Synthesis, characterization and antimicrobial studies of Mn(II) complex with N-salicyl-O-hydroxyphenyleneiminato schiff base ligand

The complex of Mn(II) with schiff base derived from 2-aminophenol and 2-hydroxybenzaldehyde has been synthesised and characterized by molar conductance, elemental analysis, FT-IR, solubility test and potentiometric studies. The elemental analysis data suggested the stoichiometry to be 1:1 [M:L]. Solubility test carried out in some common solvents showed that it is soluble in methanol, DMSO, acetone and diethylether but insoluble in benzene and ether, while in toluene is slightly soluble and these suggested the polar nature of the complex. The molar conductance measurement of the complex is 2.5 Ω-1 cm2  mol-1 which is very low suggesting that the complex is non-electrolyte. Evidence from Infrared spectral study indicated a strong band in the spectra of free ligand occurring at 1600cm-1 which assigned to ν(C=N). It shifted to lower frequency region 1520cm-1 in the complex indicating the involvement of nitrogen atom of azomethine group. The coordination of Schiff base with the metal ion as showed by the appearance of low frequency band at 430cm-1 due to metal-oxygen ν(M-O) vibration thus confirming participation of oxygen in the coordination. Further coordination of metal to azomethine nitrogen ν(M-N) is confirmed by a new band at 580cm-1. The synthesized ligand, and metal complex were screened for its antibacterial activity using gram positive (Staphylococcus aurous) and gram negative (Escherichia coli) and antifungal activity using Aspergillum niger and Candida albican as potential antimicrobials and showed moderate activity.Keywords: Schiff base; Mn(II) complex; Antimicrobial stud

Solid-state synthesis, characterization and antimicrobial studies of Ni (II), Co (II) and Cu (II) complexes 1-(4-nitrophenyl)imino]methyl)naphthalen-2-ol

Mechanochemicals synthesis has now been considered as a field of considerable interest for sustainable and green chemistry as a result of its safety, cost effectiveness and high yield. Ni (II), Co (II) and Cu (II) Metal complexes of 1-(4-nitrophenyl)imino]methyl)naphthalen-2-ol have been synthesized. The complexes were synthesized by grinding in an agate mortar with pestle. The complexes were characterized for their decomposition temperature, solubility test, magnetic susceptility, conductivity measurement and their surface functional groups were investigated using the Fourier Transform Infrared Spectroscopy (FTIR). The FTIR spectra of the free ligand showed a band at 1629cm-1 which is assigned to the stretching vibration of the azomethine. The down shifts of this band (1629cm-1) to lower frequencies in the spectra of the metal (II) complexes indicate complexation. The job’s method of continuous variation suggested a 1:2 metal-ligand ratio all the Ni (II), Co (II) and Cu (II) complexes. The lower conductivity measurement values (43, 34 and 29 Ohm-1cm2mol-1) revealed the non electrolytic nature of the complexes. The Schiff base and its complexes have been tested for antimicrobial activity against bacterial isolates (Staphylococcus aureus and Escherichia coli) and fungal isolates (Mucor sp and Aspergillus flavus). All the complexes exhibited appreciable activity on all the isolates.Keywords: Antimicrobial, Metal Complexes, Schiff base, Solid-state, 2-Hydroxy-1 napthaldehyd

Solid State Synthesis, Spectroscopic and X-ray Studies of Cu(II) Schiff base Complex Derived from 2-Hydroxy-3-methoxybenzaldehyde and 1,3- Phenylenediamine

Complex of Cu (II) with Schiff base derived from 2-Hydroxy-3-methoxybenzaldehyde and 1,3- Phenylenediamine have been mechanochemically (liquid-assistant grinding) synthesized and characterized by infrared, powder x-ray diffraction, energy dispersive X-ray and CHN analysis. Evidence from Infrared spectral study indicated a strong band in the spectra of free ligand occurring at 1619 cm-1 which assigned to ν(C=N). It shifted to lower frequency region 1587 cm-1 in the complex indicating the involvement of nitrogen atom of azomethine group. The coordination of Schiff base with the metal ion is confirmed by the appearance of low frequency band at 461 cm-1 due to metal-oxygen ν(M-O) and at 579 cm-1 due to metal azothemine nitrogen (MN) band. The Powder-XRD analysis reveals that, the patterns of the ground mixture were entirely different from the starting constituents, indicating that, all the starting materials were transformed to product, furthermore the colour of the complex was different from that of the Schiff base suggesting the formation of coordination compound. The antimicrobial activities of the synthesized Schiff base and complex were tested using serial dilution method, against bacterial strains (Escherichia coli, and Staphylococcus aureus) and fungal strain (Aspergillus flavus and Aspergillus niger). It has been observed that the complex has higher activity than the free Schiff base ligand.Keywords: Mechanochemistry, Power-X-ray, Azomethine, Ligand, Complex

Mechanochemical synthesis, characterization and antimicrobial screening of Metal (II) complexes derived from amoxicillin

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Liquid-assisted Mechanochemical Conversion of 2-hydroxy-3- methoxybenzaldehyde and Some Primary Aromatic Amines to Corresponding Schiff bases

In this paper, two Schiff bases of different solid primary aromatic amines were successfully synthesized using 1:1 and 2:1 molar ratio of 2-hydroxy-3-methoxybenzaldehyde to solid amine, by Liquid-assistant grinding. TheSchiff-bases were investigated by analytical and spectroscopic techniques using FT-IR, Powder X-ray Diffraction Energy Dispersive X-ray (EDX) Melting point and CHN microanalysis. The Schiff bases were found to be soluble in polar solvent such as methanol and ethanol but insoluble in non-polar solvent such as hexane. Evidence from Infrared spectral study indicated that, the characteristics band attributed to aldehyde stretching disappeared on the final Schiff bases and the new absorption band at 1624 - 1644 cm-1 was due to the ν(C=N) stretching vibration, which is the characteristic band of Schiff base. The Powder-XRD analysis reveals that, the PXRD patterns of the Schiff bases were different from their respective starting materials which indicate the formation of new phase of the product. The elemental  microanalysis of the Schiff base ligand is consistent with the calculated results from the empirical formula of the proposed structure of each  compound. The antimicrobial activities of the synthesized Schiff base were tested using agar well diffusion method, against different strains of bacterial and fungal isolates. The antimicrobial results indicated that, the antibacterial activity of the (H2L1) Schiff base ligand was found to be more effective against Escherichia coli.Keywords: Azomethine, Liquid-assistant grinding, Mechanochemistry, Powder x-ray, Schiff bas

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Mechanochemical synthesis: A suitable method to the synthesis of some diamines Schiff bases

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