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1st CQE Days Meeting: 44 Years Connecting People and Chemistry

A special issue of Molecules (ISSN 1420-3049).

Deadline for manuscript submissions: closed (30 April 2020) | Viewed by 22435

Special Issue Editors

Centro de Química e Bioquímica, Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
Interests: analytical chemistry; sample preparation; microextraction techniques; chromatography; hyphenated techniques (GC-MS and LC-MS); environmental analysis; biological analysis
Special Issues, Collections and Topics in MDPI journals
Centro de Química Estrutural, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
Interests: organometallic/inorganic chemistry; peptide chemistry; metal–peptide conjugates; interaction studies with biomolecules; anticancer drug design and development; drug delivery; medicinal chemistry
Special Issues, Collections and Topics in MDPI journals
Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1749-016 Lisboa, Portugal
Interests: metallic biomaterials; in vitro degradation; bioactive coatings
Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
Interests: CO2 transformation; C-H Activation; Nanomaterials; Sustainable Catalysis and Thermophysical Properties
Special Issues, Collections and Topics in MDPI journals
Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1749-016 Lisboa, Portugal
Interests: mass spectrometry; drug metabolism; drug toxicity; metabolomics; pharmacometabolomics; proteomics; chemoproteomics; computational biochemistry; bioinformatics; drug repurposing
Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
Interests: ionic liquids; molecular dynamics simulations; ab initio calculations; nanoscience; thermodynamics; physical organic chemistry
Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
Interests: molecular dynamics; nucleation; polymorphism; active pharmaceutical ingredients; crystallization; calorimetry; instrumentation; ionic liquids
Special Issues, Collections and Topics in MDPI journals
Centro de Química e Bioquímica, Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
Interests: organic synthesis; natural products; drug development; carbohydrates chemistry

Special Issue Information

Dear Colleagues,

The Centro de Química Estrutural (CQE) is one of the oldest chemical research units in Portugal. It is recognized as one of the best of European research centers, with collaborations established with the top research centers and universities across Europe, the USA, and Japan, just to mention some.

This Special Issue will cover the research performed at Centro de Química Estrutural (CQE) mostly during the 1st edition of the CQE Days meeting, with the intent of sharing information about the research work carried.

With this Special Issue, it is intended for emphasis to be placed on the cooperation with industry or other academic partners. The list of topics is not confined to what is presented in the meeting, and manuscripts discussing advances in methodologies and effects on chemical or biological processes, including experimental, computational, and/or simulation studies are welcomed. Synthesis, catalysis, materials, nanochemistry, chemistry for the environment, energy, and medicinal and biological studies are topics of interest to this issue.

Dr. Nuno Neng
Dr. Tânia S. Morais
Dr. Marta M. Alves
Dr. Ana Paula C. Ribeiro
Dr. Gonçalo J. Justino
Dr. Karina Shimizu
Dr. Carlos E. S. Bernardes
Ms. Luciana Silva
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Synthesis, catalysis and reactivity
  • Materials, soft matter, and nanochemistry
  • Sustainable chemistry for the environment, energy, and manufacturing
  • Medicinal and biological chemistry for health

Published Papers (7 papers)

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Research

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12 pages, 2028 KiB  
Article
Thermal Conductivity of Metastable Ionic Liquid [C2mim][CH3SO3]
by Daniel Lozano-Martín, Salomé Inês Cardoso Vieira, Xavier Paredes, Maria José Vitoriano Lourenço, Carlos A. Nieto de Castro, Jan V. Sengers and Klemens Massonne
Molecules 2020, 25(18), 4290; https://doi.org/10.3390/molecules25184290 - 18 Sep 2020
Cited by 15 | Viewed by 4059
Abstract
Ionic liquids have been suggested as new engineering fluids, namely in the area of heat transfer, as alternatives to current biphenyl and diphenyl oxide, alkylated aromatics and dimethyl polysiloxane oils, which degrade above 200 °C and pose some environmental problems. Recently, we have [...] Read more.
Ionic liquids have been suggested as new engineering fluids, namely in the area of heat transfer, as alternatives to current biphenyl and diphenyl oxide, alkylated aromatics and dimethyl polysiloxane oils, which degrade above 200 °C and pose some environmental problems. Recently, we have proposed 1-ethyl-3-methylimidazolium methanesulfonate, [C2mim][CH3SO3], as a new heat transfer fluid, because of its thermophysical and toxicological properties. However, there are some interesting points raised in this work, namely the possibility of the existence of liquid metastability below the melting point (303 K) or second order-disorder transitions (λ-type) before reaching the calorimetric freezing point. This paper analyses in more detail this zone of the phase diagram of the pure fluid, by reporting accurate thermal-conductivity measurements between 278 and 355 K with an estimated uncertainty of 2% at a 95% confidence level. A new value of the melting temperature is also reported, Tmelt = 307.8 ± 1 K. Results obtained support liquid metastability behaviour in the solid-phase region and permit the use of this ionic liquid at a heat transfer fluid at temperatures below its melting point. Thermal conductivity models based on Bridgman theory and estimation formulas were also used in this work, failing to predict the experimental data within its uncertainty. Full article
(This article belongs to the Special Issue 1st CQE Days Meeting: 44 Years Connecting People and Chemistry)
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14 pages, 4633 KiB  
Article
Zn(II)-to-Cu(II) Transmetalation in an Amide Functionalized Complex and Catalytic Applications in Styrene Oxidation and Nitroaldol Coupling
by Anup Paul, Luísa M. D. R. S. Martins, Anirban Karmakar, Maxim L. Kuznetsov, M. Fátima C. Guedes da Silva and Armando J. L. Pombeiro
Molecules 2020, 25(11), 2644; https://doi.org/10.3390/molecules25112644 - 06 Jun 2020
Cited by 27 | Viewed by 3134
Abstract
The mononuclear zinc(II) complex cis-[ZnL2(H2O)2] (1; L = 4-(pyridin-3-ylcarbamoyl)benzoate) was synthesized and characterized. By soaking crystals of 1 in a mixture of DMF-H2O solution containing a slight excess of Cu(NO3) [...] Read more.
The mononuclear zinc(II) complex cis-[ZnL2(H2O)2] (1; L = 4-(pyridin-3-ylcarbamoyl)benzoate) was synthesized and characterized. By soaking crystals of 1 in a mixture of DMF-H2O solution containing a slight excess of Cu(NO3)2 × 3H2O a transmetalation reaction occurred affording the related copper(II) complex trans-[CuL2(H2O)2] (2). The structures of the compounds were authenticated by single crystal X-ray diffraction revealing, apart from a change in the isomerism, an alteration in the relative orientation of the chelating carboxylate groups and of the pyridine moieties. H-bond interactions stabilize both geometries and expand them into two-dimensional (2D) networks. The transmetalation was confirmed by SEM–EDS analysis. Moreover, the thermodynamic feasibility of the transmetalation is demonstrated by density-functional theory (DFT) studies. The catalytic activities of 1 and 2 for the oxidation of styrene and for the nitroaldol (Henry) C-C coupling reaction were investigated. The copper(II) compound 2 acts as heterogeneous catalyst for the microwave-assisted oxidation of styrene with aqueous hydrogen peroxide, yielding selectively (>99%) benzaldehyde up to 66% of conversion and with a turnover frequency (TOF) of 132 h−1. The zinc(II) complex 1 is the most active catalyst (up to 87% yield) towards the nitroaldol (Henry) coupling reaction between benzaldehyde and nitro-methane or -ethane to afford the corresponding β-nitro alcohols. The reaction of benzaldehyde with nitroethane in the presence of 1 produced 2-nitro-1-phenylpropanol in the syn and the anti diastereoisomeric forms, with a considerable higher selectivity towards the former (66:34). Full article
(This article belongs to the Special Issue 1st CQE Days Meeting: 44 Years Connecting People and Chemistry)
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14 pages, 1739 KiB  
Article
A Comparison of Different Approaches to Quantify Nitric Oxide Release from NO-Releasing Materials in Relevant Biological Media
by Rosana V. Pinto, Fernando Antunes, João Pires, Ana Silva-Herdade and Moisés L. Pinto
Molecules 2020, 25(11), 2580; https://doi.org/10.3390/molecules25112580 - 02 Jun 2020
Cited by 12 | Viewed by 2900
Abstract
The development of solid materials that deliver nitric oxide (NO) are of interest for several therapeutic applications. Nevertheless, due to NO’s reactive nature, rapid diffusion and short half-life, reporting their NO delivery characteristics is rather complex. The full knowledge of this parameter is [...] Read more.
The development of solid materials that deliver nitric oxide (NO) are of interest for several therapeutic applications. Nevertheless, due to NO’s reactive nature, rapid diffusion and short half-life, reporting their NO delivery characteristics is rather complex. The full knowledge of this parameter is fundamental to discuss the therapeutic utility of these materials, and thus, the NO quantification strategy must be carefully considered according to the NO-releasing scaffold type, to the expected NO-releasing amounts and to the medium of quantification. In this work, we explore and discuss three different ways of quantifying the release of NO in different biological fluids: haemoglobin assay, Griess assay and NO electrochemical detection. For these measurements, different porous materials, namely zeolites and titanosilicates were used as models for NO-releasing platforms. The oxyhaemoglobin assay offers great sensitivity (nanomolar levels), but it is only possible to monitor the NO release while oxyhaemoglobin is not fully converted. On the other hand, Griess assay has low sensitivity in complex biological media, namely in blood, and interferences with media make NO measurements questionable. Nevertheless, this method can measure micromolar amounts of NO and may be useful for an initial screening for long-term release performance. The electrochemical sensor enabled real-time measurements in a variety of biological settings. However, measured NO is critically low in oxygenated and complex media, giving transient signals, which makes long-term quantification impossible. Despite the disadvantages of each method, the combination of all the results provided a more comprehensive NO release profile for these materials, which will help to determine which formulations are most promising for specific therapeutic applications. This study highlights the importance of using appropriate NO quantification tools to provide accurate reports. Full article
(This article belongs to the Special Issue 1st CQE Days Meeting: 44 Years Connecting People and Chemistry)
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14 pages, 5507 KiB  
Article
Bioactivity of Isostructural Hydrogen Bonding Frameworks Built from Pipemidic Acid Metal Complexes
by Paula C. Alves, Patrícia Rijo, Catarina Bravo, Alexandra M. M. Antunes and Vânia André
Molecules 2020, 25(10), 2374; https://doi.org/10.3390/molecules25102374 - 20 May 2020
Cited by 14 | Viewed by 3191
Abstract
We report herein three novel complexes whose design was based on the approach that consists of combining commercially available antibiotics with metals to attain different physicochemical properties and promote antimicrobial activity. Thus, new isostructural three-dimensional (3D) hydrogen bonding frameworks of pipemidic acid with [...] Read more.
We report herein three novel complexes whose design was based on the approach that consists of combining commercially available antibiotics with metals to attain different physicochemical properties and promote antimicrobial activity. Thus, new isostructural three-dimensional (3D) hydrogen bonding frameworks of pipemidic acid with manganese (II), zinc (II) and calcium (II) have been synthesised by mechanochemistry and are stable under shelf conditions. Notably, the antimicrobial activity of the compounds is maintained or even increased; in particular, the activity of the complexes is augmented against Escherichia coli, a representative of Gram-negative bacteria that have emerged as a major concern in drug resistance. Moreover, the synthesised compounds display similar general toxicity (Artemia salina model) levels to the original antibiotic, pipemidic acid. The increased antibacterial activity of the synthesised compounds, together with their appropriate toxicity levels, are promising outcomes. Full article
(This article belongs to the Special Issue 1st CQE Days Meeting: 44 Years Connecting People and Chemistry)
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13 pages, 798 KiB  
Article
Bar Adsorptive Microextraction Coated with Carbon-Based Phase Mixtures for Performance-Enhancement to Monitor Selected Benzotriazoles, Benzothiazoles, and Benzenesulfonamides in Environmental Water Matrices
by Samir M. Ahmad, Bruno B.C. Calado, Mariana N. Oliveira, Nuno R. Neng and J.M.F. Nogueira
Molecules 2020, 25(9), 2133; https://doi.org/10.3390/molecules25092133 - 02 May 2020
Cited by 8 | Viewed by 2208
Abstract
In the present work we propose, for the first time, bar adsorptive microextraction coated with carbon-based phase mixtures, followed by microliquid desorption and high performance liquid chromatography-diode array detection (BAμE-μLD/HPLC-DAD) analysis, to enhance the performance of the determination of traces of benzotriazoles (BTRs), [...] Read more.
In the present work we propose, for the first time, bar adsorptive microextraction coated with carbon-based phase mixtures, followed by microliquid desorption and high performance liquid chromatography-diode array detection (BAμE-μLD/HPLC-DAD) analysis, to enhance the performance of the determination of traces of benzotriazoles (BTRs), benzothiazoles (BTs), and benzenesulfonamide derivatives (BSDs) in environmental water matrices. Assessing six carbon-based sorbents (CA1, CN1, B test EUR, SX PLUS, SX 1, and R) with different selectivity properties allowed us to tailor the best phase mixture (R, 12.5%/CN1, 87.5%) that has convenient porosity, texture, and surface chemistry (pHPZC,mix ~6.5) for trace analysis of benzenesulfonamide, 1-hydroxybenzotriazole, 1H-benzotriazole, 5-methyl-1H-benzotriazole, benzothiazole, and 1,3-benzothiazol-2-ol chemicals in aqueous media. Optimized experimental conditions provided average recoveries ranging from 37.9% to 59.2%, appropriate linear dynamic ranges (5.0 to 120.0 µg L−1; r2 ≥ 0.9964), limits of detection between 1.0 and 1.4 μg L−1, and good precisions (relative standard deviation (RSD) ≤ 9.3%). The proposed methodology (BAμE(R, 12.5%/CN1, 87.5%)-μLD/HPLC-DAD) also proved to be a suitable sorption-based static microextraction alternative to monitor traces of BTRs, BTs, and BSDs in rain, waste, tap, and estuarine water samples. From the data obtained, the proposed approach showed that the BAμE technique with the addition of lab-made devices allows users to adapt the technique to use sorbents or mixtures of sorbents with the best selectivity characteristics whenever distinct classes of target analytes occur simultaneously in the same application. Full article
(This article belongs to the Special Issue 1st CQE Days Meeting: 44 Years Connecting People and Chemistry)
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22 pages, 5175 KiB  
Article
A New Family of Iron(II)-Cyclopentadienyl Compounds Shows Strong Activity against Colorectal and Triple Negative Breast Cancer Cells
by Adhan Pilon, Ana Rita Brás, Leonor Côrte-Real, Fernando Avecilla, Paulo J. Costa, Ana Preto, M. Helena Garcia and Andreia Valente
Molecules 2020, 25(7), 1592; https://doi.org/10.3390/molecules25071592 - 30 Mar 2020
Cited by 20 | Viewed by 3469
Abstract
A family of compounds with the general formula [Fe(η5-C5H5)(CO)(PPh3)(NCR)]+ has been synthesized (NCR = benzonitrile (1); 4-hydroxybenzonitrile (2); 4-hydroxymethylbenzonitrile (3); 4-aminobenzonitrile (4); 4-bromobenzonitrile (5); [...] Read more.
A family of compounds with the general formula [Fe(η5-C5H5)(CO)(PPh3)(NCR)]+ has been synthesized (NCR = benzonitrile (1); 4-hydroxybenzonitrile (2); 4-hydroxymethylbenzonitrile (3); 4-aminobenzonitrile (4); 4-bromobenzonitrile (5); and, 4-chlorocinnamonitrile (6)). All of the compounds were obtained in good yields and were completely characterized by standard spectroscopic and analytical techniques. Compounds 1, 4, and 5 crystallize in the monoclinc P21/c space group and packing is determined by short contacts between the phosphane phenyl rings and cyclopentadienyl (compounds 1 and 4) or π-π lateral interactions between the benzonitrile molecules (complex 5). DFT and TD-DFT calculations were performed to help in the interpretation of the experimental UV-Vis. data and assign the electronic transitions. Cytotoxicity studies in MDA-MB-231 breast and SW480 colorectal cancer-derived cell lines showed IC50 values at a low micromolar range for all of the compounds in both cell lines. The determination of the selectivity index for colorectal cells (SW480 vs. NCM460, a normal colon-derived cell line) indicates that the compounds have some inherent selectivity. Further studies on the SW480 cell line demonstrated that the compounds induce cell death by apoptosis, inhibit proliferation by inhibiting the formation of colonies, and affect the actin-cytoskeleton of the cells. These results are not observed for the hydroxylated compounds 2 and 3, where an alternative mode of action might be present. Overall, the results indicate that the substituent at the nitrile-based ligand is associated to the biological activity of the compounds. Full article
(This article belongs to the Special Issue 1st CQE Days Meeting: 44 Years Connecting People and Chemistry)
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Review

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20 pages, 6121 KiB  
Review
The Lisbon Supramolecular Green Story: Mechanochemistry towards New Forms of Pharmaceuticals
by João Luís Ferreira da Silva, M. Fátima Minas da Piedade, Vânia André, Sofia Domingos, Inês C. B. Martins and M. Teresa Duarte
Molecules 2020, 25(11), 2705; https://doi.org/10.3390/molecules25112705 - 11 Jun 2020
Cited by 7 | Viewed by 2616
Abstract
This short review presents and highlights the work performed by the Lisbon Group on the mechanochemical synthesis of active pharmaceutical ingredients (APIs) multicomponent compounds. Here, we show some of our most relevant contributions on the synthesis of supramolecular derivatives of well-known commercial used [...] Read more.
This short review presents and highlights the work performed by the Lisbon Group on the mechanochemical synthesis of active pharmaceutical ingredients (APIs) multicomponent compounds. Here, we show some of our most relevant contributions on the synthesis of supramolecular derivatives of well-known commercial used drugs and the corresponding improvement on their physicochemical properties. The study reflects, not only our pursuit of using crystal engineering principles for the search of supramolecular entities, but also our aim to correlate them with the desired properties. The work also covers our results on polymorphic screening and describes our proposed alternatives to induce and maintain specific polymorphic forms, and our approach to avoid polymorphism using APIs as ionic liquids. We want to stress that all the work was performed using mechanochemistry, a green advantageous synthetic technique. Full article
(This article belongs to the Special Issue 1st CQE Days Meeting: 44 Years Connecting People and Chemistry)
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