Anion Lattice Research Articles

Superionic Conduction in K3SbS4 Enabled by Cl‐Modified Anion Lattice

AbstractAll‐solid‐state potassium batteries emerge as promising alternatives to lithium batteries, leveraging their high natural abundance and cost‐effectiveness. Developing potassium solid electrolytes (SEs) with high room‐temperature ionic conductivity is critical for realizing efficient potassium batteries. In this study, we present the synthesis of K2.98Sb0.91S3.53Cl0.47, showcasing a room‐temperature ionic conductivity of 0.32 mS/cm and a low activation energy of 0.26 eV. This represents an increase of over two orders of magnitude compared to the parent compound K3SbS4, marking the highest reported ionic conductivity for non‐oxide potassium SEs. Solid‐state 39K magic‐angle‐spinning nuclear magnetic resonance on K2.98Sb0.91S3.53Cl0.47 reveals an increased population of mobile K+ ions with fast dynamics. Ab initio molecular dynamics (AIMD) simulations further confirm a delocalized K+ density and significantly enhanced K+ diffusion. This work demonstrates diversification of the anion sublattice as an effective approach to enhance ion transport and highlights K2.98Sb0.91S3.53Cl0.47 as a promising SE for all‐solid‐state potassium batteries.

Superionic Conduction in K3SbS4 Enabled by Cl-Modified Anion Lattice.

All-solid-state potassium batteries emerge as promising alternatives to lithium batteries, leveraging their high natural abundance and cost-effectiveness. Developing potassium solid electrolytes (SEs) with high room-temperature ionic conductivity is critical for realizing efficient potassium batteries. In this study, we present the synthesis of K2.98Sb0.91S3.53Cl0.47, showcasing a room-temperature ionic conductivity of 0.32 mS/cm and a low activation energy of 0.26 eV. This represents an increase of over two orders of magnitude compared to the parent compound K3SbS4, marking the highest reported ionic conductivity for non-oxide potassium SEs. Solid-state 39K magic-angle-spinning nuclear magnetic resonance on K2.98Sb0.91S3.53Cl0.47 reveals an increased population of mobile K+ ions with fast dynamics. Ab initio molecular dynamics (AIMD) simulations further confirm a delocalized K+ density and significantly enhanced K+ diffusion. This work demonstrates diversification of the anion sublattice as an effective approach to enhance ion transport and highlights K2.98Sb0.91S3.53Cl0.47 as a promising SE for all-solid-state potassium batteries.

Structure and ionic conduction enhancement mechanisms at CeO2/SrTiO3 heterointerfaces

Fluorite-perovskite heterointerfaces garner great interest for enhanced ionic conductivity for application in electronic and energy devices. However, the origin of observed enhanced ionic conductivity as well as the details of the atomic structure at these interfaces remain elusive. Here, systematic, multi-stoichiometry computational searches and experimental investigations are performed to obtain stable and exact atomic structures of interfaces between CeO2 and SrTiO3—two archetypes of the corresponding structural families. Local reconstructions take place at the interface because of mismatched lattices. TiO2 terminated SrTiO3 causes a buckled rock salt CeO interface layer to emerge. In contrast, SrO terminated SrTiO3 maintains the fluorite structure at the interface compensated by a partially occupied anion lattice. Moderate enhancement in oxygen diffusion is found along the interface by simulations, yet evidence to support further significant enhancement is lacking. Our findings demonstrate the control of interface termination as an effective pathway to achieve desired device performance.

Why Is the Bandgap of GaP Indirect While That of GaAs and GaN Are Direct?

Many III–V semiconductors possess direct bandgaps and are thus widely applied in optoelectronics. Although GaN (either in wurtzite phase or zinc blende phase), GaAs, and GaSb are well‐known direct‐gap semiconductors, GaP exhibits an indirect bandgap nevertheless. In this work, the generic rule of energy gaps in GaN, GaP, and GaAs of the zinc blende phase is analyzed, and the trends of gap variation are studied concerning the lattice constant and anion electronegativity. It turns out that GaP actually manifests a normal behavior, the reason why GaN surprisingly has a direct gap is analyzed through examining and perturbing its valence band as well as conduction band (CB). The CB electron shows a non‐negligible probability to emerge near the N cores. The attractive nucleus potential pulls down the CB more strongly at Γ, which is in principle further supported through an analysis of the Kronig–Penney model. The difference between GaP and GaN in this respect is also analyzed in detail.

Composition, structure, and wear resistance of (TiZrNbMoTa)CxN1-x high entropy alloy carbonitride coatings prepared by reactive radio-frequency magnetron sputtering

HEN has high hardness and good toughness but a high coefficient of friction and poor wear resistance. In this study, a high hardness, toughness, and wear-resistant HECxN1-x coating was prepared by reactive radio-frequency magnetron sputtering (RFMS) technology. The phase composition, microstructure, mechanical properties, and tribological properties of the HEN and HECxN1-x coatings were investigated. The results show that all coatings have single-phase rock salt structures. The double anion lattice structure of the HECxN1-x coating produces a high lattice distortion effect and grain refinement effect, which realizes the strengthening and hardening of the coating. When the [C]/([C] + [N]) ratio is 0.3, the hardness of the HECxN1-x coating reaches the maximum value of 41.7GPa, and when the [C]/([C] + [N]) ratio is 0.4, the coating toughness reaches the maximum value of 0.91GPa, which are 48 % and 203 % higher than HEN. The self-lubricating effect of supersaturated precipitated amorphous carbon makes the HECxN1-x coating achieve excellent tribological properties. Among them, HEC0.5N0.5 coating has the best tribological properties, its coefficient of friction (COF) is 0.391, which is 148 % lower than that of HEN coating, and the wear rate is reduced to 1/15 of HEN coating, which is one order of magnitude reduction. Introducing the C element based on HEN can effectively solve the problems of high friction coefficient and poor wear resistance of high entropy nitride ceramic coatings.

Transforming Li3PS4 Via Halide Incorporation: a Path to Improved Ionic Conductivity and Stability in All‐Solid‐State Batteries

AbstractTo enhance Li+ transport in all‐solid‐state batteries (ASSBs), harnessing localized nanoscale disorder can be instrumental, especially in sulfide‐based solid electrolytes (SEs). In this investigation, the transformation of the model SE, Li3PS4, is delved into via the introduction of LiBr. 31P nuclear magnetic resonance (NMR)unveils the emergence of a glassy PS43− network interspersed with Br−. 6Li NMR corroborates swift Li+ migration between PS43− and Br−, with increased Li+ mobility indicated by NMR relaxation measurements. A more than fourfold enhancement in ionic conductivity is observed upon LiBr incorporation into Li3PS4. Moreover, a notable decrease in activation energy underscores the pivotal role of Br− incorporation within the anionic lattice, effectively reducing the energy barrier for ion conduction and transitioning Li+ transport dimensionality from 2D to 3D. The compatibility of Li3PS4 with Li metal is improved through LiBr incorporation, alongside an increase in critical current density from 0.34 to 0.50 mA cm−2, while preserving the electrochemical stability window. ASSBs with 3Li3PS4:LiBr as the SE showcase robust high‐rate and long‐term cycling performance. These findings collectively indicate the potential of lithium halide incorporation as a promising avenue to enhance the ionic conductivity and stability of SEs.

Synthesis and Thermal Studies of Two Phosphonium Tetrahydroxidohexaoxidopentaborate(1-) Salts: Single-Crystal XRD Characterization of [iPrPPh3][B5O6(OH)4]·3.5H2O and [MePPh3][B5O6(OH)4]·B(OH)3·0.5H2O.

Two substituted phosphonium tetrahydoxidohexaoxidopentaborate(1-) salts, [iPrPPh3][B5O6(OH)4]·3.5H2O (1) and [MePPh3][B5O6(OH)4]·B(OH)3·0.5H2O (2), were prepared by templated self-assembly processes with good yields by crystallization from basic methanolic aqueous solutions primed with B(OH)3 and the appropriate phosphonium cation. Salts 1 and 2 were characterized by spectroscopic (NMR and IR) and thermal (TGA/DSC) analysis. Salts 1 and 2 were thermally decomposed in air at 800 °C to glassy solids via the anhydrous phosphonium polyborates that are formed at lower temperatures (<300 °C). BET analysis of the anhydrous and pyrolysed materials indicated they were non-porous with surface areas of 0.2-2.75 m2/g. Rhe recrystallization of 1 and 2 from aqueous solution afforded crystals suitable for single-crystal XRD analyses. The structure of 1 comprises alternating cationic/anionic layers with the H2O/pentaborate(1-) planes held together by H-bonds. The cationic planes have offset face-to-face (off) and vertex-to-face (vf) aromatic ring interactions with the iPr groups oriented towards the pentaborate(1-)/H2O layers. The anionic lattice in 2 is expanded by the inclusion of B(OH)3 molecules to accommodate the large cations; this results in the formation of a stacked pentaborate(1-)/B(OH)3 structure with channels occupied by the cations. The cations within the channels have vf, ef (edge-to-face), and off phenyl embraces. Both H-bonding and phenyl embrace interactions are important in stabilizing these two solid-state structures.

Configurational and Dynamical Heterogeneity in Superionic Li5.3PS4.3Cl1.7−xBrx

AbstractThe correlation between lattice chemistry and cation migration in high‐entropy Li+ conductors is not fully understood due to challenges in characterizing anion disorder. To address this issue, argyrodite family of Li+ conductors, which enables structural engineering of the anion lattice, is investigated. Specifically, new argyrodites, Li5.3PS4.3Cl1.7−xBrx (0 ≤ x ≤ 1.7), with varying anion entropy are synthesized and X‐ray diffraction, neutron scattering, and multinuclear high‐resolution solid‐state nuclear magnetic resonance (NMR) are used to determine the resulting structures. Ion and lattice dynamics are determined using variable‐temperature multinuclear NMR relaxometry and maximum entropy method analysis of neutron scattering, aided by constrained ab initio molecular dynamics calculations. 15 atomic configurations of anion arrangements are identified, producing a wide range of local lattice dynamics. High entropy in the lattice structure, composition, and dynamics stabilize otherwise metastable Li‐deficient structures and flatten the energy landscape for cation migration. This resulted in the highest room‐temperature ionic conductivity of 26 mS cm−1 and a low activation energy of 0.155 eV realized in Li5.3PS4.3Cl0.7Br, where anion disorder is maximized. This study sheds light on the complex structure–property relationships of high‐entropy superionic conductors, highlighting the significance of heterogeneity in lattice dynamics.

Unlocking the chemical space in anti-perovskite conductors by incorporating anion rotation dynamics

Anti-perovskite compounds have drawn significant research interest as promising next-generation electrolytes for solid-state batteries, due to the high chemical stability against Li-metal, the negligible electronic conductivity and low cost. However, the low ionic conductivity, and the deficient fundamental understandings of ion transports impede the further optimization of the lithium anti-perovskite electrolytes. Herein, we reveal that exchanging anion lattice sites in the anti-perovskite could promote the structure stabilities and ionic conductivities simultaneously, by incorporating the rotational dynamics of anion clusters and strengthening the coupling between Li migrations and cluster rotations. Based on high-throughput calculations by density functional theory (DFT), twelve new anti-perovskite materials are predicted to exhibit superionic conductivity, among which the highest ionic conductivity of 10.9 mS/cm in Li3BrSO4 can be achieved (hundreds of times higher than the ionic conductivity of typical Li3OCl antiperovskite, 0.021 mS/cm). Furthermore, the local difference frequency center is proposed to quantitatively characterize the coupled degree of Li migration and cluster rotation, revealing the contribution of paddlewheel effect to the ionic conductivity. Our proposed cation-anion dynamics coupling in site-exchanged and cluster-based antiperovskites not only open a new avenue for understanding the key role played by rotational dynamics on fast lithium mobility, but also can be generally applied to develop other fast ionic conductors with cluster dynamics.

X-ray and Neutron Diffraction Studies of SrTe2FeO6Cl, an Oxide Chloride with Rare Anion Ordering.

The oxychloride SrTe2FeO6Cl is obtained by high-temperature solid-state synthesis under inert conditions in closed reaction vessels. The compound crystallizes in a novel monoclinic crystal structure that is described in the space group P121/n1 (No. 14). The unit cell parameters, a = 10.2604(1) Å, b = 5.34556(5) Å, c = 26.6851(3) Å, and β = 93.6853(4)°, and atomic parameters were determined from synchrotron diffraction data, starting from a model that was obtained from single-crystal X-ray diffraction data. The anion lattice exhibits a rare ordering of oxide and chloride ions: one-dimensional zig-zag ladders of chlorine (squarelike motif) are surrounded by an oxygen matrix. Two different iron sites coordinated solely to oxygen are present in the structure, one octahedral and one square pyramidal, both distorted. Similarly, two different strontium coordinations are present; the first homoleptic coordinated to eight oxygen atoms and the second heteroleptic coordinated to four oxygen and four chlorine atoms in a fac-like manner. The lone pair of Te(IV) is directed toward the larger chlorine atoms. Magnetic susceptibility measurements confirm that Fe is +3 (d5) in the high-spin electronic configuration, exhibiting an almost ideal spin-only moment, μeff = 5.65 μB Fe-1. The slightly negative Weiss constant (θCW = -39 K) suggests dominating antiparallel spin-to-spin coupling in the paramagnetic temperature range, agreeing with an observed long-range antiferromagnetic spin ordering below Néel temperature, TN ∼ 13 K, and a broad second order-like anomaly in the specific heat measurement data. Low-temperature neutron diffraction data reveal that the antiferromagnetic ordered phase is C-type, with a k-vector (1/2, 1/2, 0) and ordered moment of 4.14(7) μB. The spin structure can be described as antiferromagnetic ordered layers stacked along the a-axis, forming layers of squares that alternate along the c-axis.

Molecular dynamics simulation unveiling anion charge and lattice volume dependent Li ion diffusion in lithium compounds

To fill knowledge gaps between anion sublattice models and real lithium compounds in terms of the influence of Li-anion interaction on Li ion diffusion, herein, molecular dynamics calculations were applied to systematically study impacts of anion charge and lattice volume on Li ion diffusion in lithium battery materials. Regardless of different Li occupation patterns, Li sublattice type, anion sublattice types and Li ion diffusion channels, there is a universal physical picture of anion charge dependent activation energy (Ea) for Li ion diffusion in lithium compounds, and that is the more negative anion charges increase Ea for Li ion diffusion and then decrease them. While large lattice volumes not always reduce Ea for Li ion migration, and even increase Ea, distinguished from the traditional understandings. These physical pictures of anion charge and lattice volume dependent Ea guide us to apply strains and choose appropriate elements for doping or substituting lithium compounds to reduce Ea for fast Li ion diffusion.

Study on synergy effect of hydrated ionic radius and oxidation state for pre-intercalated cations towards highly reversible magnesium ions batteries

Magnesium ions batteries (MIBs) are promising in that Mg anode shows high theoretical volumetric capacity (3833 mAh cm−3) and is dendrite free deposition upon charging. However, the higher charge/radius ratio of Mg2+ with bivalent nature shows strong electrostatic interaction between Mg2+ and host anion lattice of VS4in situ grown on N doped tubular graphene (VS4/N-TG), causing the sluggish reaction kinetics and poorer structural stability. Therefore, there is great need to develop strategy for modifying VS4/N-TG. Although interlayer pre-intercalation is an effective way to improve the overall cell performance, the systematic study about the various ionic radius and oxidation states of pre-intercalated cations on modulating electronic structure to enhance the electrochemical performance has not been focused. In this study, cations pre-intercalation engineering is achieved in VS4/N-TG for constructing M0.06VS4/N-TG cathode via electrochemical method. After the systematic study about the effect of hydrated ionic radius and oxidation state of various pre-intercalated cations on electrochemical performance of M0.06VS4/N-TG, pre-intercalated Mg2+ with moderate hydrated ionic radius and oxidation state would enlarge the interchain spacing for facilitating magnesium working ions transportation and maintaining structural stability, as well as change the oxidation states of V element as V2+ and V3+ to enhance the electrochemical reactivity. Therefore, Mg0.06VS4/N-TG deliver superior electrochemical properties, including the excellent cycling stability with nearly 100% capacity retention ratio after 1500 cycles, high specific capacity about 170 mAh/g at 50 mA g−1, superior rate capability (107 mAh/g at 1000 mA g−1) and high anti-self-discharge behavior. The highlighted synergic effect of the hydrated ionic radius and oxidation state would guide more energy storage devices design for obtaining the excellent electrochemical performance.

Modelling diffusion in large anion binary rock-salt compounds

Anion diffusion in binary rocksalt systems with large anions was studied using first principles methods. Representative materials for which experimental data was readily available, KCl and PbS from alkali halides and metal monochalcogenides, respectively, were considered. Several migration pathways, including single vacancies, vacancy pairs and interstitial pathways were investigated and their migration energies were determined. Activation energies were calculated for each pathway and compared with the experimental results. We found that Cl diffuses mostly due to vacancy pairs (Schottky dimers); and after accounting for relativistic phenomena, S diffuses through cation vacancies formed from dissociated Schottky pairs. Our theoretical results are in agreement with experimental reports. These results contrast with studies of diffusion of smaller anions that prefer to migrate via interstitial pathways. Moreover, we investigated the role of the base-interstitial site, a novel, stable, and energetically competitive interstitial site, in the diffusion of anions in binary rock salt materials. We found that the base-interstitial site is an intermediate hopping site for interstitial anion diffusion in KCl and PbS rock-salt structures. The anion base-interstitial is found to form a triatomic entity with the nearest lattice anions that affects the electronic structure relative to the tetrahedral (body) interstitial.

Correlated factors for Li-ion migration in ionic conductors with the fcc anion sublattice.

The development of solid-state electrolytes (SSEs) with high lithium ionic conductivities is critical for the realization of all-solid-state Li-ion batteries. Crystal structure distortions, Li polyhedron volumes, and anion charges in SSEs are reported to affect the energy landscapes, and it is paramount to investigate their correlations. Our works uncover the cooperative effect of lithium site distortions, anion charges, and lattice volumes on Li-ion migration energy barrier in superionic conductors of LiMS2 (M = Sc, Ti, V, Cr, Mn, Fe, Co, and Ni) and Li2MO3 (M = Sc, Ti, V, Cr, Mn, Fe, Co, and Ni). Combined with the Least Absolute Shrinkage and Selection Operator analyses, the volume and Continuous symmetrical methods (CSMs) of Li tetrahedral (Tet) sites appear to have a larger effect on the manipulation of Ea for Li migration, compared to that of Li octahedral (Oct) sites, which is further confirmed by the results from the face-centered cubic (fcc) anion lattice model. For the Tet-Oct-Tet Li migration path, the CSM (the volume of Li site) has a negative (positive) correlation with Ea, while for the Oct-Tet-Oct Li migration paths, opposite correlations have been observed. The understanding of the correlation between site preference, anion charge, lattice volume, and structural distortion as well as the prediction model of Ea in terms of these three factors, namely, C-V-D model, could be useful for the design of solid-state electrolytes with lower activation energy.

About the Impact of Defect Phases on the Thermoelectric Properties of Cr3S4–xSex

Phase relations in Cr3S4 and the substituted system Cr3S4–x Se x are studied to determine the influence of chemical substitutions on the thermoelectric properties. In addition to the expected equilibrium phase crystallizing in the monoclinic space group I2/m, some samples exhibit a defect phase with Cr2S3‐like structure. The defect phase can be observed in a few samples prior to sintering, with the majority being phase‐pure Cr3S4. The defect phase can, however, be introduced in phase‐pure samples through in situ heating. It can be proven that the defect phase has an influence on the thermoelectric properties, by lowering the electrical and thermal conductivity, while increasing the Seebeck coefficient. Substitution in the anion lattice of Cr3S4 with Se lowers the thermal conductivity. The improvement is mainly achieved through a reduction of the electronic contribution to the thermal conductivity, leading to total values as low as 1.6 Wm−1 K−1 for the substituted system in comparison to the pristine material 2.3 Wm−1 K−1.

Study structural, surface morphological and magnetic properties of Mn(1-x) Znx Fe2O4 by solid state reaction method

The powder of Mn-Zn ferrite having the chemical formula Mn(1-x)ZnxFe2O4 where x varies from 0, 0.1, 0.2, 0.3, 0.4, and 0.5 were synthesized by solid state Reaction method. The X-Ray Diffraction studies confirm the formation of spinel cubic structure. The particle size was calculated by X-ray broadening studies. Also the structural parameters like Lattice Constant, X-ray density, bulk density (d), Porosity (P), ionic radius (Ra , Rb) and anion parameter or the oxygen positional parameter for all the samples. The micro structural features of the samples were obtained using a Scanning Electron Microscopy (SEM). The magnetic properties of Mn(1-x)ZnxFe2O4 ferrites were strongly affected by the Zn content. The saturation magnetization increased. It may be due to relatively high orbital contribution of Mn2+ ions to magnetic moment, which gives large induced anisotropy.

Re-delocalization of localized d-electrons in VO2(R)-VS4 hetero-structure enables high performance of rechargeable Mg-ion batteries

Rechargeable Mg-ion batteries (MIBs) have attracted much more attentions by virtue of the high capacity from the two electrons chemistry. However, the reversible Mg2+ diffusion in cathode materials is restricted by the strong interactions between the high-polarized bivalent Mg2+ ions and anionic lattice. Herein, we design and propose a hetero-structural VO2(R)-VS4 cathode, in which the re-delocalized d-electrons can effectively shield the polarity of Mg2+ ions. Theoretically, the electrons should spontaneously transfer from VS4 to VO2(R) through the interfaces of hetero-structure due to the lower work function value of VS4. Furthermore, the internal electrons transfer lead to the electronic injection into VO2(R) from VS4 and the partially broken V-V dimers, indicating the presence of lone pair electrons and charge re-delocalization. Benefiting from the shield effect of re-delocalized electrons, and the weakened attraction between cations and O/S anions enables more S2−-S22− redox groups to participate the electrochemical reactions and compensate the double charge of Mg2+ ions. Accordingly, VO2(R)-VS4 hetero-structure exhibits a high specific capacity of 554 mA h g−1 at 50 mA g−1. It is believed that the charge re-delocalization of cathode extremely boost the Mg2+ ions migration for the high-capacity of MIBs.

DNA and the origins of life in micaceous clay

Reproducible imaging of DNA by atomic force microscopy was a useful predecessor to Ned Seeman’s DNA nanotechnology. Many of the products of DNA nanotechnology were imaged in the atomic force microscope. The mica substrate used in this atomic force microscopy research formed the inspiration for the hypothesis that micaceous clay was a likely habitat for the origins of life. Montmorillonite clay has been a successful substrate for the polymerization of amino acids and nucleotides into peptides and DNA oligomers in research on life’s origins. Mica and montmorillonite have the same anionic lattice, with a hexagonal spacing of 0.5 nm. Micas are nonswelling clays, with potassium ions (K+) holding the crystal sheets together, providing a stable environment for the processes and molecular complexes needed for the emergence of living cells. Montmorillonite crystal sheets are held together by smaller sodium ions (Na+), which results in swelling and shrinking during wet-dry cycles, providing a less stable environment. Also, the cells in all types of living systems have high intracellular K+ concentrations, which makes mica a more likely habitat for the origins of life than montmorillonite. Finally, moving mica sheets provides mechanical energy at the split edges of the sheets in mica “books.” This mechanical energy of mica sheets, moving open and shut, in response to fluid flow, may have preceded chemical energy at life’s origins, powering early prebiotic processes, such as the formation of covalent bonds, the interactions of molecular complexes, and the budding off of protocells before the molecular mechanism of cell division had developed.

A Novel Interstitial Site in Binary Rock-Salt Compounds.

The energetic and mechanical stability of interstitial point defects in binary rock-salt materials were studied using the first-principles method. A novel, stable, and energetically competitive interstitial site (base-interstitial) was identified for anion interstitials in rock-salts. The formation energies of base-interstitial defects were compared with well-explored tetrahedral (body-interstitial) and split interstitials and were found to be energetically highly competitive. For alkali halides and silver bromide, the lowest formation energies are associated with the base-interstitial site and the <110> split interstitial, which are therefore the predominant interstitial sites. However, split interstitials were found to be the energetically preferred configuration in metal monochalcogenide systems. Electronic band structures are affected by the presence of interstitial defects in rock-salt structures. In particular, the Fermi level is shifted below the valence band maxima for the body, base, and split interstitials in metal halides, indicating p-type conductivity. However, the Fermi level remains within the bandgap for metal monochalcogenides, indicating no preferred conductivity for base- and split-interstitial defects. Allowing the defects to be charged changes the relative stability of the interstitial sites. However, the new base-interstitial site remains preferred over a range of potentials for alkali halides. The anion base-interstitial is found to form a triatomic entity with the nearest lattice anions that affect the electronic structure relative to the body interstitial. The discovery of a new interstitial site affects our understanding of defects in binary rock-salts, including structure and dynamics as well as associated thermodynamic and kinetic properties that are interstitial dependent.

New Carboxylate Anionic Sm-MOF: Synthesis, Structure and Effect of the Isomorphic Substitution of Sm3+ with Gd3+ and Tb3+ Ions on the Luminescent Properties

Two new compounds, namely {(NMe2H2)}[Ln(TDA)(HCOO)] 0.5H2O, Ln = Sm3+ (Sm-TDA) and Gd3+ (Gd-TDA), where TDA3− is the anion of 1H-1,2,3-triazole-4,5-dicarboxylic acid (H3TDA), were synthesized by the solvothermal method in a DMF:H2O mixture. According to single-crystal X-ray diffraction data, the compounds are 3d-MOFs with an anionic lattice and dimethylammonium cations occupying part of the cavities. Based on these compounds, two series of mixed-metal complexes, [NMe2H2][SmxLn1-x(TDA)(HCOO)], (x = 0.9 (Sm0.9Ln0.1-TDA), x = 0.8 (Sm0.8-Ln0.2-TDA)…Sm0.02Ln0.98-TDA, Ln = Tb, Gd), were also obtained and characterized by powder XRD. The luminescent properties of the compounds were studied and it was shown that the resulting compounds are two- or three-component emitters with the possibility of fine color tuning by changing the intensities of fluorescence and phosphorescence of the ligand, as well as the luminescence of Sm3+ and Tb3+ f-ions.