Magnetic and Luminescent Properties of Isostructural 2D Coordination Polymers Based on 2-Pyrimidinecarboxylate and Lanthanide Ions

Amalia García-García; Andoni Zabala-Lekuona; Ainhoa Goñi-Cárdenas; Javier Cepeda; José M. Seco; Alfonso Salinas-Castillo; Duane Choquesillo-Lazarte; Antonio Rodríguez-Diéguez

doi:10.3390/cryst10070571

Magnetic and Luminescent Properties of Isostructural 2D Coordination Polymers Based on 2-Pyrimidinecarboxylate and Lanthanide Ions

Crystals ◽

10.3390/cryst10070571 ◽

2020 ◽

Vol 10 (7) ◽

pp. 571

Author(s):

Amalia García-García ◽

Andoni Zabala-Lekuona ◽

Ainhoa Goñi-Cárdenas ◽

Javier Cepeda ◽

José M. Seco ◽

...

Keyword(s):

Coordination Polymers ◽

Single Molecule ◽

Density Functional ◽

Magnetic Measurements ◽

Luminescent Properties ◽

Rare Earth Ions ◽

Lanthanide Ions ◽

Ligand Field ◽

Bridging Ligands ◽

Metal Centers

A couple of isostructural coordination polymers with the general formula [Ln4(pymca)4(AcO)8]n have been obtained from reactions between pyrimidine-2-carboxylate (pymca) ligand and rare-earth ions (Ln = Dy (1), Nd (2)). These two-dimensional compounds have been characterized and the crystal structures have been solved by single-crystal X-ray diffraction technique, resulting in layers along the bc plane based on pymca and acetate anions that act as bridging ligands between metal atoms. Given that pymca and acetate anions possess carboxylate and hetero-nitrogen groups, it is possible to build a coordination polymer whose metal centers have a nine coordination. Furthermore, static and dynamic magnetic measurements of compound 1 reveal the lack of single molecule-magnet (SMM) behavior in this system due to the following two effects: (i) the ligand field does not stabilize magnetic ground states well separated from excited states, and (ii) anisotropy axes are not collinear, according to results with Magellan software. On another level, luminescent properties of compounds 1 and 2 are attributed to singlet π-π* transitions centered on pymca ligand as corroborated by time-dependent density functional theory (TD-DFT) calculations.

Download Full-text

Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding

10.26434/chemrxiv.10316681.v1 ◽

2019 ◽

Author(s):

Andrew Rosen ◽

M. Rasel Mian ◽

Timur Islamoglu ◽

Haoyuan Chen ◽

Omar Farha ◽

...

Keyword(s):

Density Functional ◽

Metal Organic Frameworks ◽

Redox Activity ◽

Screening Methods ◽

Bridging Ligands ◽

Metal Centers ◽

Computational Screening ◽

Open Metal Sites ◽

Metal Organic ◽

Unsaturated Metal Sites

Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O2 and N2 adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br-, μ-Cl-, μ-F-, μ-SH-, or μ-OH- groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O2 affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O2. In contrast with O2 adsorption, N2 adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V2+ open metal sites. As one example from the screening study, we predict that exchanging the μ-Cl- ligands of M2Cl2(BBTA) (H2BBTA = 1H,5H-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH- groups would significantly enhance the strength of O2 adsorption at the open metal sites without a corresponding increase in the N2 affinity. Experimental investigation of Co2Cl2(BBTA) and Co2(OH)2(BBTA) confirms that the former exhibits only weak physisorption, whereas the latter is capable of chemisorbing O2 at room temperature. The chemisorption behavior is attributed to the greater electron-donating character of the μ-OH- ligands and the presence of H-bonding interactions between the μ-OH- bridging ligands and the O2 adsorbate.

Download Full-text

Recent advances in lanthanide coordination polymers and clusters with magnetocaloric effect or single-molecule magnet behavior

Dalton Transactions ◽

10.1039/d1dt02797b ◽

2021 ◽

Author(s):

Jun-Jie Hu ◽

Yan Peng ◽

Sui-Jun Liu ◽

He-Rui Wen

Keyword(s):

Quantum Computing ◽

Low Temperature ◽

Magnetocaloric Effect ◽

Coordination Polymers ◽

Single Molecule ◽

Information Storage ◽

Lanthanide Ions ◽

Single Molecule Magnets ◽

Single Molecule Magnet ◽

Lanthanide Coordination Polymers

The molecular magnetorefrigerant materials for low-temperature magnetic refrigeration and single-molecule magnets for high-density information storage and quantum computing have received extensive attention from chemists and magnetic experts. Lanthanide ions with...

Download Full-text

Solvent Influence in Obtaining Diverse Coordination Symmetries of Dy(III) Metal Centers in Coordination Polymers: Synthesis, Characterization, and Luminescent Properties

Crystal Growth & Design ◽

10.1021/acs.cgd.9b01599 ◽

2020 ◽

Vol 20 (5) ◽

pp. 2973-2984 ◽

Cited By ~ 2

Author(s):

Nithi Phukan ◽

Soumyabrata Goswami ◽

Sophie Lipstman ◽

Israel Goldberg ◽

Bharat Kumar Tripuramallu

Keyword(s):

Coordination Polymers ◽

Luminescent Properties ◽

Metal Centers ◽

Solvent Influence

Download Full-text

Crystal structures, topologies and luminescent properties of three Zn(ii)/Cd(ii) coordination networks based on naphthalene-2,6-dicarboxylic acid and different bis(imidazole) linkers

RSC Advances ◽

10.1039/c4ra14862b ◽

2015 ◽

Vol 5 (21) ◽

pp. 16190-16198 ◽

Cited By ~ 19

Author(s):

Zhi-Hao Yan ◽

Wen Wang ◽

Liangliang Zhang ◽

Xiaowei Zhang ◽

Lei Wang ◽

...

Keyword(s):

Metal Ions ◽

Dicarboxylic Acid ◽

Crystal Structures ◽

Coordination Polymers ◽

Structural Diversity ◽

Luminescent Properties ◽

Coordination Networks ◽

Bridging Ligands

Three new coordination polymers (CPs) based on H2ndc acid have been synthesized and structurally characterized. Three CPs exhibit structural diversity depending on different bis(imidazole) bridging ligands and center metal ions.

Download Full-text

Magnetic anisotropy and interaction between f-electronic systems in dinuclear inverted-sandwich-type lanthanide-phthalocyanine complexes

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424614500795 ◽

2014 ◽

Vol 18 (10n11) ◽

pp. 933-936 ◽

Cited By ~ 1

Author(s):

Satoshi Tsuchiya ◽

Akira Fuyuhiro ◽

Takamitsu Fukuda ◽

Naoto Ishikawa

Keyword(s):

Magnetic Susceptibility ◽

Magnetic Anisotropy ◽

Single Molecule ◽

Magnetic Measurements ◽

Field Potential ◽

Magnetic Interaction ◽

Ligand Field ◽

Electronic Systems ◽

Sandwich Type ◽

Paramagnetic Shifts

The first detection and characterization of magnetic interaction between two 4f electronic systems in the dinuclear "inverted-sandwich-type" phthalocyanine complex with terbium ions and that of dysprosium ions are presented. Temperature dependent magnetic measurements for the diterbium complex, (μ-phthalocyaninato)bis[di(2,2,6,6-tetramethylheptane-3,5-dionato)terbium], show that the value of magnetic susceptibility times temperature, χT, sharply decreases as temperature is lowered, indicating the presence of an antiferromagnetic-type interaction between the Tb 3+ ions in the dinuclear complex. Similar temperature dependence was observed for the corresponding dinuclear dysprosium complex. These results are completely opposite to those observed for Pc triple-decker dinuclear terbium or dysprosium complexes, which are known to function as single molecule magnets. The NMR signals for the protons on the Pc ligand of the diterbium complex show up-field paramagnetic shifts due to the partially-filled 4f shells of the metal ions. This again makes sharp contrast to the triple-deckers, for which large down-field paramagnetic shifts are observed. These intriguing results seen in the NMR and magnetic susceptibility measurements are explained assuming the ligand field potential of the inverted-sandwich complexes gives strong easy-plain-type magnetic anisotropy, where Jz value of the lowest sublevel has a small value, while sandwich-type Pc3Ln2 ( Ln = Tb or Dy ) complexes have a strong easy-axis-type magnetic anisotropy.

Download Full-text

Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding: Design Rules and Ambient Temperature O2 Chemisorption in a Cobalt−Triazolate Framework

10.26434/chemrxiv.10316681.v2 ◽

2020 ◽

Author(s):

Andrew Rosen ◽

M. Rasel Mian ◽

Timur Islamoglu ◽

Haoyuan Chen ◽

Omar Farha ◽

...

Keyword(s):

Density Functional ◽

Metal Organic Frameworks ◽

Redox Activity ◽

Screening Methods ◽

Bridging Ligands ◽

Metal Centers ◽

Computational Screening ◽

Open Metal Sites ◽

Metal Organic ◽

Unsaturated Metal Sites

Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O2 and N2 adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br-, μ-Cl-, μ-F-, μ-SH-, or μ-OH- groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O2 affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O2. In contrast with O2 adsorption, N2 adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V2+ open metal sites. As one example from the screening study, we predicted that exchanging the μ-Cl- ligands of M2Cl2(BBTA) (H2BBTA = 1H,5H-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH- groups would significantly enhance the strength of O2 adsorption at the open metal sites without a corresponding increase in the N2 affinity. Experimental investigation of Co2Cl2(BBTA) and Co2(OH)2(BBTA) confirms that the former exhibits weak physisorption of both N2 and O2, whereas the latter is capable of chemisorbing O2 at room temperature in a highly selective manner. The O2 chemisorption behavior is attributed to the greater electron-donating character of the μ-OH- ligands and the presence of H-bonding interactions between the μ-OH- bridging ligands and the reduced O2 adsorbate.

Download Full-text

STM Spectroscopy of Star-Type Molecular Magnet

Dhaka University Journal of Science ◽

10.3329/dujs.v60i1.10343 ◽

2012 ◽

Vol 60 (1) ◽

pp. 87-91

Author(s):

MS Alam ◽

FA Chowdhury ◽

RW Saalfrank ◽

AV Postnikov ◽

P Müller

Keyword(s):

Single Molecule ◽

Density Functional ◽

Scanning Tunneling Spectroscopy ◽

Scanning Tunneling ◽

Molecular Magnet ◽

Large Signal ◽

Tunneling Microscopy ◽

Functional Theory ◽

Metal Centers ◽

Stm Images

In order to achieve a better understanding of how scanning tunneling microscopy (STM) images of metallo-complexes are related to the geometric and electronic structure, we performed scanning microscopy (STM) and scanning tunneling spectroscopy (STS) techniques on [FeIIIFeIII 3L6] (L= N-methylaminediethanolate) star-type tetranuclear molecular magnet. The experiments were performed under ambient condition. We were able to image single molecule by STM with submolecular resolution. In our STS measurements we found a rather large signal at the positions of iron ion centers in the molecules. This direct addressing of metal centers was further confirmed by density functional theory (DFT) calculations.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10343 Dhaka Univ. J. Sci. 60(1): 87-91 2012 (January)

Download Full-text

Magnetic and Electrical Behaviors of the Homo- and Heterometallic 1D and 3D Coordination Polymers Based on the Partial Decomposition of the [Cr(C2O4)3]3− Building Block

Materials ◽

10.3390/ma13235341 ◽

2020 ◽

Vol 13 (23) ◽

pp. 5341

Author(s):

Lidija Kanižaj ◽

Pavla Šenjug ◽

Damir Pajić ◽

Luka Pavić ◽

Krešimir Molčanov ◽

...

Keyword(s):

Coordination Polymers ◽

Building Block ◽

Magnetic Measurements ◽

Three Dimensional ◽

Magnetic Interaction ◽

X Ray Diffraction ◽

Metal Centers ◽

Strongly Coupled ◽

Partial Decomposition ◽

Oxalate Group

One-dimensional (1D) oxalate-bridged homometallic {[Mn(bpy)(C2O4)]·1.5H2O}n (1) (bpy = 2,2’-bipyridine) and heterodimetallic {[CrCu3(bpy)3(CH3OH)(H2O)(C2O4)4][Cu(bpy)Cr(C2O4)3]·CH2Cl2·CH3OH·H2O}n (2) coordination polymers, as well as the three-dimensional (3D) heterotrimetallic {[CaCr2Cu2(phen)4(C2O4)6]·4CH3CN·2H2O}n (3) (1,10-phenanthroline) network, have been synthesized by a building block approach using a layering technique, and characterized by single-crystal X-ray diffraction, infrared (IR) and impedance spectroscopies and magnetization measurements. During the crystallization process partial decomposition of the tris(oxalato)chromate(III) happened and 1D polymers 1 and 2 were formed. The antiferromagnetic interactions between the manganese(II) ions were mediated by oxalate ligands in the chain [Mn(bpy)(C2O4)]n of 1, with intra-chain super-exchange interaction ? = (−3.134 ± 0.004) K; magnetic interaction between neighbouring chains is negligible making this system closer than other known Mn-chains to the ideal 1D Heisenberg antiferromagnet. Compound 2 comprises a 1D coordination anion [Cu(bpy)Cr(C2O4)3]nn− (Cr2–Cu4) with alternating [Cr(C2O4)3]3− and [Cu(bpy)]2+ units mutually bridged through the oxalate group. Another chain (Cr1–Cu3) is similar, but involves a homodinuclear unit [Cu(bpy)(H2O)(µ-C2O4)Cu(bpy)(CH3OH)]2+ (Cu1–Cu2) coordinated as a pendant group to a terminal oxalate oxygen. Magnetic measurements showed that the Cu1−Cu2 cationic unit is a strongly coupled antiferromagnetic dimer, independent from the other magnetic ions within ferromagnetic chains Cr1–Cu3 and Cr2–Cu4. A 3D polymer {[CaCr2Cu2(phen)4(C2O4)6]·4CH3CN·2H2O}n (3) comprising three different metal centers (Ca2+, Cr3+ and Cu2+) oxalate-bridged, contains Ca2+ atoms as nodes connected with four Cr3+ atoms through oxalate ligands. The network thus formed can be reduced to an underlying graph of diamondoid (dia) or (66) topology. Magnetization of 3 shows the ferromagnetic oxalate-bridged dimers [CuIICrIII], whose mutual interaction could possibly originate through the spin polarization of Ca2+ orbitals. Compounds 1 and 3 exhibit lower electrical conductivity at room temperature (RT) in comparison to compound 2.

Download Full-text

Single-Ion Magnet and Photoluminescence Properties of Lanthanide(III) Coordination Polymers Based on Pyrimidine-4,6-Dicarboxylate

Magnetochemistry ◽

10.3390/magnetochemistry7010008 ◽

2021 ◽

Vol 7 (1) ◽

pp. 8

Author(s):

Oier Pajuelo-Corral ◽

Jose Angel García ◽

Oscar Castillo ◽

Antonio Luque ◽

Antonio Rodríguez-Diéguez ◽

...

Keyword(s):

Coordination Polymers ◽

Single Molecule ◽

Visible Region ◽

Emission Spectra ◽

Lanthanide Ions ◽

Quantum Yields ◽

Nitrate Anion ◽

Absolute Quantum

Herein, we report the magnetic and photoluminescence characterization of coordination polymers (CP) built from the combination of lanthanide(III) ions, pyrimidine-4,6-dicarboxylate (pmdc) ligand and a co-ligand with formula {[Dy(μ-pmdc)(μ-ox)0.5(H2O)3]·2H2O}n (1-Dy), {[Dy(μ3-pmdc)(μ-ox)0.5(H2O)2] ~2.33H2O}n (2-Dy), {[Dy2(μ3-pmdc)(μ4-pmdc)(μ-ox)(H2O)3]·5H2O}n (3-Dy), {[Ln(μ3-pmdc)(μ-ox)0.5(H2O)2]·H2O}n (where Ln(III) = Nd (4-Nd), Sm (4-Sm), Eu (4-Eu) and Dy (4-Dy)) and {[Dy(μ4-pmdc)(NO3)(H2O)]·H2O}n (5-Dy). It must be noted the presence of oxalate anion acting as ditopic co-ligand in compounds 1-Dy, 2-Dy, 3-Dy and 4-Ln, whereas in 5-Dy the nitrate anion plays the role of terminal co-ligand. Direct current measurements carried out for the dysprosium-based CPs reveal almost negligible interactions between Dy3+ ions within the crystal structure, which is confirmed by computed values of the exchange parameters J. In addition, alternating current measurements show field-induced single-molecule magnet (SMM) behavior in compounds 1-Dy, 2-Dy, 4-Dy and 5-Dy, whereas slight-frequency dependence is also observed in 3-Dy. Solid state emission spectra performed at room temperature for those compounds emitting in visible region confirm the occurrence of significant ligand-to-lanthanide charge transfer in view of the strong characteristic emissions for all lanthanide ions. Emission decay curves were also recorded to estimate the emission lifetimes for the reported compounds, in addition to the absolute quantum yields. Among them, the high quantum yield of 25.0% measured for 4-Eu is to be highlighted as a representative example of the good emissive properties of the materials.

Download Full-text

2D-metal–organic coordination polymers of lanthanides (La(iii), Pr(iii) and Nd(iii)) with redox-active dioxolene bridging ligands

CrystEngComm ◽

10.1039/d0ce00767f ◽

2020 ◽

Vol 22 (28) ◽

pp. 4675-4679 ◽

Cited By ~ 1

Author(s):

Alexandr D. Kharitonov ◽

Olesya Y. Trofimova ◽

Irina N. Meshcheryakova ◽

Georgy K. Fukin ◽

Mikhail N. Khrizanforov ◽

...

Keyword(s):

Coordination Polymers ◽

Active Networks ◽

Lanthanide Ions ◽

Bridging Ligands ◽

Redox Active ◽

Metal Organic

2D-coordination redox-active networks bearing t-Bu-substituted anilic bridged ligands and lanthanide ions were synthesized and characterized.

Download Full-text