Synthesis, Spectroscopy, Cyclic Voltammetry, and Magnetic Studies on Nickel(II) Complexes with N2S3 and N2S2 Donor Macrocyclic Ligands

2005 ◽  
Vol 35 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Sulekh Chandra ◽  
Rajiv Kumar
Keyword(s):  
Cyclic Voltammetry ◽  
Macrocyclic Ligands ◽  
Magnetic Studies

Copper (II) complexes of a macrocyclic binucleating ligand which exhibit two-electron oxidation and two-electron reduction. Structure of [Cu2(C24H34N4O2)(CH3OH)2](ClO4)2, a macrocyclic dicopper(II) complex involving coordinated methanol

1987 ◽  
Vol 65 (12) ◽  
pp. 2815-2823 ◽  
Author(s):  
Sanat K. Mandal ◽  
Laurence K. Thompson ◽  
Kamalaksha Nag ◽  
Jean-Pierre Charland ◽  
Eric J. Gabe
Keyword(s):  
Cyclic Voltammetry ◽  
Oxidation State ◽  
Variable Temperature ◽  
Antiferromagnetic Exchange ◽  
Borohydride Reduction ◽  
Magnetic Studies ◽  
Weakly Bound ◽  
Mixed Oxidation ◽  
Binuclear Species ◽  
Electron Reduction

The saturated ligand H2L1, derived by template condensation of 4-methyl-2,6-diformylphenol and 1,3-diaminopropane, followed by borohydride reduction, generates binuclear, antiferromagnetically coupled, copper(II) complexes which exhibit cyclic voltammetry involving two one-electron oxidation steps (E1/2 = 1.1 to 1.2 V, 1.3 to 1.4 V; Pt/CH3CN/SCE) and two one-electron reduction steps (E1/2 = −0.75 to −0.76 V, −0.89 to −0.90 V (GC/DMSO/SCE) with the formation of Cu(III)–Cu(III) and Cu(I)–Cu(I) and mixed oxidation state species. A trinuclear derivative, [Cu2(L1)(CuCl4)], appears to contain a spin-coupled binuclear species bound to a magnetically isolated tetrachlorocuprate(II) entity. The complex [Cu2(L1)(CH3OH)2](ClO4)2 forms brown crystals with a = 8.6516(7), b = 11.6832(9), c = 16.7205(6) Å, β = 92.596(5)°, P21/n, Z = 2, Rf = 0.037 and has a copper–copper separation of 3.088(1) Å and two weakly bound trans-axial methanol molecules (Cu—O, 2.413(4) Å). Variable temperature magnetic studies on [Cu2(L1)(ClO4)2] and [Cu2(L1)](ClO4)2 indicate strong antiferromagnetic exchange (−2J = 824 ± 5cm−1, 827 ± 7cm−1, respectively) in both cases.

MAGNETIC STUDIES OF Clb-COMPOUNDS OF TRANSITION METALS

1971 ◽  
Vol 32 (C1) ◽  
pp. C1-74-C1-75 ◽  
Author(s):  
K. ENDO ◽  
Y. FUJITA ◽  
R. KIMURA ◽  
T. OHOYAMA ◽  
M. TERADA
Keyword(s):  
Transition Metals ◽  
Magnetic Studies

MAGNETIC STUDIES OF FeNdB COMPOSITIONALLY MODULATED THIN FILMS

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-1807-C8-1808
Author(s):  
B. Martinez ◽  
M. A. Moreu ◽  
J. Tejada
Keyword(s):  
Thin Films ◽  
Magnetic Studies

Synthesis, Spectral and Antimicrobial Investigation of 2-(Naphthalenel-ylamino)-2- Phenylacetonitrile and 1, 10-Phenanthroline with Five Divalent Transition Metal Ions

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
Mohammed Al-Amery1 ◽  
Ashraf Saad Rasheed ◽  
Dina A. Najeeb
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Molar Conductance ◽  
Octahedral Geometry ◽  
Mixed Ligand ◽  
Gram Negative Bacteria ◽  
Magnetic Studies ◽  
Gram Positive Bacteria

Five new mixed ligand metal complexes have been synthesized by the reaction of divalent transition metal ions (Hg, Ni, Zn, Cu and Cd) with 2-(naphthalen-l-ylamino)-2-phenylacetonitrile (L1 ) and 1,10-phenanthroline (L2). The coordination likelihood of the two ligands toward metal ions has been suggested in the light of elemental analysis, UV-Vis spectra, FTIR, 1H-NMR, flam atomic absorption, molar conductance and magnetic studies. Results data suggest that the octahedral geometry for all the prepared complexes. Antibacterial examination of synthesized complexes in vitro was performed against four bacterias. Firstly, Gram-negative bacteria namely, Pseudomonas aerugin and Escherichia. Secondly, Gram-positive bacteria namely, Bacillus subtilis, Staphylococcuaurouss. Results data exhibit that the synthesized complexes exhibited more biological activity than tetracycline pharmaceutical.

Exchange-Biasing in a Dinuclear Dysprosium(III) Single-Molecule Magnet with a Large Energy Barrier for Magnetization Reversal

2019 ◽  
Author(s):  
Tian Han ◽  
Marcus J. Giansiracusa ◽  
Zi-Han Li ◽  
You-Song Ding ◽  
Nicholas F. Chilton ◽  
...  
Keyword(s):  
Single Molecule ◽  
Magnetization Reversal ◽  
Energy Barrier ◽  
Magnetic Hysteresis ◽  
Large Energy ◽  
Magnetic Studies ◽  
Bridging Ligands ◽  
Single Molecule Magnet ◽  
Exchange Biasing

A dichlorido-bridged dinuclear dysprosium(III) single-molecule magnet [Dy<sub>2</sub>L<sub>2</sub>(<i>µ</i>-Cl)<sub>2</sub>(THF)<sub>2</sub>] has been made using a diamine-bis(phenolate) ligand, H<sub>2</sub>L. Magnetic studies show an energy barrier for magnetization reversal (<i>U</i><sub>eff</sub>) around 1000 K. Exchange-biasing effect is clearly seen in magnetic hysteresis with steps up to 4 K. <i>Ab</i> initio calculations exclude the possibility of pure dipolar origin of this effect leading to the conclusion that super-exchange <i>via</i> the chloride bridging ligands is important.

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