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Funding Information: This research was funded by Fundação para a Ciência e Tecnologia through FEDER (European Fund for Regional Development)-COMPETE-QREN-EU (ref. UID/FIS/04650/2013 and UID/FIS/04650/2019) and E-Field—“Electric-Field Engineered Lattice Distortions (E-FiELD) for optoelectronic devices”, ref. PTDC/NAN-MAT/0098/2020. C.S.B.G. acknowledges funding from Fundação para a Ciência e Tecnologia FCT/MCTES through projects UIDB/50006/2020, UIDP/50006/2020 and LA/P/0008/2020 of the Associate Laboratory for Green Chemistry—LAQV, UIDB/04378/2020, UIDP/04378/2020 and LA/P/0140/2020 of UCIBIO and Associate Laboratory i4HB, respectively. Funding Information: We acknowledge national funds (OE), through FCT − Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of article 23 of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. Publisher Copyright: © 2023 by the authors. A polymorph of glycyl-L-alanine HI.H2O is synthesized from chiral cyclo-glycyl-L-alanine dipeptide. The dipeptide is known to show molecular flexibility in different environments, which leads to polymorphism. The crystal structure of the glycyl-L-alanine HI.H2O polymorph is determined at room temperature and indicates that the space group is polar (P21), with two molecules per unit cell and unit cell parameters a = 7.747 Å, b = 6.435 Å, c = 10.941 Å, α = 90°, β = 107.53(3)°, γ = 90° and V = 520.1(7) Å3. Crystallization in the polar point group 2, with one polar axis parallel to the b axis, allows pyroelectricity and optical second harmonic generation. Thermal melting of the glycyl-L-alanine HI.H2O polymorph starts at 533 K, close to the melting temperature reported for cyclo-glycyl-L-alanine (531 K) and 32 K lower than that reported for linear glycyl-L-alanine dipeptide (563 K), suggesting that although the dipeptide, when crystallized in the polymorphic form, is not anymore in its cyclic form, it keeps a memory of its initial closed chain and therefore shows a thermal memory effect. Here, we report a pyroelectric coefficient as high as 45 µC/m2K occurring at 345 K, one order of magnitude smaller than that of semi-organic ferroelectric triglycine sulphate (TGS) crystal. Moreover, the glycyl-L-alanine HI.H2O polymorph displays a nonlinear optical effective coefficient of 0.14 pm/V, around 14 times smaller than the value from a phase-matched inorganic barium borate (BBO) single crystal. The new polymorph displays an effective piezoelectric coefficient equal to (Formula presented.), when embedded into electrospun polymer fibers, indicating its suitability as an active system for energy harvesting. publishersversion published

Funding Information: This research was funded by the Fundação para a Ciência e Tecnologia FCT/MCTES through projects UIDB/50006/2020, UIDP/50006/2020 and LA/P/0008/2020 of the Associate Laboratory for Green Chemistry—LAQV, UIDB/04378/2020, UIDP/04378/2020 and LA/P/0140/2020 of UCIBIO and Associate Laboratory i4HB, respectively. Funding Information: The authors acknowledge LabRMN at FCT-UNL and Rede Nacional de RMN (RNRMN) for access to the facilities. The NMR spectrometers are part of The National NMR Facility, supported by FCT (ROTEIRO/0031/2013—PINFRA/22161/2016) (co-financed by FEDER through COMPETE 2020, POCI, and PORL and FCT through PIDDAC). Data Mass Spectrometry obtained by the Laboratório de Análises/LAQV REQUIMTE—Chemistry department FCT University NOVA of Lisbon. The SCXR determinations were performed in house (equipment financed by national funds through project RECI/BBBBEP/0124/2012 from FCT/MCTES). Publisher Copyright: © 2023 by the authors. A series of nine cationic heteroleptic aryl-BIAN-copper(I) (BIAN = bis-iminoacenaphthene) complexes with the general formula [Cu((E-C6H4)2BIAN)(PPh3)2][X] (E = p-Me, p-iPr, o-iPr; X = BF4, OTf, NO3) 1X–3X were synthesized and fully characterized using several analytical techniques, including NMR spectroscopy and single-crystal X-ray diffraction. Except for complexes 2BF4 and 3BF4, which were already reported in our previous works, all remaining complexes are herein described for the first time. Two different strategies were used for the preparation of the complexes: complexes bearing BF4− or OTf− counter-ions (1BF4, 1OTf, 2OTf, and 3OTf) were obtained using the appropriate copper(I) precursors [Cu(NCMe)4][BF4] or [Cu(NCMe)4][OTf], whereas for derivatives 1NO3–3NO3, [Cu(PPh3)2NO3] was used. Their activity as catalysts for the copper azide-alkyne cycloaddition (CuAAC) was assessed alongside other high activity, previously reported Cu(I) complexes. Comparative studies to determine the influence of the counter-ion and of the aryl substituents were performed. All complexes behaved as active catalysts under neat reaction conditions, at 25 °C and in short reaction times without requiring the use of any additive, with complex 2NO3 being the most efficient derivative, along with other NO3−-bearing complexes. publishersversion published

Funding Information: This work was supported by the Associate Laboratory Institute for Health and Bioeconomy – i4HB (project LA/P/0140/2020) which are financed by national funds from FCT/MCTES. FCT/MCTES is also acknowledged for supporting the National Portuguese NMR Network (ROTEIRO/0031/2013–PINFRA/22161/2016, cofinanced by FEDER through COMPETE 2020, POCI, PORL, and FCT through PIDDAC). A. C. acknowledges financing from Fundação Calouste Gulbenkian, grant no. 219201, and from the Angolan Embassy in Lisbon, Portugal, INAGBE grant. Dr. Ramesh Pandian is acknowledged for the initial acquisition and processing of single crystal X-ray data. Publisher Copyright: © 2023 The Author(s) The kinetics and thermodynamics of the pH-dependent multistate of species generated by the trans-chalcone of n-pyridinebenzopyrylium (n = 2′, 3′) were studied by UV–vis spectroscopy, 1H NMR and HPLC-MS, and the results compared with those reported for n = 4′. Due to the slow kinetics of the multistate species interconversion, the conjugation of these techniques has shown to be a powerful tool to investigate the behaviour of these systems. The species involved in the multistate are mutatis mutandis the same observed in anthocyanins and related compounds except for the flavylium cation, which was not observed in these systems even in very acidic medium. The rates of the interconversion of the multistate species upon pH stimuli are much slower than in anthocyanins. The compound bearing the pyridine nitrogen in position 2′ gives two novel products absorbing in the visible. Formation of the new products is particularly efficient from the thermal evolution of the photochemical products obtained upon light irradiation of the protonated trans-chalcone in a mixture of methanol:acidic water (1:1). This confirms the unique capacity of the substituents in position 2′ in giving intramolecular reactions involving the benzopyrylium core. Crystal structures for the three pyridine chalcone compounds (n = 2′, 3′, 4′) were obtained and the respective structures discussed. publishersversion published

LA/P/0140/2020 DL 57/2016 Norma transitória. In Portugal, publications with mechanochemical methods date back to 2009, with the report on mechanochemical strategies for the synthesis of metallopharmaceuticals. Since then, mechanochemical applications have grown in Portugal, spanning several fields, mainly crystal engineering and supramolecular chemistry, catalysis, and organic and inorganic chemistry. The area with the most increased development is the synthesis of multicomponent crystal forms, with several groups synthesizing solvates, salts, and cocrystals in which the main objective was to improve physical properties of the active pharmaceutical ingredients. Recently, non-crystalline materials, such as ionic liquids and amorphous solid dispersions, have also been studied using mechanochemical methods. An area that is in expansion is the use of mechanochemical synthesis of bioinspired metal-organic frameworks with an emphasis in antibiotic coordination frameworks. The use of mechanochemistry for catalysis and organic and inorganic synthesis has also grown due to the synthetic advantages, ease of synthesis, scalability, sustainability, and, in the majority of cases, the superior properties of the synthesized materials. It can be easily concluded that mechanochemistry is expanding in Portugal in diverse research areas. publishersversion published

Funding Information: This research was funded by national funds through FCT?Funda??o para a Ci?ncia e a Tecnologia, I.P., Project MOSTMICRO-ITQB (refs. UIDB/04612/2020 and UIDP/04612/2020), and IF/00109/2014/CP1244/CT0007. This work was also supported by FCT fellowships number PD/BD/135483/2018 (M.I.P.S.L.) and SFRH/BD/1444412019 (G.F.). Clara S. B. Gomes acknowledges the Associate Laboratory for Green Chemistry?LAQV and the Applied Molecular Biosciences Unit?UCIBIO, which are financed by national funds from Funda??o para a Ci?ncia e a Tecnologia (UIDB/50006/2020, UIDP/50006/2020, UIDB/04378/2020, UIDP/04378/2020, respectively).The NMR spectra were acquired at CERMAX?ITQB, integrated in the National NMR Network and are partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI, PORL and FCT through PIDDAC). Mass spectroscopy measurements were obtained by the UniMass Laboratory at ITQB-NOVA, Portugal. Clara S. B. Gomes acknowledges the XTAL?Macromolecular Crystallography group for granting access to the X-ray diffractometer. X-ray infrastructure financed by FCT-MCTES through project RECI/BBB-BEP/0124/2012. Funding Information: Funding: This research was funded by national funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., Project MOSTMICRO-ITQB (refs. UIDB/04612/2020 and UIDP/04612/2020), and IF/00109/2014/CP1244/CT0007. This work was also supported by FCT fellowships number PD/BD/135483/2018 (M.I.P.S.L.) and SFRH/BD/1444412019 (G.F.). Clara S. B. Gomes acknowledges the Associate Laboratory for Green Chemistry—LAQV and the Applied Molecular Biosciences Unit—UCIBIO, which are financed by national funds from Fundação para a Ciência e a Tecnologia (UIDB/50006/2020, UIDP/50006/2020, UIDB/04378/2020, UIDP/04378/2020, respectively). Funding Information: Acknowledgments: The NMR spectra were acquired at CERMAX—ITQB, integrated in the National NMR Network and are partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI, PORL and FCT through PIDDAC). Mass spectroscopy measurements were obtained by the UniMass Laboratory at ITQB-NOVA, Portugal. Clara S. B. Gomes acknowledges the XTAL—Macromolecular Crystallography group for granting access to the X-ray diffractometer. X-ray infrastructure financed by FCT-MCTES through project RECI/BBB-BEP/0124/2012. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Organometallic derivatization of nucleosides is a highly promising strategy for the im-provement of the therapeutic profile of nucleosides. Herein, a methodology for the synthesis of metalated adenosine with a deprotected ribose moiety is described. Platinum (II) N-heterocyclic carbene complexes based on adenosine were synthesized, namely N-heterocyclic carbenes bearing a protected and unprotected ribose ring. Reaction of the 8-bromo-2′,3′,5′-tri-O-acetyladenosine with Pt (PPh3)4 by C8−Br oxidative addition yielded complex 1, with a PtII centre bonded to C-8 and an unprotonated N7. Complex 1 reacted at N7 with HBF4 or methyl iodide, yielding protic carbene 2 or methyl carbene 3, respectively. Deprotection of 1 to yield 4 was achieved with NH4OH. Deprotected compound 4 reacted at N7 with HCl solutions to yield protic NHC 5 or with methyl iodide yielding methyl carbene 6. Protic N-heterocyclic carbene 5 is not stable in DMSO solutions leading to the formation of compound 7, in which a bromide was replaced by chloride. The cis-influence of complexes 1–7 was examined by31P{1H} and195Pt NMR. Complexes 2, 3, 5, 6 and 7 induce a decrease of1 JPt,P of more than 300 Hz, as result of the higher cis-influence of the N-heterocyclic carbene when compared to the azolato ligand in 1 and 4. publishersversion published

The electronically saturated and air-stable complexes [Ni(η5-C5H5)(Mes-BIAN)][PF6] (1) and [Ni(η5-C5H5)(Mes-DAD)][PF6] (2) were found to behave as efficient catalyst precursors for the polymerisation of ethylene under mild reaction conditions (temperature and pressure), when activated with small excesses of AlEt2Cl (DEAC), and exhibiting activities in the range 4×104 to 22×104 g PE/(mol Ni·h·bar). Compound 2 was synthesised and fully characterised as reported hereby for the first time, and exhibits a catalytic activity of ca. 30×104 g PE/(mol Ni·h·bar) in the polymerisation of ethylene. The reactivity of these complexes towards DEAC was found to lead to the formation of diamagnetic cationic Ni(II) complexes (4 and 3, respectively) containing the same initial cation [Ni(η5-C5H5)(α-diimine)]+ and a [AlEtCl3]- anion, whereby α-diimine = BIAN (1 and 4) and DAD (2 and 3). In the corresponding reaction of complex [Ni(η5-C5H5)(Mes-BIAN)][PF6] (1), an unusual paramagnetic complex incorporating a cationic trinuclear α-diimine Ni cluster (5), containing five bridging Cl ligands and a [AlCl4]- anion, was also isolated and fully characterised, in which the cyclopentadienyl ligand was absent. The intermediates 3 and 5 also catalysed efficiently the polymerisation of ethylene when the DEAC co-catalyst was used in slight excess. The polyethylene produced (ca. 10×104 to 30×104 g PE/(mol Ni·h·bar), respectively) showed branching numbers ranging from 7 to 75 branches/1000 carbon atoms according to 1H NMR spectroscopy analysis. These findings are surprising given that the new 18-electron nickel precursors show remarkable properties towards ethylene polymerisation catalysis when activated with a small excess of aluminium activator under mild conditions, and also that some unusual intermediates responsible for the observed activity were isolated and characterised by X-ray crystallography.