Spectral Study of Some Lanthanides Complexes with Quaternary Pyridinium Ligands

Some lanthanides complexes with two N-heterocyclic ligands derived from 4,4`-bipyridinium and 1,2-bis-(4-pyridinium) ethane (noted BP and BPE) were studied in presence of triethylamine and methanol in view of their application as cytotoxic agents. Absorption spectra have been recorded by UV-Vis spectroscopy during the complexation process in solution. The ligands demonstrate preferential arrangements in lanthanide�s electronic structure which is identified much clearly in ultraviolet range. La(III)-BP solution indicates absorption at lmax= 206 nm while La(III)-BPE at lmax of 208 nm. The solution from the Nd(III)-BPE complex synthesis shows the highest absorbance at lmax= 220 nm, compared with Nd(III)-BP at lmax= 212 nm. The bathochromic shifts of the spectral bands can be assigned to the physical interaction of Ln(III) ions with ligands. No major changes were observed in the absorption, hypsochromic and hyperchromic effects when varying the ligand. The complexes spectral properties were performed by dissolving them in methanol in three phases until a complete dissolution of the precipitates was achieved.

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Effects of Methane Fermentation on Spectral Properties of Fulvic Acid Extracted from Peat through Liquid Acid Precipitation

Journal of Chemistry ◽

10.1155/2020/5084508 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Li-Tong Ma ◽

Ya-Nan Lu ◽

Ya-Xiong Wang

Keyword(s):

Fulvic Acid ◽

Spectral Properties ◽

Fermentation Process ◽

Acid Precipitation ◽

Alkali Solution ◽

Precipitation Method ◽

Methane Fermentation ◽

Liquid Acid ◽

Vis Spectroscopy ◽

Benzene Rings

The effects of acid precipitation with different liquid acids on spectral properties of fulvic acid extracted from peat was studied to select the most appropriate liquid acid for the acid precipitation step of the alkali solution acid precipitation method, and the new process mechanism of peat utilization by coupling methane fermentation and extraction of fulvic acid was analyzed. The alkali solution acid precipitation method was adopted to extract fulvic acid from the methane-fermented group and methane-unfermented group. Different liquid acids were used to conduct acid precipitation during the extraction. And then, the characterizations of fulvic acid samples were conducted through Fourier infrared spectroscopy, UV-Vis spectroscopy, and fluorescence spectroscopy. The yield and content of fulvic acid decreased significantly after methane fermentation. During the methane fermentation process, some fulvic acid was consumed and utilized by microorganisms to promote the methane fermentation process, resulting both in the decrease of methyl, hydroxyl, and ether bonds and in the increase of methylene, carbonyl, conjugated double bond, benzene rings, and other groups. The E4/E6 ratio shows that the E4/E6 ratio of fulvic acid was decreased after methane fermentation, and the fermentation consumed the functional group with simpler structure such as aliphatic chain hydrocarbon of fulvic acid while the structure with a higher degree of aromatization and conjugate cannot be consumed. When conducting acid precipitation with different liquid acids, the yield of fulvic acid was the highest through acid precipitation with phosphoric acid. The fulvic acid obtained through acid precipitation with nitric acid has a higher content, more benzene rings, and the highest degree of aromatization.

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Starch-Capped AgNPs’ as Potential Cytotoxic Agents against Prostate Cancer Cells

Nanomaterials ◽

10.3390/nano11020256 ◽

2021 ◽

Vol 11 (2) ◽

pp. 256

Author(s):

Mariana Morais ◽

Vera Machado ◽

Francisca Dias ◽

Carlos Palmeira ◽

Gabriela Martins ◽

...

Keyword(s):

Prostate Cancer ◽

Cell Cycle ◽

Anticancer Agents ◽

Cellular Proliferation ◽

Cytoplasmic Membrane ◽

Chemical Properties ◽

Cytotoxic Agents ◽

Morphological Aspect ◽

Therapeutic Approaches ◽

Vis Spectroscopy

One of the major therapeutic approaches of prostate cancer (PC) is androgen deprivation therapy (ADT), but patients develop resistance within 2–3 years, making the development of new therapeutic approaches of great importance. Silver nanoparticles (AgNPs) synthesized through green approaches have been studied as anticancer agents because of their physical-chemical properties. This study explored the cytotoxic capacity of starch-capped AgNPs, synthesized through green methods, in LNCaP and in PC-3 cells, a hormonal-sensitive and hormone-resistant PC cell line, respectively. These AgNPs were synthesized in a microwave pressurized synthesizer and characterized by ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Their cytotoxicity was assessed regarding their ability to alter morphological aspect (optical microscopy), induce damage in cytoplasmic membrane (Trypan Blue Assay), mitochondria (WST-1 assay), cellular proliferation (BrdU assay), and cell cycle (Propidium iodide and flow-cytometry). AgNPs showed surface plasmon resonance (SPR) of approximately 408 nm and average size of 3 nm. The starch-capped AgNPs successfully induced damage in cytoplasmic membrane and mitochondria, at concentrations equal and above 20 ppm. These damages lead to cell cycle arrest in G0/G1 and G2/M, blockage of proliferation and death in LNCaP and PC-3 cells, respectively. This data shows these AgNPs’ potential as anticancer agents for the different stages of PC.

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Four novel cobalt(II) succinate coordination polymers with N-heterocyclic ligands: crystal structures, spectral properties, magnetism and computational study

Chemical Papers ◽

10.1007/s11696-020-01206-1 ◽

2020 ◽

Vol 74 (11) ◽

pp. 3741-3753

Author(s):

Marek Brezovan ◽

Vladimír Kuchtanin ◽

Ján Moncol ◽

Ján Pavlik ◽

Ľubor Dlháň ◽

...

Keyword(s):

Crystal Structures ◽

Coordination Polymers ◽

Spectral Properties ◽

Computational Study ◽

Heterocyclic Ligands

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Synthesis, Crystal Structure and Spectral Properties of Copper(II) 2-Chloronicotinato Complexes with N-Heterocyclic Ligands

Nova Biotechnologica et Chimica ◽

10.1515/nbec-2016-0019 ◽

2016 ◽

Vol 15 (2) ◽

pp. 190-199 ◽

Cited By ~ 2

Author(s):

Jozef Miklovič ◽

Dušan Valigura ◽

Ingrid Svoboda ◽

Ján Moncol ◽

Milan Mazúr

Keyword(s):

Crystal Structure ◽

Spectral Properties ◽

Crystal Structure Analysis ◽

Synthesis And Characterization ◽

Epr Spectrum ◽

Heterocyclic Ligands ◽

Coordination Polyhedra ◽

X Ray ◽

Good Agreement

Abstract The synthesis and characterization of nine new copper(II) complexes [Cu(2-Clnic)2L2] (where 2-Clnic is 2-chloronicotinate anion, L is imidazole – Im, benzimidazole – Bim, furo[3,2-c]pyridine – FP, 2-methylfuro[3,2-c]pyridine – MFP, or [1]benzofuro[3,2-c]pyridine – BFP), [Cu(2-Clnic)2(INA)] (where INA is isonicotinamide), [Cu(2-Clnic)2(4-py)]·H2O (where 4-py is 4-methylpyridine) and [Cu2(2-Clnic)4(IQ)2] (where IQ is isoquinoline) are reported. The characterizations were based on elemental analysis, infrared, electronic and EPR spectra. The dimeric character of [Cu2(2-Clnic)4(IQ)2] is assumed on the EPR spectrum and the other spectral methods. The crystal structure of the [Cu(2-Clnic)2(Bim)2] and [Cu(2-Clnic)2(FP)2] complexes have been determined by X-ray crystal structure analysis. Both complexes exhibit the hexacoordination coordination polyhedra around copper atom that lies in the crystallographic center of symmetry. The distorted tetragonal-bipyramidal (4+2) arrangement is in good agreement with spectral data that have suggested an asymmetric chelate coordination of the carboxylic group.

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Copper(II) complexes with β-diketones and N-donor heterocyclic ligands: Crystal structure, spectral properties, and cytotoxic activity

Polyhedron ◽

10.1016/j.poly.2014.12.026 ◽

2015 ◽

Vol 89 ◽

pp. 1-8 ◽

Cited By ~ 33

Author(s):

Janaina do Couto Almeida ◽

Drielly A. Paixão ◽

Ivana M. Marzano ◽

Javier Ellena ◽

Marcos Pivatto ◽

...

Keyword(s):

Crystal Structure ◽

Cytotoxic Activity ◽

Spectral Properties ◽

Heterocyclic Ligands

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Leaf-Level Spectral Fluorescence Measurements: Comparing Methodologies for Broadleaves and Needles

Remote Sensing ◽

10.3390/rs11050532 ◽

2019 ◽

Vol 11 (5) ◽

pp. 532 ◽

Cited By ~ 7

Author(s):

Paulina Rajewicz ◽

Jon Atherton ◽

Luis Alonso ◽

Albert Porcar-Castell

Keyword(s):

Chlorophyll Fluorescence ◽

Spectral Properties ◽

Correction Method ◽

Integrating Sphere ◽

Baseline Correction ◽

Spectral Bands ◽

Fluorescence Measurements ◽

Custom Made ◽

Leaf Level ◽

Broadleaf Species

Successful measurements of chlorophyll fluorescence (ChlF) spectral properties (typically in the wavelength range of 650–850 nm) across plant species, environmental conditions, and stress levels are a first step towards establishing a quantitative link between solar-induced chlorophyll fluorescence (SIF), which can only be measured at discrete ChlF spectral bands, and photosynthetic functionality. Despite its importance and significance, the various methodologies for the estimation of leaf-level ChlF spectral properties have not yet been compared, especially when applied to leaves with complex morphology, such as needles. Here we present, to the best of our knowledge, a first comparison of protocols for measuring leaf-level ChlF spectra: a custom-made system designed to measure ChlF spectra at ambient and 77 K temperatures (optical chamber, OC), the widely used FluoWat leaf clip (FW), and an integrating sphere setup (IS). We test the three methods under low-light conditions, across two broadleaf species and one needle-like species. For the conifer, we characterize the effect of needle arrangements: one needle, three needles, and needle mats with as little gap fraction as technically possible. We also introduce a simple baseline correction method to account for non-fluorescence-related contributions to spectral measurements. Baseline correction was found especially useful in recovering the spectra nearby the filter cut-off. Results show that the shape of the leaf-level ChlF spectra remained largely unaffected by the measurement methodology and geometry in OC and FW methods. Substantially smaller red/far-red ratios were observed in the IS method. The comparison of needle arrangements indicated that needle mats could be a practical solution to investigate temporal changes in ChlF spectra of needle-like leaves as they produced more reproducible results and higher signals.

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Antibacterial and Energy Gap Correlation of PVA/SA Biofilms Doped With Selenium Nanoparticles

Biointerface Research in Applied Chemistry ◽

10.33263/briac105.62366244 ◽

2020 ◽

Vol 10 (5) ◽

pp. 6236-6244

Keyword(s):

Spectral Data ◽

Pathogenic Bacteria ◽

Energy Gap ◽

Selenium Nanoparticles ◽

Structural Variations ◽

Optical Energy Gap ◽

Optical Energy ◽

Spectral Bands ◽

Vis Spectroscopy ◽

Ft Ir

Polymeric thin biofilms of polyvinyl alcohol (PVA)/sodium alginate (SA) doped with a different mass fraction of synthesized selenium nanoparticles were successfully synthesized using traditional solution casting routine. Obtained samples were studied for their structural variations using Fourier transform infrared (FT-IR), and ultravilot/visible (UV/Vis.) spectroscopy. FT-IR spectral data reveals the appearance of spectral bands characterized the functional groups of both PVA and SA structural units in their positions. UV/vis. spectral data was employed to calculate the optical energy gap of prepared samples. Antibacterial tests against pathogenic bacteria were performed and correlated to the optical energy gap.

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