Dinuclear Cu(II) 1,2,3-Triazole-Bridged Complex with Ferromagnetic Coupling

2013 ◽  
Vol 66 (9) ◽  
pp. 1029 ◽  
Author(s):  
Shi-Qiang Bai ◽  
Lu Jiang ◽  
Jing-Lin Zuo ◽  
Chun-Hua Yan ◽  
T. S. Andy Hor

A new dinuclear Cu(ii) complex [Cu2Cl4(L1)2] (1) (L1 = 1-(2-picolyl)-4-hexyl-1H-1,2,3-triazole) has been synthesised and characterised by single-crystal X-ray diffraction (XRD) and powder XRD, thermogravimetric analysis, electron paramagnetic resonance spectrum, photoluminescence, and magnetic measurements. Complex 1 shows double 1,2,3-triazoles bridging the dinuclear Cu2N4 moiety, in which the bridging N=N bond indicates basal-apical asymmetric mode with 112.6° torsion angle of Cu–N=N–Cu. Different from most azole-bridged dinuclear Cu(ii) with antiferromagnetic couplings, complex 1 shows an intramolecular weak ferromagnetic interaction (J = 0.91 cm–1).

2016 ◽  
Vol 09 (03) ◽  
pp. 1650039 ◽  
Author(s):  
Jingyuan Piao ◽  
Li-Ting Tseng ◽  
Kiyonori Suzuki ◽  
Jiabao Yi

Na-doped ZnO nanorods have been fabricated through a hydrothermal method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses indicate that the d spacing of ZnO increases with increasing doping concentration, suggesting the effective incorporation of dopant Na in the samples. Electron paramagnetic resonance (EPR) measurements indicate that there are shallow donors in pure ZnO samples and the shallow donors are strongly prohibited by Na doping. In addition, the resonance at g = 2.005 suggests the formation of Zn vacancies. Magnetic measurements indicate that pure ZnO is paramagnetic and Na doping leads to ferromagnetism at room temperature. Moreover, 0.5% Na-doped ZnO nanorods exhibits the largest saturation magnetization.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2123
Author(s):  
Maria Râpă ◽  
Maria Stefan ◽  
Paula Popa ◽  
Dana Toloman ◽  
Cristian Leostean ◽  
...  

The electrospun nanosystems containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and 1 wt% Fe doped ZnO nanoparticles (NPs) (with the content of dopant in the range of 0–1 wt% Fe) deposited onto polylactic acid (PLA) film were prepared for food packaging application. They were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), antimicrobial analysis, and X-ray photoelectron spectrometry (XPS) techniques. Migration studies conducted in acetic acid 3% (wt/wt) and ethanol 10% (v/v) food simulants as well as by the use of treated ashes with 3% HNO3 solution reveal that the migration of Zn and Fe falls into the specific limits imposed by the legislation in force. Results indicated that the PLA/PHBV/ZnO:Fex electrospun nanosystems exhibit excellent antibacterial activity against the Pseudomonas aeruginosa (ATCC-27853) due to the generation of a larger amount of perhydroxyl (˙OOH) radicals as assessed using electron paramagnetic resonance (EPR) spectroscopy coupled with a spin trapping method.


2007 ◽  
Vol 555 ◽  
pp. 95-100
Author(s):  
D. Milivojević ◽  
Jovan Blanuša ◽  
V. Spasojević ◽  
V. Kusigerski ◽  
B. Babić-Stojić

Zn-Mn-O semiconductor crystallites with nominal manganese concentration x = 0.01, 0.02, 0.04 and 0.10 were synthesized by a solid state reaction route using oxalate precursors. Thermal treatment procedure was carried out in air at different temperatures in the range 400 - 900°C. The samples were investigated by X-ray diffraction, magnetization measurements and electron paramagnetic resonance. X-ray analysis reveals that dominant crystal phase in the Zn-Mn-O system corresponds to the wurtzite structure of ZnO. Room temperature ferromagnetism is observed in the Zn-Mn-O samples with lower manganese concentration, x ≤ 0.04, thermally treated at low temperature (500°C). Saturation magnetization in the sample with x = 0.01 is found to be 0.05 μB/Mn. The ferromagnetic phase seems to be developed by Zn diffusion into Mn-oxide grains.


1996 ◽  
Vol 03 (01) ◽  
pp. 853-855 ◽  
Author(s):  
A. KASUYA ◽  
H. IWASAKI ◽  
Y. SAITO ◽  
M. OKUDA ◽  
H. TAKAHASHI ◽  
...  

Graphitic polyhedrons encaging YC 2 of 30–70 nm in diameter have been synthesized by an arc-discharge method. Our measurements identify that YC 2 crystallizes in a body-centered tetragonal and becomes type-II superconductor below 3.9 K. The transition temperature shows very small size dependence, and is nearly equal to previous measurements on bulk YC 2 in vacuum. Although YC 2 is hygroscopic, our samples yield reliable and reproducible experimental results in our electron microscope, x-ray diffraction, paramagnetic resonance, and magnetization measurements in air under magnetic field up to 3000 Oe and temperatures down to 1.7 K.


2012 ◽  
Vol 217-219 ◽  
pp. 737-740
Author(s):  
Han Jie Huang

In this work, a visible light-induced LaVO4/TiO2 composite has been characterized by powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and spin-trapping electron paramagnetic resonance (EPR) to reveal the structure and visible light photocatalytic mechanism for the decompostion of benzene in gas-phase. Based on the experimental results, a visible light-induced photochemical processes on LaVO4/TiO2 are proposed and elucidated.


2014 ◽  
Vol 02 (02) ◽  
pp. 114-120
Author(s):  
Tanguturi Ravindra Reddy ◽  
Krishnan Thyagarajan ◽  
Ovidio Almanza Montero ◽  
Sanapa Reddy Lakshmi Reddy ◽  
Tamio Endo

2017 ◽  
Vol 10 (02) ◽  
pp. 1650077 ◽  
Author(s):  
Spartak S. Khutsishvili ◽  
Nikolay I. Tikhonov ◽  
Marina V. Lesnichaya ◽  
Gania Dolmaa ◽  
Tamara I. Vakul’skaya ◽  
...  

A novel comparative study of paramagnetic properties of new silver- and gold-containing nanocomposites based on humic substances, extracted from medicinal muds, brown coal and shale deposits of Mongolia, has been carried out by electron paramagnetic resonance (EPR) spectroscopy. The change in the paramagnetic properties of metal nanocomposites obtained after metal introduction as compared with the starting substances has been found out. The dependence of stability, antioxidant activity and spin density on the nature and mass content of metal in the nanocomposites has been determined. Metal-containing nanocomposites are characterized by cw-EPR, X-ray diffraction (XRD) and atomic absorption analysis. It is shown that the resulting magnetic bioactive nanocomposites are stable for a long period thus suggesting their prospective use in medicine.


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