent with the value of 0.045 for the fully substituted 5,10,15,20-tetrapentafluorophenylporphyrin (dichloromethane solutions). The redox potentials of the reductive processes of monoanion and dianion formation are also sensitive to the number of pentafluoro substituents, shifting 180 mV to more positive values for the P0/P-1process ongoing from the monopentafluoro to the tris-pentafluorophenyl substituted derivative.

Syntheses of two water-soluble phthalocyanines (Pc) containing 5-aminolevulinic acid (ALA) linked to the core structure are described. These compounds were prepared by using original functionalizations, and they present remarkable structural and photophysical features, indicating that they could be applied to photodynamic therapy (PDT).

Ultrafine systems of zinc oxide and cerium oxide for use as ultraviolet filter were synthesized by a non-alkoxide sol–gel process at different temperatures, to obtain solid materials (40 and 70 °C), that were characterized by X-ray diffraction, scanning electron microscopy, UV–vis reflectance. Their catalytic and photocatalytic activities were also evaluated. ZnO:CeO 2 systems present higher UV absorption and transparency in the visible region. The photocatalytic activity of ZnO:CeO 2 systems for the oxidation of organic materials is much smaller than that of titania, ceria and zinc oxide, suggesting that ZnO:CeO 2 systems are promising candidates for use as optical materials in UV-filters.

A simple synthesis of new amphiphilic chlorin derivatives from protoporphyrin-IX dimethyl ester is reported. The preparation of such compounds is based in a straightforward methodology, which involves the Diels–Alder reaction of protoporphyrin-IX dimethyl ester with maleic anhydride followed by addition of nucleophilic species to the initially formed cycloadducts, a transformation, which is highly regioselective. Preliminary photophysical studies with the new compounds show that they meet adequate features for PDT applications.

This work reports on the synthesis and characterization of the ligand 3-hexadecylpentane-2,4-dione (Hhdacac) and its Eu 3+ complexes Eu(hdacac)6 � 2H2O, Eu(hdacac)6 � phen and Eu(hdacac)6 � tta, where phen and tta denote 1,10-phenanthroline and thenoyltrifluoroacetone, respectively. These new compounds present long carbon chains and their expected miscibility into non-polar ambients is confirmed by the emission spectra of Eu(hdacac)6 � tta in hexane. Moreover, the amphiphilic properties of Eu(hdacac)6 complexes allow the obtainment of thin luminescent films by the Langmuir–Blodgett technique. In both cases (solids and films), the typical antenna effect of b-diketonates is observed. The alluring characteristics of these compounds raise great interest in many fields of Materials Science, like photo- and electro-luminescent materials (mainly thin ‘‘organic’’ films), metal catalysts or probes in non-polar solutions, and Langmuir–Blodgett films of several compositions. For the characterization of these products, nuclear magnetic resonance spectroscopy ( 1 H NMR), thermogravimetric analysis, elementary analyses (C, H), scanning electron microscopy (energy dispersive X-ray

A route for coordination of Eu3+ by dibenzoylmethane (DBM) covalently bonded inside hexagonal mesoporous silica was established here to produce the highly luminescent nanomaterial SiDBM−Eu(DBM)2. Thermogravimetry, luminescence, X-ray diffraction, N2 adsorption, FTIR, FTRaman, 29Si NMR, and 13C NMR in solid-state techniques were used to characterize SiDBM−Eu(DBM)2. The 29Si NMR spectrum proved that the DBM was covalently bonded to a silica framework. Thermogravimetric and titration data showed the 6.4 × 10-2 mmol of Eu3+ per gram of silica, and each Eu3+ is coordinated by three DBMs in SiDBM−Eu(DBM)2. SEM images confirmed that this material is formed by nanoaggregates with 200 nm diameter. N2 adsorption isotherms showed the SiDBM−Eu(DBM)2 complex with 800 m2 g-1 and 6.4 nm of porous diameter, characterizing mesoporosity of this nanomaterial. SiDBM−Eu(DBM)2 showed an efficient DBM to Eu3+ intramolecular energy process, namely, antenna effect, which favored a highly luminescent behavior in this modified hexa...

This paper reports on the synthesis, characterization and photophysical properties of the Tb3+ organophosphonates, TbH(O3PR)2, methylphosphonate (R = CH3), ethylphosphonate (R = C2H5), propylphosphonate (R = C3H7), and phenylphosphonate (R = C6H5). The layered Tb3+ organophosphonates were characterized by X-ray diffraction, IR spectroscopy, TG and elemental analysis. The interlayer distances of the Tb3+ organophosphonates evaluated by the X-ray diffractogram were 9.50 Angstrom for TbH(O3PCH3)2, 12.18 Angstrom for TbH(O3PC2H5)2, 14.84 Angstrom for TbH(O3PC3H7)2 and 15.20 Angstrom for TbH(O3PC6H5)2. The Tb3+ luminescence data revealed highly green emissive materials when they were excited at 368 nm, where the characteristic 5D4 --7FJ (J=6, 5, 4 and 3) transitions of Tb3+ were observed at 488, 543, 585 and 619 nm, respectively. The lifetime of the Tb(3+ 5)D4 --7F5 transition (lambda(exc)=368 nm and lambda(em)=543 nm) for the Tb3+ organophosphonates was evaluated from the decay curves, which values were of 2.88, 2.22, 2.14 and 2.59 ms, respectively for TbH(O3PCH3)2, TbH(O3PC2H5)2, TbH(O3PC3H7)2 and TbH(O3PC6H5)2. TG analysis revealed that these materials are thermally highly stable, with no water molecule in their composition, which makes them potential luminophores.

The sol-gel process is a methodology used to obtain organic-inorganic hybrid solids, which open new possibilities in the field of material science. The sol-gel technique offers a low temperature attractive approach for introducing organic molecules into amorphous materials. In order to introduce tetrakis (2-hydroxy-5-nitrophenyl)porphyrin covalently bounded to a silicate matrix, the inorganic precursor 3-isocyanatopropyltriethoxysilane was added (molar ratio 2:1) to the porphyrin solution in anhydrous dimethylformamide and triethylamine. The isolated porphyrin and the hybrid porphyrinosilica have excitation maximum centred at 400 nm and 424 nm, respectively and the emission spectra for both materials has bands centred at 650 nm and 713 nm. The formation of hybrid matrix was investigated by FTIR.

Silica gel was functionalised with chloropropyl groups through the sol-gel process and then a b-diketone was incorporated into the support. Afterwards, Eu3+ ion and its chelates of 1,10-phenantroline (phen) and 2,2'-bipyridine (bpy), red phosphors, were supported on such silica. Luminescence studies of Eu3+ bound to this new material have shown that there is an increase in the intensity of the emission when the ion is isolated by ligands in the silica matrix. The energy transfer from the ligands phen and bpy to Eu3+ ion was observed in the excitation spectra, which present new bands ascribed to the ligands and/or complex. The Eu3+-functionalised silica was characterised by TGA and FTIR. TGA analysis showed that there is a large loss of mass around 300 °C, which is ascribed to the organic part of the material. The FTIR spectra presented the vibration modes for Si-C and -CH2-. The luminescent properties of the ions surrounding the Eu3+ ion were studied. The decay curve displayed a bi-exponential behaviour, indicating that there is more than one site of Eu3+ on the surface of the silica.

This work describes a simple and economical experiment for the extraction and purification of chlorophyll a from Spirulina maxima. Extraction and purification of natural compounds can be considered one of the most illustrative experiments that can be performed in Organic Chemistry courses. Particularly, the chromatography of dyes and pigments allows students to have a better comprehension of the chromatography separations. These compounds represent an important class of organic pigments applied in pharmaceutical, cosmetic, detergent compositions, and various other fields and can be extracted from plants and algae. To extract, separate and purify chlorophyll a from associated pigments such as xanthophylls, carotenes, and pheophytins, very costly processes are reported. The present approach is perfectly adequate for use in Chemistry experiments for undergraduate students.

Porphyrin was incorporated in a silicate network, via a covalent bond, by grafting a functional group with 3-aminopropyltriethoxysilane, using a sol–gel process. We have carried out the synthesis and measured the absorption spectra, nuclear magnetic resonance spectra, infrared (IR) spectra, luminescence spectra and lifetime of these hybrid silicates, porphyrinosilicas. These samples contained the following free-base porphyrins: meso-tetrakis- p -chlorobenzoylporphyrin, meso-tetrakis-2,6-dichloro-3-chlorosulfonylphenylporphyrin. The obtained porphyrinosilicas have similar absorption and luminescence spectra to the free base porphyrins in solution. IR spectra confirm the formation of monomeric species. Lifetime measurement for porphyrinosilica reveals that 32% ± 2% of porphyrin is covalently bonded to the silica network.

In this work, we report the synthesis and properties of TiO 2 and of an organic–inorganic hybrid of TiO 2 where the inorganic network was obtained by hydrolysis (sol–gel process) of the titanium tetraisopropoxide precursor. Both materials were prepared and dried in air. The organic oligomer was synthesized by esterification between ethylene glycol and dipicolinic acid, using Eu 3+ as probe. These materials were studied by luminescence and infrared spectroscopies, thermogravimetric analysis and X-ray diffraction. The results obtained for the hybrid material show the formation of two crystalline polymers. Eu 3+ has been used as structural probe due to its photophysical properties and also as emission center for luminescent materials and the luminescence data indicate that Eu 3+ occupies one kind of site that is isolated from water molecules and OH groups.

This work considers some aspects of the chemistry involved in the preparation and description of silicon oxide functionalized by sol–gel process. In this work we studied the synthesis and measured the properties of silicon oxide functionalized with 3-chloropropyl, through a sol–gel process. Thermogravimetic analysis, infrared spectra, and elemental analyses were measured. The samples were prepared in the following proportions of tetraethylorthosilicate (TEOS): 3-chloropropyl trimethoxisilane molar ratio: 1:0, 1:1, 2:1, 3:1 and 4:1. The thermogravimetric data for the resulting materials established the `minimum formulae' 2:0, 3:1, 4:1, 7:1 and 11:1, respectively. As expected, the relative amount of water is inversely proportional to the presence of propyl groups. Infrared data show Si–C and –CH2– vibration modes at 1250 to 1280 and 2920 to 2940 cm−1, respectively. Thermogravimetric data and infrared spectra showed that inorganic polymers contained organic polymers.

A new organic–inorganic hybrid material with interpenetrating polymer networks was synthesized with a phase of SiO 2 made by sol–gel chemistry and an organic phase made from a polymeric resin obtained by polyesterification between metal chelate complexes (formed by metallic ions and α-hydroxycarboxylic acids) and a polyfunctional alcohol. One modification in this method consists in preparing organic polymers doped with europium III/dipicolinic acid or terbium III/1,2-phenylenedioxidiacetic acid complexes. Europium and terbium luminescent properties were used as probe to obtain structural information about the hybrid gel. To the organic polymers we added tetraorthosilicates to obtain transparent and luminescent organic–inorganic hybrid materials through the sol–gel process. Luminescent and infrared spectra and thermogravimetric properties were measured.

The interaction of OH− with Fe(TPP)+, Fe(TDCPP)+, Fe(TMP)+ and Fe(TFPP)+ in 1,2-dichloroethane was studied by titrating FeP solutions with aliquots of a solution of tetrabutylammonium hydroxide in acetonitrile. The number of OH− ions (n) coordinated to the FeP and the stability constants (βn) for the FeP-OH− complexes were calculated from UV-Vis absorbance data and iron spin states were determined through EPR spectroscopy. Fe(TMP)+ forms a high-spin mono-hydroxo complex, while Fe(TPP)+ and Fe(TDCPP)+ form high-spin bis-hydroxo complexes. To our knowledge, this is the first time that the formation of bis-hydroxo complexes from Fe(TPP)+ has been reported, and this was possible because the studies were carried out in basic organic media. In this same medium, FeIII-FeII reduction upon OH− addition to Fe(TFPP)+ was observed, without concomitant formation of the μ-oxo dimeric species [Fe(TFPP)]2O.

A topic of constant investigation in recent decades has been the study of electron and/or energy transfer reactions in supramolecular systems. The energy transfer between donor-acceptor depends on the influence of the substituent in the intersystem crossing. The competition between the radiative and non-radiative processes also depends on other factors such as temperature, solvent and energy gap. In this work, we have studied the suppression of the emission of monocarboxyphenyl porphyrins after addition of rare earth ions (RE(III)). The porphyrin emission decreases with the addition of RE(III), no matter which ion is present. When Eu(III) was used, the emission of this ion was not observed either. This suppression happens due to the effect of the heavy atom and not due to the energy transfer through electronic levels between the porphyrin and the RE(III). After the addition of RE(III), the lifetime for MCTPPH2 started to decay biexponentially, indicating the formation of a new species (MCTPPH2-RE(III)) of a shorter lifetime. The presence of NO2 groups in the ortho mesoaryl positions of MCTNPPH2 and the presence of Zn(II) in Zn(MCTPP) decreased both the porphyrin lifetime and emission due to an increase in the spin-orbit coupling.

The photophysical properties of the Eu 3+ :bfa (1,1,1,-trifluoro-4-phenyl butane-2,4-dione), Eu 3+ :hfa (1,1,1,5,5,5-hexafluoro pentane-2,4-dione) and Eu 3+ :tta(1,1,1-trifluoro-4-tenoyl butane-2,4-dione) systems oriented in K 2 SO 4 crystal matrices were studied. The luminescence data for these systems revealed them to be highly luminescent materials. Characteristic Eu 3+ transitions were observed in their emission spectra, when excited at 330 nm for Eu 3+ :bfa, 318 nm for Eu 3+ :hfa, and 350 nm for Eu 3+ :tta. Lifetimes for the 5 D 0 → 7 F 2 transition of the beautiful red luminescent hourglass inclusions of the following ionic pairs: Eu 3+ : β -diketonates Eu 3+ :bfa ( λ exc =330 nm, λ em =612 nm), Eu 3+ :hfa ( λ exc =318 nm, λ em =612 nm), and Eu 3+ :tta ( λ exc =350 nm, λ em =612 nm) in K 2 SO 4 crystal matrix at room temperature are 0.90, 0.86 and 0.85 ms, respectively.

[RE(czb)3(H2O)2] complexes (where RE = Eu3+, Tb3+, Gd3+; and czb = 4-(9H-carbazol-9-yl)benzoato) have been synthesized and characterized. The Gd3+ complex was used to determine the triplet state energy of the czb ligand. Photoluminescence measurements of the complexes have been carried out under UV excitation. The Tb3+ complex exhibited a strong green luminescence indicating an efficient antenna effect, whereas the Eu3+ complex showed low red luminescence and the Gd3+ complex a blue-green luminescence from the ligand. The luminescence lifetimes and quantum yields have also been measured for the evaluation of the spectroscopic behavior of the complexes.

Photophysical properties of porphyrins in aqueous solutions are strongly affected by aggregation. One possible solution to this problem is to encapsulate the porphyrin into polymeric spheres, to provide an environment where the photosensitizer can be administered in its monomeric form in such treatments as photodynamic therapy. Here we report the microencapsulation of the meso-tetrakis(4-sulphonatophenyl) porphyrin (TPPS(4)) photosensitizer by the ultrasonic spray-drying technique. The encapsulated TPPS(4) was morphologically characterized by scanning electron microscopy, and its photophysical properties were studied and compared with those of a physical blend of dextrin and TPPS(4). We successfully encapsulated TPPS(4) into dextrin microspheres, and the encapsulated photosensitizer displays higher luminescence intensity than that of the prepared physical blends.

A new mesoporous catalyst was prepared by the reaction between 3-aminopropyltrimethoxisylane and Cu(II)-hexadecafluorophthalocyanine, followed by co-condensation of tetraethylorthosilicate around a micelle formed by n-dodecylamine. The surfactant was removed from the pores by continuous extraction with ethanol, giving the Si-CuF16Pc catalyst. This catalyst was characterized by SEM, FTIR, TGA, 29Si NMR, N2 adsorption and X-ray diffraction. SEM images confirmed that the catalyst material is formed by nanoaggregates with a diameter of 100 nm. N2 adsorption isotherms showed that Si-CuF16Pc has a surface area of approximately 200 m2 g(-1) and a porous diameter of 7.7 nm, characterizing the mesoporosity of this product. This novel material shows an excellent photocatalytic activity, degrading almost 90% of 2,4-dichlorophenoxyacetic acid (2,4-D) up to 30 min, while only approximately 40% of photodegradation was obtained in its absence.

This paper presents the alkaline battery (MnO2/Zn) as a useful device in the teaching of chemistry. The preparation of the battery, the materials used in the preparation of the MnO2 electrode, the mechanism of energy storage and the parameters often used in the understanding of general batteries are discussed in detail. In addition, a schedule and a questionnaire that can be applied in an experimental class have been developed, which allow the assembly of an alkaline battery, its discharge using a galvanostatic or a load-resistance procedure, and the elaboration of a report based on the main text. This experimental class has been offered in the chemistry course of FFCLRP.

Photodynamic therapy (PDT) is based on the accumulation of a photosensitizer, such as a porphyrin or a chlorin, in a malignant tissue after its administration. Chlorins exhibit photophysical properties similar to those of the porphyrin macrocycles, but with intensified and red-shifted Q bands, making chlorin-containing systems even better candidates for PDT. In this contribution, we report the synthesis of 5,10,15-tris(pentafluorophenyl)-20-(4-pyridyl)porphyrin, (2) and its transformation to the novel chlorin derivatives 4, (5,10,20-tris(pentafluorophenyl)-15-(4-pyridyl)-tetrahydro-1H- N-methyl-pyrrolo [3,4-b]porphyrin and 5, (5,10,15-tris(pentafluorophenyl)-20-(4-pyridyl)-tetrahydro-1H- N-methyl-pyrrolo[3,4-b]porphyrin) by 1,3-dipolar cycloaddition with an azomethine ylide. The new products have been characterized by UV-Vis, ¹H NMR and FAB-MS. The photophysics, photochemical and photobleaching properties of chlorin 4 have been evaluated. Its quantum yield of photobleaching (phiPb, mol Einstein-1) was 0.047±0.014. In order to demonstrate the production of ¹O2 when 4 is used as a photosensitizer, uric acid tests have been carried out. The results indicate that chlorin 4 can be considered a promising photosensitizer in PDT. A terapia fotodinâmica (TFD) está baseada na administração e no acúmulo de fotossensibilizador, por exemplo, de tipo porfirina ou clorina, em tecidos doentes. As clorinas apresentam propriedades fotofísicas semelhantes àquelas das porfirinas, mas com intensificação e deslocamento das bandas Q, o que faz com que sejam bons candidatos para TFD. Neste trabalho relata-se a síntese da 5,10,15-tris(pentafluorofenil)-20-(4-piridil)porfirina, (2), e das clorinas isômeras 4, (5,10,20-tris(pentafluorofenil)-15-(4-piridil)-tetra-hidro-1H- N-metil-pirrolo[3,4-b]porfirina e 5, (5,10,15-tris(pentafluorofenil)-20-(4-piridil)-tetra-hidro-1H- N-metil-pirrolo[3,4-b]porfirina, obtidas a partir de 2, por reação de cicloadição 1,3-dipolar com um ileto azometínico, e respectivas caracterizações estruturais por UV-Vis, RMN e EM-FAB. Foram avaliadas as propriedades fotofísicas, fotoquímicas e fotodegradativas para a nova clorina 4, obtida com melhor rendimento que o seu isômero 5. O rendimento quântico de fotodegradação (fiFd, mol Einstein-1) foi de 0,047±0,014. Foram ainda realizados testes com ácido úrico para demonstrar a capacidade do fotossensibilizador na produção de ¹O2. Os resultados mostraram que a nova clorina 4 pode ser considerada como um bom fotossensibilizador para TFD.

The hydroxynitrophenylporphyrins, 5,10,15,20-tetrakis(2-hydroxy-5-nitrophenyl)porphyrin and 5-mono(carboxyphenyl)-10,15,20-tris(2-hydroxy-5-nitrophenyl)porphyrin described in this work were prepared through Adler's method. These compounds were characterized by ¹H NMR and light absorption and emission spectroscopy in the visible region. In order to demonstrate the involvement of ¹O2 production, the uric (UA) acid test was carried out, which considers the decrease in the absorbance of UA at 293 nm following laser light irradiation of a solution containing UA and a photosensitizer. The results obtained demonstrate that these hydroxynitrophenylporphyrins can be considered as promising photosensitizers in PDT. As hidroxinitrofenilporfirinas, 5,10,15,20-tetrakis(2-hidroxi-5-nitrofenil)porfirina e 5-mono(carboxifenil)-10,15,20-tris(2-hidroxi-5-nitrofenil)porfirina , estudadas neste trabalho, foram preparadas pelo método de Adler e caracterizadas por ¹H RMN e por espectroscopia de absorção e emissão na região espectral visível. A formação de ¹O2 foi constatada através do teste do ácido úrico (AU), o qual consiste na observação do decréscimo na absorbância da banda do AU em 293 nm, após irradiação da solução, com laser, contendo o fotossenssibilizador e o AU. Os resultado obtidos indicaram que as hidroxinitrofenilporfirinas podem ser consideradas potenciais fotossensibilizadores para terapia fotodinâmica.

Muitos compostos modelo contendo porfirinas têm sido preparados num esforço para entender o sistema de fotossíntese e os processos de aproveitamento de energia solar. Sistemas doadores-receptores contendo porfirinas têm sido freqüentemente estudados para testar várias descrições teóricas sobre transferência de elétrons. O estudo de parâmetros fotoquímicos e fotofísicos como a distância para transferência de energia, geometria molecular e a diferença de potencial eletrônico, tem se mostrado importante para a definição da transferência eletrônica em porfirinas. Neste trabalho apresentamos a síntese, purificação e caracterização por espectroscopia UV/Vis, ¹H e 19F RMN, luminescência e tempos de vida de novos modelos moleculares de porfirinas, que permitam investigar esses parâmetros. Utilizou-se o dímero Zn,Mn(TPPF4)2pip e seus monômeros ZnTPPF4pipH e MnF5TPP. A caracterização do ZnMn(TPPF4)2pip, foi dificultada devido a presença de Mn+3, devido ao forte acoplamento dos orbitais dpi do manganês e o sistema pi da porfirina, que aumenta a interação manganês-porfirina mudando o espectro eletrônico UV/Vis e distorcendo os sinais de ¹H e 19F RMN do dímero. A presença de Mn+3 desloca E1/2 do anel porfirínico para valores mais negativos, o que resulta em reduções mais difíceis, impedindo a transferência de energia da Znporfirina para a Mnporfirina. Porphyrins have revealed that factors as the energy transfer distance, molecular geometry and the difference of electronic potential, are important in a well defined electronic transfer. Porphyrin- containing donor-acceptor systems have been usefully employed to test various theoretical descriptions of electron transfer. The objective of this paper consists on the synthesis, purification and characterization by UV/Vis spectroscopy, ¹H and 19F NMR, luminescence and lifetime of new molecular models, allowing the investigation of energy transfer parameters. This study was accomplished using the dimer Zn,Mn(TPPF4)2pip and its monomers ZnTPPF4pipH and MnF5TPP. The dimer characterization, Zn,Mn(TPPF4)2pip, was difficult due to the presence of Mn3+. The strong overlap between dpi orbitals of manganese and the porphyrin pi system increases the interaction manganese-porphyrin in changing the UV/Vis electronic spectrum and distorting the ¹H and 19F NMR signals of dimer. The presence of Mn3+ shifts the reduction potential of E1/2 of the porphyrin ring to more negatives values, what results in more difficult reductions, disabling the transfer of energy from Zincporphyrin to Manganeseporphyrin.