Estekatzaile piridinikoetan eta trantsizio-metaletan oinarritutako koordinazio-konposatuen prestaketa: egitura-dibertsitate zabalaren analisia ezaugarri magnetiko eta lumineszenteei begira

LABURPENA (euskaraz) Lan honek azido 2-hidoxilo-6-metil-nikotiniko ligandoz eta lehenengo trantsizio-serieko metalez osatutako koordinazio-konposatu berrien sintesia eta karakterizazioa du helburu nagusitzat. Konposatuak sintetizatu ondoren, bere karakterizazioa teknika esperimental desberdinak erabiliz egin da: analisi elementala (AE), infragorri espektroskopia (FT-IR) eta X-izpien bidezko difrakzioa hautsean (PXRD), laginen purutasuna determinatzeko. Monokristala lortu egin deneko kasuetan, haren kristal egitura ebatzi da X-izpien bidezko difrakzioaren (SCXRD) bitartez. Ezaugarri lumineszenteak dituen Zn(II)-z eta Na(I)-z osatutako konposatu bat lortu da, igorpen fluoreszente eta fosforeszenteak erakusten dituena. Konposatu honen lumineszentzia prozesuan sakontzeko asmoz, kalkulu teorikoak egin dira bertan ematen diren elektroi-trantsizioak esleitzeko asmoz. Konposatu horiek interes handia dute gailu argitsuetan edota sentsoreetan aplikatuak izateko dituzten aukerengatik. Bestalde, potentzialki ezaugarri magnetikoak dituzten konposatuak ere lortu dira. Lortutako konposatuen artean, Mn(III)-z eratutako konposatu bat lortu da, printzipioz ezaugarri magnetiko interesgarriak erakutsi ditzakeenak, zehazki iman molekular gisa jokatzeko gaitasuna izan baitezake. Horrelako materialak, gaur egun, aplikazio askotan erabiltzeko aukera ematen dute, material magnetiko berrietarako oinarri gisa erabiliz, adibidez, datuak biltegiratzeko.ABSTRACT (english): The main goal of the present work consists in the synthesis and characterization of new coordination compunds starting based on 2-hydroxy-6-methylnicotinic acid and different first-row transition metals. Once synthesized, these compounds have been characterized by means of several experimental techniques: elemental analysis (AE), infrared spectroscopy (FT-IR) and powder X-ray diffraction (PXRD) in order to determine the purity of the samples. Additionally, crystal structures have been solved for those compounds obtained as single crystals by means of X-ray diffraction (SCXRD). One of the reported compounds, a Zn(II) and Na based compound, shows fluorescent and phosphorescent emissions. In order to get deeper insigths into the luminescence process, theoretical calculations have been performed to assign the electronic transitions. These compounds are of great interest due to their applicability in devices for solid-state lighting or sensors. On the other hand, many compounds with potential magnetic properties have been also obtained. Among them, it is worth noting one compound formed by Mn(III) atoms since it may a priori exhibit interesting magnetic properties, in particular behaving as single-molecule magnets. These sorts of compounds are known for their potential applications in different fields, being used as a basis for developing new magnetic materials with multiple aplications, such as data storage

Estekatzaile piridinikoetan eta trantsizio-metaletan oinarritutako koordinazio-konposatuen prestaketa: egitura-dibertsitate zabalaren analisia ezaugarri magnetiko eta lumineszenteei begira

LABURPENA (euskaraz) Lan honek azido 2-hidoxilo-6-metil-nikotiniko ligandoz eta lehenengo trantsizio-serieko metalez osatutako koordinazio-konposatu berrien sintesia eta karakterizazioa du helburu nagusitzat. Konposatuak sintetizatu ondoren, bere karakterizazioa teknika esperimental desberdinak erabiliz egin da: analisi elementala (AE), infragorri espektroskopia (FT-IR) eta X-izpien bidezko difrakzioa hautsean (PXRD), laginen purutasuna determinatzeko. Monokristala lortu egin deneko kasuetan, haren kristal egitura ebatzi da X-izpien bidezko difrakzioaren (SCXRD) bitartez. Ezaugarri lumineszenteak dituen Zn(II)-z eta Na(I)-z osatutako konposatu bat lortu da, igorpen fluoreszente eta fosforeszenteak erakusten dituena. Konposatu honen lumineszentzia prozesuan sakontzeko asmoz, kalkulu teorikoak egin dira bertan ematen diren elektroi-trantsizioak esleitzeko asmoz. Konposatu horiek interes handia dute gailu argitsuetan edota sentsoreetan aplikatuak izateko dituzten aukerengatik. Bestalde, potentzialki ezaugarri magnetikoak dituzten konposatuak ere lortu dira. Lortutako konposatuen artean, Mn(III)-z eratutako konposatu bat lortu da, printzipioz ezaugarri magnetiko interesgarriak erakutsi ditzakeenak, zehazki iman molekular gisa jokatzeko gaitasuna izan baitezake. Horrelako materialak, gaur egun, aplikazio askotan erabiltzeko aukera ematen dute, material magnetiko berrietarako oinarri gisa erabiliz, adibidez, datuak biltegiratzeko.ABSTRACT (english): The main goal of the present work consists in the synthesis and characterization of new coordination compunds starting based on 2-hydroxy-6-methylnicotinic acid and different first-row transition metals. Once synthesized, these compounds have been characterized by means of several experimental techniques: elemental analysis (AE), infrared spectroscopy (FT-IR) and powder X-ray diffraction (PXRD) in order to determine the purity of the samples. Additionally, crystal structures have been solved for those compounds obtained as single crystals by means of X-ray diffraction (SCXRD). One of the reported compounds, a Zn(II) and Na based compound, shows fluorescent and phosphorescent emissions. In order to get deeper insigths into the luminescence process, theoretical calculations have been performed to assign the electronic transitions. These compounds are of great interest due to their applicability in devices for solid-state lighting or sensors. On the other hand, many compounds with potential magnetic properties have been also obtained. Among them, it is worth noting one compound formed by Mn(III) atoms since it may a priori exhibit interesting magnetic properties, in particular behaving as single-molecule magnets. These sorts of compounds are known for their potential applications in different fields, being used as a basis for developing new magnetic materials with multiple aplications, such as data storage

A Luminescent MOF Based on Pyrimidine-4,6-dicarboxylate Ligand and Lead(II) with Unprecedented Topology

In the present work, we report on a 3D MOF of {[Pb5(μ3-OH)(μ3-NO3)3(μ6-pmdc)3]·H2O}n formula (pmdc = pyrimidine-4,6-dicarboxylate) synthesized by an oven-heated, solvent-free procedure. The large connectivity afforded by the three ligands in their coordination to lead(II) ions grows cubic building units characterized by a central Pb atom with an unusual coordination index of 12 and 6 pmdc ligands occupying the faces. These cubic units are linked to one another giving rise to a quite condensed structure that represents an unprecedented topology showing the (4·62)6(43)2(45·610)3(45·68·82)6(46·69)6(612·83) point symbol. The crystalline material has been characterized by routine physico-chemical techniques to confirm its purity, and its thermal behaviour has been also studied by thermogravimetric and thermodiffractometric analyses. The solid presents a greenish blue photoluminescent emission based on pmdc ligands, as revealed by time-dependent density-functional theory (TDDFT) calculations, which is substantially more intense than in the free H2pmdc ligand according to its improved quantum yield. The emissive capacity of the material is further analysed according to decreasing temperature of the polycrystalline sample, finding that sizeable, long-lasting phosphorescence is present.This research was funded by Gobierno Vasco/Eusko Jaurlaritza (IT1755-22, IT1722-22 and IT1500-22) and Junta de Andalucía (ProyExcel_00386 and FQM-394). This publication is also part of the I+D+i projects of PGC2018-102052-A-C22 and PGC2018-102052-B-C21 codes, funded by MCIN/ AEI/10.13039/501100011033/ and “FEDER Una manera de hacer Europa”

Lanthanide(III) Ions and 5-Methylisophthalate Ligand Based Coordination Polymers: An Insight into Their Photoluminescence Emission and Chemosensing for Nitroaromatic Molecules

The work presented herein reports on the synthesis, structural and physico-chemical characterization, luminescence properties and luminescent sensing activity of a family of isostructural coordination polymers (CPs) with the general formula [Ln2(μ4-5Meip)3(DMF)]n (where Ln(III) = Sm (1Sm), Eu (2Eu), Gd (3Gd), Tb (4Tb) and Yb (5Yb) and 5Meip = 5-methylisophthalate, DMF = N,N-dimethylmethanamide). Crystal structures consist of 3D frameworks tailored by the linkage between infinite lanthanide(III)-carboxylate rods by means of the tetradentate 5Meip ligands. Photoluminescence measurements in solid state at variable temperatures reveal the best-in-class properties based on the capacity of the 5Meip ligand to provide efficient energy transfers to the lanthanide(III) ions, which brings intense emissions in both the visible and near-infrared (NIR) regions. On the one hand, compound 5Yb displays characteristic lanthanide-centered bands in the NIR with sizeable intensity even at room temperature. Among the compounds emitting in the visible region, 4Tb presents a high QY of 63%, which may be explained according to computational calculations. At last, taking advantage of the good performance as well as high chemical and optical stability of 4Tb in water and methanol, its sensing capacity to detect 2,4,6-trinitrophenol (TNP) among other nitroaromatic-like explosives has been explored, obtaining high detection capacity (with Ksv around 105 M−1), low limit of detection (in the 10−6–10−7 M) and selectivity among other molecules (especially in methanol).This work has been funded by University of the Basque Country (GIU20/028), Gobierno Vasco/Eusko Jaurlaritza (IT1755-22 and IT1500-22), Junta de Andalucía (FQM-394 and B-FQM-734-UGR20, B-FQM-478-UGR20 and ProyExcel_00386) and the Spanish Ministry of Economy and Competitiveness (MCIU/AEI/FEDER, UE) (PGC2018-102052-A-C22, PGC2018-102052-B-C21 and PID2020-117344RB-I00)

Combined experimental and theoretical investigation on the magnetic properties derived from the coordination of 6-methyl-2-oxonicotinate to 3d-metal ions

Five new compounds are reported herein starting from 2-hydroxy-6-methylnicotinic acid (H2h6mnic) and first-row transition metal ions, although H2h6mnic shows a prototropy in solution to lead to the 6-methyl-2-oxonicotinate (6m2onic) ligand that is the molecule eventually present in the compounds. The structural and chemical characterization reveals the following chemical formulae: {[MnNa(μ-6m2onic)(μ-6m2onic)(MeOH)]·HO·MeOH} (1Mn), {[MNa(μ-6m2onic)(μ-6m2onic)(μ-HO)(HO)](NO)} [M = Co (2Co) and Ni (3Ni)], 2[Cu(6m2onic)(μ-6m2onic)(MeOH)]·[Cu(6m2onic)(μ-6m2onic)]·2[Cu(6m2onic)(MeOH)]·32HO (4Cu) and {[Cu(μ-6m2onic)]·6HO} (5Cu) (where 6m2onic = 6-methyl-2-oxonicotinate). An unusual structural diversity is observed for the compounds, ranging from isolated complexes (in 4Cu), 1D arrays (in 1Mn and 5Cu) and 3D frameworks (in 2Co and 3Ni). Magnetic properties have been studied for all compounds. Analysis of the magnetic dc susceptibility and magnetization data for 4Cu and 5Cu suggests the occurrence of ferromagnetic exchange, which is well explained by broken-symmetry and CASSCF calculations. The sizeable easy-plane magnetic anisotropy present in compound 2Co allows for a field-induced magnet behaviour with an experimental effective energy barrier of 16.2 cm, although the slow relaxation seems to be best described through Raman and direct processes in agreement with the results of ab initio calculations.This work has been funded by the Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) (PGC2018-102052-A-C22, PGC2018-102052-B-C21), University of the Basque Country (GIU20/028), Gobierno Vasco/Eusko Jaurlaritza (IT1005-16, IT1291-19), and Junta de Andalucía (FQM-394 and B-FQM-734-UGR2). OPC thanks his predoctoral fellowship to UPV/EHU. The authors thank for technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF)