Lattice Framework Research Articles

Magnetic quasi-atomic electrons driven reversible structural and magnetic transitions between electride and its hydrides

In electrides, interstitial anionic electrons (IAEs) in the quantized energy levels at cavities of positively charged lattice framework possess their own magnetic moment and interact with each or surrounding cations, behaving as quasi-atoms and inducing diverse magnetism. Here, we report the reversible structural and magnetic transitions by the substitution of the quasi-atomic IAEs in the ferromagnetic two-dimensional [Gd2C]2+·2e− electride with hydrogens and subsequent dehydrogenation of the canted antiferromagnetic Gd2CHy (y > 2.0). It is demonstrated that structural and magnetic transitions are strongly coupled by the presence or absence of the magnetic quasi-atomic IAEs and non-magnetic hydrogen anions in the interlayer space, which dominate exchange interactions between out-of-plane Gd−Gd atoms. Furthermore, the magnetic quasi-atomic IAEs are inherently conserved by the hydrogen desorption from the Pbar{3} 1m structured Gd2CHy, restoring the original ferromagnetic state of the Rbar{3}m structured [Gd2C]2+·2e− electride. This variable density of magnetic quasi-atomic IAEs enables the quantum manipulation of floating electron phases on the electride surface.

Reforming of Exotic, but Environmental-Friendly Electrolyte Material Ca12Al14O33

Recently, lowering industrial CO2 emission is required in worldwide. Acquirement of the CO2 molecule decomposition technique is the most important step for business continuity especially in high temperature material manufacturing such as steel, cement and glass due to the processes necessarily entail CO2 emission. For this reason, we focused on direct electrolysis of CO2 by solid oxide electrolysis cell (SOEC) from the limited options because of its high energy efficiency, compatibility with decomposition targets of gas phase and effective utilization of waste heat. Nevertheless, in the case of our company that manufacturing glass in worldwide, it was roughly estimated that a total of at least 1 km2 surface area of SOEC would be needed to achieve zero-carbon emission. Thus, from these viewpoints, we considered it might be helpful to add robust and environmental-friendly materials to current group of materials that can be applicable for SOEC. The complex oxide Ca12Al14O33 (C12A7) which was reported by A. R. West et al. in 1988 as having the potential for electrolyte applications only consists of abundant atoms in earth’s crust1. C12A7 have unique crystal structure which is characterized positively charged zeolite-like lattice framework with 12 crystallographic cages of ~0.4 nm in diameter per unit cell. The 1/6 cages are randomly occupied by remaining oxide ions (O2-) to maintain charge neutrality. The intra-cage oxide ions work as ion carrier and then C12A7 work as oxide ion conducting electrolyte. Negative point of C12A7 as an electrolyte is its low, 1/10 or less of that of 8YSZ, ionic conductivity. In this study, we try to substitute constituent elements of C12A7 for other elements having larger valence than Ca2+ and/or Al3+. This attempt was expected to increase the charge of lattice framework and concentration of intra-cage oxide ion. We found that some additional elements can modify ionic conductivity of C12A7.[1] M. Lacerda, J. T. S. Irvine, F. P. Glasser, A. R. West Nature 332 525-526 (1988).

Electron Spin Decoherence Dynamics in Magnetic Manganese Hybrid Organic-Inorganic Crystals: The Effect of Lattice Dimensionality.

Organic-inorganic metal hybrids with their tailorable lattice dimensionality and intrinsic spin-splitting properties are interesting material platforms for spintronic applications. While the spin decoherence process is extensively studied in lead- and tin-based hybrids, these systems generally show short spin decoherence lifetimes, and their correlation with the lattice framework is still not well-understood. Herein, we synthesized magnetic manganese hybrid single crystals of (4-fluorobenzylamine)2MnCl4, ((R)-3-fluoropyrrolidinium)MnCl3, and (pyrrolidinium)2MnCl4, which represent a change in lattice dimensionality from 2D and 1D to 0D, and studied their spin decoherence processes using continuous-wave electron spin resonance spectroscopy. All manganese hybrids exhibit nanosecond-scale spin decoherence time τ2 dominated by the symmetry-directed spin exchange interaction strengths of Mn2+-Mn2+ pairs, which is much longer than lead- and tin-based metal hybrids. In contrast to the similar temperature variation laws of τ2 in 2D and 0D structures, which first increase and gradually drop afterward, the 1D structure presents a monotonous rise of τ2 with the temperatures, indicating the strong correlation of spin decoherence with the lattice rigidity of the inorganic framework. This is also rationalized on the basis that the spin decoherence is governed by the competitive contributions from motional narrowing (prolonging the τ2) and electron-phonon coupling interaction (shortening the τ2), both of which are thermally activated, with the difference that the former is more pronounced in rigid crystalline lattices.

A systematic design of multifunctional lattice structures with energy absorption and phononic bandgap by topology and parameter optimization

ABSTRACT Lattice structure can realize excellent multifunctional characteristics because of its huge design space, and the cellular configuration directly affects the lattice structural performance and lightweight. A novel energy-absorbing multifunctional lattice structure with phononic bandgap is presented by topology and parameter optimization in this paper. First, the two-dimensional (2D) cellular configuration is lightweight designed by using independent continuous mapping (ICM) topology optimization method. The 2D cell is reconstructed by geometric parameters and rotated into a three-dimensional (3D) cell by using chiral shape to achieve bandgap. Subsequently, the surrogated model with energy absorption as the object and first-order natural frequency as the constraint is established to optimize a parametric 3D cell based on the Response Surface Methodology (RSM). Finally, the lattice structures are assembled with dodecagonal staggered arrangements to avoid the deformation interference among the adjacent cells. In addition, the lattice structural energy absorption and bandgap characteristics are analyzed and discussed. Compared to Kelvin lattice structure, the optimal lattice structure shows significant improvement in energy absorption efficiency. Besides, the proposed design also performs well in damping characteristics of the high-frequency and wide-bandgap. The lattice structural optimization design framework has great meaning to achieve the equipment structural lightweight and multi-function in the aerospace field.

On the Cyclicity of Dilated Systems in Lattices: Multiplicative Sequences, Polynomials, Dirichlet-type Spaces and Algebras

Abstract The aim of these notes is to discuss the completeness of the dilated systems in a most general framework of an arbitrary sequence lattice X, including weighted ℓ p spaces. In particular, general multiplicative and completely multiplicative sequences are treated. After the Fourier–Bohr transformation, we deal with the cyclicity property in function spaces on the corresponding infinite dimensional Reinhardt domain 𝔻 X ∞ \mathbb{D}_X^\infty . Functions with (weakly) dominating free term and (in particular) linearly factorable functions are considered. The most attention is paid to the cases of the polydiscs 𝔻 X ∞ , | ℂ N = 𝔻 N \mathbb{D}_X^\infty ,|{\mathbb{C}^N} = {\mathbb{D}^N} and the ℓ p-unit balls 𝔻 X ∞ , | ℂ N = 𝔹 p N \mathbb{D}_X^\infty ,|{\mathbb{C}^N} = \mathbb{B}_p^N , in particular to Dirichlet-type and Dirichlet–Drury–Arveson-type spaces and algebras, as X = ℓ p ( ℤ + N , ( 1 + α ) s ) X = {\ell ^p}\left( {_ + ^N,{{\left( {1 + \alpha } \right)}^s}} \right)) , s = (s 1, s 2, … ) and X = ℓ p ( ℤ + N , ( α ! | α | ! ) t ( 1 + | α | ) s ) X = {\ell ^p}\left( {\mathbb{Z}_ + ^N,\,\,{{\left( {{{\alpha !} \over {\left| \alpha \right|!}}} \right)}^t}{{\left( {1 + \left| \alpha \right|} \right)}^s}} \right) , s,t ≥ 0, as well as to their infinite variables analogues. We priviledged the largest possible scale of spaces and the most elementary instruments used.

PO-01-187 FEASIBILITY OF FLUOROLESS PULMONARY VEIN ISOLATION USING A SINGLE-SHOT CONFORMABLE PULSED FIELD ABLATION CATHETER

Fluoroless pulmonary vein isolation (PVI) using point-by-point ablation catheters guided by electroanatomical mapping (EAM) systems is standard practice in many operators’ practice. While “single-shot” PVI tools have a streamlined procedural workflow, and with a safety profile enhanced by the emergence of pulsed field ablation (PFA) technology, these catheters have not been able to support a completely fluoroless workflow. A novel 8-Fr single-shot large lattice catheter with integrated magnetically-tracked EAM and PFA capabilities has been developed. To report for the first time the feasibility of performing single-shot PVI using a completely fluoroless approach. This 8 Fr PFA catheter (SpherePVI; Affera-Medtronic Inc) has a conformable large lattice framework that is expandable to 34 mm in diameter to permit “customization” to varying pulmonary vein anatomies (see Figure). It was delivered using an 8.5 Fr deflectable sheath (Agilis, Abbott Inc), and used with a custom EAM system (Prism-1; Affera-Medtronic Inc.) to render PV and left atrial anatomy. The PFA generator (HexaPULSE; Affera-Medtronic Inc) delivered biphasic waveforms (5 sec per application; 1.3-2.0 kV[±]); goal of 1-3 lesions per PV) from six elements situated circumferentially around the equatorial plane of the lattice. These cases conducted at a single center as part of a first-in-human study (NCT05115214): under general anesthesia, ICE was used to guide transeptal puncture and catheter positioning; fluoroscopy was initially used, followed by completely fluoroless ablation (using only ICE and EAM). The fluoroless cohort (n = 4 AF pts) was well matched with the control cohort (n = 5 AF pts) with similar baseline characteristics except for having more male patients (see Table). PVI was 100% successful in both groups. For PVI, both the number of PFA lesions delivered (16.3±0.5 vs 16.6±0.9 in the fluoroless and control groups, respectively) and the PVI ablation times (time only during lesion application; 1.6±0.0 min vs 1.6±0.1 min), and transpired time (defined as time transpiring between first to last lesion application; 8.3±1.1 min vs 9.6±2.2 min) were comparable. The total fluoroscopy time in the control group was 5.5±2.7 min. There were no serious adverse events in either group. This case series provides the proof-of-principle that fluoroless single-short PVI is feasible, safe and effective using a conformable large lattice PFA catheter.

Mechanical Properties of Single Crystal Organic–Inorganic Hybrid Perovskite MAPbX3 (MA = CH3NH3, X = Cl, Br, I)

Mechanical properties are among the crucial parameters for multilayer hybrid perovskite-based devices. Here, the mechanical properties of the high-quality single-crystalline MAPbX3 (MA = CH3NH3, X = Cl, Br, I), including the hardness (H) and Young’s modulus (E), are systematically studied using the three-dimensional nanoindentation (3D nanoindentation) method. In the sequence of Cl, Br, and I, the hardness and Young’s modulus of MAPbX3 decrease gradually. The hardness of MAPbX3 ranges from 0.31 to 0.57 GPa, and Young’s modulus values are less than 30 GPa. The low hardness and Young’s modulus are attributed to the weak lattice framework composed of Pb-X and the weak hydrogen bond between CH3NH3+ and the octahedron. The relationship between the hardness and Young’s modulus of MAPbX3 is also described. Generally, this work provides the favorable parameters required to further support the design and modification of investigations regarding perovskite-based devices.

Lattice theory of torsion classes: Beyond 𝜏-tilting theory

The aim of this paper is to establish a lattice theoretical framework to study the partially ordered set t o r s A \mathsf {tors} A of torsion classes over a finite-dimensional algebra A A . We show that t o r s A \mathsf {tors} A is a complete lattice which enjoys very strong properties, as bialgebraicity and complete semidistributivity. Thus its Hasse quiver carries the important part of its structure, and we introduce the brick labelling of its Hasse quiver and use it to study lattice congruences of t o r s A \mathsf {tors} A . In particular, we give a representation-theoretical interpretation of the so-called forcing order, and we prove that t o r s A \mathsf {tors} A is completely congruence uniform. When I I is a two-sided ideal of A A , t o r s ( A / I ) \mathsf {tors} (A/I) is a lattice quotient of t o r s A \mathsf {tors} A which is called an algebraic quotient, and the corresponding lattice congruence is called an algebraic congruence. The second part of this paper consists in studying algebraic congruences. We characterize the arrows of the Hasse quiver of t o r s A \mathsf {tors} A that are contracted by an algebraic congruence in terms of the brick labelling. In the third part, we study in detail the case of preprojective algebras Π \Pi , for which t o r s Π \mathsf {tors} \Pi is the Weyl group endowed with the weak order. In particular, we give a new, more representation theoretical proof of the isomorphism between t o r s k Q \mathsf {tors} k Q and the Cambrian lattice when Q Q is a Dynkin quiver. We also prove that, in type A A , the algebraic quotients of t o r s Π \mathsf {tors} \Pi are exactly its Hasse-regular lattice quotients.

Modulating the local electronic structure via Al substitution to enhance the electrochemical performance of Li-rich Mn-based cathode materials

The performance degradation caused by irreversible O2 release and structural collapse has seriously hindered the commercialization of Li-rich Mn-based oxide cathode materials (LMOs). Herein, a Li-rich Mn-based cathode material Li1.2Ni0.2Mn0.6−xAlxO2 (x = 0.02, 0.04, 0.06) via the substitution of Mn by Al was designed. By introducing additional strong Al-O bonds into the local atomic coordination around O and transition metal (TM) to modulate the local electronic structure, the TM 3d-O 2p and non-bonding O-2p band are transferred to lower energy, thus increasing the redox reaction potential. The substitution of Al also enhances the interaction with oxygen and increases the oxygen vacancy formation energy, which stabilizes the lattice oxygen framework and ultimately further inhibits the structural transition (layered → spinel phase) caused by the reduction of TM ions during the cycling process and improves the stability of the layered structure. The results show that the voltage decay of the Al-doped sample is only 0.349 V after 300 cycles, which is much lower than the 0.578 V of the pristine sample. Assembled as a full cell using LMNA2 as the cathode and commercial graphite as the anode, it exhibited a specific energy density of 454.3 Wh kg−1 at 0.1 C, with a capacity retention rate of over 86% after 100 cycles. This research provides a novel idea for the future development of LMOs for high voltage and energy density applications.

Localizing Oxygen Lattice Evolutions Eliminates Oxygen Release and Voltage Decay in All-Mn-Based Li-Rich Cathodes.

All-Mn-based Li-rich cathodes Li2 MnO3 have attracted extensive attention because of their cost advantage and ultrahigh theoretical capacity. However, the unstable anionic redox reaction (ARR), which involves irreversible oxygen releases, causes declines in cycling capacity and intercalation potential, thus hindering their practical applications. Here, it is proposed that introducing stacking-fault defects into the Li2 MnO3 can localize oxygen lattice evolutions and stabilize the ARR, eliminating oxygen releases. The thus-made cathode has a highly reversible capacity (320mA h g-1 ) and achieves excellent cycling stability. After 100 cycles, the capacity retention rate is 86% and the voltage decay is practically eliminated at 0.19mV per cycle. Attributing to the stable ARR, samples show reduced stress-strain and phase transitions. Neutron pair distribution function (nPDF)measurements indicate that there is a structure response of localized oxygen lattice distortion to the ARR and the average oxygen lattice framework is well-preserved which is a prerequisite for the high cycle reversibility.

Multi Jet Fusion printed lattice materials: characterization and prediction of mechanical performance

Multi Jet Fusion (MJF) is a 3D-printing process capable of fabricating large-scale polymer structures. Herein, we present a framework for MJF-printed lattices with tunable stiffness and strength based on an empirical analysis of structural behavior.

Perovskite-phase interfacial intercalated layer-induced performance enhancement in SrFeO<sub><i>x</i></sub>-based memristors

SrFeO<sub><i>x</i></sub> (SFO) is a kind of material that can undergo a reversible topotactic phase transformation between an SrFeO<sub>2.5</sub> brownmillerite (BM) phase and an SrFeO<sub>3</sub> perovskite (PV) phase. This phase transformation can cause drastic changes in physical properties such as electrical conductivity, while maintaining the lattice framework. This makes SFO a stable and reliable resistive switching (RS) material, which has many applications in fields like RS memory, logic operation and neuromorphic computing. Currently, in most of SFO-based memristors, a single BM-SFO layer is used as an RS functional layer, and the working principle is the electric field-induced formation and rupture of PV-SFO conductive filaments (CFs) in the BM-SFO matrix. Such devices typically exhibit abrupt RS behavior, i.e. an abrupt switching between high resistance state and low resistance state. Therefore, the application of these devices is limited to the binary information storage. For the emerging applications like neuromorphic computing, the BM-SFO single-layer memristors still face problems such as a small number of resistance states, large resistance fluctuation, and high nonlinearity under pulse writing. To solve these problems, a BM-SFO/PV-SFO double-layer memristor is designed in this work, in which the PV-SFO layer is an oxygen-rich interfacial intercalated layer, which can provide a large number of oxygen ions during the formation of CFs and withdraw these oxygen ions during the rupture of CFs. This allows the geometric size (e.g., diameter) of the CFs to be adjusted in a wide range, which is beneficial to obtaining continuously tunable, multiple resistance states. The RS behavior of the designed double-layer memristor is studied experimentally. Compared with the single-layer memristor, it exhibits good RS repeatability, small resistance fluctuation, small and narrowly distributed switching voltages. In addition, the double-layer memristor exhibits stable and gradual RS behavior, and hence it is used to emulate synaptic behaviors such as long-term potentiation and depression. A fully connected neural network (ANN) based on the double-layer memristor is simulated, and a recognition accuracy of 86.3% is obtained after online training on the ORHD dataset. Comparing with a single-layer memristor-based ANN, the recognition accuracy of the double-layer memristor-based one is improved by 69.3%. This study provides a new approach to modulating the performance of SFO-based memristors and demonstrates their great potential as artificial synaptic devices to be used in neuromorphic computing.

Robust willow tree method under Lévy processes

The cosine willow tree method (Ma et al., 2021) provides a first lattice framework to price options and calculate risk measures under various Lévy process models. However, it may fail under some circumstances due to the failure in moment matching by the Johnson curve. In this paper, we propose a more robust approach to construct a willow tree via numerical integration. Since the moment matching by the Johnson curve is avoided, the new approach provides a better convergence than the cosine willow tree method. Finally, numerical experiments are carried out to support our claims.

Comparative study of Tb, Gd and Dy-doped ZnO nanoparticles

In the present study Terbium (Tb), Dysprosium (Dy), and Gadolinium (Gd) doped ZnO nanoparticles Zn1-x(Tb; Dy; Gd)xO [where, x = 0.02] were prepared by conventional sol–gel method. Already synthesized samples of the above-said concentration were compared for their structural and magnetic properties using XRD, FTIR, and VSM. Though Tb, Dy, and Gd all belong to the same family of rare earth ions due to differences in their ionic radii and magnetic moments, the structural properties of ZnO vary in all cases despite taking equal dopant concentrations of all the dopant ions. XRD profiles of all the compositions exhibit hexagonal wurtzite-type crystallinity belonging to the P63mnc space group. FTIR spectra of all the compositions possess broad hump representing the hydroxyl group and small kinks at 553 cm−1 and 472 cm−1 corresponding to ZnO stretching vibration. Magnetic transformations from diamagnetic to weak ferromagnetic were observed due to the intrusion of rare earth ions in the lattice framework of host ZnO as pristine ZnO displays diamagnetic ordering.

3D-printed SiC lattices integrated with lightweight quartz fiber/silica aerogel sandwich structure for thermal protection system

A lightweight thermal protection/insulation integrated sandwich structure for the aerospace thermal protection system (TPS) was developed with the aim of achieving superior mechanical strength and thermal insulation properties. On the one hand, the lattice frameworks of silicon carbide (SiC) ceramic thermally insulated components with body-centered lattice core (BCLC) were fabricated by selective laser sintering (SLS) 3D printing technology; on the other hand, the sol–gel process was applied to fill quartz fibers reinforced silica (Qf/SiO2) aerogel into the hollow parts of the BCLCs to form a sandwich structure, thus further enhancing the mechanical and thermal insulation properties. To explore the impact of lattice core structure gradient on performance, we designed two types of BCLCs, single-layer one and double-layer one. By comparing the properties of the sandwich structures with the BCLCs, it was found that after the hot surface temperature was kept at 1000℃ for 1500 s, the backside temperature of the single-layer and double-layer sandwich structures decreased by 69.15℃ and 112.73℃, respectively, implying that the thermal insulation efficiency increased by 8.75 % and 13.85 %, respectively. Remarkably, it was precisely due to the filling of the Qf/SiO2 aerogels that the compressive strength of the single-layer and double-layer sandwich structures reached 119.41 MPa and 35.16 MPa, respectively, which were successfully improved by 238.56 % and 256.23 %, respectively, in comparison with the BCLCs structures. Consequently, this study provides an efficient and reliable method for the preparation of thermal protection/insulation integrated components by using 3D printing technology combined with the sol–gel method, which has broader significance among academic and industrial communities.

Selective hydroxylation of benzene to phenol via C[sbnd]H activation over mesoporous Fe2O3-TiO2 using H2O2

The omnipresence of CH bonds in organic molecules enamors chemists for the functionalization of CH bonds towards value-added molecular scaffolds. Mesoporous Fe2O3-TiO2 mix-oxide catalyst has been successfully synthesized via a triblock-copolymer (P123) mediated sol-gel method and catalytically tested in selective hydroxylation of benzene. The as-synthesized catalysts were comprehensively characterized by powder XRD, Raman spectroscopy, FT-IR, N2-physisorption, FESEM, HRTEM, XPS, and NH3-TPD techniques. The physicochemical characterizations evidence that Fe(III) ions incorporate into the pure anatase TiO2 lattice framework and the crystallite size decreases as iron concentration increases. The XPS analyses confirm the Fe3+ state (BE 710.3 eV) in Fe-O-Ti with a peak at 712.1 eV for Fe3+ of Fe2O3. The NH3-TPD results show that the 5 wt% Fe-TiO2 has a higher total acidity of 105 µmol/g. Interestingly, a further increase in iron amount decreases the total acidity. Herein, we observe that the surface acidity directs the selectivity towards phenol. The effect of different reaction parameters was carefully investigated. Under the optimized conditions, 5% Fe-TiO2 with notified strong acid sites gives a higher phenol yield of 31.2% with > 99% selectivity; moreover, the catalyst is reusable at least four times.

Ab Initio Simulation of Dielectric and Optical Properties of Ices Ih and III and Lattice Frameworks of Hydrates sI and sH

Ab Initio Simulation of Dielectric and Optical Properties of Ices Ih and III and Lattice Frameworks of Hydrates sI and sH

Latticed-Confined Conversion Chemistry of Battery Electrode.

The electrochemical conversion reaction, usually featured by multiple redox processes and high specific capacity, holds great promise in developing high-energy rechargeable battery technologies. However, the complete structural change accompanied by spontaneous atomic migration and volume variation during the charge/discharge cycle leads to electrode disintegration and performance degradation, therefore severely restricting the application of conventional conversion-type electrodes. Herein, latticed-confined conversion chemistry is proposed, where the "intercalation-like" redox behavior is realized on the electrode with a "conversion-like" high capacity. By delicately formulating the high-entropy compounds, the pristine crystal structure can be preserved by the inert lattice framework, thus enabling an ultra-high initial Coulombic efficiency of 92.5% and a long cycling lifespan over a thousand cycles after the quasistatic charge-discharge cycle. This lattice-confined conversion chemistry unfolds a ubiquitous insight into the localized redox reaction and sheds light on developing high-performance electrodes toward next-generation high-energy rechargeable batteries.

Eliminating crystal water enables enhanced sodium storage performance in an oxalate-phosphate cathode material

The oxalate-phosphate polyanion-mixed cathode materials are promising for sodium-ion batteries (SIBs) due to their unique open-framework structures and high voltage property. However, materials of this type generally contain crystal water molecules in the lattice frameworks, which may affect their energy storage properties. This work aims to disclose the impacts of crystal water on physiochemical and electrochemical properties of Na 2 (VO) 2 (HPO 4 ) 2 (C 2 O 4 )•2H 2 O (NVPC-W). It shows that the water molecules can be eliminated by vacuum drying at 150°C. The elimination of water molecules does not change the crystal phase of the material, while the obtained Na 2 (VO) 2 (HPO 4 ) 2 (C 2 O 4 ) (NVPC) exhibits significant improvements in cycling stability, Coulombic efficiency, as well as rate performances. Kinetics analysis indicates that the existence of lattice water molecules hinders sodium-ion diffusion and promotes the degradation of electrodes. We believe the findings can help to develop high-performance cathode materials. The crystal water eliminated Na 2 (VO) 2 (HPO 4 ) 2 (C 2 O 4 ) material exhibits significant improvements in cycling stability, Coulombic efficiency, as well as rate performances. Kinetics analysis indicates that the existence of lattice water molecules hinders sodium-ion diffusion and promotes the degradation of electrodes.

Structure elucidation of a bimetallic μ‐hydroxo‐bridged Cu(II)‐flufenamate‐bpy complex and cytotoxic evaluation against MDA‐MB‐231 and A549 carcinoma cell lines

In this work, we report the synthesis, spectral characterization, and in vitro biological assessment of a bimetallic copper complex with formulation [Cu2(fluf)3(bpy)2(μ‐OH)(H2O)] (complex 1) as a potential chemotherapeutic agent. The structural elucidation of synthesized complex was ascertained by various spectroscopic methods, namely, UV–vis, Fourier transform infrared (FTIR), electron paramagnetic resonance (EPR), and single‐crystal X‐ray diffraction studies. Complex 1 crystalizes in a monoclinic crystal system with space group P21/c, and the lattice parameters were recorded as a = 18.95 Å, b = 17.81 Å, c = 20.56 Å, and α = γ = 90° and β = 117.12° per unit cell. The density functional theory (DFT) studies were performed to comprehend the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) electron densities over the complex 1 and the energy difference in between them. Hirshfeld surface studies were performed to understand the various non‐covalent interactions including OH····O, NH····H, and CH····O, which determined the stability of crystal lattice framework. The preliminary in vitro binding studies of complex 1 with human serum albumin (HSA) and bovine serum albumin (BSA) targets was carried out to determine the binding mode and to evaluate its cytotoxic potential using various biophysical techniques. The antioxidant activity of complex 1 was examined against the free radical 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) using ascorbic acid as standard, which demonstrated higher radical scavenging activity (IC50 = 14 μM). Furthermore, the cytotoxic action of complex 1 was evaluated using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay against MDA‐MB‐231 (triple‐negative breast) and A549 (lung) cancer cell lines, which revealed remarkable cytotoxicity of the complex against the tested cancer cell lines that was reflected in their low IC50 values.