Structural and magnetic studies of a zigzag chain copper(II) complex and a dipolar spin-coupled copper(II) dimer with the versatile ligand 5-[(2-carboxyphenyl)azo]-1,3-dimethylbarbituric acid

Author(s):  
Enrique Colacio ◽  
José Ruiz ◽  
José M. Moreno ◽  
Raikko Kivekäs ◽  
Markku R. Sundberg ◽  
...  
2014 ◽  
Vol 70 (8) ◽  
pp. 754-757 ◽  
Author(s):  
Judith Caballero-Jiménez ◽  
Yasmi Reyes Ortega ◽  
Sylvain Bernès ◽  
Roberto Escudero

The title complex,catena-poly[di-μ3-acetato-κ6O:O:O′-tetra-μ2-acetato-κ4O:O;κ4O:O′-diaquabis(pyridine-κN)trimanganese(II)], [Mn3(CH3COO)6(C6H5N)2(H2O)2]n, is a true one-dimensional coordination polymer, in which the MnIIcentres form a zigzag chain along [010]. The asymmetric unit contains two metal centres, one of which (Mn1) lies on an inversion centre, while the other (Mn2) is placed close to an inversion centre on a general position. Since all the acetates behave as bridging ligands, although with different μ2- and μ3-coordination modes, a one-dimensional polymeric structure is formed, based on trinuclear repeat units (Mn1...Mn2...Mn2′), in which the Mn2 and Mn2′ sites are related by an inversion centre. Within this monomeric block, the metal–metal separations are Mn1...Mn2 = 3.36180 (18) Å and Mn2...Mn2′ = 4.4804 (3) Å. Cation Mn1, located on an inversion centre, displays an [MnO6] coordination sphere, while Mn2, on a general position, has a slightly stronger [MnO5N] ligand field, as the sixth coordination site is occupied by a pyridine molecule. Both centres approximate an octahedral ligand field. The chains are parallel in the crystal structure and interactviahydrogen bonds involving coordinated water molecules. However, the shortest metal–metal separation between two chains [5.3752 (3) Å] is large compared with the intrachain interactions. These structural features are compatible with a single-chain magnet behaviour, as confirmed by preliminary magnetic studies.


2010 ◽  
Vol 63 (11) ◽  
pp. 1565 ◽  
Author(s):  
Qing-Yan Liu ◽  
Yu-Ling Wang ◽  
Zi-Yi Du ◽  
Zeng-Mei Shan ◽  
Er-Lei Yang ◽  
...  

{[Cu4(µ3-OH)2(SIP)2(imz)2]·(H2O)2}n (1) and {[Zn3(µ2-OH2)2(SIP)2(phen)3(H2O)3]·(H2O)5}n (2) were obtained under hydrothermal conditions (SIP = 5-sulfoisophthalate, imz = imidazole, and phen = 1,10-phenanthroline). Compound 1 features a novel 3D network based on tetranuclear [Cu4(µ3-OH)2] secondary building unit; its topological structure is similar to that of rutile. Compound 2 is a 1D zigzag chain containing dinuclear [Zn2(µ2-OH2)2(phen)2] and mononuclear [Zn(phen)(H2O)] units. Variable-temperature magnetic studies reveal the existence of dominant ferromagnetic interactions within the tetranuclear copper(ii) cluster in compound 1. Further magnetic measurements indicate that compound 1 has the zero-field splitting parameters D = –0.29 cm–1 and E = 0.00052 cm–1, and g = 2.11 based on ST = 2. Compound 2 exhibits a blue fluorescence emission band at 458 nm on excitation at 391 nm, with a lifetime of 5.78 ns.


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

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

Author(s):  
Mohammed Al-Amery1 ◽  
Ashraf Saad Rasheed ◽  
Dina A. Najeeb

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.


2019 ◽  
Author(s):  
Tian Han ◽  
Marcus J. Giansiracusa ◽  
Zi-Han Li ◽  
You-Song Ding ◽  
Nicholas F. Chilton ◽  
...  

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.


2018 ◽  
Vol 10 (5) ◽  
pp. 05005-1-05005-5
Author(s):  
I. D. Stolyarchuk ◽  
◽  
I. Rogalska ◽  
S. V. Koretskii ◽  
I. Stefaniuk ◽  
...  

1982 ◽  
Vol 53 (3) ◽  
pp. 1888-1890 ◽  
Author(s):  
C. P. Landee ◽  
R. D. Willett ◽  
F. Waldner

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