SYNTHESIS OF NOVEL MANGANESE-BASED SINGLE-MOLECULE NANOMAGNETS

2002 ◽  
Vol 01 (05n06) ◽  
pp. 455-459 ◽  
Author(s):  
JINKWON KIM ◽  
HAENGKYU CHO ◽  
AHKILESH K. GUPTA ◽  
JIN MOOK LIM ◽  
YOUNGKYU DO

New Mn12 single-molecule nanomagnets [ Mn 12 O 12( O 2 CCHCl 2)( H 2 O )4]· 2CH 2 Cl 2· H 2 O and [ Mn 12 O 12( O 2 CCHCl 2)( H 2 O )4]· 2CH 3 C 6 H 5· 4H 2 O and novel Mn18 complexes [ M 18 O 14( O 2 CR )18( hmp )4( hmpH )2( H 2 O )2] (R=Me, Et) have been synthesized and characterized by single crystal X-ray crystallography and dc- and ac-magnetic susceptibility measurements. Mn12 complexes show characteristic SMM properties, such as temperature-dependent out-of-phase ac-susceptibility. Mn18 does not show relaxation behaviors down to 2.0 K, but reveals magnetic anisotropy in reduced magnetization experiment.

2013 ◽  
Vol 68 (9) ◽  
pp. 971-978 ◽  
Author(s):  
Inga Schellenberg ◽  
Ute Ch. Rodewald ◽  
Christian Schwickert ◽  
Matthias Eul ◽  
Rainer Pöttgen

The ternary antimonides RE4T7Sb6 (RE=Gd-Lu; T =Ru, Rh) have been synthesized from the elements by arc-melting and subsequent annealing in an induction furnace. The samples have been characterized by powder X-ray diffraction. Four structures were refined on the basis of single-crystal X-ray diffractometer data: U4Re7Si6 type, space group Im3m with a=862.9(2) pm, wR2=0.0296, 163 F2 values for Er4Ru7Sb6; a=864.1(1) pm, wR2=0.1423, 153 F2 values for Yb4Ru7Sb6; a=872.0(2) pm, wR2=0.0427, 172 F2 values for Tb4Rh7Sb6; and a=868.0(2) pm, wR2=0.0529, 154 F2 values for Er4Rh7Sb6, with 10 variables per refinement. The structures have T1@Sb6 octahedra and slightly distorted RE@T26Sb6 cuboctahedra as building units. The distorted cuboctahedra are condensed via all trapezoidal faces, and this network leaves octahedral voids for the T1 atoms. The ruthenium-based series of compounds was studied by temperature-dependent magnetic susceptibility measurements. Lu4Ru7Sb6 is Pauli-paramagnetic. The antimonides RE4Ru7Sb6 with RE=Dy, Ho, Er, and Tm show Curie-Weiss paramagnetism. Antiferromagnetic ordering occurs at 10.0(5), 5.1(5) and 4.0(5) K for Dy4Ru7Sb6, Ho4Ru7Sb6 and Er4Ru7Sb6, respectively, while Tm4Ru7Sb6 remains paramagnetic. Yb4Ru7Sb6 is an intermediate-valent compound with a reduced magnetic moment of 3.71(1) μB per Yb as compared to 4.54 μB for a free Yb3+ ion


2017 ◽  
Vol 72 (7) ◽  
pp. 511-515 ◽  
Author(s):  
Sebastian Stein ◽  
Lukas Heletta ◽  
Rainer Pöttgen

AbstractGdCuMg has been synthesized by induction-melting of the elements in a sealed niobium ampoule followed by annealing in a muffle furnace. The sample was studied by powder and single crystal X-ray diffraction: ZrNiAl type, P6̅2m (a=749.2(4), c=403.3(1) pm), wR2=0.0242, 315 F2 values and 15 variables. Temperature dependent magnetic susceptibility measurements have revealed an experimental magnetic moment of 8.54(1) μB per Gd atom. GdCuMg orders ferromagnetically below TC=82.2(5) K and based on the magnetization isotherms it can be classified as a soft ferromagnet.


1999 ◽  
Vol 602 ◽  
Author(s):  
H. Sato ◽  
T. Enoki ◽  
K. Wakiya ◽  
M. Isobe ◽  
Y. Ueda ◽  
...  

AbstractA comprehensive study of transport properties and magnetism on β-MnO2 reveals the strong coupling between the conduction electrons and the localized spins which are supposed to form a magnetic helix below TN ∼ 92 K. We also show the direct evidences of the helical magnetism by means of the measurements of the anisotropy in the magnetic susceptibility and the observation of x ray magnetic scatterings on a single crystal of β-MnO2. These results are consistent with proper-type helix model proposed by Yoshimori [J. Phys. Soc. Jpn. 14, p. 807 (1959)]. This model also qualitatively agrees with the anisotropy in magnetoresistance that appears below TN. The pitch of the magnetic helix is not commensurate to the lattice and it is slightly temperature dependent. The intensity of several Bragg peaks drastically changes at TN suggesting that the magnetic ordering is accompanied by a lattice distortion.


2013 ◽  
Vol 68 (11) ◽  
pp. 1191-1197 ◽  
Author(s):  
Bastian Reker ◽  
Bernard Chevalier ◽  
Oliver Niehaus ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen

The ternary stannides PrZnSn and NdZnSn were synthesized by induction-melting of the elements in sealed tantalum tubes. They were characterized by powder and single-crystal X-ray diffraction: YPtAs-type structure, P63=mmc, a = 455:4(1) and c = 1650:3(2) pm, wR2=0.0266, 297 F2 for PrZnSn and a = 453:7(1) and c = 1637:0(4) pm, wR2=0.1558, 234 F2 for NdZnSn with 12 variables per refinement. PrZnSn and NdZnSn are AlB2 superstructures with slightly puckered and ordered [Zn3Sn3] hexagons in AA´BB´ stacking sequence along the crystallographic c axis. Hydrogenation results in the new hexagonal hydrides PrZnSnH1:5 (a = 447:98(8) and c = 1707:5(5) pm) and NdZnSnH1:5 (a = 448:28(8) and c = 1689:8(2) pm). Filling of RE3Zn tetrahedra by hydrogen leads to anisotropic changes of the lattice parameters and a drastic flattening of the [Zn3Sn3] layers. Temperature-dependent magnetic susceptibility measurements show Curie-Weiss behavior for PrZnSn and NdZnSn with experimental magnetic moments close to the free-ion values of RE3+. Magnetic ordering is detected at 4.7 (PrZnSn) and 6:5 K (NdZnSn). Hydrogenation induces ferromagnetism with increased ordering temperatures of 12.0 (PrZnSnH1:5) and 14:5 K (NdZnSnH1:5).


2021 ◽  
Author(s):  
Emil Andreasen Klahn ◽  
Andreas Munch Thiel ◽  
Rasmus B. Degn ◽  
Iurii Kibalin ◽  
Arsen Gukasov ◽  
...  

We present the magnetic anisotropy of two isostructural pentagonal-bipyramidal complexes, [Ln(H2O)5(HMPA)2]I3.2HMPA (HMPA=hexamethylphosphoramide, Ln=Dy, Ho). Using ac magnetic susceptibility measurements, we find magnetic relaxation barriers of 600 K and 270 K...


1983 ◽  
Vol 38 (4) ◽  
pp. 426-427 ◽  
Author(s):  
Arndt Simon ◽  
Karl Peters ◽  
Harry Hahn

Abstract The structure of the title compound has been determined by X-ray crystallography. The title compound is synthesized from the elements at 600 °C. Its crystal structure, derived from powder data [3] is refined by single crystal diffractometer data. The structure is trigonal (P3̅ml, α = 684.1(1), c = 724.4(1) pm); Pd2+ cations and PS43- anions form a network with an anti-Claudetite (AS2O3) type structure. The PS4 units are distinctly distorted from ideal tetrahedral symmetry. The Pd atoms have a planar environment of 4 S atoms.


2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Stergios Zanias ◽  
Giannis S. Papaefstathiou ◽  
Catherine P. Raptopoulou ◽  
Konstantinos T. Papazisis ◽  
Vasiliki Vala ◽  
...  

As part of our interest into the bioinorganic chemistry of gallium, gallium(III) complexes of the azole ligands 2,1,3-benzothiadiazole (btd), 1,2,3-benzotriazole (btaH), and 1-methyl-4,5-diphenylimidazole (L) have been isolated. Reaction of btaH or btd withGaBr3orGaCl3resulted in the mononuclear complexes[GaBr3(btaH)2](1) and[GaCl3(btd)2](2), respectively, while treatment ofGaCl3with L resulted in the anionic complex(LH)2[GaCl4](3). All three complexes were characterized by single-crystal X-ray crystallography and IR spectroscopy, while their antiproliferative activities were investigated against a series of human and mouse cancer cell lines.


2012 ◽  
Vol 16 (01) ◽  
pp. 154-162 ◽  
Author(s):  
Edwin W.Y. Wong ◽  
Daniel B. Leznoff

The reduction of magnesium phthalocyanine (MgPc) with 2.2 equivalents of potassium graphite in 1,2-dimethoxyethane (DME) gives [K2(DME)4]PcMg(OH)(1) in 67% yield. Compound 1 was structurally characterized using single crystal X-ray crystallography and was found to be a monomeric, heterometallic complex consisting of a μ3-OH ligand that bridges a [MgIIPc3-]- anion to two potassium cations solvated by four DME molecules. An absorption spectrum of 1 confirms the Pc ligand is singly reduced and has a 3–charge. The solid-state structure of 1 does not indicate breaking of the aromaticity of the Pc ligand. Compound 1 is only the second Pc3- complex and the first reduced MgPc to be isolated and structurally characterized.


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