Magnetic and Spectroscopic Studies on Copper(II) and Chromium(III) Complexes With Sulfur Chelating Ligands

1986 ◽  
Vol 39 (4) ◽  
pp. 605 ◽  
Author(s):  
AC Fabretti ◽  
C Preti ◽  
L Tassi ◽  
G Tosi ◽  
P Zannini
Keyword(s):  
Magnetic Moment ◽  
Spectroscopic Studies ◽  
Chelating Ligands ◽  
Conductivity Measurements ◽  
Bonding Parameters ◽  
Ligand Interactions ◽  
Different Temperatures ◽  
Metal Ligand

A number of complexes of chromium(III) and copper(II) with heterocyclic dithiocarbamate ligands is reported. The newly prepared compounds are characterized on the basis of near- i.r . and far- i.r . spectroscopy, electronic and e.p.r . spectra, conductivity measurements and magnetic moment studies at different temperatures. The dithio ligands exhibit bidentate behaviour acting as S,S′-donors in all the complexes. The chromium(III) compounds have g values in the 1.991-1.999 range and nephelauxetic parameters indicative of an appreciable metal- ligand covalency. The e.p.r . data of the copper(II) derivatives provide parameters typical of sulfur coordination in planar CuS4 chromophores ; the α bonding parameters are indicative of strongly covalent metal- ligand interactions.

scholarly journals Metal–ligand interactions in complexes of cyclen-based ligands with Bi and Ac

2021 ◽  
Author(s):  
Attila Kovács ◽  
Zoltán Varga
Keyword(s):  
Basis Sets ◽  
Ring Size ◽  
Complex Stability ◽  
Chelating Ligands ◽  
Ligand Interactions ◽  
Bonding Properties ◽  
State Method ◽  
Targeting Vector ◽  
Pendant Arms ◽  
Metal Ligand

AbstractThe structural and bonding properties of Bi and Ac complexes with cyclen-based chelating ligands have been studied using relativistic DFT calculations in conjunction with TZ2P all-electron basis sets. Besides the parent cyclen ligand, the study has covered its extensions with pyridine-type (Lpy), carboxylate (DOTA, DOTPA), picolinate (MeDO2PA) and phosphonate (DOTMP) pendant arms. The effect of the cyclen ring size has been probed by increasing it from [12]aneN4 to [16]aneN4. Additional extensions in the DOTA complexes included the H2O ligand at the 9th coordination site as well as the p-SCN-Bn substituent (a popular linker to the targeting vector). The study focuses on the complex stability, the nature of bonding and the differences between Ac and Bi in the complexes. The metal–ligand interactions have been analysed by the Extended Transition State method combined with Natural Orbitals of Chemical Valence theory and Quantum Theory of Atoms in Molecules models.

scholarly journals Different manifestations of enhanced π-acceptor ligation at every redox level of [Os(9-OP)L2]n, n = 2+, +, 0, − (9-OP− = 9-oxidophenalenone and L = bpy or pap)

2016 ◽  
Vol 45 (45) ◽  
pp. 18241-18251 ◽  
Author(s):  
Arijit Singha Hazari ◽  
Alexa Paretzki ◽  
Jan Fiedler ◽  
Stanislav Zalis ◽  
Wolfgang Kaim ◽  
...  
Keyword(s):  
Donor And Acceptor ◽  
Ligand Interactions ◽  
Redox Level ◽  
Metal Ligand

Enhanced metal–ligand and ligand–ligand interactions are promoted in an osmium complex with non-innocent donor and acceptor ligands.

Residual Magnetic Moment Influences the Features of Fe3s XPS Spectrum: A Case Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Ranjan K Sahu
Keyword(s):  
Magnetic Moment ◽  
Magnetic Domain ◽  
Anomalous Behavior ◽  
Spectral Features ◽  
Different Temperatures ◽  
Magnetic Origin ◽  
Xps Study ◽  
Increasing Temperature ◽  
Curie Temperature Tc

Background: Fe 3sXPS spectrumexhibits doublet peak instead of predicted singlet peak based on spin-orbit coupling theory. This anomalous behavior is considered to be magnetic origin. However, the effect of residual magnetic moment to the features of Fe3s doublet peakis not understood fully. Objective: This study aims to verify the effect of residual magnetic moment on the spectral features of Fe3s XPS spectrum of magnetic material. Method: As a case study, we have carried out a high temperature XPS study of the Fe 3s spectrum of magnetic domain aligned (MDA) sample with composition composed of SrFe10.8Al1.2O19. In addition, the XPS data have been compared with the data acquired at different temperatures of magnetic domain non-aligned (MDNA) sample. Results: The results show that the majority peak intensity and minority peak width of Fe 3s spectrum of MDA are smaller than those of the MDNA sample, and they increase systematically with increasing temperature. However, it is noted that the features of Fe3s spectrum of both MDA and MDNA samples are completely overlapped near and above the Curie temperature, Tc ~ 670K. Conclusion: The analysis of XPS data suggests that the residual magnetic moment influences the spectral features of Fe3s spectrum. These results provide evidences that it is important to consider the contribution of residual magnetic moment while deriving information from Fe 3s XPS spectrum of MDA sample.

scholarly journals Reversible Assembly of Terpyridine Incorporated Norbornene-Based Polymer via a Ring-Opening Metathesis Polymerization and Its Self-Healing Property

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1173 ◽  
Author(s):  
Jookyeong Lee ◽  
Hwi Moon ◽  
Keewook Paeng ◽  
Changsik Song
Keyword(s):  
Ring Opening ◽  
Transition Metal Ions ◽  
Self Healing ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
Ligand Interactions ◽  
Healing Agent ◽  
Healing Property ◽  
External Stimuli ◽  
Metal Ligand

We induced a terpyridine moiety into a norbornene-based polymer to demonstrate its self-healing property, without an external stimulus, such as light, heat, or healing agent, using metal–ligand interactions. We synthesized terpyridine incorporated norbornene-based polymers using a ring-opening metathesis polymerization. The sol state of diluted polymer solutions was converted into supramolecular assembled gels, through the addition of transition metal ions (Ni2+, Co2+, Fe2+, and Zn2+). In particular, a supramolecular complex gel with Zn2+, which is a metal with a lower binding affinity, demonstrated fast self-healing properties, without any additional external stimuli, and its mechanical properties were completely recovered.

scholarly journals Plasmonic Resonant Nanoantennas Induce Changes in the Shape and the Intensity of Infrared Spectra of Phospholipids

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 62
Author(s):  
Fatima Omeis ◽  
Zahia Boubegtiten-Fezoua ◽  
Ana Filipa Santos Seica ◽  
Romain Bernard ◽  
Muhammad Haseeb Iqbal ◽  
...  
Keyword(s):  
Spectral Properties ◽  
Field Enhancement ◽  
Spectroscopic Studies ◽  
Biological Molecules ◽  
Future Application ◽  
Spectral Signature ◽  
Electric Field Enhancement ◽  
Low Concentrations ◽  
Surface Enhanced ◽  
Different Temperatures

Surface enhanced infrared absorption spectroscopic studies (SEIRAS) as a technique to study biological molecules in extremely low concentrations is greatly evolving. In order to use the technique for identification of the structure and interactions of such biological molecules, it is necessary to identify the effects of the plasmonic electric-field enhancement on the spectral signature. In this study the spectral properties of 1,2-Dipalmitoyl-sn-glycero-3 phosphothioethanol (DPPTE) phospholipid immobilized on gold nanoantennas, specifically designed to enhance the vibrational fingerprints of lipid molecules were studied. An AFM study demonstrates an organization of the DPPTE phospholipid in bilayers on the nanoantenna structure. The spectral data were compared to SEIRAS active gold surfaces based on nanoparticles, plain gold and plain substrate (Si) for different temperatures. The shape of the infrared signals, the peak positions and their relative intensities were found to be sensitive to the type of surface and the presence of an enhancement. The strongest shifts in position and intensity were seen for the nanoantennas, and a smaller effect was seen for the DPPTE immobilized on gold nanoparticles. This information is crucial for interpretation of data obtained for biological molecules measured on such structures, for future application in nanodevices for biologically or medically relevant samples.

scholarly journals Synthesis and characterization of novel metal complexes of (pentulose-?-lactone-2,3-enedibenzoate barbituric acid) with some metal ions

2013 ◽  
Vol 10 (3) ◽  
pp. 597-606
Author(s):  
Baghdad Science Journal
Keyword(s):  
Atomic Absorption ◽  
Magnetic Moment ◽  
Sodium Methoxide ◽  
Barbituric Acid ◽  
Molar Conductivity ◽  
Alkaline Media ◽  
Synthesis And Characterization ◽  
Conductivity Measurements ◽  
Vis Spectroscopy

New (pentulose-?-lactone-2,3-enedibenzoate barbituric acid) (L) have been synthesized by reaction of (5-C-dimethyl malonyl-pentulose-?-lactone-2,3-enedibenzoate) with urea in alkaline media (sodium methoxide). (Ca+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2 and Hg+2) complexes of (pentulose-?-lactone-2,3-enedibenzoate barbituric acid) (L) have been prepared and characterized by (1H and 13CNMR), FTIR, (U.V-Vis) spectroscopy, Atomic absorption spectrophotometer (A.A.S), Molar conductivity measurements and Magnetic moment measurements, and the following general formula has been given for the prepared complexes [MLCl2(H2O)].XH2O, where M = (Ca+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2, Hg+2), X = five molecules with (Cd+2) complex, L = (pentulose-?-lactone-2,3-enedibenzoate barbituric acid).

Metal–ligand interactions in Fe(II)-dioxime complexes

2008 ◽  
Vol 867 (1-3) ◽  
pp. 1-4 ◽  
Author(s):  
Balázs Krámos ◽  
Attila Kovács
Keyword(s):  
Ligand Interactions ◽  
Metal Ligand
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