João Carlos Lima

João Carlos Lima
Universidade NOVA de Lisboa | NOVA · Department of Chemistry

Ph.D.

About

239
Publications
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Introduction
João Carlos Lima currently works at the Department of Chemistry, New University of Lisbon. João Carlos does research in Photochemistry, Spectroscopy and Physical Chemistry. Their current project is 'Self-assembly of gold(I) complexes in water'.
Additional affiliations
January 2012 - present
Universitat de Barcelona
January 2008 - present
Universitat Jaume I
January 2006 - December 2012
Universidade NOVA de Lisboa

Publications

Publications (239)
Article
Full-text available
Reactive oxygen species (ROS) are dangerous sources of macromolecular damage. While most derive from mitochondrial oxidative phosphorylation, their production can be triggered by exogenous stresses, surpassing the extinction capacity of intrinsic antioxidant defense systems of cells. Here, we report the antioxidant activity of FucoPol, a fucose-ric...
Article
Full-text available
A set of 3-ethynylaryl coumarin dyes with mono, bithiophenes and the fused variant, thieno [3,2-b] thiophene, as well as an alkylated benzotriazole unit were prepared and tested for dye-sensitized solar cells (DSSCs). For comparison purposes, the variation of the substitution pattern at the coumarin unit was analyzed with the natural product 6,7-di...
Article
Full-text available
The synthesis of two new phosphane-gold(I)-napthalimide complexes has been performed and characterized. The compounds present luminescent properties with denoted room temperature phosphorescence (RTP) induced by the proximity of the gold(I) heavy atom that favors intersystem crossing and triplet state population. The emissive properties of the comp...
Article
The synthesis of four novel gold(i)-phosphane complexes coordinated to 9-phenanthrene chromophore has been carried out through the reaction of 9-phenanthreneboronic acid and the corresponding AuClPR3 (PR3 = PPh3 for triphenylphosphane (1a); 1,4-bis(diphenylphosphanyl)butane or dppb (2b); bis(diphenylphosphanyl)acetylene or dppa (2c); (AuCl)2(diphos...
Article
This study reports the performance of FucoPol, a fucose-containing bacterial polysaccharide, as a photostable agent with high absorption yield at concentrations as low as 0.02% (w/v). FucoPol is non-cytotoxic, efficiently protects from UVA and UVB at concentrations of 0.02–2% (w/v) and 0.2–2% (w/v), respectively, has over 94% overall photostability...
Article
Full-text available
To this day, the recognition and high affinity binding of biomolecules in water by synthetic receptors remains challenging, while the necessity for systems for their sensing, transport and modulation persists. This problematic is prevalent for the recognition of peptides, which not only have key roles in many biochemical pathways, as well as having...
Article
Current societies demand sustainable synthetic procedures and accordingly the combination of two photocatalytic reactions in a one-pot process is a very appealing chemical tool. In the present work, we disclose a simple and unprecedented photocatalytic “one-pot two-steps” protocol for the chemoselective and C-3 regioselective oxidative thiocyanatio...
Article
The synthesis of two series of gold(I) complexes containing the general formulae PR 3 -Au-C≡C-phenanthrene (PR 3 = PPh 3 ( 1a / 2a ), PMe 3 ( 1b / 2b ), PNaph 3 ( 1c / 2c )) or (diphos)(Au-C≡C-phenanthrene) 2 (diphos = 1,1- bis (diphenylphosphino)methane, dppm ( 1d / 2d ); 1,4- bis (diphenylphosphino)butane, dppb ( 1e / 2e )) have been synthesized....
Article
Full-text available
The reproducibility of chemical synthesis is of crucial importance for both chemical industry and research. The development of simple yet robust methods and algorithms that generate a set of data to help the community access their method's reproducibility is desirable. We report a method for obtaining, processing and analyzing recorded images, usin...
Article
The pyranoanthocyanins present in red wine display great potential as photosensitizers in bio-inspired Dye-Sensitized Solar Cells (DSSCs). Following a biomimetic approach, a series of amino-π-bridge-pyranoanthocyanin derivatives were employed as dye sensitizers in DSSCs. The dimethylamine group was selected to take advantage of its electron-donor c...
Article
Several dinuclear terphenyl phosphine copper(I) halide complexes of composition [CuX(PR2Ar')]2 (X = Cl, Br, I; R = hydrocarbyl, Ar' = 2,6-diarylterphenyl radical), 1-5, have been isolated from the reaction of CuX with 1 equiv of the phosphine ligand. Most of them have been characterized by X-ray diffraction studies in the solid state, thus allowing...
Article
We report the cryoprotective potential of FucoPol, a fucose-containing bacterial exopolysaccharide produced by Enterobacter A47. In vitro cryopreservation assays of Vero, Saos-2, HFFF2 and C2C12 cell lines exposed to a validated non-cytotoxic 2.5 mg/ml FucoPol concentration demonstrated a consistent post-thaw metabolic viability increase. Calorimet...
Article
Full-text available
Two new bis(aryl‐imino)‐acenaphthene, Ar‐BIAN (Ar = 2,4,6‐trimethylphenyl = mes) ligands, bearing the NO 2 group in the naphthalene moiety of the iminoacenaphtene at para‐ (5‐NO 2 ) and meta‐ (4‐NO 2 ) position, of formulations 1,2‐bis(mes‐imino)‐5‐nitroacenaphthene, 1 , and 1,2‐bis(mes‐imino)‐4‐nitroacenaphthene, 2 , were synthesized. Their respec...
Article
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Silver sulfide (Ag2S) is a low band gap material, which absorbs near-infrared light and is of great importance in areas such as nanotechnology and biomedicine. We report the influence of the starting reagents, synthesis time, and light radiation on the geometry and size of silver sulfide nanoparticles and on the fraction of metallic Ag obtained in...
Article
The synthesis of five novel cyclometalated platinum(II) compounds containing five different alkynyl-chromophores was achieved by the reaction of the previously synthesized Pt-Cl cyclometalated compound (1) with the corresponding RC≡CH by a Sonogashira reaction. It was observed that the spectral and photophysical characteristics of the cyclometalate...
Article
Full-text available
A new generation of advanced materials developed by molecular imprinting technology showing a stimuli-responsive functionality are emerging. The switchable ability to control the uptake/release of the target analyte by action of external stimulus combined with a remarkable selectivity and specificity, makes these functional materials very attractiv...
Article
Five new Ru(II) polypyridyl complexes bearing N‐(arylsulfonyl)‐8‐amidoquinolate ligands and three of their biscyclometalated Ir(III) congeners have been prepared and employed as photocatalysts (PCs) in the photooxidation of benzylamines with O 2 . In particular, the new Ru(II) complexes do not exhibit photoluminescence but they harvest visible ligh...
Article
Different gold microstructures have been synthesized by using supramolecular gold(I) organometallic compounds as templates and Ag nanoparticles as reducing agent. The use of fibers resulting from supramolecular assemblies of neutral gold(I) compounds, gives rise to the formation of microrods. The use of supramolecular assemblies from ionic molecule...
Article
Full-text available
A new 2,7,10,15-tetraethynyldibenzo[g,p]chrysene ligand (1) and two tetranuclear gold(I) derivatives containing PPh3 (3) and PMe3 (4) phosphines were synthesized and characterized by 1H and 31P NMR, IR spectroscopy, and high-resolution mass spectrometry. The compounds were studied in order to analyze the effect of the introduction of gold(I) on the...
Article
Thermally activated delayed fluorescence (TADF) has revolutionized the field of organic light emitting diodes owing to the possibility of harvesting non-emissive triplet states and converting them in emissive singlet states. This mechanism generates a long-lived delayed fluorescence component which can also be used in sensing oxygen concentration,...
Article
Full-text available
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⁻) a...
Article
A new organometallic alkynyl-gold(I) complex, capable of exhibiting Aggregation Induced Emission was designed and synthesized. The linear complex structure possesses a central Au(I) atom, bearing two axial ligands: (1) 1,3,5-Triaza-7-phosphaadamantane; and (2) 2-acetamido-7-ethynyl-1,8-naphthyridine. While the former accounts for its partial solubi...
Article
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 w...
Article
Full-text available
Thermally activated delayed fluorescence (TADF) and TADF-organic light-emitting diodes (OLEDs) systems are being given increasing attention in research nowadays. Much more work has been done for organic-based materials in this field, but the use of TADF organometallic systems has also emerged in recent years. In particular, TADF-based gold compound...
Article
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 grant...
Chapter
“Measuring the fluorescence of a sample” refers in common terms to measuring the emission of light emitted by substances following excitation by light. The term comprises both fluorescence and phosphorescence (emission from spin allowed or spin forbidden transitions, respectively) and relates more to the nature of the equipment used: the spectroflu...
Article
The comparison of the ground-state reactivity of anthocyanins and aurones model compounds (i.e. with and without the furano bridge) have shown that the kinetic paradigm does not depend on the bridge but only on the hydroxyl substituent pattern: Independently on the presence of the bridge: i) bell shaped kinetics for those with two hydroxyl substitu...
Article
The synthesis of three gold(I) tripodal complexes derived from tripropargylamine and containing the water soluble phosphines PTA (1, 3,5-triaza-7-phosphaadamantane), DAPTA (3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane) and TPPTS (triphenylphosfine-3,3’,3’’-trisulfonic acid trisodium salt) is here described. The three complexes are observ...
Article
Anthocyanins are the main polyphenolic dyes found in young red wines, which are transformed into more stable structures such as pyranoanthocyanins, during wine ageing and maturation. While anthocyanins practically lose their red color between pH 1 and 5, as a result of the formation of colorless hemiketals, pyranoanthocyanins practically do not cha...
Article
A tripodal coumarin derivative shows complex photoreactivity, changing from intra- to intermolecular photodimerization with increasing concentration. At high concentration, the compound undergoes efficient photopolymerization, resulting in the formation of polymeric...
Article
Full-text available
Membrane distillation (MD) has recently gained considerable attention as a valid process for the production of fresh-water due to its ability to exploit low grade waste heat for operation and to ensure a nearly feed concentration-independent production of high-purity distillate. Limitations have been related to polarization phenomena negatively aff...
Chapter
In this chapter, the current state of knowledge regarding anthocyanin chemistry and the corresponding reversible multistate system of the chemical species is presented. Mathematical equations to account for the kinetics and thermodynamics of the multistate system of anthocyanins are presented in a simple form to allow their use by non-specialists....
Article
As in supramolecular chemistry, complexity could also be achieved through a bottom-up approach. Anthocyanins and related compounds such as the compound (E)-6-(dimethylamino)-4-(4-(dimethylamino)-2-hydroxybenzylidene)-1,2,3,4-tetrahydroxanthylium chloride (1), here reported, exhibit this type of complexity. The thermodynamics and kinetics of the com...
Article
The thermodynamic and kinetic behavior of 4-(2,4-dihydroxybenzylidene)-6-hydroxy-1,2,3,4-tetrahydroxanthylium chloride was studied in detail. Similarly to anthocyanins, this compound generates a multistate of species that are reversibly interconverted by pH stimuli. The multistate system was studied by NMR and UV–visible (conventional spectroscopy...
Article
Full-text available
Cryopreservation of biological tissue has had a big spotlight in the field of medicine, as it aims for long-term storage of whole organs for transplantation and constant improvement of biobanking methodologies. However, current procedures still struggle with cryoprotectant cytotoxicity, optimal freeze-thaw rates and efficient carrier formulas. The...
Article
Full-text available
Undoped and manganese doped zinc sulfide nanoparticles were produced by a fast, one-step and two-component microwave-assisted synthesis method. The solid phase retains around 78% of the initial Mn concentration, as revealed by Particle Induced X-ray Emission analysis. X-ray diffraction patterns confirmed zinc blende structure and in the transmissio...
Article
An electronic spectral and photophysical characterization of three gold(I) complexes containing heterocyclic chromophores differing in the number and arrangement of pyridine rings (pyridine, bipyridine, and terpyridine, with the acronyms pD, bD, and tD respectively) was performed. Quantum yields of fluorescence, internal conversion and triplet stat...
Article
Invited for the cover of this issue are the groups of Laura Rodríguez, Alexandra R. Fernandes, João Carlos Lima, Pedro V. Baptista, and Kari Rissanen at the Universitat de Barcelona, Universidade Nova de Lisboa, and University of Jyväskylä. The image depicts the direct effect of the phosphine on the different biological activity of Au(I) complexes....
Article
The biological activity of a series of gold(I) complexes presenting the same chromophoric unit (4‐ethynylanile) and that differ on the phosphine located at the second coordination position was performed and shows, among other things, that mononuclear complexes are more cytotoxic against A2780 ovarian cells, whereas dinuclear complexes are effective...
Article
Full-text available
A series of novel donor-acceptor-donor (D-AD) compounds featuring dibenzothiophene (DBT) and phenothiazine (PTZ) units are presented. A different degree of steric hindrance between the donor and acceptor fragments is achieved by the systematic changes of donor substituents (methyl, iso-propyl, tert-butyl groups). This leads to the tuning of photoph...
Article
A series of 4‐ethynylaniline gold(I) complexes containing monophosphanes (1,3,5‐triaza‐7‐phosphaadamantane, PTA, 2; 3,7‐diacetyl‐1,3,7‐triaza‐5‐fosfabiciclo[3.3.1]nonane, 3; and PR3, being R = naphtyl, 4; phenyl, 5 and ethyl, 6) and diphosphanes (bis(diphenylphosphino)acetylene, dppa, 7; trans‐diphenylphosphineethene, dppet, 8; 1,2‐bis(diphenylphos...
Article
This work describes the development of a new selective photocontrollable molecularly imprinted-based sorbent for the selective enrichment/pre-concentration of dimethoate from spiked olive oil samples. To achieve this goal an improved molecularly imprinted strategy relying on the embedding of a functional monomer containing an azobenzene chromophore...
Article
Copper-cysteine interactions play an important role in Biology and herein we used the copper-substituted rubredoxin (Cu-Rd) from Desulfovibrio gigas to gain further insights into the copper-cysteine redox chemistry. EPR spectroscopy results are consistent with Cu-Rd harboring a CuII center in a sulfur-rich coordination, in a distorted tetrahedral s...
Article
Full-text available
With the purpose of modifying organic fluorescent dyes based on the coumarin scaffold, and developing and evaluating a route to its incorporation into a polymeric backbone, a study was conducted on the co-polymerization of 3-vinylcoumarins with styrene and methyl acrylate using 2,2-azobis(isobutyronitrile) (AIBN) as the radical initiator. The struc...
Article
Selective base pairing is the foundation of DNA recognition. Here, we elucidate the molecular and structural details of a FRET-based two-component molecular beacon relying on Steady-state Fluorescence Spectroscopy, Small-angle X-ray Scattering (SAXS), Microscale Thermophoresis (MST) and Differential Electrophoretic Mobility. This molecular beacon w...
Article
A set of coumarin dyes with styryl and phenylethynyl π-bridge at the 3-position were tested for dye-sensitized solar cells (DSSCs). The natural product 6,7-dihydroxycoumarin (Esculetin) was used as starting material. Crucial steps for extension of the conjugated system involved Sonogashira and regioselective Heck arylation reactions, yielding highl...
Article
Full-text available
The reaction of the gold polymers containing bipyridyl and terpyridyl units, [Au(C≡CC15H10N3)]n and [Au(C≡CC10H7N2)]n, with the water-soluble phosphines 1,3,5-triaza-7-phosphatricyclo[3.3.1.13.7]decane and 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane gives rise to the formation of four gold(I) alkynyl complexes that self-assemble in wate...
Article
Full-text available
A series of alkynyl gold(I) tri and tetratopic metallaligands of the type [Au3(C≡C-R)3(μ3-triphosphane)] (R = 2,2’-bipyridin-5-yl or C10H7N2, 2,2’:6’,2’’-terpyridin-4-yl or C15H10N3; triphosphane = 1,1,1-tris(diphenylphosphanyl)ethane or triphos, 1,3,5-tris(diphenylphosphanyl)benzene or triphosph) and [Au4(C≡C-R)4(μ4-tetraphosphane)] (R = C10H7N2,...
Article
Full-text available
Photothermal Therapy (PTT) impact in cancer therapy has been increasing due to the enhanced photothermal capabilities of a new generation of nanoscale photothermal agents. Among these nanoscale agents, gold nanoshells and nanorods have demonstrated optimal properties for translation of near infra-red radiation into heat at the site of interest. How...
Article
A Layered Lanthanide Hydroxide (LLH) material based on europium (LEuH, Eu8(OH)20Cl4.6H2O) was intercalated with 2,6-naphtalenedicarboxylate (NDC) yielding a material presenting the bright red luminescence characteristic of Eu3 +, both by direct excitation of europium and energy transfer from NDC. The material behaves as a sensor towards anions whic...
Article
Suzuki-Miyaura reaction of 8-iodochrysin, then, reduced by LiAlH4 to give the corresponding 3-deoxyanthocyanidins. At pH=1.0 the stable form is the 8-substituted flavylium cation in both compounds. At higher pH values the quinoidal bases are the stable species and some evidence for the 6,8-rearrangement was achieved, but the respective spectral var...