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Full-Text Articles in Chemistry
Analysis Of Copper(Ii) Using The Ascorbate/Oxygen System – A Valuable Undergraduate Resource, Sean Tobin, John Cassidy, Kevin Kurian, Tony Betts
Analysis Of Copper(Ii) Using The Ascorbate/Oxygen System – A Valuable Undergraduate Resource, Sean Tobin, John Cassidy, Kevin Kurian, Tony Betts
Articles
In deionised water, ascorbic acid (AH−), through oxidation by oxygen in the presence of copper(II), was found to degrade with zero-order kinetics. The magnitude of the reaction rate varied directly with the copper(II) concentration. At a higher pH (7.4), the same reaction was found to be pseudo-first order. Once again, the magnitude of the rate increased linearly with copper(II) concentration at a micromolar level. Dissolved oxygen levels, in excess AH− and trace copper(II), displayed similar kinetics under both conditions. Monitoring of either AH− levels or dissolved oxygen concentration was found to be a useful novel undergraduate practical laboratory for trace …
Cu(Ii) Phenanthroline-Phenazine Complexes Dysregulate Mitochondrial Function And Stimulate Apoptosis, Garret Rochford, Zara Molphy, Kevin Kavanagh, Malachy Mccann, Michael Devereux, Andrew Kellett, Orla L. Howe
Cu(Ii) Phenanthroline-Phenazine Complexes Dysregulate Mitochondrial Function And Stimulate Apoptosis, Garret Rochford, Zara Molphy, Kevin Kavanagh, Malachy Mccann, Michael Devereux, Andrew Kellett, Orla L. Howe
Articles
Herein we report an in-depth study on the cytotoxic mechanism of action of four developmental cytotoxic copper(II) complexes: [Cu(phen)2]2+ (Cu-Phen); [Cu(DPQ)(Phen)]2+ (Cu-DPQ-Phen); [Cu(DPPZ)(Phen)]2+; and [Cu(DPPN)(Phen)]2+ (where Phen = 1,10-phenanthroline, DPQ = dipyrido[3,2-f:20,30-h]quinoxaline, DPPZ = dipyrido[3,2-a:20,30-c]phenazine, and DPPN = benzo[i]dipyrido[3,2-a:20,30-c]phenazine). This complex class is known for its DNA intercalative properties and recent evidence—derived from an in vivo proteomic study—supports the potential targeting of mitochondrial function. Therefore, we focused on mitochondrial-mediated apoptosis related to cytotoxic activity and the potential impact these agents have on mitochondrial function. The Cu(II) complexes demonstrated superior activity regardless of aromatic extension within the phenazine ligand to the …
Highly Selective Fluorimetric Turn-Off Detection Of Copper (Ii) By Two Different Mechanisms In Calix[4]Arene-Based Chemosensors And Chemodosimeters, Justine O'Sullivan, John Colleran, Brendan Twamley, Frances Heaney
Highly Selective Fluorimetric Turn-Off Detection Of Copper (Ii) By Two Different Mechanisms In Calix[4]Arene-Based Chemosensors And Chemodosimeters, Justine O'Sullivan, John Colleran, Brendan Twamley, Frances Heaney
Articles
Isoxazolo‐pyrene tethered calix[4]arenes selectively detect copper(II) ions without interference from related perchlorate ions. The fluorescence emission of the probes, synthesised by nitrile oxide alkyne cycloaddition, and characterised by spectroscopic and crystallographic data, is rapidly reduced by Cu(II) ions. Detection limits are in the micromolar or sub‐micromolar range (0.3–3.6 μM) based on a 1 : 1 sensor:analyte interaction. Voltammetric behaviour and 1H NMR data provide new insights into the sensing mechanism which is dependent on the calixarene substitution pattern. When the calixarene lower rim is fully substituted, Cu(II) detection occurs through a traditional chelation mechanism. In contrast, for calixarenes 1,3‐disubstituted on …
Isolation And Spectroscopic Characterization Of Zn(Ii), Cu(Ii), And Pd(Ii) Complexes Of 1,3,4-Thiadiazole-Derived Ligand, Dariusz Karcz, Arkadiusz Matwijczuk, Bozena Boron, Bernadette Creaven, Leszek Fiedor, Andrzej Niewiadomy, Mariusz Gagos
Isolation And Spectroscopic Characterization Of Zn(Ii), Cu(Ii), And Pd(Ii) Complexes Of 1,3,4-Thiadiazole-Derived Ligand, Dariusz Karcz, Arkadiusz Matwijczuk, Bozena Boron, Bernadette Creaven, Leszek Fiedor, Andrzej Niewiadomy, Mariusz Gagos
Articles
A series of complexes incorporating Zn(II), Cu(II), and Pd(II) ions, and 4-(5-heptyl-1,3,4-thiadiazol-2-yl)benzene-1,3-diol (L1) as model ligand, was synthesized in order to examine the nature of potential interactions between biologically active ligands, 1,3,4-thiadiazoles and metal ions with proven biological relevance. The structures of the compounds isolated were characterized using a number of spectroscopic methods including IR, Uv–vis, AAS, steady state and time-resolved fluorescence (TRF). The results obtained suggest that the L1-Zn(II) and L1-Pd(II) complexes consist of one molecule of L1 and one acetate ion acting as ligands, while the L1-Cu(II) complex adapts a 2:1 (L1: metal) stoichiometry. The coordination of L1 …
Quantification Of Copper Content With Laser Induced Breakdown Spectroscopy As A Potential Indicator Of Offal Adulteration In Beef, Maria Piedad Casado-Gavalda, Yash Dixit, David Geulen, Raquel Cama-Moncunill, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Patrick J. Cullen, Carl Sullivan
Quantification Of Copper Content With Laser Induced Breakdown Spectroscopy As A Potential Indicator Of Offal Adulteration In Beef, Maria Piedad Casado-Gavalda, Yash Dixit, David Geulen, Raquel Cama-Moncunill, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Patrick J. Cullen, Carl Sullivan
Articles
Laser induced breakdown spectroscopy (LIBS) is an emerging technique in the field of food analysis which provides various advantages such as minimal sample preparation, chemical free, rapid detection, provision of spatial information and portability. In this study, LIBS was employed for quantitative analysis of copper content in minced beef samples spiked with beef liver over three independent batches. Copper content was determined with graphite furnace atomic absorption spectroscopy (GFAAS) in order to obtain reference values for modelling. Partial least square regression (PLSR) was performed to build a calibration and validation model. A calibration model with a high Rcv2 of 0.85 …