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Sandra Gago
LAQV-REQUIMTE, Chemistry Department, Faculty of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal

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Review
Published: 07 June 2021 in Surfaces
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Antiseptics and disinfectants are extensively used for a variety of topical and hard-surface applications. A wide variety of biocides as active chemical agents is found in these products, including alcohols, phenols, iodine, and chlorine. Many of these active agents demonstrate broad-spectrum antimicrobial activity; however, the mode of action of these agents is not well-documented. This review is focused on several examples of ionic systems based on ionic surfactants and ionic liquids as well as nanomaterials and nanoparticles acting as antiseptics and disinfectants for surfaces. It is important to note that many of these biocides may be used singly or in combination in a variety of products, which vary considerably in activity against microorganisms. Antimicrobial activity can be influenced by several factors such as formulation effects, presence of an organic load, synergy, temperature, dilution, and test method. The most promissory compounds based on ionic systems and nanomaterials published in mainly the last decade is chronologically reported in this review.

ACS Style

Francisco Faísca; Luis Filipe; Zeljko Petrovski; Miguel Santos; Sandra Gago; Luís Branco. Ionic Systems and Nanomaterials as Antiseptic and Disinfectant Agents for Surface Applications: A Review. Surfaces 2021, 4, 169 -190.

AMA Style

Francisco Faísca, Luis Filipe, Zeljko Petrovski, Miguel Santos, Sandra Gago, Luís Branco. Ionic Systems and Nanomaterials as Antiseptic and Disinfectant Agents for Surface Applications: A Review. Surfaces. 2021; 4 (2):169-190.

Chicago/Turabian Style

Francisco Faísca; Luis Filipe; Zeljko Petrovski; Miguel Santos; Sandra Gago; Luís Branco. 2021. "Ionic Systems and Nanomaterials as Antiseptic and Disinfectant Agents for Surface Applications: A Review." Surfaces 4, no. 2: 169-190.

Journal article
Published: 16 May 2021 in Dyes and Pigments
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The fact that many copigments such as cinnamic acids exhibit an acid-base equilibrium at moderately acidic pH values have not been taken in consideration in the copigmentation models and respective equations. In this work, the copigmentation constants of malvidin-3-O-glucoside and sinapic acid (pKa = 4.5) is reported. The flavylium cation (AH+) in moderately acid medium (pH ≤ 6) can be considered a monoprotic acid in equilibrium with its conjugated base (CB) equal to the sum of the concentrations of quinoidal base (A), hemiketal (B), cis and trans chalcones (Cc and Ct), with equilibrium constant K'a. Based on this behavior a new mathematical expression to account for the copigmentation of AH+ and CB was deduced. The system was also studied by a series of reverse pH jumps monitored by stopped flow and a previously reported procedure was extended to consider the acid-base equilibrium of the copigment. The copigmentation constant of the flavylium cation with the acidic form of the copigment, CP, is 243 M−1, and no copigmentation with the basic form of the copigment, CP(−), was observed. This was explained by the very small superposition of these two species in the pH domain. The copigmentation constants of CB with the acidic and basic forms of the copigment, calculated from the UV–Vis measurements are respectively KCBCP = 53 M−1 and KCBCP(−) = 78 M−1. The reverse pH jumps monitored by stopped flow allowed the calculation of the copigmentation constants of the acidic form of the copigment (CP) with quinoidal base (A), hemiketal (B) and cis-chalcone (Cc), respectively KACP = 531 M−1, KBCP = 17, KCcCP = 41 M−1 as well as with the basic form of the copigment KACP(−) = 196 M−1, KBCP(−) = 79, KCcCP(−) = 94 M−1. The reverse pH jumps followed by a standard spectrophotometer allows for determination of KCtCP = 55 M−1 and KCcCP(−) = 80 M−1 and KCBCP = 54 M−1 and KCBCP(−)=89 M−1. The estimated error for all copigmentation constants is circa 10%.

ACS Style

Joana Oliveira; Joana Azevedo; André Seco; Johan Mendoza; Nuno Basílio; Victor de Freitas; Fernando Pina. Copigmentation of anthocyanins with copigments possessing an acid-base equilibrium in moderately acidic solutions. Dyes and Pigments 2021, 193, 109438 .

AMA Style

Joana Oliveira, Joana Azevedo, André Seco, Johan Mendoza, Nuno Basílio, Victor de Freitas, Fernando Pina. Copigmentation of anthocyanins with copigments possessing an acid-base equilibrium in moderately acidic solutions. Dyes and Pigments. 2021; 193 ():109438.

Chicago/Turabian Style

Joana Oliveira; Joana Azevedo; André Seco; Johan Mendoza; Nuno Basílio; Victor de Freitas; Fernando Pina. 2021. "Copigmentation of anthocyanins with copigments possessing an acid-base equilibrium in moderately acidic solutions." Dyes and Pigments 193, no. : 109438.

Paper
Published: 19 April 2021 in Dalton Transactions
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Several organic salts based on the combination of two different choline derivative cations and MnCl3, GdCl4 and TbCl4 as anions were immobilized in mesoporous silica nanoparticles (MSNs) by a two-step synthetic method.

ACS Style

Andreia Forte; Sandra Gago; Manuela Lopes Ribeiro Carrott; Peter J. M. Carrott; Celso Alves; Fernando Teodoro; Rui Pedrosa; Isabel M. Marrucho; Luis C. Branco. Mesoporous silica nanoparticles with manganese and lanthanide salts: synthesis, characterization and cytotoxicity studies. Dalton Transactions 2021, 50, 8588 -8599.

AMA Style

Andreia Forte, Sandra Gago, Manuela Lopes Ribeiro Carrott, Peter J. M. Carrott, Celso Alves, Fernando Teodoro, Rui Pedrosa, Isabel M. Marrucho, Luis C. Branco. Mesoporous silica nanoparticles with manganese and lanthanide salts: synthesis, characterization and cytotoxicity studies. Dalton Transactions. 2021; 50 (24):8588-8599.

Chicago/Turabian Style

Andreia Forte; Sandra Gago; Manuela Lopes Ribeiro Carrott; Peter J. M. Carrott; Celso Alves; Fernando Teodoro; Rui Pedrosa; Isabel M. Marrucho; Luis C. Branco. 2021. "Mesoporous silica nanoparticles with manganese and lanthanide salts: synthesis, characterization and cytotoxicity studies." Dalton Transactions 50, no. 24: 8588-8599.

Journal article
Published: 07 April 2021 in International Journal of Molecular Sciences
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Anthocyanins are the basis of the color of angiosperms, 3-deoxyanthocyanins and sphagnorubin play the same role in mosses and ferns, and auronidins are responsible for the color in liverworts. In this study, the color system of cyanidin-3-O-glucoside (kuromanin) as a representative compound of simpler anthocyanins was fully characterized by stopped flow. This type of anthocyanin cannot confer significant color to plants without intra- or intermolecular interactions, complexation with metals or supramolecular structures as in Commelina communis. The anthocyanin’s color system was compared with those of 3-deoxyanthocyanins and riccionidin A, the aglycone of auronidins. The three systems follow the same sequence of chemical reactions, but the respective thermodynamics and kinetics are dramatically different.

ACS Style

Fernando Pina; Alfonso Alejo-Armijo; Adelaide Clemente; Johan Mendoza; André Seco; Nuno Basílio; António Parola. Evolution of Flavylium-Based Color Systems in Plants: What Physical Chemistry Can Tell Us. International Journal of Molecular Sciences 2021, 22, 3833 .

AMA Style

Fernando Pina, Alfonso Alejo-Armijo, Adelaide Clemente, Johan Mendoza, André Seco, Nuno Basílio, António Parola. Evolution of Flavylium-Based Color Systems in Plants: What Physical Chemistry Can Tell Us. International Journal of Molecular Sciences. 2021; 22 (8):3833.

Chicago/Turabian Style

Fernando Pina; Alfonso Alejo-Armijo; Adelaide Clemente; Johan Mendoza; André Seco; Nuno Basílio; António Parola. 2021. "Evolution of Flavylium-Based Color Systems in Plants: What Physical Chemistry Can Tell Us." International Journal of Molecular Sciences 22, no. 8: 3833.

Journal article
Published: 05 February 2021 in Pharmaceutics
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Mesoporous silica nanoparticles (MSNs) are very promising nanomaterials for treating bacterial infections when combined with pharmaceutical drugs. Herein, we report the preparation of two nanomaterials based on the immobilization of ciprofloxacin in mesoporous silica nanoparticles, either as the counter-ion of the choline derivative cation (MSN-[Ch][Cip]) or via anchoring on the surface of amino-group modified MSNs via an amide bond (MSN-Cip). Both nanomaterials were characterized by TEM, FTIR and solution 1H NMR spectroscopies, elemental analysis, XRD and N2 adsorption at 77 K in order to provide the desired structures. No cytotoxicity from the prepared mesoporous nanoparticles on 3T3 murine fibroblasts was observed. The antimicrobial activity of the nanomaterials was determined against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Klebsiella pneumoniae) bacteria and the results were promising against S. aureus. In the case of B. subtilis, both nanomaterials exhibited higher antimicrobial activity than the precursor [Ch][Cip], and in the case of K. pneumoniae they exhibited higher activity than neutral ciprofloxacin.

ACS Style

Blanca De Juan Mora; Luís Filipe; Andreia Forte; Miguel Santos; Celso Alves; Fernando Teodoro; Rui Pedrosa; Manuela Ribeiro Carrott; Luís Branco; Sandra Gago. Boosting Antimicrobial Activity of Ciprofloxacin by Functionalization of Mesoporous Silica Nanoparticles. Pharmaceutics 2021, 13, 218 .

AMA Style

Blanca De Juan Mora, Luís Filipe, Andreia Forte, Miguel Santos, Celso Alves, Fernando Teodoro, Rui Pedrosa, Manuela Ribeiro Carrott, Luís Branco, Sandra Gago. Boosting Antimicrobial Activity of Ciprofloxacin by Functionalization of Mesoporous Silica Nanoparticles. Pharmaceutics. 2021; 13 (2):218.

Chicago/Turabian Style

Blanca De Juan Mora; Luís Filipe; Andreia Forte; Miguel Santos; Celso Alves; Fernando Teodoro; Rui Pedrosa; Manuela Ribeiro Carrott; Luís Branco; Sandra Gago. 2021. "Boosting Antimicrobial Activity of Ciprofloxacin by Functionalization of Mesoporous Silica Nanoparticles." Pharmaceutics 13, no. 2: 218.

Research article
Published: 20 January 2021 in Journal of Agricultural and Food Chemistry
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Anthocyanins co-pigmentation models with application on 1:1 complexes were revisited, and their limitations were critically commented. The flavylium multistate of species is dramatically simplified to a single acid–base equilibrium between flavylium cation and its conjugated base CB, equal to the sum of quinoidal base, hemiketal, and cis and trans-chalcones. Bearing this, a new equation that simultaneously allows calculation of the co-pigmentation constant with flavylium cation (KAH+CP) and with its conjugated base CB (KCBCP) was deduced. This equation can be used at a fixed co-pigment concentration with pH as a variable or at fixed pH and co-pigment concentration variable. A global fitting of all data allows us to calculate both association constants with good accuracy. The model was applied to the co-pigmentation of malvidin-3-glucoside with caffeine and pentagalloyl glucose (PGG). Caffeine gives rise to complexes not only with flavylium cation KAH+CP = 125 ± 7 M–1 but also with CB with KCBCP = 23 ± 3 M–1. PGG complexes exclusively with flavylium cation, KAH+CP = 914 ± 10 M–1, and the possible interaction with quinoidal base is lower than the detection limits that the inherent experimental error permits.

ACS Style

Joana Oliveira; Joana Azevedo; Natércia Teixeira; Paula Araújo; Victor de Freitas; Nuno Basílio; Fernando Pina. On the Limits of Anthocyanins Co-Pigmentation Models and Respective Equations. Journal of Agricultural and Food Chemistry 2021, 69, 1359 -1367.

AMA Style

Joana Oliveira, Joana Azevedo, Natércia Teixeira, Paula Araújo, Victor de Freitas, Nuno Basílio, Fernando Pina. On the Limits of Anthocyanins Co-Pigmentation Models and Respective Equations. Journal of Agricultural and Food Chemistry. 2021; 69 (4):1359-1367.

Chicago/Turabian Style

Joana Oliveira; Joana Azevedo; Natércia Teixeira; Paula Araújo; Victor de Freitas; Nuno Basílio; Fernando Pina. 2021. "On the Limits of Anthocyanins Co-Pigmentation Models and Respective Equations." Journal of Agricultural and Food Chemistry 69, no. 4: 1359-1367.

Communication
Published: 03 November 2020 in Chemical Communications
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We report on the application of novel small-molecule highly crystalline pentacyclic diamides possessing significant OTFT and OLED potential.

ACS Style

Carolina S. Marques; Hugo Cruz; Simon E. Lawrence; Sandra Gago; João P. Prates Ramalho; Jorge Morgado; Luís C. Branco; Anthony J. Burke. Ambipolar pentacyclic diamides with interesting electrochemical and optoelectronic properties. Chemical Communications 2020, 56, 14893 -14896.

AMA Style

Carolina S. Marques, Hugo Cruz, Simon E. Lawrence, Sandra Gago, João P. Prates Ramalho, Jorge Morgado, Luís C. Branco, Anthony J. Burke. Ambipolar pentacyclic diamides with interesting electrochemical and optoelectronic properties. Chemical Communications. 2020; 56 (94):14893-14896.

Chicago/Turabian Style

Carolina S. Marques; Hugo Cruz; Simon E. Lawrence; Sandra Gago; João P. Prates Ramalho; Jorge Morgado; Luís C. Branco; Anthony J. Burke. 2020. "Ambipolar pentacyclic diamides with interesting electrochemical and optoelectronic properties." Chemical Communications 56, no. 94: 14893-14896.

Full paper
Published: 20 October 2020 in ChemistrySelect
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ACS Style

Hugo Cruz; Neide Gomes; Fatima Mirante; Salete S. Balula; Luís C. Branco; Sandra Gago. Polyoxometalates‐Based Ionic Liquids (POMs‐ILs) for Electrochemical Applications. ChemistrySelect 2020, 5, 12266 -12271.

AMA Style

Hugo Cruz, Neide Gomes, Fatima Mirante, Salete S. Balula, Luís C. Branco, Sandra Gago. Polyoxometalates‐Based Ionic Liquids (POMs‐ILs) for Electrochemical Applications. ChemistrySelect. 2020; 5 (39):12266-12271.

Chicago/Turabian Style

Hugo Cruz; Neide Gomes; Fatima Mirante; Salete S. Balula; Luís C. Branco; Sandra Gago. 2020. "Polyoxometalates‐Based Ionic Liquids (POMs‐ILs) for Electrochemical Applications." ChemistrySelect 5, no. 39: 12266-12271.

Correction
Published: 24 September 2020 in ACS Omega
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ACS Style

Johan Mendoza; Nuno Basílio; Victor De Freitas; Fernando Pina. Correction to “New Procedure to Calculate All Equilibrium Constants in Flavylium Compounds: Application to the Copigmentation of Anthocyanins”. ACS Omega 2020, 5, 25476 -25476.

AMA Style

Johan Mendoza, Nuno Basílio, Victor De Freitas, Fernando Pina. Correction to “New Procedure to Calculate All Equilibrium Constants in Flavylium Compounds: Application to the Copigmentation of Anthocyanins”. ACS Omega. 2020; 5 (39):25476-25476.

Chicago/Turabian Style

Johan Mendoza; Nuno Basílio; Victor De Freitas; Fernando Pina. 2020. "Correction to “New Procedure to Calculate All Equilibrium Constants in Flavylium Compounds: Application to the Copigmentation of Anthocyanins”." ACS Omega 5, no. 39: 25476-25476.

Research article
Published: 17 April 2020 in Science Advances
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The molecular structure of the medieval watercolor known as folium has finally been solved in the 21st century. The interdisciplinary approach taken was the key to producing extracts that had been prepared following medieval instructions, and shows the blue/purple chromophore as the major dye in Chrozophora tinctoria fruits (shell). A multi-analytical characterization of its structure was made using HPLC-DAD-MS, GC-MS, NMR (1H, 13C, COSY, HSQC, HMBC, INADEQUATE), and computational studies. The results demonstrate that the blue compound corresponds to 6′-hydroxy-4,4′-dimethoxy-1,1′-dimethyl-5′-{[3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl]oxy}-[3,3′-bipyridine]-2,2′,5,6(1H,1′H)-tetraone, a hermidin derivative, which we named chrozophoridin. Experimental data and computational modeling studies show that this mono-glycosylated dimer is represented by two stable isomers (atropisomers). This is an indispensable piece of knowledge for the characterization of this medieval dye in works of art such as medieval manuscript illuminations and for testing its stability and contributes to the preservation of our cultural heritage.

ACS Style

P. Nabais; J. Oliveira; F. Pina; N. Teixeira; V. de Freitas; N. F. Brás; A. Clemente; M. Rangel; A. M. S. Silva; M. J. Melo. A 1000-year-old mystery solved: Unlocking the molecular structure for the medieval blue from Chrozophora tinctoria, also known as folium. Science Advances 2020, 6, eaaz7772 .

AMA Style

P. Nabais, J. Oliveira, F. Pina, N. Teixeira, V. de Freitas, N. F. Brás, A. Clemente, M. Rangel, A. M. S. Silva, M. J. Melo. A 1000-year-old mystery solved: Unlocking the molecular structure for the medieval blue from Chrozophora tinctoria, also known as folium. Science Advances. 2020; 6 (16):eaaz7772.

Chicago/Turabian Style

P. Nabais; J. Oliveira; F. Pina; N. Teixeira; V. de Freitas; N. F. Brás; A. Clemente; M. Rangel; A. M. S. Silva; M. J. Melo. 2020. "A 1000-year-old mystery solved: Unlocking the molecular structure for the medieval blue from Chrozophora tinctoria, also known as folium." Science Advances 6, no. 16: eaaz7772.

Full paper
Published: 16 April 2020 in European Journal of Inorganic Chemistry
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A Zn,Al layered double hydroxide (LDH) with [Cp*MoO3]– (Cp* = η5‐C5Me5) anions in the interlayer has been prepared by a direct coprecipitation method. The intercalated LDH and the mixed metal oxide (MMO) obtained after its calcination were characterized by elemental and thermogravimetric analyses, powder X‐ray diffraction (PXRD), FT‐IR and FT‐Raman spectroscopies, 13C and 27Al MAS NMR, and scanning electron microscopy. The observed basal spacing of 17.1 Å for the LDH Zn,Al‐Cp*MoO3 (corresponding to a gallery height of 12.3 Å) suggests that the guest anions self‐assemble into dimers via offset face‐to‐face Cp*···Cp* interactions, which facilitates hydrogen‐bonding interactions between the oxido ligands of the complexes and the layer hydroxyl groups, while positioning the hydrophobic aromatic rings towards the center of the galleries. Calcination of Zn,Al‐Cp*MoO3 at 550 °C under air gave an MMO comprising well‐dispersed ZnO, α‐ZnMoO4 and ZnAl2O4 (spinel) oxides in a molar of ca . 1.4:1.6:1. The MMO exhibited catalytic activity for the epoxidation of cis ‐cyclooctene with tert‐butylhydroperoxide (TBHP) as terminal oxidant, with quantitative yield of the epoxide being achieved within 24 h at 85 °C.

ACS Style

Ana C. Gomes; Patrícia Neves; Sandra Gago; Anabela A. Valente; Isabel S. Gonçalves; Martyn Pillinger. Intercalation of (η5 -Pentamethylcyclopentadienyl)trioxomolybdenum(VI) in a Layered Double Hydroxide. European Journal of Inorganic Chemistry 2020, 2020, 2408 -2416.

AMA Style

Ana C. Gomes, Patrícia Neves, Sandra Gago, Anabela A. Valente, Isabel S. Gonçalves, Martyn Pillinger. Intercalation of (η5 -Pentamethylcyclopentadienyl)trioxomolybdenum(VI) in a Layered Double Hydroxide. European Journal of Inorganic Chemistry. 2020; 2020 (25):2408-2416.

Chicago/Turabian Style

Ana C. Gomes; Patrícia Neves; Sandra Gago; Anabela A. Valente; Isabel S. Gonçalves; Martyn Pillinger. 2020. "Intercalation of (η5 -Pentamethylcyclopentadienyl)trioxomolybdenum(VI) in a Layered Double Hydroxide." European Journal of Inorganic Chemistry 2020, no. 25: 2408-2416.

Journal article
Published: 30 March 2020 in Phytochemistry
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The kinetics and thermodynamics (in acidic solutions) of the five chemical species reversibly interconnected by external stimuli (a multistate), such as pH and light, generated by the liverworts colorant riccionidin A were investigated. The degradation products of the multistate formed after 10 days at neutral pH were identified. The behaviour of riccionidin A multistate was compared with previous results reported for the equivalent systems based on 3-deoxyanthocyanidins (found in mosses and ferns) and anthocyanins (ubiquitous in angiosperms). The five chemical species have mutatis mutandis similar structures in the three multistates. The most dramatic difference is the extremely slow interconversion rate between flavylium cation and trans-chalcone in riccionidin A and related compounds multistates (tens of days) when compared with deoxyanthocyanins (a few days) and anthocyanins (several hours), at room temperature. The mole fraction distribution of the five species that constitute the multistate as a function of pH is also different in the three families of compounds. Some considerations regarding the chemical evolution of the three systems are given.

ACS Style

A. Alejo-Armijo; Johan Mendoza; A. Jorge Parola; Fernando Pina. Chemical evolution of the colour systems generated by riccionidin A, 3-deoxyanthocyanidins and anthocyanins. Phytochemistry 2020, 174, 112339 .

AMA Style

A. Alejo-Armijo, Johan Mendoza, A. Jorge Parola, Fernando Pina. Chemical evolution of the colour systems generated by riccionidin A, 3-deoxyanthocyanidins and anthocyanins. Phytochemistry. 2020; 174 ():112339.

Chicago/Turabian Style

A. Alejo-Armijo; Johan Mendoza; A. Jorge Parola; Fernando Pina. 2020. "Chemical evolution of the colour systems generated by riccionidin A, 3-deoxyanthocyanidins and anthocyanins." Phytochemistry 174, no. : 112339.

Journal article
Published: 23 March 2020 in Dyes and Pigments
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The aggregation of malvidin 3-O-(6-O-p-coumaroyl) glucoside flavylium cation (OeninCoum) in water is reported. Intra and intermolecular interactions of OeninCoum were characterized by UV–vis absorption, 1H NMR and circular dichroism (CD). Theoretical calculations were also performed to describe the intramolecular interactions. At higher temperature (>60 °C) the intermolecular aggregates are disrupted but CD signal attributed to an intramolecular interaction remains. Moreover, the kinetic and thermodynamic data for Oenin and OeninCoum at 50 °C and 25 °C shows that the increase of temperature stabilizes the quinoidal base of this later.

ACS Style

Johan Mendoza; Joana Oliveira; Paula Araújo; Nuno Basílio; Natércia Teixeira; Natercia Bras; Fernando Pina; Kumi Yoshida; Victor de Freitas. The peculiarity of malvidin 3-O-(6-O-p-coumaroyl) glucoside aggregation. Intra and intermolecular interactions. Dyes and Pigments 2020, 180, 108382 .

AMA Style

Johan Mendoza, Joana Oliveira, Paula Araújo, Nuno Basílio, Natércia Teixeira, Natercia Bras, Fernando Pina, Kumi Yoshida, Victor de Freitas. The peculiarity of malvidin 3-O-(6-O-p-coumaroyl) glucoside aggregation. Intra and intermolecular interactions. Dyes and Pigments. 2020; 180 ():108382.

Chicago/Turabian Style

Johan Mendoza; Joana Oliveira; Paula Araújo; Nuno Basílio; Natércia Teixeira; Natercia Bras; Fernando Pina; Kumi Yoshida; Victor de Freitas. 2020. "The peculiarity of malvidin 3-O-(6-O-p-coumaroyl) glucoside aggregation. Intra and intermolecular interactions." Dyes and Pigments 180, no. : 108382.

Short communication
Published: 09 December 2019 in Materials Letters: X
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Polyoxometalates (POMs) as anionic metal oxides are promising candidates for application in dye-sensitized solar cells (DSSCs) due to their peculiar properties including a reversible and multi-electron redox behavior. In this work, four polyoxometalate as ionic liquids (POM-ILs) based on the combination between phosphomolybdate anion (PMo12O403−) and organic cations such as [BMIM]+, [BPy]+, [HDPy]+ and [P6,6,6,14]+ were prepared and characterized. A detailed chemical structural elucidation by elemental analysis, ATR-FTIR, 1H and 31P NMR spectroscopies have been performed. These POM-ILs were tested as photosensitizers by adsorption to the photoanode (TiO2 film) for different times (15 min to 17 h). The DSSCs performance can be highly improved comparing the commercially available compound and POM-ILs. The electrodeposition process is an excellent alternative to adsorption in order to improve the overall efficiencies. In general, [BPy]3[PMo12O40] and [P6,6,6,14]3[PMo12O40] are the most promissory compounds for DSSC approaches.

ACS Style

Hugo Cruz; Ana Lucia Pinto; João Carlos Lima; Luís C. Branco; Sandra Gago. Application of polyoxometalate-ionic liquids (POM-ILs) in dye-sensitized solar cells (DSSCs). Materials Letters: X 2019, 6, 100033 .

AMA Style

Hugo Cruz, Ana Lucia Pinto, João Carlos Lima, Luís C. Branco, Sandra Gago. Application of polyoxometalate-ionic liquids (POM-ILs) in dye-sensitized solar cells (DSSCs). Materials Letters: X. 2019; 6 ():100033.

Chicago/Turabian Style

Hugo Cruz; Ana Lucia Pinto; João Carlos Lima; Luís C. Branco; Sandra Gago. 2019. "Application of polyoxometalate-ionic liquids (POM-ILs) in dye-sensitized solar cells (DSSCs)." Materials Letters: X 6, no. : 100033.

Journal article
Published: 05 December 2019 in Materials
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In the present work, five 2-styryl-1-benzopyrylium salts and their relative self-assembly processes towards TiO2 nanocrystalline layers were evaluated as photosensitizers in dye-sensitized solar cells (DSSCs). Integration of these 2-styryl-1-benzopyrylium salts with the semiconductor allow for the performance of highly specific functions suitable for smart applications in material science. Spectroscopic and photoelectrochemical measurements conducted on these five bio-inspired dyes, in solution and upon adsorption onto titanium dioxide films, allowed detailed discussion of the anchoring ability of the different donor groups decorating the 2-styryl-1-benzopyrylium core and have demonstrated their ability as photosensitizers. Our results suggest that the introduction of a dimethylamino group in position 4′ of the 2-styryl-1-benzopyrylium skeleton can alter the conjugation of the molecule leading to larger absorption in the visible region and a stronger electron injection of the dye into the conduction band of TiO2. Moreover, our experimental data have been supported by theoretical calculations with the aim to study the energy of the excited states of the five compounds. In this specific case, the simulations reported contributed to better describe the properties of the compounds used and to help create the necessary basis for the design of new and targeted bio-inspired molecules.

ACS Style

Giuseppe Calogero; Ilaria Citro; Gioacchino Calandra Sebastianella; Gaetano Di Marco; Ana Marta Diniz; A. Jorge Parola; Fernando Pina. A Photoelectrochemical Study of Bioinspired 2-Styryl-1-Benzopyrylium Cations on TiO2 Nanoparticle Layer for Application in Dye-Sensitized Solar Cells. Materials 2019, 12, 4060 .

AMA Style

Giuseppe Calogero, Ilaria Citro, Gioacchino Calandra Sebastianella, Gaetano Di Marco, Ana Marta Diniz, A. Jorge Parola, Fernando Pina. A Photoelectrochemical Study of Bioinspired 2-Styryl-1-Benzopyrylium Cations on TiO2 Nanoparticle Layer for Application in Dye-Sensitized Solar Cells. Materials. 2019; 12 (24):4060.

Chicago/Turabian Style

Giuseppe Calogero; Ilaria Citro; Gioacchino Calandra Sebastianella; Gaetano Di Marco; Ana Marta Diniz; A. Jorge Parola; Fernando Pina. 2019. "A Photoelectrochemical Study of Bioinspired 2-Styryl-1-Benzopyrylium Cations on TiO2 Nanoparticle Layer for Application in Dye-Sensitized Solar Cells." Materials 12, no. 24: 4060.

Journals
Published: 08 November 2019 in New Journal of Chemistry
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Amino-substituted pyridinechalcones configure multistate systems where a new type of flavylium derivative with potential biological activity are present.

ACS Style

Ambrósio Camuenho; A. Jorge Parola; Alfonso Alejo-Armijo; Ramesh Pandian; Clara S. B. Gomes; César A. T. Laia; Fernando Pina. A model compound for pyridinechalcone-based multistate systems. Ring opening-closure as the slowest kinetic step of the multistate. New Journal of Chemistry 2019, 43, 18229 -18239.

AMA Style

Ambrósio Camuenho, A. Jorge Parola, Alfonso Alejo-Armijo, Ramesh Pandian, Clara S. B. Gomes, César A. T. Laia, Fernando Pina. A model compound for pyridinechalcone-based multistate systems. Ring opening-closure as the slowest kinetic step of the multistate. New Journal of Chemistry. 2019; 43 (46):18229-18239.

Chicago/Turabian Style

Ambrósio Camuenho; A. Jorge Parola; Alfonso Alejo-Armijo; Ramesh Pandian; Clara S. B. Gomes; César A. T. Laia; Fernando Pina. 2019. "A model compound for pyridinechalcone-based multistate systems. Ring opening-closure as the slowest kinetic step of the multistate." New Journal of Chemistry 43, no. 46: 18229-18239.

Journal article
Published: 06 November 2019 in Dyes and Pigments
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The similarity between 2,6-Bis(2-hydroxyarylidene)cyclohexanones and 2′-hydroxychalcones in generating respectively styrylflavylium and flavylium cations was explored. The complex pH and light dependent multistate of species of the asymmetric of 2,6-Bis(2-hydroxyarylidene)cyclohexanone bearing a diethyl amine in position 7 of the flavylium cation was studied by pH jumps, monitored by UV–vis spectrophotometry, stopped flow, and NMR. The possible structural isomers corresponding to the migration of the amine substituent at the benzopyrylium to ring B of the flavylium cation via chalcone, or spiro species were not detected. However, cis and trans isomers from the pendent arm take place and a photochromic system involving flavylium cation switching from red to blue was characterized. In acidic medium the flavylium cation and the hemiketal protonated at the amine substituent are the equilibrium species. In moderately acidic solutions the spiro is the most stable species and in very basic medium the ionized trans-chalcone.

ACS Style

A. Alejo-Armijo; Livia Corici; Ildiko Buta; Liliana Cseh; Artur Moro; A. Jorge Parola; J. C. Lima; Fernando Pina. Multistate of chemical species of 2,6-Bis(arylidene)cyclohexanones. On the role of chalcone and spiro species. Dyes and Pigments 2019, 174, 108013 .

AMA Style

A. Alejo-Armijo, Livia Corici, Ildiko Buta, Liliana Cseh, Artur Moro, A. Jorge Parola, J. C. Lima, Fernando Pina. Multistate of chemical species of 2,6-Bis(arylidene)cyclohexanones. On the role of chalcone and spiro species. Dyes and Pigments. 2019; 174 ():108013.

Chicago/Turabian Style

A. Alejo-Armijo; Livia Corici; Ildiko Buta; Liliana Cseh; Artur Moro; A. Jorge Parola; J. C. Lima; Fernando Pina. 2019. "Multistate of chemical species of 2,6-Bis(arylidene)cyclohexanones. On the role of chalcone and spiro species." Dyes and Pigments 174, no. : 108013.

Journal article
Published: 25 September 2019 in Fuel
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A novel composite has been prepared through the immobilization of the Keggin sandwich-type [Sm(PMo11O39)2]11− anion (SmPOM) on large-pore silica spheres previously functionalized with trimethylammonium groups (TMA). The resulting [email protected] material has been evaluated as heterogeneous catalyst in a biphasic desulfurization 1:1 diesel/extraction solvent system using H2O2 as oxidant. Preliminary experiments were conducted with different extraction solvents, acetonitrile and [BMIM]PF6 ionic liquid. The optimized extractive and catalytic oxidative desulfurization system (ECODS) with [BMIM]PF6 was able to reach complete sulfur removal from a model diesel containing 2100 ppm S in just 60 min (10 min of initial extraction + 50 min of catalytic step). The reutilization of catalyst and extraction phase has been successfully performed without loss of desulfurization efficiency in consecutive cycles, turning the process more sustainable and cost-effective. The remarkable results with simulated diesel have motivated the application of the catalyst in the desulfurization of untreated real diesel and 74% of efficiency was achieved after only 2 h for three consecutive cycles.

ACS Style

Fátima Mirante; Ana C. Alves; Diana Julião; Pedro Marques de Almeida; Sandra Gago; Rita Valençad; Jorge C. Ribeiro; Baltazar de Castro; Carlos M. Granadeiro; Salete S. Balula. Large-pore silica spheres as support for samarium-coordinated undecamolybdophosphate: Oxidative desulfurization of diesels. Fuel 2019, 259, 116213 .

AMA Style

Fátima Mirante, Ana C. Alves, Diana Julião, Pedro Marques de Almeida, Sandra Gago, Rita Valençad, Jorge C. Ribeiro, Baltazar de Castro, Carlos M. Granadeiro, Salete S. Balula. Large-pore silica spheres as support for samarium-coordinated undecamolybdophosphate: Oxidative desulfurization of diesels. Fuel. 2019; 259 ():116213.

Chicago/Turabian Style

Fátima Mirante; Ana C. Alves; Diana Julião; Pedro Marques de Almeida; Sandra Gago; Rita Valençad; Jorge C. Ribeiro; Baltazar de Castro; Carlos M. Granadeiro; Salete S. Balula. 2019. "Large-pore silica spheres as support for samarium-coordinated undecamolybdophosphate: Oxidative desulfurization of diesels." Fuel 259, no. : 116213.

Paper
Published: 13 September 2019 in Physical Chemistry Chemical Physics
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While in the ground state the proton at the hydroxyl in position 4′ is more acidic, in the excited state it is the proton at the hydroxyl in position 7.

ACS Style

Alfonso Alejo-Armijo; Nuno Basílio; Adilson A. Freitas; António L. Maçanita; João C. Lima; A. Jorge Parola; Fernando Pina. Ground and excited state properties of furanoflavylium derivatives. Physical Chemistry Chemical Physics 2019, 21, 21651 -21662.

AMA Style

Alfonso Alejo-Armijo, Nuno Basílio, Adilson A. Freitas, António L. Maçanita, João C. Lima, A. Jorge Parola, Fernando Pina. Ground and excited state properties of furanoflavylium derivatives. Physical Chemistry Chemical Physics. 2019; 21 (38):21651-21662.

Chicago/Turabian Style

Alfonso Alejo-Armijo; Nuno Basílio; Adilson A. Freitas; António L. Maçanita; João C. Lima; A. Jorge Parola; Fernando Pina. 2019. "Ground and excited state properties of furanoflavylium derivatives." Physical Chemistry Chemical Physics 21, no. 38: 21651-21662.

Journal article
Published: 31 August 2019 in Solar Energy
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Herein, a series of 3-O-glucosilated pyranoanthocyanin derivatives were synthesized following a bio-mimetic approach. The compounds were studied by means of UV–Vis spectroscopy in order to establish their chemical equilibria and determine the stability of the colored species over the pH range. The resistance of pyranoanthocyanins to hydration grants this family of compounds, closely related to anthocyanins, increased color stability. Finally, the synthetized compounds were successfully applied as light harvesters in DSSCs and relations between dye structure and cell efficiency were found. The influence of different linker units (carboxylate, catechol) and electron-donor groups (methoxy, hydroxyl, methyl), as well as the presence of sugar moieties have impact in the various parameters related to DSSC efficiency. An overall efficiency of 1.57% was obtained for the best performing compound, methylpyranocyanidin-3-O-glucoside. The impact of using different additives was also studied and the results compared with other families.

ACS Style

Ana Lucia Pinto; Joana Oliveira; Paula Araújo; Giuseppe Calogero; Victor Freitas; Fernando Pina; A. Jorge Parola; J. Carlos Lima. Study of the multi-equilibria of red wine colorants pyranoanthocyanins and evaluation of their potential in dye-sensitized solar cells. Solar Energy 2019, 191, 100 -108.

AMA Style

Ana Lucia Pinto, Joana Oliveira, Paula Araújo, Giuseppe Calogero, Victor Freitas, Fernando Pina, A. Jorge Parola, J. Carlos Lima. Study of the multi-equilibria of red wine colorants pyranoanthocyanins and evaluation of their potential in dye-sensitized solar cells. Solar Energy. 2019; 191 ():100-108.

Chicago/Turabian Style

Ana Lucia Pinto; Joana Oliveira; Paula Araújo; Giuseppe Calogero; Victor Freitas; Fernando Pina; A. Jorge Parola; J. Carlos Lima. 2019. "Study of the multi-equilibria of red wine colorants pyranoanthocyanins and evaluation of their potential in dye-sensitized solar cells." Solar Energy 191, no. : 100-108.