Susceptibility Measurements Research Articles

Investigation of slow magnetic relaxation in a series of 1D polymeric cyclobutane-1,1-dicarboxylates based on LnIIIVIV2 units (LnIII = Tb, Dy, Ho, Er, Tm, Yb): rare examples of VIV-4f single-molecule magnets.

The reactions of VOSO4·3H2O with Na2(cbdc) (cbdc2- - dianion of cyclobutane-1,1-dicarboxylic acid) and lanthanide(III) nitrates taken in a molar ratio of 1 : 2 : 1 were found to yield a series of isostructural heterometallic compounds [NaLn(VO)2(cbdc)4(H2O)10]n (1Ln, Ln = Tb, Dy, Ho, Er, Tm, Yb). These compounds are constructed from trinuclear anionic units [Ln(VO)2(cbdc)4(H2O)8]- ({LnV2}-) linked by Na+ ions into 1D polymeric chains. The crystal structures of 1Dy and 1Er were determined by single-crystal X-ray diffraction (XRD), and their isostructurality with 1Tb, 1Ho, 1Tm, and 1Yb was proved by powder X-ray diffraction (PXRD). According to alternating current (ac) magnetic susceptibility measurements, 1Dy, 1Er, and 1Yb exhibited field-induced slow relaxation of magnetization. Compound 1Er is the first representative of ErIII-VIV single-molecule magnets. Measuring the temperature dependences of the phase memory time (Tm) for 1Dy and 1Yb using pulsed EPR spectroscopy allowed us to observe the phenomenon of phase relaxation enhancement (PRE) at temperatures below 30 K. In future, this phenomenon may contribute to the evaluation of relaxation times of the lanthanide ions.

Evaluation and real-world experience of a neutralization susceptibility screening assay for broadly neutralizing anti-HIV-1 antibodies.

Development of a screening assay for the clinical use of broadly neutralizing antibodies (bnAbs) is a priority for HIV therapy and cure initiatives. We assessed the PhenoSense Monoclonal Antibody (mAb) Assay (Labcorp-Monogram Biosciences) which is CLIA-validated and has been used prospectively and retrospectively in multiple recent bnAb clinical trials. When performed on pre-ART plasma and on-ART longitudinal PBMC samples sourced from a recent clinical trial, the PhenoSense mAb Assay produced robust reproducibility, concordance across sample types, and expected ranges in the susceptibility measures of bnAbs in clinical development. PhenoSense mAb applied retrospectively to baseline samples from three recent studies correlated with published laboratory-based study evaluations, but baseline bnAb susceptibility was not consistently predictive of durable virus suppression. Assessment of the feasibility of the assay in four recent clinical studies provides estimates of assay success rate and processing time. The PhenoSense mAb Assay provides reproducible bnAb susceptibility measurements across relevant sample types yet was not consistently predictive of virus suppression. Logistical and operational assay requirements can impact timely clinical trial conduct. These results inform bnAb studies in development.

Spin reorientation and the interplay of magnetic sublattices in Er2CuMnMn4O12.

Through a combination of magnetic susceptibility, specific heat, and neutron powder diffraction measurements we have revealed a sequence of four magnetic phase transitions in the columnar quadruple perovskite Er2CuMnMn4O12. A key feature of the quadruple perovskite structural framework is the complex interplay of multiple magnetic sublattices via frustrated exchange topologies and competing magnetic anisotropies. It is shown that in Er2CuMnMn4O12, this phenomenology gives rise to multiple spin-reorientation transitions driven by the competition of easy-axis single ion anisotropy and the Dzyaloshinskii-Moriya interaction; both within the manganese B-site sublattice. At low temperature, one Er sublattice orders due to a finite f-d exchange field aligned parallel to its Ising axis, while the other Er sublattice remains non-magnetic until a final, symmetry-breaking phase transition into the ground state. This non-trivial low-temperature interplay of transition metal and rare-earth sublattices, as well as an observed k = (0, 0, ½) periodicity in both manganese spin canting and Er ordering, raises future challenges to develop a complete understanding of the R2CuMnMn4O12 family.

Synthesis, Characterization, Biological Potency, and Molecular Docking of Co2+, Ni2+, and Pd2+ Complexes Derived From Carbohydrazone Ligand and Its Application in Dye Removal

ABSTRACTAs a result of the Schiff base condensation reaction between carbohydrazide and 4‐aminoacetophenone, novel HL ligand [(Z)‐N′‐((Z)‐1‐(4‐aminophenyl)ethylidene)‐2‐(1‐(4‐aminophenyl)ethylidene)hydrazine‐1‐carbohydrazide] and three coordination compounds were successfully obtained with the formulas of [Co2(L)(Cl)3(H2O)].Cl, [Ni2(L)(Cl)2(H2O)2].Cl.H2O, and [Pd (HL)(Cl)(H2O)].Cl, the obtained structures were analyzed using analytical and spectroscopic techniques such as Fourier‐transform infrared (FT‐IR), NMR, UV–Vis, molar conductivity, elemental analysis, and magnetic susceptibility measurements. Additionally, thermal stabilities, kinetic, and thermodynamic parameters were estimated utilizing thermogravimetric analysis. The structures were confirmed through quantum chemical computations. The antioxidant, anticancer, and antimicrobial biological efficacies of the ligand and its metal chelates were assessed. The ligand shows optimistic results as an antioxidant, while Co2+ and Pd2+ complexes showed the highest antimicrobial activities. The DNA binding affinity and cleavage of the isolated compounds were evaluated. Furthermore, the fluorescence spectrum of ligand in the absence and presence of Co2+ was recorded in order to investigate the interaction affinity along with the limit of detection. Another application of this work is the removal of methylene blue and crystal violet dyes from wastewater and reusability, through an inventive synthesis of a cellulose‐based material “LDC” Schiff base.

Prediction of MRI relaxometry in the presence of hepatic steatosis by Monte Carlo simulations.

To develop Monte Carlo simulations to predict the relationship of with liver fat content at 1.5T and 3.0T. For various fat fractions (FFs) from 1% to 25%, four types of virtual liver models were developed by incorporating the size and spatial distribution of fat droplets. Magnetic fields were then generated under different fat susceptibilities at 1.5T and 3.0T, and proton movement was simulated for phase accrual and MRI signal synthesis. The synthesized signal was fit to single-peak and multi-peak fat signal models for and proton density fat fraction (PDFF) predictions. In addition, the relationships between and PDFF predictions were compared with in vivo calibrations and Bland-Altman analysis was performed to quantitatively evaluate the effects of these components (type of virtual liver model, fat susceptibility, and fat signal model) on predictions. A virtual liver model with realistic morphology of fat droplets was demonstrated, and and PDFF values were predicted by Monte Carlo simulations at 1.5T and 3.0T. predictions were linearly correlated with PDFF, while the slope was unaffected by the type of virtual liver model and increased as fat susceptibility increased. Compared with in vivo calibrations, the multi-peak fat signal model showed superior performance to the single-peak fat signal model, which yielded an underestimation of liver fat. The -PDFF relationships by simulations with fat susceptibility of 0.6ppm and the multi-peak fat signal model were ( , ) at 1.5T and ( , ) at 3.0T. Monte Carlo simulations provide a new means for -PDFF prediction, which is primarily determined by fat susceptibility, fat signal model, and magnetic field strength. Accurate -PDFF calibration has the potential to correct the effect of fat on quantification, and may be helpful for accurate measurements in liver iron overload. In this study, a Monte Carlo simulation of hepatic steatosis was developed to predict the relationship between and PDFF. Furthermore, the effects of fat droplet morphology, fat susceptibility, fat signal model, and magnetic field strength were evaluated for the -PDFF calibration. Our results suggest that Monte Carlo simulations provide a new means for -PDFF prediction and this means can be easily generated for various regimes, such as simulations with higher fields and different echo times, as well as correction of magnetic susceptibility measurements for liver iron quantification.

Structural origin of relaxation in dense colloidal suspensions

Amorphous solids relax via slow molecular rearrangement induced by thermal fluctuations or applied stress. Microscopic structural signatures predicting these structural relaxations have been long searched for but have so far only been found in dynamic quantities such as vibrational quasi-localized soft modes or with structurally trained neural networks. A physically meaningful structural quantity remains elusive. Here, we introduce a structural order parameter derived from the mean-field caging potential experienced by the particles due to their neighbors, which reliably predicts the occurrence of structural relaxations. The structural parameter, derived from density functional theory, provides a measure of susceptibility to particle rearrangements that can effectively identify weak or defect-like regions in disordered systems. Using experiments on dense colloidal suspensions, we demonstrate a strong correlation between this order parameter and the structural relaxations of the amorphous solid. In quiescent suspensions, this correlation increases with density, when particle rearrangements become rarer and more localized. In sheared suspensions, the order parameter reliably pinpoints shear transformations; the applied shear weakens the caging potential due to shear-induced structural distortions, causing the proliferation of plastic deformation at structurally weak regions. Our work paves the way to a structural understanding of the relaxation of a wide range of amorphous solids, from suspensions to metallic glasses.

Fermi surface and Lifshitz transitions of a ferromagnetic superconductor under external magnetic fields

Lifshitz transitions are being increasingly recognized as significant in a wide variety of strongly correlated and topological materials, and understanding the origin and influence of Lifshitz transitions is leading to deeper understanding of key aspects of magnetic, transport, or quantum critical behavior. In the ferromagnetic superconductor UCoGe, a magnetic field applied along the c axis has been shown to induce a series of anomalies in both transport and thermopower that may be caused by Lifshitz transitions. The need to understand the subtleties of the relationship between magnetism, superconductivity and a heavy-electron Fermi surface in the ferromagnetic superconductors makes it important to explore if and why a series of magnetic-field-induced Lifshitz transitions occurs in UCoGe. Here we report magnetic susceptibility measurements of UCoGe, performed at temperatures down to 45 mK and magnetic fields (μ0H||c) up to 30 T. We observe a series of clearly defined features in the susceptibility, and multiple sets of strongly field-dependent de Haas-van Alphen oscillations, from which we extract detailed field dependence of the quasiparticle properties. We complement our experimental results with density functional theory band structure calculations, and include a simple model of the influence of magnetic field on the calculated Fermi surface. By comparing experimental and calculated results, we determine the likely shape of the Fermi surface and identify candidate Lifshitz transitions that could correspond to two of the features in susceptibility. We connect these results to the development of magnetization in the system. Published by the American Physical Society 2024

Synthesis, characterization and antimicrobial Studies of complexes of some metal ions with 5(2-hydroxy benzylidine) -2-thio ether -1, 3, 4-thiadiazole

A new series of Fe (III) , Co (II) , Ni (II) and Cu (II) complexes of the Schiff base, 5 (2-hydroxy benzylidine) -2-thio ether -1, 3, 4-thiadiazole were prepared and characterized .The imine behaves as a bidentate. The nature of bonding and the stereochemistry of the complexes were deduced from metal analyses, infrared, electronic spectra,magnetic susceptibility and conductivity measurements, an octahedral geometry was suggested for all complexes except the copper complex has a square planar geometry .preliminary in vitro tests for antimicrobial activity show that all the prepared compounds except iron complex display good activity to gram positive Staphelococcus aures and gram negative Escherchia coli.

Ta4SBr11: A Cluster Mott Insulator with a Corrugated, Van der Waals Layered Structure.

The compound Ta4SBr11 was prepared by a comproportionation reaction of tantalum bromide with tantalum and elemental sulfur. The crystal structure, as refined by single-crystal X-ray diffraction, is composed of clusters with Ta4S cores, arranged in corrugated van der Waals layers. Individual layers appear to be displaced relative to each other along one direction. Successful crystal growth in a melt of CsBr yielded black platelets of Ta4SBr11, which were used to investigate the electrical properties of the compound. The electronic structure was studied by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and by density functional theory (DFT) band structure calculations, revealing this material to be a small-gap semiconductor. DFT results, in combination with magnetic susceptibility measurements, suggest that metallicity originating from the one unpaired Ta d electron per cluster is most likely suppressed by electronic correlations, forming a cluster Mott insulator.

Dilution induced magnetic localization in Rb(Co[formula omitted]Ni[formula omitted])2Se2 single crystals

We report experimental studies on a series of Rb(Co1−xNix)2Se2 (0.02 ≤x≤ 0.9) powder and single crystal samples using x-ray diffraction, neutron diffraction, magnetic susceptibility, and electronic transport measurements. All compositions are metallic and adopt the body-centered tetragonal structure with I4/mmm space group. Anisotropic magnetic susceptibilities measured on single crystal samples suggest that Rb(Co1−xNix)2Se2 undergo an evolution from ferromagnetism to antiferromagnetism, and finally to paramagnetism with increasing Ni concentration. Neutron diffraction measurements on the samples with x = 0.1, 0.4, and 0.6 reveal an A-type antiferromagnetic order with moments lying in the ab plane. The moment size changes from 0.69 (x=0.1) to 2.80μB (x=0.6) per Co ions. Our results demonstrate that dilution of the magnetic Co ions by substitution of nonmagnetic Ni ions induces magnetic localization and evolution from itinerant to localized magnetism in Rb(Co1−xNix)2Se2.

Middle - Late Eocene cold and wet climatic interval in East Asia: Evidence from lacustrine sediments of the lower Huoshaogou Formation in the Hexi Corridor, NE Tibetan Plateau

Knowledge of the climate of the Late Eocene is important for understanding the global climatic shift from a global Warmhouse to a Coolhouse. We obtained a climatic record for the interval of 38.10–36.33 Ma based on sedimentary facies analysis combined with measurements of color indices (CI) and magnetic susceptibility (MS) of the lower Huoshaogou Formation in the westernmost Hexi Corridor, Northeastern Tibetan Plateau. Our results reveal the following temporal sequence of sedimentary environments: delta plain, shore–shallow lake, deep lake, and braided river. The records of MS and CI co-vary with changes in sedimentary facies and color, respectively. The various proxy indicators indicate an overall warm and dry climate interrupted by a cold and wet interval in the middle part of the section during ~37.67–36.44 Ma, corresponding to a thick, greenish-colored lacustrine sedimentary layer with high values of lightness and low valuer of MS, frequency-dependent MS and redness. We suggest that this event was driven by the diversion of westerly winds due to the uplift of the southern Tibetan Plateau, together with the Tethys Sea retreat and the short-lived emergence or enhancement of the Asian monsoon.

Effect of N-7 alkylation on Cu (II) binding with 6-chloropurine: Influence of anions and magnetic studies.

This study investigates the anion-directed assembly of discrete copper (II) complexes. The ligands of choice are two unusual N7-alkyl-purine-based neutral ligands. These ligands facilitate the exclusive coordination through the N3 and N9 positions, preventing polymeric chain formation. Perchlorate ions promoted the formation of discrete paddlewheel-like complexes with the general formula [Cu2(μ-Pur)4(CH3CN)2]4+,while chloride ions yielded chloride-bridged dimers of the form [Cu2(Pur)2(μ-Cl)2Cl2]. Copper-copper bond distances within these complexes ranged from 2.92 to 2.98 Å. Magnetic susceptibility measurement of chloride-bridged complexes exhibited antiferromagnetic coupling, whereas paddlewheel complexes displayed more complex alternating ferromagnetic and antiferromagnetic interactions. Chloride-bridged compounds exhibited strong near-infrared absorption.

Critical current density and AC magnetic susceptibility of high-quality FeTe0.5Se0.5 superconducting tapes

Iron telluride-selenium superconducting materials, known for their non-toxicity, ease of preparation, simple structure, and high upper critical fields, have attracted much research interest in practical application. In this work, we conducted electrical transport measurements, magneto-optical imaging, and AC magnetic susceptibility measurements on FeTe0.5Se0.5 superconducting long tapes fabricated via reel-to-reel pulsed laser deposition. Our transport measurements revealed a high critical current density that remains relatively stable even with increasing external magnetic fields, reaching over 1 × 105 A/cm2 at 8 K and 9 T. The calculated pinning force density indicates that normal point pinning is the primary mechanism in these tapes. The magneto-optical images demonstrated that the tapes show homogeneous superconductivity and uniform distribution of critical current density. The AC magnetic susceptibility measurements also confirmed their strong flux pinning nature of withstanding high magnetic field. Based on these characteristics, FeTe0.5Se0.5 superconducting tapes show promising prospects for applications under high magnetic field.

The Synthesis of Melamine Cored Schiff Bases and Investigation of Heteronuclear Metal Complexes

In this study, 2,4,6-triamino-s-triazine (melamine) is the starting material. The condensation reaction of melamine and 4-hydroxybenzaldehyde resulted in the formation of the monopodal Schiff base. An oxygen-bridged monopodal complex of [(Fe(III)Salophen)Cl] ligand complex with monopodal Schiff base ligand was then obtained. Tripodal Schiff base ligand was obtained by condensing 2-hydroxybenzaldehyde with a monopodal complex and this ligand in some transition metal complexes were synthesized. As a result, the ligand and complexes of this ligand were isolated, as well as elemental analyses, FT-IR, 1H-NMR, TGA and magnetic susceptibility measurements of the obtained compounds were taken to elucidate their structures.

Microwave-Assisted, Preparation, Characterization, and Biological Activities of Schiff Bases Derived from 4-Aminoantipyrine with Acetonyl Acetone for Some New Rare-Earth Metals

Five new lanthanide complexes based on azomethine (Schiff bases) ligands have been synthesized, including La, Nd, Er, Gd, and Dy. Complexes were synthesized using the azomethine Schiff bases resulting from condensation reactions between 4-aminoantipyrine and acetonylacetone. The structural characteristics of azomethine obtained are characterized quantitatively and qualitatively through various techniques, including elemental analyses, magnetic susceptibility measurement, molar conductivity, infrared, ultraviolet absorption, GC-mass, and 1H- and 13C-NMR spectroscopy studies. The structural characteristics of Ln+3 complexes indicate that the complexes possess a composition of a specific type. Based on the elemental analyses, magnetic susceptibility measurement, molar conductivity, and ultraviolet absorption spectroscopy data, it can be inferred that the central metal ion is surrounded by a coordination number of 10, the general formula of [Ln(L)2(NO3)]·nNO3nH2O. The physical measurements confirmed that the synthesized complexes exhibit non-electrolyte behavior and paramagnetic properties. The antibacterial activity of the compounds was assessed in vitro against 4 pathogenic strains: E. coli, S. aureus, K. pneumoniae, and S. mutans. The evaluation was conducted using the agar disc spreading method. The results demonstrated that certain complexes exhibited significant antibacterial efficacy in comparison to the biological activity of the ligand.

Synthesis and characterization of a two-dimensional antiferromagnet KNiB4O6F3 with triangular spin lattice

We prepared a layered antiferromagnet KNiB4O6F31 by hydrothermal synthesis, and characterized its structure and physical properties by X-ray diffraction, magnetization and specific heat measurements as well as thermal stability, FTIR and UV-vis-NIR measurements. 1 consists of layers of composition [NiB4O6F3]- separated by layers of K+ cations. And Ni2+ ions are arranged in slightly distorted triangular pattern in each [NiB4O6F3]- layer. The magnetic susceptibility measurements indicate no divergence between the zero-field-cooled and field-cooled curves down to 7.9 K, below which a long-range order takes place as verified by specific heat measurements. The M(H) curve linearly increases when the field is weak (below ∼2 T), confirming that the ground state of 1 is antiferromagnetic. At 7 T, the magnetization of 1 is 1.67 μB which is lower than the saturation magnetization.

Synthesis, characterization and biological studies of transition metal complexes of dehydroacetic acid Schiff bases derived from 3-aminomethyl pyridine

The solid metal complexes of Cu (II), Ni (II), Fe (III), Co (II), Mn (II) and Cd (II) with DHA Schiff base ligand derived from DHA and aromatic primary amine 3-aminomethyl pyridine were synthesized and characterized by elemental analysis, spectroscopic techniques (FTIR, UV-VIS, 1HNMR and XRD), magnetic susceptibility measurement, thermogravimetric analysis and differential thermal analysis (TGA/DTA) and investigated for biological activities like anti-bacterial, ant-fungal, antioxidant and anticancer activity. The structure of synthesized DHA Schiff base ligand and all metal complexes were confirmed by spectroscopic methods, stability of complexes was studied by TGA/DTA. DHA Schiff base ligand and all metal complexes were found to be biologically active.

Magnetostratigraphy of the upper Jurassic and Lower Cretaceous deposits of the Bolshekhetskaya structural terrace

Relevance. The confinement of hydrocarbon deposits to certain stratigraphic horizons, poor knowledge of the northeast of Western Siberia and adjacent territories, including the magnetostratigraphic method, with their oil and gas potential (over the past 10 years, four unique hydrocarbon deposits have been discovered here), the boreal nature of the deposits, and the need for remote magnetostratigraphic correlations. Aim. To create a magnetostratigraphic reference section of the northeast of Western Siberia. Objects. Sections of deep wells of the Pendomayakhskaya, Vostochno Suzunskaya, Vostochno Lodochnaya and Gorchinskaya areas of the Bolshekhetskaya structural terrace, which exposed the Lower Cretaceous and upper parts of the Upper Jurassic (Yanovstan Formation) deposits. Methods. Paleomagnetic studies were carried out according to standard methods and included sampling of core samples with an "up-down" orientation, sample preparation (kappametry, marking of samples, photographing, sawing), measurement of magnetic susceptibility, temporary cleaning (the samples were located along the field during a week, then a week-against the field with determination of residual magnetization), complete demagnetization by alternating magnetic field, plotting of complete demagnetization, mass cleaning, determination of components of natural residual magnetization, assessment of paleomagnetic stability, identification of forward and reverse polarity zones, construction of paleomagnetic sections. To construct the magnetostratigraphic sections given in this article, the paleomagnetic and biostratigraphic data are linked. For this purpose, magnetochrons were identified using biostratigraphic analysis. Results. The authors have compiled a composite magnetostratigraphic section of the boundary Jurassic-Cretaceous deposits of the Bolshekhetskaya structural terrace and identified four magnetozones with subzones of direct and reverse polarity, compared with the Berriasian ammonite scale. The high information content of the results of magnetostratigraphy research under boreal conditions was noted.

The Arpu Kuilpu meteorite: In‐depth characterization of an H5 chondrite delivered from a Jupiter Family Comet orbit

AbstractOver the Nullarbor Plain in South Australia, the Desert Fireball Network detected a fireball on the night of June 1, 2019 (7:30 pm local time), and 6 weeks later recovered a single meteorite (42 g) named Arpu Kuilpu. This meteorite was then distributed to a consortium of collaborating institutions to be measured and analyzed by a number of methodologies including SEM‐EDS, EPMA, ICP‐MS, gamma‐ray spectrometry, ideal gas pycnometry, magnetic susceptibility measurement, μCT, optical microscopy, and accelerator and noble gas mass spectrometry techniques. These analyses revealed that Arpu Kuilpu is an unbrecciated H5 ordinary chondrite, with minimal weathering (W0‐1) and minimal shock (S2). The olivine and pyroxene mineral compositions (in mole%) are Fa: 19.2 ± 0.2 and Fs: 16.8 ± 0.2, further supporting the H5 type and class. The measured oxygen isotopes are also consistent with an H chondrite (δ17O‰ = 2.904 ± 0.177; δ18O‰ = 4.163 ± 0.336; Δ17O‰ = 0.740 ± 0.002). Ideal gas pycnometry measured bulk and grain densities of 3.66 ± 0.02 and 3.77 ± 0.02 g cm−3, respectively, yielding a porosity of 3.0% ± 0.7. The magnetic susceptibility of this meteorite is log χ = 5.16 ± 0.08. The most recent impact‐related heating event experienced by Arpu Kuilpu was measured by 40Ar/39Ar chronology to be 4467 ± 16 Ma, while the cosmic ray exposure age is estimated to be between 6 and 8 Ma. The noble gas isotopes, radionuclides, and fireball observations all indicate that Arpu Kuilpu's meteoroid was quite small (maximum radius of 10 cm, though more likely between 1 and 5 cm). Although this meteorite is a rather ordinary ordinary chondrite, its prior orbit resembled that of a Jupiter Family Comet (JFC) further lending support to the assertion that many cm‐ to m‐sized objects on JFC orbits are asteroidal rather than cometary in origin.

Synthesis, Characterization and In-vitro Antibacterial Activity Studies of Oxovanadium (IV) Complexes of α-Amino Acid Schiff Bases and 1,10-Phenanthroline Ligands

Oxovanadium(IV) complexes of the type [VO(L)(phen)] (VO-1 to VO-5) have been synthesized and characterized by FTIR and UV-Vis spectra, molar conductance, melting points, and magnetic susceptibilities measurements, where L= N-salicylidene-β-alanine (sal-ala), N-salicylidene-glycine (sal-gly), N-salicylidene-DL-β-phenylalanine (sal-pheala), N-salicylidene-leucine (sal-leu), and N-salicylidene-DL-methionine (sal-met), and phen is 1,10-phenanthtroline. The infrared spectral data reveals that the tridentate nature of the amino acid-based Schiff base ligand and the coordination of the ligand through azomethine nitrogen, phenolic oxygen and carboxylate oxygen with vanadyl (VO2+) ion. All of these complexes were determined to be non-electrolyte in nature, according to conductivity measurements. The magnetic moment measurements have been attributed that these complexes are paramagnetic and have d1 configuration of vanadium (IV) ion. The antimicrobial activity of the synthesized complexes was evaluated against four pathogenic bacteria viz. Escherichia coli, Proteus vulgaris, Bacillus subtilis and Staphylococcus aureus.