I GIOVANI E LA CHIMICA IN ABRUZZO workshop di giovani ricercatori chimici
5-6 LUGLIO 2021
Book of Abstracts
Società Chimica Italiana – Università degli Studi dell’Aquila
Copyright © 2021. All Rights Reserved
ISBN 978-88-94952-22-3 (Electronic Version)
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T3 workshop di giovani ricercatori chimici 0 5 / 0 7 / 2 0 2 1
8:50 - 9:00 OPENING REMARKS
INDUSTRIAL TALK IL RUOLO DELLA CHIMICA PER LO SVILUPPO SOSTENIBILE 9:00 - 9:30 Dott.ssa Cristiana Gaburri, Direttore della Direzione Tecnico-Scientifica - Federchimica
ORGANOCATALYZED MICHAEL ADDITION TO NITROALKENES VIA MASKED ACETALDEHYDE Valeria Nori - Università degli Studi dell'Aquila ORANGE PEELS-DERIVED HYDROCHAR FOR CHEMICAL SENSING APPLICATIONS Antonella Satira - Università degli Studi “Mediterranea” di Reggio Calabria
TOWARDS AN ELECTRIFYING FUTURE: NEW APPROACHES IN ORGANIC SYNTHESIS Alessia Petti - University of Greenwich SCIENTIFIC TALKS PHYTOCOMPOUND-EXFOLIATED GRAPHENE AS ALTERNATIVE REDOX- 9:30 - 10:40 ACTIVE NANOMATERIAL FOR (BIO)SENSORS DEVELOPMENT 7 min presentation Filippo Silveri - Università degli Studi di Teramo + CATALYTIC DEOXYGENATION OF DIFFERENT VEGETABLE OILS USING 3 min discussion TRANSITION METAL CATALYSTS SUPPORTED ON FLY ASH CENOSPHERES Giuseppe Di Vito Nolfi - Università degli Studi dell'Aquila EXPLORING DETECTORS FOR LEGEND 200 THROUGH MATERIAL SCREENING AND CHARACTERIZATION OF DETECTOR’S CONNECTIONS BY HR-ICP-MS Francesco Ferella - Università degli Studi dell'Aquila/INFN WATER-SOLUBLE CARVACROL PRODRUGS AND RELATIVE FORMULATIONS WITH ANTIMICROBIAL AND ANTIFUNGAL PROPERTIES Annalisa Di Rienzo - Università degli Studi “G. d’Annunzio” di Chieti-Pescara BREAK 10:40 - 10:55 Chair: Prof. Marco Chiarini AMINOCATALYSIS PERFORMED BY SUPRAMOLECULAR FIBRILS Arianna Sinibaldi - Università degli Studi dell'Aquila SPENT LITHIUM-COBALT BATTERIES AS AN EFFICIENT HETEROGENEOUS CATALYST FOR THE REDUCTIVE UPGRADING OF BIOMASS DERIVED FURAN PROMOTED Emilia Paone - Università degli Studi “Mediterranea” di Reggio Calabria POLYSACCHARIDE-BASED FILMS AS SUSTAINABLE ACTIVE FOOD PACKAGING SCIENTIFIC TALKS Francesco Gabriele - Università degli Studi dell'Aquila 10:55 - 12:15 ON RESIN CLICK CHEMISTRY MEDIATED SYNTHESIS OF NOVEL ENKEPHALIN SCIENTIFIC TALKS ANALOGUES WITH POTENT ANTINOCICEPTIVE ACTIVITY 7 min presentation Marilisa Pia Dimmito - Università degli Studi “G. d’Annunzio” di Chieti-Pescara +
3 min discussion THERMODYNAMICS OF THE HYDROLYSIS OF LITHIUM SALTS: PATHWAYS TO THE INORGANIC SEI COMPONENTS Simone Di Muzio - Università degli Studi dell'Aquila THE IMPACT OF CHARGE IN A NI(II) POLYMERIZATION CATALYSTS
Maria Voccia - Università degli Studi di Salerno GEOGRAPHICAL DISCRIMINATION OF HIGH VALUE ITALIAN BELL PEPPER (CAPSICUM ANNUUM) VARIETIES BY MEANS OF ICP-OES MULTI-ELEMENTAL ANALYSIS COUPLED WITH CHEMOMETRICS Francesca Di Donato - Università degli Studi dell'Aquila LIPOSOMES AS POTENTIAL DRUG CARRIES FOR LEVODOPA Elena Allegritti - Università degli Studi dell'Aquila BREAK 12:15 - 12:30 QUANDO LA SCIENZA INCONTRA L’AGRICOLTURA: L’EVOLUZIONE INDUSTRIAL TALK DELL’AGRI-BUSINESS NELL’ECONOMIA MONDIALE 12:30 - 13:00 Dott. Juan Fernando Mejia, Microbials Science Manager - Valagro 0 6 / 0 7 / 2 0 2 1
8:50 - 9:00 OPENING REMARKS
INDUSTRIAL TALK IL CONSULENTE IN BREVETTI - UNA PROFESSIONE TRA SCIENZA E DIRITTO 9:00 - 9:30 Dr. Vera Munchow – Adexe s.r.l.
A BIOGAS PRODUCTION FROM ANCHOVIES RESIDUES AFTER NUTRACEUTICS EXTRACTION Daniela Maria Pizzone - Università degli Studi “Mediterranea” di Reggio Calabria SPECTROSCOPIC FINGERPRINTING AND CHEMOMETRICS FOR THE DISCRIMINATION OF ITALIAN EMMER LANDRACES SCIENTIFIC TALKS Martina Foschi - Università degli Studi dell'Aquila 9:30 - 10:30 CERIA-SUPPORTED METAL NANOPARTICLES FOR CO ABATEMENT IN COMBUSTION EXHAUST GASES 7 min presentation Andrea Lazzarini - Università degli Studi dell'Aquila + 3 min discussion ISOLATION OF AMAROGENTIN, THE BITTER PRINCIPLE OF GENTIANA LUTEA ROOTS Lucia Palumbo - Università degli Studi “G. d’Annunzio” di Chieti-Pescara IMMOBILIZATION OF CANDIDA RUGOSA LIPASE IN ALGINATE BEADS FOR CATALYTIC PURPOSE Alice Vetrano - Università degli Studi dell'Aquila SYNTHESIS AND CHARACTERIZATION OF LINEAR PEPTIDES ANALOGUES OF ENDOMORPHINE-2 AND MET/LEU-ENKEPHALIN CONTAINING A FREIDINGER Γ- LACTAM Alice Della Valle - Università degli Studi “G. d’Annunzio” di Chieti-Pescara BREAK 10:30 - 10:50 Chair: Prof. Armando Carlone
MULTI-WAY CHEMOMETRIC ANALYSIS OF HPLC-DAD SPECTRO- CHROMATOGRAMS Alessandra Biancolillo - Università degli Studi dell'Aquila CALIXARENE-BASED ARTIFICIAL IONOPHORES FOR CHLORIDE TRANSPORT ACROSS NATURAL LIPOSOMAL BILAYER Serena Pilato - Università degli Studi “G. d’Annunzio” di Chieti-Pescara
SYNTHESIS OF VALUABLE HETEROCYCLIC SCAFFOLDS BY MEANS OF CASCADE REACTIONS OF 2-ALKYNYLANILINE DERIVATIVES WITH ELECTROPHILES SCIENTIFIC TALKS Vincenzo Marsicano - Università degli Studi dell'Aquila
10:50 - 11:50 USE OF COATED SUPERPARAMAGNETIC IRON OXIDE NANOPARTICLES 7 min presentation (SPIONS) AS VERSATILE SUPPORT FOR THE PREPARATION OF RECYCLABLE + HETEROGENEOUS CATALYSTS 3 min discussion Roberta Colaiezzi - Università degli Studi dell'Aquila
PREPARATION OF POROUS GRAPHENE-BASED SUBSTRATES OXIDE FOR CELL GROWTH Samanta Moffa - Università degli Studi “G. d’Annunzio” di Chieti-Pescara INVESTIGATION OF ANTIBACTERIAL ACTIVITY OF CU(II) PYRAZOLATE COORDINATION POLYMERS Patrizio Campitelli - Università di Camerino BREAK 11:50 - 12:15
INDUSTRIAL TALK NEW PROCESS APPROACH FOR “OLD” API – THE EXAMPLE OF TRAZODONE 12:15 - 12:45 Dr Guido Furlotti – Fine Chemicals – Process Development Manager - Angelini Pharma S.p.A.
CLOSING REMARKS AND AWARDS CERIMONY Scientific Committee: Chief Fabio Marinelli Università degli Studi dell'Aquila - Presidente SCI Abruzzo Members Armando Carlone Università degli Studi dell'Aquila Marco Chiarini Università degli Studi di Teramo Marcello Crucianelli Università degli Studi dell'Aquila Antonella Fontana Università degli Studi di Chieti-Pescara Samantha Reale Università degli Studi dell'Aquila
Organising Committee: Chief Fabio Marinelli Università degli Studi dell'Aquila - Presidente SCI Abruzzo Members Armando Carlone Università degli Studi dell'Aquila Marco Chiarini Università degli Studi di Teramo Marcello Crucianelli Università degli Studi dell'Aquila Antonella Fontana Università degli Studi di Chieti-Pescara Samantha Reale Università degli Studi dell'Aquila Valeria Nori Università degli Studi dell'Aquila
Technical assistant for OnLine meeting: Maurizio Cironi Università degli Studi dell'Aquila
Oral Communications
T8 Liposomes as potential drug carries for levodopa Elena Allegritti,a Sara Battista,a Maria Anna Maggi,b María Luisa González Rodríguez,cLuisa Giansanti.a a Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio 1, 67100, Coppito, L’Aquila bHortus Novus, Via Collepietro, 67100, L’Aquila cDepartamento de Farmacia y Tecnología Farmacéutica, Universidad de Sevilla, Calle Profesor García González 2, 41012, Sevilla
e-mail (primo autore) [email protected]
Parkinson's disease (PD) is the second most common age-related neurodegenerative disorder andaffects an estimated 10 million sufferers worldwide. It is characterized by a progressive loss of dopaminergic neurons in the substantia nigra, resulting in low brain dopamine concentration1.Dopamine itself is unable to cross the blood brain barrier (BBB) and cannot be used to treat PD, while levodopa (L-DOPA,Figure 1), a precursor, can reach the target site. This pro-drug is still considered the gold standard therapy used to treat PD, despite the fact thatit is easily oxidized becoming inactive and less than the 3% of the administered L-DOPA gets to the brain, leadingto significant side effects2.Therefore, there is a need to develop new strategies that are able to extend and control the release of this drug.
Figure 1: L-DOPA, L-ascorbic acid and quercetin structures
Liposomes, which are sphere-shaped vesicles, could be suitable levodopa carriers: in addition to being biocompatible, they have a structure that gives them the ability to load also antioxidant molecules together with L-DOPA in order to prevent its oxidation and to retard the progression of PD. Furthermore, liposomes have gained attraction as a formulation to deliver drugs to the brain by intranasal administrationbecause this approach grants direct access to the brain circumventing needs to cross the BBB3. Based on these premises, L-DOPA and natural antioxidants (L-ascorbic acid or quercetin, Figure 1)were included in mixed liposomesformulated with structurally related lipidsto investigate the effect of liposomes composition.
1 Poewe, W., Seppi, K., Tanner, C. et al., Nat Rev Dis Primers, 2017, 3, 17013. 2 Poewe, W., Antonini, A., Zijlmans, J., Burkhard, P. R., Vingerhoets, F., Clin Interv Aging, 2010, 5, 229. 3 Hong, S-S.; Oh, K.T.; Choi, H-G., Lim, S-J., Pharmaceutics, 2019, 11, 540.
T1 Multi-way chemometric analysis of HPLC-DAD spectro-chromatograms Alessandra Biancolillo,a Maria Anna Maggi, Alessandra De Martino, Federico Marini, Fabrizio Ruggieri, Angelo Antonio D’Archivio a Dipartimento di Scienze fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio, 67100, Coppito, L’Aquila b Hortus Novus, Viale Aldo Moro 28 D, 67100, L'Aquila, Italy c Dipartimento di Chimica, Università di Roma “La Sapienza”, Piazzale Aldo Moro 5, 00185, Roma
Reversed-phase high-performance liquid chromatography (HPLC) coupled with photometric, or mass-spectrometry detection plays a relevant role in the field of food quality control and geographical discrimination. Often, the interest is on specific major components responsible of the peculiarities of the samples. Conventionally, the peak intensities observed in conventional HPLC chromatograms, obtained by photometric detectors working at a predefined wavelength, are adopted for authentication/characterization of a food product. HPLC coupled with Diode array detection (DAD) allows the simultaneous acquisition of information on the retention behavior and structure-related spectral patterns of the solutes, providing richer information in comparison with that given by a univariate chromatogram. In the present study, a multi-way methodology for the analysis of the comprehensive information carried by the HPLC-DAD spectro-chromatogram is proposed. This novel strategy has been tested on a classification problem, related to the discrimination of PDO saffron of L'Aquila from other samples of the same spice1. The novel methodology exploits the multi-way nature of data, avoiding discarding any source of information. Consequently, the entire spectro-chromatogram is handled by N-Partial Least Squares (N-PLS) and then classified by Linear Discriminant Analysis (LDA). The proposed strategy has been compared with a more traditional analysis of the chromatograms at specific wavelengths. Both approaches provided satisfactory accuracies; the best results from the prediction point of view (estimated on an external set of samples) were achieved by the multi- way methodology. In fact, this latter approach provided the most accurate results and, eventually, its combination with VIP analysis led to a further improvement of predictions. This achievement indicates that three-way spectro-chromatograms contain relevant information for the characterization of the investigated samples, which is lost restricting the analysis to only few specific wavelengths.
Bibliografia 1Biancolillo, A.; Maggi, M.A.; De Martino, A.; Marini, F.; Ruggieri, F.; D’Archivio, A.A., Food Control, 2020, 110, 107022.
T2 INVESTIGATION OF ANTIBACTERIAL ACTIVITY OF Cu(II) PYRAZOLATE COORDINATION POLYMERS Patrizio Campitelli,a Corrado Di Nicola,a Alessia Tombesi,a Claudio Pettinari, b Fabio Marchetti,a Riccardo Pettinari,b Simona Galli,c Stefania Scuri b aScuola di Scienze e Tecnologie e bScuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, Via S. Agostino 1, 62032, Camerino (MC), cDipartimento di Scienza e Alta Tecnologia, Università degli Studi dell’Insubria, Via Valleggio 11, 22100, Como
Coordination polymers (CPs) are a class of inorganic-organic hybrid polymers formed by coordination entities repeating in one, two or three dimensions, introduced by Robson and Hoskins for the first time in 1989.1 Since then, a wide range of coordination polymers based on different metals and organic linkers have been synthesized and employed in numerous applications such as heterogeneous catalysis, conductivity, magnetism, nanoelectronics and photo/electroluminescence. After the first generation of CPs based on polytopic carboxylates linkers, CPs with nitrogen-donor ligands such as pyrazolates, imidazolates, triazolates and tetrazolates too have been reported. In the past few years, we have focused our attention on the reaction between copper(II) acetate and pyrazole or 4-X-pyrazole (X= NO2,Cl,Br,I) in different polar solvents.2 Eight novel Cu(II)-pyrazolate CPs have been obtained and fully characterised by IR, TGA/DTA, UV, E.A and magnetic susceptibility. Their structures have been solved from XRPD showing square planar trans-CuN2O2 metal centre in the case of [Cu(μ-pz)(μ-OH)]n or octahedral trans-CuN4O2 metal centre for the other CPs. Recently, the antibacterial activity of such eight CPs against Gram-negative (P. aeruginosa, E. coli) and Gram-positive (S. aureus) bacteria has been tested (Figure 1), given the well documented bactericidal activity of Cu(II) compounds to a wide range of microorganisms.3 Several biological tests have been conducted in order to investigate not only the activity, but the mechanism involved: Bacterial Growth Inhibition, Propidium Iodide (PI) Intake, detection of Reactive Oxygen Species (ROS), Lipid Peroxidation and Biofilm tests. Results have demonstrated for all Cu(II)-pyrazolate CPs a better antimicrobial activity against Gram- than Gram+ and suggested two plausible action mechanisms: metal ions release and production of ROS which degrade lipids, proteins and nucleic acids.
Figure 1 Sketch of Cu pyrazolate CPs; on the right, E. coli growth in presence(down) and in absence(top) of [Cu(NO2-pz)2]n 1Hoskins, B. F.; Robson, R.; J. Am. Chem. Soc., 1989, 111, 15, 5962 2Di Nicola, C.; Tombesi, A.; Moroni, M.; Vismara, R.; Marchetti, F.; Pettinari, R.; Nardo, L.; Vesco, G.; Galli, S.; Casassa, S.; Pandolfo, L.; Pettinari, C.; CrystEngComm, 2020, 22, 3294 3Rauf, A.; Ye, J.; Zhang, S.; Qi, Y.; Wang, G.; Che, Y.; Ning, G.; Dalton Trans., 2019,48, 17810
T3 Use of coated SuperParamagnetic Iron Oxide Nanoparticles (SPIONs) as versatile support for the preparation of recyclable heterogeneous catalysts
Roberta Colaiezzi, Andrea Lazzarini, Andrea Di Giuseppe, Marcello Crucianelli Department of Physical and Chemical Sciences, University of L’Aquila, Via Vetoio (COPPITO 1-2), 67100, L’Aquila, Italy
Magnetic iron oxide nanoparticles (NPs) have great potential, among others, as magnetic recyclable nano-catalysts, as information storage materials, in adsorption/separation processes and, even, in biomedical applications. Focusing on the catalytic research field, the importance of the recyclability of a heterogeneous catalyst is an aspect that is arousing much interest in the scientific community1. Silica-coated superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized to be used as a starting core for easily recoverable heterogeneous catalyst supports. Both the properties of the magnetic core and the cover shell have been finely tuned, with particular attention in optimizing the thickness of the silica layer. A complete set of characterization techniques was employed to reveal the characteristics of the catalyst. We are currently developing a procedure for the heterogenization of organometallic complexes based on Mo containing Schiff Bases in the organic ligand, shown in Figure 1.
Figure 1: synthetic procedure of the heterogeneous catalysts
For this reason, the efficiency of the coating is essential to provide a tailored anchor point for the active phase of the catalyst. The oxidation of cis-cyclooctene with tert-butyl hydroperoxide in the presence of SPION was used as a reaction probe to verify the reactivity, if any, of the coated NPs, as it is, and the effectiveness of the silica shield2. The results of these tests showed its chemical inertness confirming the absence of side reactions catalyzed by iron oxide or modifications of the magnetic core. This reaction was also used as a model reaction for preliminary catalytic tests, which showed high yields and selectivity, as well as good recyclability.
References 1M. B.Gawande, Y. Mongab, R. Zborila, R.K.Sharmab, Coord. Chem. Rev.2015, 288, 118. 2A. Lazzarini, R. Colaiezzi, M. Passacantando, F. D’Orazio, L. Arrizza, F. Ferella, M. Crucianelli, J. Phys. Chem. Solids, 2021, 153, 110003.
T4 SYNTHESIS AND CHARACTERIZATION OF LINEAR PEPTIDES ANALOGUES OF ENDOMORPHINE-2 AND MET/LEU-ENKEPHALIN CONTAINING A FREIDINGER g-LACTAM
Alice Della Valle,a Azzurra Stefanucci,a Giuseppe Scioli,a Adriano Mollica a a Department of Pharmacy, University of Chieti-Pescara “G. d’Annunzio”, via dei Vestini, 66100, Chieti
The aim of this work is the design and the synthesis of linear analogues of endomorphine-2 and Met/Leu-enkephalin with a local restriction in the linear sequence. The new peptides retain the pharmacophoric residue of the original endomorphine-2 and Met/Leu-enkephalin with the incorporation of a Freidinger g-lactam in position 2 or 3 (Figure 1). The Freidinger g- lactam is considered a mimetic of L-Proline residue, which is fundamental for the correct spatial orientation of the endomorphine-2 backbone in the binding site of µ-receptor1. The Freidinger g-lactam was obtained by sulphur-methylation of L/D-Methionine following a stereoselective intramolecular cyclization into the peptide sequence. Results show a high antinociceptive effect in the formalin test in vivo for the peptide series D after subcutaneous administration, according to a good efficacy in the mobilization of calcium in the µ-opioid receptor in the functional assay.
Figure 1. Structures of final products obtained
References
1Freidinger, R.M., Veber, D.F., Hirschmann, R., Paege, L.M. Int. J. Pept. Protein Res. 1980, Vol. 16, 464.
T5 GEOGRAPHICAL DISCRIMINATION OF HIGH VALUE ITALIAN BELL PEPPER (Capsicum annuum) VARIETIES BY MEANS OF ICP- OES MULTI-ELEMENTAL ANALYSIS COUPLED WITH CHEMOMETRICS Francesca Di Donato,a Alessandra Biancolillo, Angelo Antonio D’Archiviob a Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetotio, 66100, L’Aquila
Bell Pepper, a berry obtained from some varieties of the Capsicum annuum species, represents one of the key ingredients of several traditional dishes, also as seasoning, because it is traditionally left to air-dry, then toasted and reduced to powder. Specific varieties of Italian pepper have been awarded by quality marks as confirmation of their unique organoleptic peculiarities and their link to the production area. It is the case of Peperone di Senise (Basilicata, Italy), labelled as Protected Geographical Indication (PGI) by the European Commission (EAmbrosia), and Peperone di Altino (Abruzzo, Italy), included by the Slow Food Foundation for Biodiversity in the list of traditional food to safeguard (Altino Sweet Pepper - Presìdi Slow Food - Slow Food Foundation). Due to the market value of these protected products, their authenticity is often compromised by fraudulent practices, so tools for assess their authentication are needed. In order to achieve this goal, Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) was used to analyze 50 samples of bell pepper from Senise and Altino, equally represented, expecting appreciable differences in the multi-elemental composition of peppers cultivated in different countries. Eventually, both classification approach of Partial Least Squares-Linear Discriminant Analysis (PLS-LDA) and class modelling approach of Soft Independent Modelling of Class Analogies (SIMCA) were calibrated and validated with the aim of discriminate between the two different types of bell pepper samples and authenticate them. Both PLS-DA and SIMCA model achieved optimal accuracy in external validation, confirming that the multi-elemental pattern provided by ICP- OES coupled to microwave digestion can be considered a powerful descriptor of bell pepper geographical origin, also between nearby cultivation sites.
Bibliografia 1eAmbrosia, Retrieved June 9, 2021, https://ec.europa.eu/info/food-farming-fisheries/food-safety-and- quality/certification/quality-labels/geographical-indications-register/details/EUGI00000013409. 2Altino Sweet Pepper - Presìdi Slow Food - Slow Food Foundation. Retrieved June 9, 2021, https://www.fondazioneslowfood.com/en/slow-food-presidia/altino-sweet-pepper/.
T6 ON RESIN CLICK CHEMISTRY MEDIATED SYNTHESIS OF NOVEL ENKEPHALIN ANALOGUES WITH POTENT ANTINOCICEPTIVE ACTIVITY
Marilisa Pia Dimmito,a Azzurra Stefanucci,a Alice Della Valle,a Giuseppe Scioli,a Adriano Mollica,a aDepartment of Pharmacy, University “G. D’Annunzio” of Chieti-Pescara, Via dei Vestini 31, 66100, Chieti.
Cu(I)-catalyzed 1,3-dipolar cycloaddition of azides and alkynes (CuAAC) is a biorthogonal reaction, which leads to the formation of 1,4-disubstituted 1,2,3-triazoles;1 this reaction has become popular in peptide chemistry, as 1,2,3-triazole has structural and electronic characteristics similar to those of the peptide bond.2 The 1,2,3-triazole ring is stable to metabolic degradation and capable of hydrogen bonding with biomolecular targets.3 DPDPE ((D-Pen2, D-Pen5)-Enkephalin) represents one of the most successful designed cyclic opioid peptides highly selective for δ-opioid receptor (DOP).4 Even if DPDPE is widely used as radiolabelled standard for in vitro assays, it hasn’t translated to therapeutic application due to a lack of activity when given peripherally, intrinsic metabolic instability and low blood brain barrier penetration.5 In this work we reported the solid-phase peptide synthesis (SPPS) of two novel cyclic enkephalin analogues, namely NOVA1 and NOVA2 (Figure 1),6 by on-resin CuAAC, with the aim to explore the biological profile of these two novel entities incorporating a triazole bridge. We found that NOVA2 showed good affinity and selectivity for the μ-opioid receptor, with Ki of 59.2 nM, EC50 of 12.9 nM and EMax of 87.3% and a long lasting anti-nociceptive effect in mice in comparison to DPDPE. According with our findings, CuAAC is a promising approach for the development of novel therapeutics that could be used in the treatment of pain.
Figure 1. Structures of novel DPDPE analogues, NOVA1 and NOVA2.
References
1Angell, Y.L.; Burgess, K. Chem. Soc. Rev. 2007, 36, 1674-1689. 2Castro, V.; Rodríguez, H.; Albericio, F. ACS Comb. Sci., 2016, 18, 1-14. 3Oueis, E.; Jaspars, M.; Westwood, N. J.; Naismith J.H. Angew Chem. Int. Ed. Engl., 2016, 55, 5842-5845. 4Kramer, T.H.; Bartosz-Bechowski, H.; Davis, P.; Hruby, V.J.; Porreca, F.; Life Sci., 1997, 61, 129-135. 5Weber, S.J. et al. J. Pharmacol. Exp. Ter, 1993, 266, 1649-1655. 6Stefanucci, A.; Dimmito, M.P.; Mollica A. et al. Sci. Reports, 2019, 9, 5771.
T7 Thermodynamics of the hydrolysis of lithium salts: pathways to the inorganic SEI components Simone Di Muzioa,b , Sergio Brutti,b,c , Annalisa Paolone b. aDipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio, 67100, L’Aquila, bIstituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, P.le Aldo Moro, 00185, Roma, c Dipartimento di Chimica, Università “La Sapienza”, P.le Aldo Moro, 00185, Roma.
In recent years, large efforts have been devoted to the search and improvement of innovative and performing batteries. Lithium-ion types (LiBs) are more expensive than other types but their properties, in terms of energy densities, electrochemical stability and number of cycles, are more encouraging 1.
Fig. 1: LiPF6 structure
One of the most common lithium salts used in the electrolytes of this kind of device is Lithium hexafluorophosphate (LiPF6). This salt could been hydrolyzed by reaction with traces of undesired water, giving rise to solid decomposition by-products, that may precipitate as a part of the solid-electrolyte interphase (SEI), inevitably present in batteries2. The hydrolysis of fluorinated salts plays a key role in the formation of the SEI layer: we have investigated on the thermodynamic and mechanism of this process by computational approaches. We proposed a general approach based on thermochemical cycles and first principle thermodynamics calculations to study the reactions in heterogeneous systems. In fact, the precipitation of insoluble phases from the solvent alter remarkably the chemical evolution of the aprotic electrolyte system in solution. Overall, we proposed a mechanism for the hydrolysis of LiPF6 and other fluorinated salts. We have studied all reactions considering the effect of temperature and the role of heterogeneous phase on global thermodynamic profile. This Project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 814464.
Bibliografia 1Scrosati, B.; Garche, J., J. Power Sources, 2010, 195, 2419-2430. 2Solchenbach, S. et.al , J.Electrochem Soc., 2018, 165, A3022-A3028.
T8 WATER-SOLUBLE CARVACROL PRODRUGS AND RELATIVE FORMULATIONS WITH ANTIMICROBIAL AND ANTIFUNGAL PROPERTIES Annalisa Di Rienzo,a Lisa Marinelli,a Marilisa Pia Dimmito,a Antonio Di Stefano,a Blase Billack,b Ivana Cacciatore.a aDepartment of Pharmacy, “G. D’Annunzio” University of Chieti-Pescara, Via dei Vestini 31, 66100, Chieti, bDepartment of Pharmaceutical Sciences, Collage of Pharmacy and Health Science, St. John’s University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
Carvacrol (CAR), a natural monoterpene particularly abundant in plants belonging to the Lamiaceae family, has recently attracted much attention for its antimicrobial and antifungal activity [1]. However, CAR has disadvantageous chemical-physical properties such as low water solubility and high volatility, which hamper its potential pharmacological uses [2]. Here, the synthesis and antimicrobial evaluation of 23 carvacrol prodrugs (WSCP1-23), against a panel of selected gram-positive, gram-negative bacteria and fungi, are reported [3]. Results revealed that WSCP1-3 (Figure 1) were water-soluble prodrugs, possessed a greater antimicrobial profile comparable to that of CAR and a lack of toxicity towards HaCaT cells. WSCP1-3 displayed also antifungal properties against Candida albicans, inhibiting the yeast plasma membrane H+-ATPase (Pma1p), an essential target in fungi [4]. However, WSCP1-3 underwent to rapid hydrolysis in simulated fluids and human plasma. To further deepen these data, intravaginal formulations of WSCP1-3 have been prepared and tested in vivo against fluconazole (FLU)-sensitive and -resistant Candida albicans in a mouse model of vulvovaginal candidiasis (VVC). Results showed that intravaginal WSCP1-3 formulations, administered at test doses of 50 mg/kg, exhibited antifungal efficacy showing a remarkable decrease in infection by ~120-fold compared to the control (infected and untreated-animals). Taken together these data, intravaginal WSCP1 formulation proved to be a promising antifungal agent in vivo.
Figure 1. Chemical structures of CAR and WSCP1-3 prodrugs. References 1Marinelli, L., Di Stefano, A; Cacciatore, I.; Phytochemistry Rev., 2018, 17, 903-921. 2Naghdi Badi, H.; Abdollahi, M.; Mehrafarin, A.; Ghorbanpour, M.; Tolyat, M.; Qaderi, A.; Ghiaci Yekta, M; J. Med. Plants, 2017, 16, 1-32. 3Marinelli, L.; Fornasari, E.; Eusepi, P.; Ciulla, M.; Genovese, S.; Epifano, F.; Fiorito, S.; Turkez, H.; Örtücü, S.; Mingoia, M.; Simoni, S.; Pugnaloni, A.; Di Stefano, A.; Cacciatore, I.; Eur. J. Med. Chem., 2019, 178, 515-529. 4Menon, S.; Liang, X.; Vartak, R.; Patel, K.; Di Stefano, A.; Cacciatore, I.; Marinelli, L.; Billack, B.; Pharmaceutics, 2021, 13, 633.
T9 Catalytic deoxygenation of different vegetable oils using transition metal catalysts supported on Fly Ash Cenospheres. Giuseppe Di Vito Nolfia, Leucio Rossia, Katia Galluccib aDipartimento di Scienze Fisiche e Chimiche. Università degli Studi dell’Aquila. Via Vetoio snc – Coppito; 67100. L’Aquila; b Università degli studi dell’Aquila DIIIE, 67100 L’Aquila, Italy
Fossil fuel depletion and global warming have focused the attention on the production of biofuels that are environmental friendly and derived from renewable feedstocks. Similar chemical composition between vegetable oils and petroleum derivatives makes them an ideal 1 substrate for biofuels synthesis, moreover the biofuels produced are CO2 neutral (Figure 1).
Figure 1: Green Diesel life cycle
The catalytic deoxygenation (DO) reaction of vegetable oils is an efficient process for the synthesis of Green Diesel (C15-C18 hydrocarbons), a biofuel fully compatible with mineral diesel and with numerous advantages over biodiesel2. During the DO process, vegetable oils are converted in hydrocarbons via hydrodeoxygenation (HDO, loss of H2O), decarbonylation 3 (DCO, loss of CO and H2O) and decarboxylation (DCO2, loss of CO2) . In this work, we present the results obtained from the investigation of DO reaction of different vegetable oils over transition metal catalysts supported on Fly Ash Cenosphere (FAC), a by-product of coal combustion. Reaction mixture’s hydrocarbon distribution, reaction selectivity and textural properties of catalysts used were discussed. Bibliography 1. McKendry P. Energy production from biomass (part 1): Overview of biomass. Bioresour Technol. 2002;83(1):37-46. 2. Knothe G. Biodiesel and renewable diesel: A comparison. Prog Energy Combust Sci. 2010;36(3):364- 373. 3. Veriansyah B, Han JY, Kim SK, et al. Production of renewable diesel by hydroprocessing of soybean oil: Effect of catalysts. Fuel. 2012;94:578-585.
T10 Exploring detectors for LEGEND 200 throughmaterial screening and characterization of detector’s connections by HR-ICP-MS Francesco Ferellaa,b a INFN, Gran Sasso National Laboratories, via G. Acitelli 22, I-67100, Assergi (L’Aquila), Italy b Department of Physical and Chemical Sciences, University of L’Aquila, via Vetoio, I-67100, L’Aquila, Italy
[email protected] The GERDA (Germanium Detector Array) collaboration operates bare high-purity germanium detectors (HPGe) made out isotopically enriched material inside a cryogenic fluid shield to search for the neutrinoless double beta decay (0ʋββ) of 76Ge[1]. Its successor, the LEGEND-200 (Large Enriched Germanium Experiment for Neutrinoless ββ Decay) experiment will re-use the GERDA experimental infrastructures at the Gran Sasso National Laboratories[2]. The mass of HPGe detectors will be enlarged up to 200 kg to probe 0ʋββ half-lives beyond 1026 years. A fundamental characteristic of detectors is related to use of materials with low activity, low weight, and high capacity to shifting light; scintillation process is performed by correct functioning of detectors’s connection system to avoid noise and interference, hence materials used for this system must have a very low contamination in such way as a contribute to low background. LEGEND setup regard optical fibers (fig. 1) consist on large amount of material directly connected to detectors, his capacity to shifting light is due to TPB coating[3].
Fig.1 Setup of connection system based on optical fibers used for LEGEND experiment. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) has been used to characterize all materials used in this assembly, to search for impurities inside the samples and to monitor the contamination level[4]. High-Resolution ICP-MS was used to determine amount of impurities regard to natural radioactive elements (Pb, Th, U, K)[5], lower detection limits were reached improving our analysis. Search of materials with low level of contamination, as optical fibers, TPB, nylon foils, will be discussed to make a preliminary screening related to materials to be used for detectors assembly. Bibliography
1GERDA Collaboration, Eur. Phys. J., 2018, 78, 388
2D’Andrea V., LEGEND Collaboration, Conference proceeding, 2019, arXiv:1905.06572v1
3Janicsko Csathy J., Bobe T., Kratz J., Schoenert S., Wiesinger Ch., JINST, 2016, arXiv:1606.04254v1
4Povinec P.P., Nisi S., et al., J. Radioanal. Nucl. Chem., 2018, 318, 677-684
5Ferella F., Nisi. S., Marchegiani F., Physics, 2021, 3, 71-84
T11 SPECTROSCOPIC FINGERPRINTING AND CHEMOMETRICS FOR THE DISCRIMINATION OF ITALIAN EMMER LANDRACES Martina Foschi,a Alessandra Biancolillo,a Simona Vellozzi,b Federico Marini,b Angelo Antonio D'Archivio,a Ricard Boquéc a Department of Physical and Chemical Sciences, University of L'Aquila, Via Vetoio, 67100, Coppito, L'Aquila b Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185, Roma c Department of Analytical Chemistry and Organic Chemistry, Universitat Rovira i Virgili, Campus Sescelades, Edifici N4, C/Marcel⋅lí Domingo s/n, 3007, Tarragona [email protected]
Emmer is a traditional Italian wheat species attracting growing attention for its high nutritive and dietary value. One-hundred and forty-seven emmer samples, harvested in 2019 in three traditional production areas (Garfagnana, Monteleone di Spoleto, Gran Sasso and Monti della Laga National Park), were investigated by Mid-Infrared (MIR) and Near-Infrared (NIR) spectroscopy in order to develop a non-destructive and routine-compatible method for the geographical traceability of these high-valued landraces. Multiclass Partial Least Squares- Discriminant Analysis (PLS-DA) was applied on the collected fingerprinting profiles. Eventually, Data-Fusion strategies have been employed to combine the different information sources and classify the samples according to the geographical origin. The most accurate predictions were provided by the Sequential and Orthogonalized-Partial Least Squares- Discriminant Analysis (SO-PLS-DA) model1, which misclassified only one test sample over 44 (in external validation). Finally, a chemical interpretation of the most discriminant variables was performed.
Fig.1: Structure of emmer caryopsis (to the left); the most discriminant variables (to the right) obtained from the VIP analysis and highlighted on both the MIR and NIR mean spectra. Bibliografia 1Biancolillo, A.; Måge, I.; Næs, T.; Chemom. Intell. Lab. Syst., 2015, 141, 58–67.
T12 Polysaccharide-based films as sustainable active food packaging Francesco Gabriele,a Alice Vetrano,a Nicoletta Spreti,a Raimondo Germani,b a Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio, 67100, L’Aquila. b Centro di Eccellenza CEMIN (Materiali Innovativi Nanostrutturali per applicazioni Chimica Fisiche e Biomediche) Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Via Elce di Sotto, 06123, Perugia.
Over the last years, the use of natural polymers has emerged as alternatives to synthetic petroleum-based ones to reduce the environmental impact of plastic wastes; with regard to the bio-based polymers extracted directly from biomass, polysaccharides display remarkable biodegradability, renewability and availability.1 Chitosan, a polysaccharide derived by the partial deacetylation of chitin, is a biocompatible and biodegradable polycationic macromolecule with intrinsic antimicrobial properties.2 In this work, films based on ionically and covalently cross-linked chitosan were prepared by means of the solvent casting method starting from its hydrogel form. To improve the properties of the resulting films, glycerol was added as plasticizer and succinic acid was used both to solubilize and to cross-link the biopolymer chains, as shown in Figure 1.
Figure 1: Chitosan (a) and alginate (b) hydrogels and (c) preparation methods of polysaccharide-based food packaging. The physicochemical properties of neutralized and non-neutralized chitosan-succinic acid membranes were evaluated and compared. The neutralization process significantly improved the mechanical, thermal and water vapor barrier properties of the polysaccharide-based membranes. Furthermore, the addition of the strong base to the hydrogel promotes the formation of amide bonds, as suggested by FTIR analysis, and demonstrated by acid-base titration. A preliminary study was addressed to the application of alimentary sodium alginate for the preparation of edible coatings or films. It is currently used as food additive (E401) and can easily form hydrogels by the coordination of divalent cations (Figure 1). The favorable features of polysaccharide-based films include the possibility to easily incorporate active substances that make such materials suitable for the application in the field of the active packaging.
1 Galiano, F.; Briceño, K.; Marino, T.; Molino, A.; Christensen, K.V.; Figoli, A.; Journal of Membrane Science, 2018, 564, 562-586. 2 Kumar, S.; Mukherjee, A.; Dutta, J.; Trends in Foods Science & Technology, 2020, 97, 196-209.
T13 Ceria-supported metal nanoparticles for CO abatement in combustion exhaust gases A. Lazzarini1*, L. Atzori2, L. Arrizza3, F. Ferella4, G. Cutrufello2, M. Crucianelli1 1 DSFC, University of L’Aquila, via Vetoio (COPPITO 2), 67100, L’Aquila, IT 2 DSCG, University of Cagliari, Cittadella Universitaria (Blocco D) - S.S. 554 bivio per Sestu - 09042 Monserrato (CA), IT 3 Centre for Microscopy, University of L’Aquila, via Vetoio (COPPITO 1), 67100, L’Aquila, IT 4 DIIIE, University of L’Aquila, piazzale Ernesto Pontieri, Monteluco di Roio, 67100, L’Aquila, IT
* e-mail: [email protected]
Ceria samples with different morphologies have been prepared to be employed as catalytic supports for carbon monoxide oxidation produced from incomplete industrial combustion processes. The use of cerium oxide, which is able to act as oxygen reservoir whenever the reaction environment presents a lack of molecular oxygen, is meant to compensate the fluctuating real operating conditions this catalyst has to undergo, acting synergically with the nanoparticle phase. CeO2 have been synthesized in the form of nanoparticles, rods and flower-like shaped.1
Figure 1. SEM images of CeO2 supports in the form of NPs (a), nanorods (b) and flowerlike (c). We reproduced a state-of-the-art catalyst (Pt-based) and deposited Ni, Fe and alloyed NPs2 for such reaction, supported onto different CeO2 morphologies. The synthesized catalysts materials were characterized with ATR-IR, XRD, SEM-EDX, ICP-MS and BET techniques.
Preliminary catalytic tests were performed using low CO and O2 concentration in the reaction feed,3 to be as close as possible to the real system, showing conversion values for Ni catalyst comparable to Pt one.
Bibliografia 1 M. Peymani et al.; Int. J. Hydrog. Ener., 2016, 41, 6316. A. Lolli et al.; Microporous Mesoporous Mater., 2016, 226, 466. H. Li et al.; ACS Appl. Mater. Interfaces, 2010, 2, 838. 2 M. J. Kahlich et al.; J. Catal., 1997, 171, 93. L. Tan et al.; J. Porous Mater., 2017, 24, 795. H. Wu et al.; J. Phys. Chem. Solids, 2010, 71, 290. M. Peymani et al.; Int. J. Hydrog. Ener., 2016, 41, 6316. 3 D. Jiang et al.; ACS Catal., 2020, 10, 11356.
T14 SYNTHESIS OF VALUABLE HETEROCYCLIC SCAFFOLDS BY MEANS OF CASCADE REACTIONS OF 2-ALKYNYLANILINE DERIVATIVES WITH ELECTROPHILES Vincenzo Marsicano,a Antonio Arcadi a a Dipartimento di Scienze Fisiche e Chimiche, Università degli studi dell’Aquila, Via Vetoio, 67100, Coppito (AQ) [email protected]
Traditionally, complex organic architectures, such as heterocyclic compounds, have been built using the so-called “one bond per step” approach. In the 21st century, however, this strategy is not competitive anymore because of economical cost, operational length and the production of significant amounts of waste, especially since the complexity of the organic structures sought is increasing more and more. Cascade reactions, enabling the generation of multiple covalent bonds in a one-pot fashion, have gained a lot of attention in the past decades as an alternative strategy to improve the efficiency of synthetic pathways.1 Their implementation is therefore one of the main goals of modern organic chemistry. Functionalised alkynes, such as 2-alkynylaniline derivatives, are interesting platforms for cascade one-pot reactions, because they bear multiple reactive sites with different reactivity; the triple bond, in fact, could undergo different types of reaction depending on the reaction conditions and/or the catalyst/promoter used, in a perfect divergent way. Herein we would like to report the results we have obtained in the past years on the use of these derivatives to generate nitrogen-containing heterocycles, 2 which are of great importance for their pharmacological and physico-chemical properties.
1 a) Green, N. J.; Sherburn, M. S. Multi-Bond Forming Processes in Efficient Synthesis. Aust. J. Chem. 2013, 66, 267-283; b) Tietze, L. F.; Haunert, F. Domino Reaction in Organic Synthesis. An Approach to Efficiency, Elegance, Ecological Benefit, Economic Advantage and Preservation of Our Resources in Chemical Transformations. In Stimulating Concepts in Chemistry; Vögtle, F.; Stoddart, J. F.; Shibasaki, M.; Wiley-VCH, 2000, pp 39-64. 2 a) Marsicano, V.; Arcadi, A.; Chiarini, M.; Fabrizi, G.; Goggiamani, A.; Iazzetti, A. Sequential Condensation / Biannulation Reactions of β-(2-Aminophenyl)-α,β-Ynones with 1,3-Dicarbonyls. Org. Biomol. Chem. 2021, Advance Article. b) Marsicano, V.; Arcadi, A.; Chiarini, M.; Fabrizi, G.; Goggiamani, A.; Iazzetti, A. Synthesis of functionalised 2,3-dihydroquinolin-4(1: H)-ones vs. quinoline or N -alkenylindole derivatives through sequential reactions of 2-alkynylanilines with ketones. Org. Biomol. Chem. 2021, 19, 421-438. c) Arcadi, A.; Aschi, M.; Chiarini, M.; Marinelli, F.; Marsicano, V.; Portalone, G. Experimental results and computational insight into sequential reactions of β-(2-aminophenyl)-α,β-ynones with aryl isocyanates/benzoyl isothiocyanate. Org. Biomol. Chem. 2020, 18, 9438-9447. d) Marsicano, V.; Chiarini, M.; Marinelli, F.; Arcadi, A. Synthesis of Polycyclic Quinolines by Means of Brønsted Acid Mediated Reaction of β-(2-Aminophenyl)- α,β-Ynones with Ketones. Adv. Synth. Catal. 2019, 361, 2365-2370.
T15 PREPARATION OF POROUS GRAPHENE-BASED SUBSTRATES OXIDE FOR CELL GROWTH Samanta Moffa,a Serena Pilato,a Daniele Capista,b Maurizio Passacantando,b Francesca Diomede,c Jacopo Pizzicannella,d Antonella Fontanaa a Dipartimento di Farmacia, Università “G. d’Annunzio” di Chieti-Pescara, Via dei Vestini, 66100, Chieti, b Dipartimento di Scienze Fisiche e Chimiche, Università di L’Aquila, Via Vetoio, 67100, L’Aquila, c Dipartimento di Tecnologie Innovative in Medicina & Odontoiatria, Università “G. d’Annunzio” di Chieti- Pescara, Via dei Vestini, 66100, Chieti, d dASL02 Lanciano-Vasto-Chieti,Ospedale “Ss. Annunziata”, Chieti
Graphene oxide is produced from graphene, thanks to an oxidation reaction and can be functionalized through different chemical reactions.1 It is used in various fields, including tissue engineering. The goal of this work is to set up and characterize GO-based porous substrates, so that they act as scaffolds to evaluate the growth of cardiac cells. The porous substrates were produced on a glass base. The slides, activated with the UV/ozone lamp, were immersed in a solution of APTES and incubated with a solution of GO and one of PEI, in order to lead to the formation of a three-dimensional porous material. The goal was therefore to obtain different substrates: a single layer of GO; one of GO and one of PEI; two layers of GO alternating with one of PEI and 5 layers of GO alternating with 3 of PEI. The obtained substrates were characterized by SEM, adsorption-desorption and AFM measurements, while the chemical properties were studied by means of IR spectroscopy, Raman spectroscopy and XPS. The XPS analysis showed that the alternation of incubations with GO and PEI solutions led to the functionalization of the GO and the formation of amide bonds. The thickness of the slides, which increases with incubations, and Young's modulus, which increases with decreasing GO incubations and with its degree of functionalization, were analyzed using AFM. The slides were used as substrate for the growth of HL-1 cells and then analyzed by confocal microscope and Western Blot. It emerged a greater expression of connexin-43 and Nkx-2.5. The slide with only one GO and one PEI incubation exhibits increased expression of connexin-43 protein. The slide obtained by means of five GO incubations alternating with three of PEI favors cell growth compared to the single layer. It is possible to create a substrate for the growth of myocardiocytes, characterized by a certain porosity linked to the alternation of an incubation with GO and one of PEI.
Bibliografia
1. Liu, J., Dong, J., Zhang, T. & Peng, Q. Graphene-based nanomaterials and their potentials in advanced drug delivery and cancer therapy. Journal of Controlled Release (2018) .2018.07.034.
T16 Organocatalyzed Michael Addition to Nitroalkenes via Masked Acetaldehyde V. Noria, G. Giorgianni a, A. Baschieri a, b, L. Palombi a, A. Carlone a Department of Physical and Chemical Sciences, Università degli Studi dell’Aquila, via Vetoio, 67100 L’Aquila, Italyb Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via P. Gobetti 101, 40129 Bologna, Italy
e-mail: [email protected]
In our recently published work, a novel reaction for the enantioselective enamine- catalysed addition of acetaldehyde to nitroalkenes is presented: this protocol makes use of a safe acetaldehyde precursor to access important intermediates to APIs1. Despite the great advancement in this field reported by Hayashi2 and List3, the approach still suffers from the use of relatively high catalyst loading and the use of a large excess of acetaldehyde. Furthermore, Pericàs employed paraldehyde to enable the same reaction4. Nevertheless, they used 10 equivalents of masked acetaldehyde and a relatively high catalyst loading of supported organocatalysts that bring a considerable cost contribution to the manufacture process. Herein, we overcame these issues, reporting the use of acetaldehyde dimethyl acetal in the aminocatalytic enantioselective addition to nitroalkenes. We have developed an industrially useful protocol for the Michael addition of acetaldehyde to nitroalkenes, affording the corresponding products in high yields and ee. The presented reaction makes use of a masked acetaldehyde to avoid the use of a highly toxic, flammable and reactive intermediate. Furthermore, the use of an acidic resin and low amounts of an affordable organocatalyst make the overall protocol appealing for its application in manufacture.
Figura 1Enantioselective Michael addition of masked acetaldehyde to nitroalkenes.
Bibliografia 1. Giorgianni, G.; Nori, V.; Baschieri, A.; Palombi, L.; Carlone, A., Catalysts2020, 10, 1296. 2. Hayashi, Y.; Itoh, T.;Ohkubo, M.; Ishikawa H., Angew. Chem. Int. Ed.2008, 47, 4722 3. García-García, P.;Ladépêche, A.; Halder, R.; List, B.,Angew. Chem. Int. Ed.2008, 47, 4719 4. Fan, X.; Rodríguez-Escrich, C.; Sayalero, S.; Pericàs, M. A.,Chem. Eur. J. 2013, 19, 10814
T17 Isolation of amarogentin, the bitter principle of Gentiana lutea roots L. Palumboa*, S. Fioritoa, F. Epifanoa, F. Masciolib, R. Spoglic, S. Genovesea
aDipartimento di Farmacia, Università “G. d’Annunzio” Chieti - Pescara, Via dei Vestini 31, 66100 Chieti Scalo (CH), Italy bEnrico Toro Distilleria Srl, Via Tiburtina 18, 65028 Tocco da Casauria (PE), Italy cProlabin & Tefarm Srl, Via dell’Acciaio 9, 06134 Perugia, Italy
*Email: [email protected]
Amarogentin and gentipicroside are extracted from Gentiana and Swertia spp. (Fam. Gentianaceae) and are well known to be among the most bitter naturally occurring compounds. In fact bitter index values are 58 x 106 for amarogentin, and 12 x 103 for gentiopicroside and both secondary capable to maintain their bitter taste even diluted 1: 20000 in water. For this, either as an individual compounds or part of Gentiana spp. extract, amarogentin and gentipicroside are used as a food additive for the production of liqueurs and as dietary supplements. In this communication, we describe a convenient process to selectively isolate amarogentin in quantitative yield and in part gentiopicroside from the dry extract of G. lutea roots.
Figure 1. Amarogentin Figure 2. Gentiopicroside
The process consisted in the treatment of an aqueous suspension of such an extract with a panel of solid inorganic and inorganic / organic sorbents followed by filtration, desorption, and HPLC analyses. Each sample solution was filtered through a 0.22 µm pore size Durapore® membrane before injection into the HPLC apparatus. The HPLC method was validated according to the ICH guidelines in terms of precision, accuracy, linearity, limits of detection (LOD), and limits of quantification (LOQ). Calibration curves were drawn by injecting the gentiopicroside and amarogentin stock solutions at 9 concentrations values. Finally, the amounts of gentiopicroside and amarogentin absorbed onto the sorbents listed have been obtained by subtracting the concentration of each secondary metabolite in the filtrate from the content of the same in the blank original solution of plant extract. Among the solid materials tested, those containing Mg+2 in the frame of a lamellar structure provided adsorption yields in the range 86.4 % - 99.9 %. The method we set up could be in principle useful to obtain a pure natural food additive to provide bitter taste.
T18 Spent Lithium-Cobalt Batteries as an Efficient Heterogeneous Catalyst for the Reductive Upgrading of Biomass Derived Furan promoted Emilia Paone,a,b Mariachiara Miceli,a Patrizia Frontera,a,b Francesco Mauriello,a Angela Malaraa,b a Dipartimento DICEAM, Università degli Studi Mediterranea di Reggio Calabria Loc. Feo di Vito, I-89122 Reggio Calabria, b Consorzio Interuniversitario per la Scienza e la Tecnologia dei Materiali (INSTM), 50121, Firenze
In the last years, a lot of research efforts from both academia and industry players in the recycling electronic waste. Lithium ion battery (LIB), containing cobalt oxides, represent a valid resource for the preparation of Co-based catalysts. By now, only few attempts are present in literature in the use of cobalt based catalysts directly obtained from spent LIB mainly devoted to the promotion of oxidative reactions [1,2]. Reductive catalytic processes gained a lot of attention since, once the lignocellulose is deconstructed, cellulose, hemicellulose and lignin fractions can be subsequently converted into platform chemicals, that can be further transformed into target molecules, added value chemicals, solvents and materials (Figure 1). Furfural (FUR) is surely one of two most used furan-based feedstocks since its chemical structure allows the preparation of various high-value-added chemicals [3]. In this context, the present contribution, supported by NEXT-LIB EU project funded by ERA.MIN2, is focuses on a possible reuse of spent lithium-cobalt batteries as efficient heterogeneous catalysts (BM catalyst) for the reductive upgrading of different from lignocellulosic biomasses derived molecules. By using BM as the catalyst and 2-propanol as the H-source (CTH), under batch conditions, an appreciable FUR (0.1 M) conversion into Furfuryl alcohol (FAL) was achieved after 90 minutes at 120 °C. The conversion of BPE increased by increasing the reaction temperature and it was fully converted at 180 °C. In order to evaluate the stability of BM catalyst in the CTH of FUR, a series of consecutive recycling tests at 120°C for 90 min were performed. BM catalyst maintains its activity after five consecutive reactions and only slight changes in FAL yield were found, highlighting the good stability of the catalyst, that can be directly recycle (simple washing wit 2-propanol) for the next reaction run.
Bibliografia 1 Guo, M.; Li, K.; Zhang, H.; Guo, W.; Hu, X.; Min, X.; Jia, J.; Sun, T., Sun, Ind. Eng. Chem. Res., 2020, 59, 194-204. 2Rossi, M.; Marcoccia, C.G.; Peluso, M.A.; Sambeth, J.E., Mol. Catal., 2020, 481, 110223. 3Xu, C.; Paone, E.; Rodríguez-Padrón, D.; Luque, R.; Mauriello, F., Chem. Soc. Rev., 2020, 49, 4273-4306.
T19 Towards an Electrifying Future: New Approaches in Organic Synthesis A.Petti,a K.Lam *a
a Department of Pharmaceutical, Chemical and Environmental Sciences, School of Science, University of Greenwich Chatham Maritime, Chatham, Kent, ME4 4TB (UK) [email protected]
In the last few decades, innovative synthetic approaches, able to reduce the ecological footprint, gained considerable attention within academia and industry. Organic electrochemistry is well placed in this context. Indeed, the use of electricity to drive chemical transformations allows us to overcome major drawbacks, commonly encountered in synthetic practices, such as the reliance on expensive and hazardous redox reagents or harsh reaction conditions. Despite these significant advantages, the potential of preparative electrochemistry is still far from being entirely unleashed. In this talk, two innovative and green electrochemical methods will be presented. The anodic oxidation of readily available hemioxalate salts gives easy access to highly reactive oxycarbonyl radicals. They were then used to rapidly assemble a great variety of mono- and multi-functionalised γ-butyrolactones via an unusual metal-free sp3-sp3 radical cross-coupling.1 In a similar vein, orthoesters, highly versatile building blocks, are known to be challenging to prepare using classic synthetic methodologies. Therefore, we have developed a unique electrochemical protocol to generate them from simple dithiane carboxylic acids.2 When anodically oxidised, the dithiane is converted into its corresponding orthoester in high yield, without the need for purification. Attention to the environment, easy and cost-efficient procedures, innovative reaction pathways are key points for the chemistry of the future and electrosynthesis has all the potential to be part of it!
1A. Petti, M. C. Leech, A. D. Garcia, I. C. A. Goodall, A. P. Dobbs and K. Lam, Angew. Chemie Int. Ed., 2019, 58, 45, 16115–16118. 2 A. D. Garcia, M. C. Leech, A. Petti, C. Denis, I. C. A. Goodall, A. P. Dobbs and K. Lam, Org. Lett., 2020, 22, 10, 4000–4005.
T20 CALIXARENE-BASED ARTIFICIAL IONOPHORES FOR CHLORIDE TRANSPORT ACROSS NATURAL LIPOSOMAL BILAYER Serena Pilato,a Massimiliano Aschi,b Margherita Bazzoni,c Federica Cester Bonati,c Gianpiero Cera,c Samanta Moffa,a Valentino Canale,a Michele Ciulla,a Andrea Secchi,c Arturo Arduini,c Antonella Fontana,a Gabriella Siania a Dipartimento di Farmacia, Università “G. d’Annunzio” di Chieti-Pescara, Via dei Vestini, 66100, Chieti, b Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio, 67100, Coppito, c Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parco Area delle Scienze, I-43124, Parma
Regulation of transmembrane ion transport is a fundamental process for living cells and defects in this control mechanism can cause serious diseases and even lead to death. Among the systems potentially useful as synthetic ionophores, calixarenes have recently gained considerable attention due to their ability to form complexes with a large variety of compounds and to act as a biomimetic filter. In this work, an amphiphilic calix[6]arene, alone or complexed with an axle to form a pseudorotaxane, has been embedded into liposomes prepared from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocoline (POPC) with the aim of explore the potential ability of the guests to act as artificial anion channels.
In particular, the permeability of the membrane-doped liposomes towards Cl- ions has been evaluated by determining the change in the rate of quenching of lucigenin, used as the fluorescent probe, when a Cl- concentration gradient across the membrane was created by addition of NaCl to the liposomal solution. The insertion of the calix[6]arene into liposomal bilayer slightly increased the rate of quenching of lucigenin while the presence of the axle, in the form of pseudorotaxane, favored the Cl- passage through the membrane. To evaluate the intrinsic effect of the axle on the Cl- transport across liposomal membrane, axle-containing liposomes were prepared and the Cl- induced quenching of lucigenin was very fast and dependent on the concentration of the axle. To better understand the obtained results, the interactions between the Cl- ions and aromatic moiety of the calix[6]arene have been evaluated through molecular dynamics (MD) simulations and 1H NMR titrations, with - Bu4NCl as source of Cl ions. The effect of the insertion of the guests on the lipid bilayer structure and properties, in terms of viscosity and kinetic stability, has also been investigated using the fluorescent probes pyrene and 5(6)-carboxyfluorescein (CF), respectively.
T21 BIOGAS PRODUCTION FROM ANCHOVIES RESIDUES AFTER
NUTRACEUTICS EXTRACTION Daniela Maria Pizzone,a Filippo Fazzino,a Emilia Paone,a Antonino Scurria, b Rosaria Ciriminna,b Paolo S. Calabrò.a a Dipartimento di Ingegneria Civile, dell’Energia, dell’Ambiente e dei Materiali (DICEAM), Università Mediterranea di Reggio Calabria, Via Graziella, loc. Feo di Vito, I-89124 Reggio Calabria, Italy b Istituto per lo Studio dei Materiali Nanostrutturati, CNR, via U. La Malfa 153, I-90146 Palermo, Italy.
e-mail: [email protected]
Anchovy is the largest fish catch worldwide. Its industry generates huge amount of biowaste (fish heads, bones, tails) that can be valorized through the extraction of several potentially valuable molecules, including Omega-3, that have applications as nutraceutical supplements. 1 Recently, a new green process for the recovery of Omega-3 and vitamin D3 from anchovy processing waste has been proposed employing the citrus-derived d-Limonene as extraction solvent in a closed loop process in which the biobased solvent is recycled. 2
Figure 1. Biorefinery scheme for anchovy residues. The solid residue of the extraction process (anchovy sludge, AS) was used for the evaluation of biomethane potential by anaerobic digestion (AD) tests (Figure 1). The results demonstrate that: (i) the presence of high concentrations of d-Limonene inhibit the mono-digestion of raw AS; (ii) co-digestion of AS along with carbonaceous waste showed a significant biomethane -1 potential (about 420 mL∙gVS ) thanks to the balanced carbon to nitrogen (C/N) ratio; (iii) removing residual d-Limonene by drying the AS allows a good biomethane production (about -1 3 280 mL∙gVS ).
Bibliografia 1Pagliaro, M.; Pizzone, D.M.; Scurria, A.; Lino, C.; Paone, E.; Mauriello, F.; Ciriminna, R. Sustainably Sourced Olive Polyphenols and Omega 3 Marine Lipids: A Synergy Fostering Public Health. ACS Food Sci. Technol. 2021, 1, 2, 139–145. 2Ciriminna, R.; Scurria, A.; Avellone, G.; Pagliaro, M. A Circular Economy Approach to Fish Oil Extraction. ChemistrySelect 2019, 4, 5106–5109. 3Paone, E., Fazzino, F., Pizzone, D.M., Scurria, A., Pagliaro, M., Ciriminna, R., Calabrò, P.S., 2021. Towards the anchovy biorefinery: Biogas production from anchovy processing waste after fish oil extraction with biobased limonene. Sustainabilty 2021, 13, 1–12.
T22 Orange peels-derived hydrochar for chemical sensing applications Antonella Satira,a Claudia Espro,b Francesco Mauriello,a Zakie Anajafi,b K. Moulaee,b Daniela Iannazzo,b Giovanni Nerib a Dipartimento di Ingegneria Civile, dell’Energia, dell’Ambiente e Dei Materiali (DICEAM), Università Mediterranea di Reggio Calabria, Via Graziella, Loc. Feo di Vito, I-89124 Reggio Calabria, Italy; b Dipartimento di Ingegneria, Università degli Studi di Messina, Contrada di dio, I-98158 Sant’ Agata di Militello, Messina [email protected]
At present, our society faces the identical tasks of dwindling supply oil resource depletion and waste accumulation, leading to quickly rising raw material costs and more and more expensive and pre-emptive waste disposal legislation. Moreover, one of the most important goals of green chemistry and resource efficiency, is the use of renewable raw materials, for the sustainable production of novel advanced materials, as opposed to their unsustainable production from non-renewable fossil resources such as oil, coal, and natural gas. Among advanced functional constituents, bio-carbon materials, since their excellent properties such as lightness, high porosity, good structural stability, easy conductivity, easy heat transfer, and easy processing [1], play a crucial role in the development of high-performance and sustainable materials, principally attractive as electrode materials for energy and sensing applications. Different processes have been proposed for converting the biomass precursors into carbon-based materials, but recently, much attention has been focused on hydrothermal conversion processes (HTC) performed in water at relatively low temperatures (180-350 °C) which have been shown to be more cost-effective as compared to conventional high- temperature processes [2]. The main advantages of HTC are that the optimization of residence time and temperature can allow the control of the degree of coalification of the biomass precursor and the formation of stable aromatic structure and abundant surface functional groups, furthermore, the heterogeneous wet biomass can be treated without the preliminary drying required for pyrolysis and other thermochemical techniques [2]. Here, we report an investigation on the preparation of hydrochar obtained from waste orange peels with a unique electrical and electrochemical performance which have been demonstrated to be promising for the development of chemo- and bio-sensors. Therefore, in this contribution the potentials and the peculiar features of the hydrothermal carbonization (HTC) of industrial citrus processing waste, for the production of bio-carbon, will be highlighted. Furthermore, the application of the obtained hydrochar in two electrochemical applications of high importance, having industrial, environmental, and health implications, such as the conductometric detection of
NO2 in the air at ppb (part per billion) levels, and the electrochemical determination of dopamine at nanomolar concentration will be discussed. The exploration of this single-step hydrothermal process represents a promising example of wet organic waste valorization for the green production of hydrochars with outstanding electrical and electrochemical properties and its utilization in chemical sensors, and at the same time, to avoid potential and serious environmental issues arising from the citrus processing waste management and disposal. Reference
1Gopinath, K.P.; Vo, D.V.N.; Prakash, D.G.; Joseph, A.A.; Viswanathan, S.; Arun, J.; Environ. Chem. Lett., 2020, 1–26. 2Espro, C.; Satira, A.; Mauriello, F.; Anajafi, Z.; Moulaee, K.; Iannazzo, D.; Neri, G.; Sensors & Actuators: B. Chemical, 2021, 341, 130016.
T23 Phytocompound-exfoliated graphene as alternative redox-active nanomaterial for (bio)sensors development
Filippo Silveria, Flavio Della Pellea, Daniel Rojasa, Qurat Ul Ain Bukharia, Dario Compagnonea aFaculty of Bioscience and Technology for Food, Agriculture and Environment University of Teramo, Via Renato Balzarini 1, 64100, Teramo, Italy
The use of natural phytochemicals starts being widespread in the 2D nanomaterials field. Nevertheless, a lack of studies concerning the specific molecules employed and their capacity to lead to the formation of functional materials is evident. Herein, a novel green and sonochemical liquid-phase exfoliation (LPE) strategy was optimized, exploiting the ability of a flavonoid namely catechin (CT) to exclusively assist the exfoliation of bulk graphite in aqueous dispersions, giving rise to conductive and water- soluble graphene nanoflakes (GF). The morphological and electrochemical properties of GF- CT were investigated by means of physicochemical and electrochemical techniques. Surprising, the obtained GF-CT showed redox-active properties, integrating a well-defined electro-active quinoid adducts. The few-layer graphene intercalated with CT aromatic skeleton exhibited a completely reversible electrochemical behavior (ΔEp= 28 mV, ipa/ipc = ⁓1), conferred by the residual catechol moieties, which work as electrochemical mediator. Noteworthy that the intimate electrochemistry of GF-CT was directly generated throughout the LPE of bulk graphite, with no need for electro-polymerization or chemical modification steps. The electrocatalytic activity was challenged using the material as electrode modifier towards the detection of hydrazine (HY) and β-nicotinamide adenine dinucleotide (NADH), a pollutant and a coenzyme, respectively. GF-CT based electrode achieved high sensitivity (nanomolar LODs) in extended linear ranges, performing chronoamperometry measures at low overpotential (+0.15 V). Enhanced performance compared with commercial electrode and graphene synthesized with conventional stabilizer were obtained. By using GF-CT, HY and NADH were selectively and accurately detected in environmental and biological samples (recoveries: 94-107%, RSD ≤ 8%), demonstrating the exploitability of the material even in real matrices. The intrinsic conductivity carried by GF-CT was further exploited realizing an exclusively graphene-based film, potentially suitable for the realization of flexible electrodes/devices. Thus, on course studies aim to integrate the conductive GF-CT film into modular-flexible supports, combining smart low-cost bench-top technologies (cutter printer, thermal laminator, etc.) with cheap office-grade substrates (laminating pouches, cellulosic paper, etc.), to develop enzymatic (bio)sensoristic platforms, where the quinoid integrated moieties allow the communication with the biological element. From our point of view the proposed GF-CT represents an affordable and sustainable alternative for the realization of redox-active nanostructured-materials, particularly attractive for (bio)sensing applications.
T24 Aminocatalysis performed by supramolecular fibrils Arianna Sinibaldi,a Francesca Della Penna,a Marco Ponzetti,b Francesco Fini,c Silvia Marchesan,d Andrea Baschieri,a,e Fabio Pesciaioli,a and Armando Carlone*a.
,a Department of Physical and Chemical Sciences, Università degli Studi dell'Aquila, Via Vetoio, 67100 L'Aquila,Italy; b Department of Biotechnological and Applied Clinical Sciences, Università degli Studi dell'Aquila, Via Vetoio, 67100 L'Aquila, Italy; c Department of Life Sciences, Università degli Studi di Modena e Reggio Emilia, Via G. Campi 103, 41125, Modena, Italy; eDepartment of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste,Italy eIstituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via P. Gobetti 101, 40129 Bologna, Italy
e-mail [email protected]
Asymmetric aminocatalysis has seen an incredible growth since the beginning of the last millennium1. A considerable variety of aminocatalysed reactions were discovered in the following years underlining the great power of this synthetic technology2. Industrial R&D routinely screens organocatalysis as a technology platform; however, its full applicability is sometimes hampered by the relatively high catalytic loading. By exploiting supramolecular interactions, we present small organocatalyst that are able to self-assemble. These more complex and structured architectures display enhanced catalytic activity with respect to their monomeric counterparts. This proof of concept was demonstrated and is currently studied for the evolution of new and more active catalysts.
Scheme 1: general reaction performed by fibril-catalyst.
References 1. P. Melchiorre, M. Marigo, A. Carlone, G. Bartoli, Angew. Chem. Int. Ed., 2008, 47, 6138 2. a) K. A. Ahrendt, C. J. Borths, D. W. C. MacMillan, J. Am. Chem. Soc., 2000, 122, 4243. b) B. List, R. A. Lerner, C. F. Barbas III, J. Am. Chem. Soc. 2000, 122, 2395 – 2396. c) A. M. Thayer, Chem. Eng. News, 2006, 84, 23, 15 – 24; d) M. P. Brochu, S. P. Brown, D. W. C. MacMillan, J. Am. Chem.Soc., 2004, 126, 4108 e) H. Park, B.Jeong , M. Yoo, J. Lee, M. Park, Y. Lee, M. Kim, S. Jew, Angew. Chem. Int. Ed., 2002, 41,1, 3036
T25 IMMOBILIZATION OF CANDIDA RUGOSA LIPASE IN ALGINATE BEADS FOR CATALYTIC PURPOSE Alice Vetrano,a Francesco Gabriele,a Nicoletta Spretia a Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio, 67100, L’Aquila
Enzymes are catalysts with excellent properties such as high selectivity and specificity but, despite their incomparable catalytic activities, their stability is often a weak point that must be improved. Immobilization techniques are employed to face that issue.1 Alginate is one of the most used polymers for physical entrapment thanks to its biocompatibility and biodegradability.2 In this work, six different formulations of alginate beads containing Candida rugosa lipase, which vary from one another in the concentration and residence time in the calcium chloride solution, have been investigated for catalytic purposes. The characteristics of the immobilized lipases such as immobilization efficiency, enzyme activity, thermal stability, reusability, storage stability and enzyme leakage over time were evaluated. Loading efficiency has been determined with the Bradford method resulting in a 100% immobilization yield for all six different types of beads. Hydrolytic activity of entrapped lipase has been determined by spectrophotometric measurements with the model substrate p- nitrophenyl acetate (p-NPA); the reaction is complete within the first three hours both for all type of beads and for the two cycles accomplished. Therefore, the two extreme formulations, BEADS 1 and BEADS 6, have been chosen to perform ten catalytic cycles to evaluate if there were changes in terms of activity and stability due to the difference in concentration and residence time in the calcium chloride solution (Figure 1). A) B)
Figure 1: 3D graphs of ten consecutive catalytic cycles with 10 mM p-NPA; BEADS 1 (A) and BEADS 6 (B) Another substrate, p-nitrophenyl dodecanoate (p-NPD), was tested to evaluate the diffusion of a more hydrophobic molecule into the two extreme bead compositions. The entrapment systems were characterized by stereomicroscope and SEM with Peltier plate, to investigate their surface properties, size and morphology. Given the excellent recyclability and thermal stability found for our trapping system, the beads were used in preliminary tests for the resolution of (R)-1-phenylethanol. 1Mateo, C.; Palomo, J.M.; Fernandez-Lorente, G; Guisan, J.M.; Fernandez-Lafuente R.; Enzyme and Microbial Technology, 2007, 40, 1451–1463. 2Augst, D.A.; Kong, H.J.; Mooney, D.J.; Macromolecular Bioscience, 2006, 6, 623–633.
T26 The Impact of Charge in a Ni(II) Polymerization Catalysts Maria Voccia,a* Eva Schiebel,b Laura Falivene,a Stefan Mecking,b Lucia Caporasoa a Department of Chemistry, University of Salerno, Via Giovanni Paolo II, 84084, Salerno, Italy, bDepartment of Chemistry, University of Konstanz, Universitaetsstrasse 10, D-78464, Konstanz, Germany
e-mail: [email protected]
Among the late transition metal catalysts active in the ethylene polymerization, an interesting class of compounds is represented by Ni (II) salicylaldiminato complexes1,2. Recently, a second imine donor was introduced in the form of bis(imino)-phenoxy motifs. These complexes proved to be promising candidates for obtained products whose microstructure is strictly dependent on the catalyst structure, moving from high-molecular-weight polyethylene to oligomers3. A direct comparison between neutral active catalysts (Chart 1) and their corresponding cationic analogues (Chart 2) is enabled by protonation of neutral bis(imino)phenoxy complexes.
For the neutral species compared to the highly studied mono(imino)-phenoxy complexes2,3, the second imine motif does not influence the microstructure of the polymerization’ products, being directed away from the active site. But it allows for the incorporation of a proton in proximity of the active center in an N···H+···O bridge yielding the protonated species. The bridge weakens the Ni−O bond and decreases the electron density at the metal. Experimentally, the two catalysts which in their neutral version produce linear HDPE or undergo extensive chain walking, if cationically charged always produce short chain oligomers. A mechanistic analysis by DFT methods reveals an increased propensity for β-hydride elimination compared to ethylene insertion chain growth for the cationic complexes. This results from a higher relative stability of β-agostic species vs olefin-coordinated species.
Bibliografia 1Wiedemann, T.; Voit, G.; Tchernook, A.; Roesle, P.; Göttker-Schnetmann, I.; Mecking, S., J. Am. Chem. Soc. 2014, 136, 2078-2085. 2 Falivene, L.; Wiedemann, T.; Göttker-Schnetmann, I.; Caporaso,L.; Cavallo, L.; Mecking, S.; J. Am. Chem. Soc. 2018, 140, 1305-1312. 3 Schiebel, E.; Voccia, M.; Falivene, L.; Caporaso, L.; Mecking, S.; ACS Catal. 2021, 11, 5358−5368.
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