Molar Magnetic Susceptibility Research Articles

Structure and properties of phases from solid solutions YTIn1−x Al x (T = Ni and Cu)

Abstract YNiIn and YCuIn form complete solid solutions YNiIn1−x Al x and YCuIn1−x Al x , which were characterized on the basis of X-ray powder diffraction. The ZrNiAl type crystal structures (space groups P 6 ‾ 2 m $P\overline{6}2m$ ) of YNiAl (a = 0.70386(9), c = 0.38327(4) nm, wR 2 = 0.0424), YNiIn0.77Al0.23 (a = 0.73895(9), c = 0.37707(4) nm, wR 2 = 0.0498) and YCuIn0.63Al0.37 (a = 0.73404(7), c = 0.39045(4) nm, wR 2 = 0.0314) were refined from the single crystal X-ray diffraction data. Exemplarily the electronic structure of YNiAl was studied, manifesting substantial Ni–Al bonding within the three-dimensional [NiAl] substructure. Comparison of YNiAl with isotypic YNiIn shows stronger Ni–Al bonding as compared to Ni–In. Magnetic susceptibility measurements of YNiIn1−x Al x (x = 0.1, 0.2, 0.7 and 0.9), YNiIn and YNiAl in the temperature range 3–300 K indicated Pauli paramagnetic behaviour with molar magnetic susceptibility of about 0.15–0.22 × 10−3 emu/mol.

A mono-nuclear Cu(II) complex of an unsymmetrical Schiff base ligand and its use to synthesise trinuclear CuII2MnII complexes showing anion dependent SMM behaviour

The effort for synthesis complexes of unsymmetrical Schiff base ligands derived from 2,2-dimethyl-1,3-propanediamine, o-hydroxyacetophenone and salicylaldehyde by modified Edler's method resulted in the isolation of mononuclear [CuL]·CH3OH (1), where H2L = N-(α-methylsalicylidene)-N′-(salicylidene)-2,2-dimethyl-1,3-propanediamine. Complex 1 on reaction with Mn(II) ion in presence of ClO4−, N(CN)2−, or N3− yielded three tri-nuclear complexes [(CuL)2Mn(CH3OH)2](ClO4)2·3H2O (2) [(CuL)2Mn(N(CN)2)2] (3) and [(CuL)2Mn(N3)2]∙2H2O (4), respectively. X-ray crystallography revealed square planar geometry of Cu(II) and distorted octahedral geometry of Mn(II) in the complexes. Temperature dependent molar magnetic susceptibility measurements illustrated overall anti-ferromagnetic coupling between the Cu(II) and Mn(II) centres in complexes 2–4 with exchange coupling parameters, J = −16.82 cm−1 and g = 2.06 for 2, J = −19.40 cm−1 and g = 2.10 for 3 and J = −18.98 cm−1 and g = 2.11 for 4. Among these hetero-metallic complexes only the azide derivative (4) presented prominent ac signals under an applied dc bias field. Cyclic voltammetry measurements showed reversible Cu(II)/Cu(I) couple for complex 1 whereas complexes 2–4 showed irreversible reduction of Cu(II).

A new Ruddlesden-Popper oxide LaSr3Mn1.5Fe1.5O9.71 as photocatalyst for degrading highly toxic dyes in waste water: Structural, magnetic and transport properties

This paper presents the magnetic, transport, and photo-catalytic properties of a new Sr4Ti3O10-type oxygen deficient Ruddlesden-Popper oxide LaSr3Mn1.5Fe1.5O9.71. The Rietveld refinement analysis of the PXRD data confirms the formation of the compound which crystallizes in tetragonal symmetry and adopts space group I4/mmm, tI34. The phase is found to be oxygen deficient as determined from the results of iodometric titrations. The energy band gap (Eg) obtained from the DRS study shows that the phase is semiconducting in nature at room temperature. The magnetic studies revealed that the oxygen deficient phase exhibits dominant anti-ferromagnetic (AFM) ordering with Néel temperature, TN ​= ​71 ​K owing to Fe3+―O―Fe3+, Mn4+―O―Mn4+ super-exchange interactions. The divergence between the zero field cooled (ZFC) and field cooled (FC) molar magnetic susceptibility curves at low temperatures implies that the phase shows a spin-glass transition. The temperature-dependent resistivity measurements indicate that the material exhibits insulating behavior with decreasing temperature. The conduction mechanism is discussed by fitting the resistivity data in different transport mechanism models. It has been found that the conduction mechanism is dominated by Mott’s variable range hopping model. The photo-oxidative degradation of different dye pollutants using LaSr3Mn1.5Fe1.5O9.71 as a photocatalyst was carried out under visible irradiation. The results indicate that Methylene Blue (MB) shows 99.1% degradation in 45 ​min while Rhodamine B (RhB) and Methyl Orange (MO) dyes show 99.3% and 98.6% degradation respectively in 20 ​min.

Preparation and characterization of Trivalent lanthanide ion complexes with tridentate mono azo Ligand

The lanthanide complexes of 4-(2-pyridylazo)-resorcinol are prepared in solid state. All compounds have been characterized by means of elemental analysis (C.H.N) molar conductance, magnetic susceptibility and analytical spectral studies IR and UV-Visible spectral techniques. While the complexes have additionally been characterized by differential thermal analysis data and are formulated as [Ln(C11H8N3O2)3].H2O Ln = Pr3+ , Nd3+ and Sm3+ ; [Ln(C11H8N3O2)3] Ln = Eu3+, Er3+ and Yb3+ . The results of these studies on the synthesis and structural characterization, suggest neutral lanthanide complexes in which the mono azo ligand being a uninegative (deprotonated form) and tridentate ligand. The absorption spectral profiles suggest a coordination number of nine around Ln(III) ions in the complexes.

Synthesis and characterization of Fe+2, Cu+2 and Ni+2 complexes with thiosemicarbazide-di-ortho-bromobenzylacetone Schiff base and evaluation of their cytotoxicity against breast cancer cells

In this study, Schiff base is synthesized through the reactance of di-o-bromobenzylacetone with thiosemicarbazide by acid-catalyzed condensation reaction (Aldol condensation). And using the novel Schiff base to prepare three metal complexes by reacting divalent transition metals (nickel, copper, iron) with the synthesized Schiff base. The prepared compounds were characterized by mass spectrometer, infrared spectrophotometer (FTIR), visible-ultraviolet rays (UV-Vis) and both 1H and 13C nuclear magnetic resonance spectrometer (NMR). The molar conductivity and magnetic susceptibility of the synthesized metal complexes were also measured. The cytotoxicity of the synthesized metal complexes against human breast cancer cell line MDA-MB231 was also measured in-vetro. All of the metal complexes were non-electrolyte and the predicted shape of these metal complexes is tetrahedral geometry. Results obtained from in-vetro cytotoxicity against breast cancer cell line type MDA-MB231 type showed that copper complex had best cytotoxicity with IC50 equal to 18.5µM .

Effects of vacancy co‑doping on the structure, magnetic and dielectric properties of LaFeO3 perovskite nanoparticles

Perovskite nanoparticles La1-x□xFe1-y□yO3, (y = x = 0.0, 0.01 and 0.02) were prepared using the citrate combustion method. The samples were crystallized in a single phase orthorhombic structure. The energy dispersive spectroscopy (EDS) confirms that the chemical composition is very close to the nominal one. The particle size values indicated that the samples were prepared in nano scale. The selected area electron diffraction (SAED) pattern shows the good crystallinity of the samples. The magnetic hysteresis loops indicate the antiferromagnetic properties of the samples. The molar magnetic susceptibility (χM) of LaFeO3 sample was enhanced by vacancy doping. The value of Ms of the sample La0.98□0.02Fe0.98□0.02O3 increased by a factor 1.9 than that of sample LaFeO3. The investigated samples have semiconductor-like behavior as clear from the increase in the conductivity with raising the temperature and the values of activation energies. The main conduction mechanisms in the investigated samples are the small polaron tunneling (SP) and the correlated barrier hopping (CBH).

Synthesis, Spectroscopic Study and Biological Activity of new Bidentate Schiff Base (4-(Dimethylamino) Benzylidene)-5-(3,4,5-Trimethoxybenzyl)-5 Pyrimidine-2,4-Diamine) and Transition Metal Mn(II), Ni(II) and Cu(II) Complexes

The Schiff bases ligand (L1) was synthesized by condensing (2,4-diamine (Trimethoxybenzyl 3,4,5)-5 pyrimidine) and (4-dimethylamino benzaldehyde). The transition metal complexes of [Mn(L1)2Cl2], [Ni(L1)2Cl2], and [Cu (L1)2Cl2] were then produced. The ligand and its metal complexes Mn(II), Ni(II), and Cu(II) were examined by analyzing the elemental composition, the metal content, the chloride content, and the molar conductance, FT-IR, 1H-NMR, UV-Vis spectra, magnetic susceptibility, mass spectra, and thermal analysis (TGA). The results indicated that the ligand behaves as a bidentate ligand in all of the complexes produced. The [Cu (L1)2Cl2] complex is more poisonous to microorganisms. Keywords: Ligand field, Schiff bases, Mass spectra, Charge transfer (C.T).

Crystal structure and magnetic properties of some compounds with GdNi2Ga3In type structure

Abstract The GdNi2Ga3In type crystal structures (Pnma) of the quaternary intermetallic compounds TbNi2Ga3.03(1)In0.97(1) (a = 2.41554(2), b = 0.41614(4), c = 0.92220(10) nm, wR2 = 0.0512, 2006 F 2 values, 90 parameters) and HoNi2Ga3.03(2)In0.97(2) (a = 2.41822(7), b = 0.41400(15), c = 0.9199(3) nm, wR2 = 0.0588, 1980 F 2 values, 89 parameters) were refined from the single crystal X-ray diffraction data. Single crystals were obtained by high-frequency annealing of the samples in sealed tantalum ampoules. The compounds with RE = Y, Dy and Ho are isotypic and were characterized by powder X-ray diffraction. The magnetic behaviour of the compounds RENi2Ga3In (RE = Y, Dy, Ho) was characterized by means of magnetization and dc magnetic susceptibility measurements, carried out in the temperature range 1.72–400 K in external magnetic fields up to 5 T. YNi2Ga3In was found to be a Pauli paramagnet with a molar magnetic susceptibility of about 4⋅10−5 emu mol−1 at room temperature. DyNi2Ga3In and HoNi2Ga3In are Curie-Weiss paramagnets which order antiferromagnetically below T N = 10.5 K (DyNi2Ga3In) and 4.4 K (HoNi2Ga3In).

Synthesis, Characterization and Biological Activity of Some Mixed Ligand Transitionmetal Complexes

The Schiff bases derived from Salicylaldehyde with substituted amines and alpha benzoin oxime as a primary ligand are prepared by mixed with Cobalt (II), Nickel(II) and Copper (II). Structure have been proposed from elemental examination, like IR, NMR, thermal examination and magnetic susceptibility, Spectroscopic studies suggests that coordination occurs through azomethine nitrogen, hydroxyl group and oxime of the ligand to the metal ions. Elemental analysis of Schiff bases, alpha benzoin oxime and metal complexes are confirmed to stoichiometry of the type ML1L2 where Metals are Cobalt (II) andNickel (II) L1 are Schiff bases and L2 are alpha benzoin oxime. The mixed ligand Co(II) complexes were synthesize by using α-benzoin oxime as a primary ligand and Schiff base prepared from salicylaldehyde and chloroanilines with hydroxyanilines as a secondary ligand. The metal complexes have been characterized different elemental analyses and various chemical techniques such as molar conductance, magnetic susceptibility, infrared, NMR, spectral studies and thermal analysis. The elemental analysis data is consistent with their general formulation as mixed ligand complexes MLL’.xH2O. The bondings and structures of the complexes are discussed in detail on the basis of the results of various chemical studies. All of these metal complexes and ligands have been screened for their biological activities against selected pathogenic microbial strains. The Ditch Plate Method has been used to study the antibacterial activity against E. coli, S. typhi, S. aureusandS. pyogenes.

Synthesis and Characterization Some Transition Metal Complexes of New Ligand Chalcone-Azo Derivatives from P-methoxy-4, 5-diphenyl Imidazole and Study Biological Effect of Pd(II) Complex

This paper explained synthesis of new ligand 1-(4-((4,5-bis (4-methoxy phenyl)-1H-imidazol-2-yl)diazenyl)phenyl)-3-(4-bromophenyl)prop-2-en-1-one (LBr), this ligand coordinates with (Co, Ni, Cu, Zn, Hg and Pd)(II) in mole ratio (1:2), the ligand characterized by numerous spectroscopic techniques such (UV-Visible, H-NMR, Mass, IR, C.H.N), while its complexes characterized by (UV-Visible, IR, C.H.N., electrical molar conductivity and magnetic susceptibility). The results of this study proposed an Octahedral geometry for all complexes excepting Pd(II) complex was square planer antitumor activity against breast cancer line (MCF-7) was gauged using Pd(II)complex, which has been shown selective cytotoxicity destroying cancer cells, this decides Pd(II) complex could be used to create anti-cancer medication in the forthcoming after compered between ligand has been prepared and this complex in cytotoxic effects.

Synthesis, structural elucidation, in vitro antibacterial activity, DFT calculations, and molecular docking aspects of mixed-ligand complexes of a novel oxime and phenylalanine

An oxime ligand (HL) was synthesized by the condensation of 4-biphenylhydroxymoyl chloride with 2-amino-5-bromopyridine. The oxime ligand was reacted with l-phenylalanine and metal(II) acetate salts (Co(II), Ni(II), and Cu(II)) to synthesize mixed-ligand complexes. Structural elucidation of the newly synthesized ligand and complexes was performed by elemental analysis, 13C NMR, 1H NMR, FT-IR, ICP-OES, the measurements of molar conductivity and magnetic susceptibility. The thermal properties of the compounds were characterized by TG/DTA analyses. The antibacterial activities of the compounds were evaluated in vitro by the resazurin-aided broth microdilution method. Optimized molecular geometries of the HL and its metal complexes were calculated using the density functional theory (DFT) of the B3LYP method with 6-311G (d, p) and LANL2DZ basis sets. The NMR chemical shift values, vibrational frequencies, and HOMO-(LUMO or SOMO) energies were also computed using the mentioned level. A molecular docking study was performed to demonstrate the interactions of the synthesized compound with beta-ketoacyl-ACP synthase III (KAS III), an enzyme that has a key role in bacterial survival. Based on the MIC values and binding energy scores, both in vitro and in silico studies showed that the antibacterial activity of the Cu(II) complex was better than the other studied molecules.

SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITIES OF Ni(II) AND Cu(II) COMPLEXES WITH SCHIFF BASE DERIVED FROM 2-ACETYL-5-METHYLFURAN GLYOXIME HYDRAZONE

A hydrazone Schiff base has been synthesized by the interaction of ethanolic solution of antiglyoxime hydrazine with 2-acetyl-5-methylfuran, to obtain the corresponding Schiff base L. The complexes of Ni(II) and Cu(II) of the Schiff base were synthesized and studied. The Schiff base and its metal(II) complexes characterized based on solubility, percentage yield, elemental analysis, melting/decomposition temperatures, infra- red spectral (FT-IR), conductivity measurement, magnetic susceptibility and water of crystallisation. The synthesized Schiff base and the complexes are coloured and stable at room temperature. Based on the results the prepared Schiff base and synthesized complexes are relatively soluble in most organic solvents but insoluble in distilled water. The melting point temperature of the ligand was 118oC while the decomposition temperature for metal complexes were 308 and 300oC respectively. The molar magnetic susceptibility of the complexes were 3.55 and 2.10 x 10-3 erg.G-2mol-1. The molar conductance values of 2.17 and 2.43ohm-1cm2mol-1 indicating non electrolytic nature of the complexes. The spectral data of the Schiff base showed band of 1584cm-1, revealing the formation of the azomethine. A bands of 791cm-1 indicate the metal nitrogen bond. The elemental analysis determination of the complexes and the Schiff base showed the metal ligand ratio of 1:2 (M:2L). The antibacterial and antifungal activities of the Schiff base and the metal(II) complexes were evaluated using disc diffusion method. The antibacterial assay was carried out on three pathogenic bacteria, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pneumonia and two fungi viz: Candida utilis and Saccharomyces cerevisiae. All the Schiff base

Synthesis, spectroscopic and antimicrobial studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes derived from benzoic acid bidentate Schiff base ligand

The Schiff base was synthesized by condensation of 2-hydroxy-1-naphthaldehyde with 3- aminobenzoic acid in 1:1 molar ratio. The Schiff base ligand formed complexes with Co (II), Ni (II), Cu (II) and Zn (II) acetate via mechanochemical synthesis. The synthesized compounds were characterized by solubility test, thermal analysis, FT-IR, powder x-ray diffraction, molar conductance measurement, magnetic susceptibility and elemental analysis. The Schiff base has a melting point of 190 oC. The decomposition temperature of complexes was found to be in the range 289 – 302 oC. The Schiff base and its metal (II) complexes were soluble in DMF, DMSO and sparingly soluble in acetonitrile, chloroform, diethyl ether and insoluble in n-hexane which indicate the polar nature of the synthesized compounds. The IR spectral analysis of the free Schiff base shows a band at 1622 cm-1, assigned to v(C=N) stretching vibrations. This band was shifted in the spectra of complexes (1607 – 1633 cm-1), indicating coordination of the Schiff base to the metal ion through the azomethine group. The molar conductance of complexes determined are in the range 9.51 – 14.87 Ohm-1cm2mol-1 which indicate the non-electrolytic nature in DMF. Magnetic susceptibility measurements of Co (II), Ni (II) and Cu (II) complexes exhibit a magnetic moment in the range 1.25 – 3.08 BM. The values correspond to square-planar geometry. The magnetic moment value of Zn (II) complex indicates a diamagnetic behaviour. The elemental analysis of the complexes for C, H and N determined showed that the observed and the calculated percentages of the elements are in good agreement.

Magnetic susceptibility measurement by NMR: 2. The magnetic susceptibility of NMR solvents and their chemical shifts

Most routine 1H NMR spectroscopy references the chemical shift of TMS to zero. However, its chemical shift varies with solvent and environmental conditions. Chemical shifts and magnetic susceptibilities of TMS and several NMR solvents are accurately measured over a range of temperatures. Methods for improving the measurements of chemical shifts and magnetic susceptibilities are developed and demonstrated. This makes it possible to compare chemical shifts of compounds between solvents, improving the accuracy of solvent effect measurements. The effects of polarizability and aromaticity on the chemical shift of TMS are shown. The molar magnetic susceptibilities of the deuterated solvents are similar to those of the regular protiated solvents.

Magnetically Manipulable Ionic Liquid Crystals Incorporating Neutral Radical Moiety.

With a view to fabricating a new remote input-output system by applying functional ionic liquid crystalline (ILC) materials, we have developed novel ILC compounds containing a nitroxide radical unit in the organic cations, which show an enantiotropic smectic A (SmA) phase. We have implemented the magnetic manipulation of a droplet of one of the ILC compounds on the basis of the intermolecular magnetic interactions between radical moieties. This ILC monoradical compound shows a 55 % larger increase in paramagnetic susceptibility at the solid-to-LC melting point in the first heating process than the non-ionic LC monoradical compounds. It is most likely owing to the nanosegregation of strongly bonded ionic and non-ionic moieties. The increased molar magnetic susceptibility is preserved not only in the SmA phase but also in the isotropic liquid and solid phases during the first cooling process.

Anticancer, in vitro cytotoxicity and antimicrobial properties of a Schiff base ligand, 3-((2-(-(1-(2-hydroxyphenyl)ethylidene)amino)ethyl)imino)-N-(p-tolyl)butanamide, and its metal complexes

A Schiff base ligand, 3-((2-(-(1-(2-hydroxyphenyl)ethylidene)amino)ethyl)imino)-N-(p-tolyl)butanamide, was synthesized by the condensation of o-hydroxylacetophenone, p-methylacetoacetanilide and 1,2-ethylenediamine and its V(IV)O, Cr(III), Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) complexes have been prepared. The ligand and metal complexes were characterized analytically and spectroscopically by elemental analysis, HRMS, IR, 1H NMR, 13C NMR and UV-vis spectroscopies and molar conductance and magnetic susceptibility measurements. The ligand and its metal complexes have been evaluated for their cytotoxic activity against Dalton’s Lymphoma Ascites (DLA) cell line by Trypan blue exclusion method. In vivo anticancer studies using the Cu(II) complex in Swiss Albino female mice showed its potential efficiency against EAC-induced ascites tumor and DLA-induced solid tumor with an IC50 value of 46 µg/mL. Also, the complexes were tested for antibacterial and antifungal properties against some Gram-positive bacteria, Staphylococcus aureus, Bacillus cereus and Streptococcus criceti, and Gram-negative bacteria, Escherichia coli, Klebsilla pneumoniae and Pseudomonas aeruginosa and some fungi, Pencillium expansum, Fusarium oxysporum and Aspergillus niger. The complexes exhibited potential antibacterial and antifungal properties than the ligand, H2L, and in some cases even more than those of standard antibacterial and antifungal drugs.

Synthesis and Structural Studies of Transition Metals Complexes with Poly dentate Azo dye ligand Derived from Coumarine11

The present work involves the synthesis and characterization of some transition elements complexes derived from (E)-3-((3-aminopyridin-2-yl) diazenyl)-4-hydroxy-2H-chromen-2-one as novel azo-Lewis base, LH. The new ligand was synthesized by coupling the diazonium salt of 2,6-diaminopyrimidine with alkaline solution of 4-hydroxy-coumarin. The new azo ligand was identified on the basis of C.H.N elemental analysis, EI-MS, NMR and FT-IR spectra. The direct reactions of hydrated chlorides of chromium(III),manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with the [L] solution in ethanol solvent with variety of PH range of (7.5-8.0) and the mole ratio of ligand to metal ion 1:1 in all synthesized complexes. All the metal complexes were identified by flame atomic absorption spectroscopy, FT-IR and UV-Visible spectra. Furthermore the molar conductivity and magnetic susceptibility measurements were carried out to confirm their molecular formulas, and their geometry. The data observed from elemental analyses, electronic spectra and magnetic moments revealed the octahedral environment around Cr(III), Mn(II), cobalt(II) and copper(II) ions in the formulas [Cr(L)Cl2(H2O)]Cl, [M(L)Cl2(H2O)2], M=Mn(II),Co(II) and Cu(II) while the nickel(II) and zinc(II) complex were tetrahedral geometry [M(L)Cl2].nH2O ; M=Ni and Zn(II) and n=0 and 1 respectively. All the complexes were low soluble in DMF and sparingly in ethanol and common organic solvents which revealed the monomeric in nature structures of complexes and possessing metal-chloro bonding in the inner-sphere of complexes.

Preparation, Determination and Study Toxicity Effects of new Mixed ligands Complexes Derivative from 8- Hydroxy Quinoline with Pd(II)

This academic research consists of mixed ligands 8-hydroxy quinolone and new azo ligand [ (E)-2-((4-methoxyphenyl) diazenyl)-4-methyl-1H-imidazole](PMI) both of them coordinated with (Cu ,Ni and Pd)(II) , the mole ratio was (1:1:1) . the suggestion geometrical structures of mixed ligands and its complexes have been studied by (FT.IR, UV-Visible, 1H-NMR, Mass and elementary analysis (C.H.N) ) In addition, an electrical molar conductivity and magnetic susceptibility used for complexes . The results of analytical studies evidence an Octahedral geometries of (Cu, Ni) (II) complexes while , Square planer of Pd(II) complex .It seems to be there is noticeable inhibition of cancerous cells of human Thyroid cancer (FTC133 ) compared to normal cells , which mentions to the cytotoxicity of Pd(II) complex ., this results gave good information about including good inhibition against some types of tumor like thyroid cancer and it gave decreasing in size of tumor.

3D Metal-Organic Frameworks Based on Co(II) and Bithiophendicarboxylate: Synthesis, Crystal Structures, Gas Adsorption, and Magnetic Properties.

Three new 3D metal-organic porous frameworks based on Co(II) and 2,2′-bithiophen-5,5′-dicarboxylate (btdc2−) [Co3(btdc)3(bpy)2]·4DMF, 1; [Co3(btdc)3(pz)(dmf)2]·4DMF·1.5H2O, 2; [Co3(btdc)3(dmf)4]∙2DMF∙2H2O, 3 (bpy = 2,2′-bipyridyl, pz = pyrazine, dmf = N,N-dimethylformamide) were synthesized and structurally characterized. All compounds share the same trinuclear carboxylate building units {Co3(RCOO)6}, connected either by btdc2– ligands (1, 3) or by both btdc2– and pz bridging ligands (2). The permanent porosity of 1 was confirmed by N2, O2, CO, CO2, CH4 adsorption measurements at various temperatures (77 K, 273 K, 298 K), resulted in BET surface area 667 m2⋅g−1 and promising gas separation performance with selectivity factors up to 35.7 for CO2/N2, 45.4 for CO2/O2, 20.8 for CO2/CO, and 4.8 for CO2/CH4. The molar magnetic susceptibilities χp(T) were measured for 1 and 2 in the temperature range 1.77–330 K at magnetic fields up to 10 kOe. The room-temperature values of the effective magnetic moments for compounds 1 and 2 are μeff (300 K) ≈ 4.93 μB. The obtained results confirm the mainly paramagnetic nature of both compounds with some antiferromagnetic interactions at low-temperatures T < 20 K in 2 between the Co(II) cations separated by short pz linkers. Similar conclusions were also derived from the field-depending magnetization data of 1 and 2.

Tuning Magnetic Relaxation in Square-Pyramidal Dysprosium Single-Molecule Magnets Using Apical Alkoxide Ligands

Tuning Magnetic Relaxation in Square-Pyramidal Dysprosium Single-Molecule Magnets Using Apical Alkoxide Ligands