70 research outputs found
Supplementary data for the article: Uraev, A. I.; Nefedov, S. E.; Lyssenko, K. A.; Vlasenko, V. G.; Ikorskii, V. N.; Garnovskii, D. A.; Makarova, N. I.; Levchenkov, S. I.; Shcherbakov, I. N.; Milenković, M. R.; Borodkin, G. S. Synthesis, Structure, Spectroscopic Studies and Magnetic Properties of Cu2N2O4-, Cu2N2O2(S2)-, Cu2N2S4-Chromophores Based on Aminomethylene Derivatives of Pyrazole-5-One(Thione). Polyhedron 2020, 188, 114623. https://doi.org/10.1016/j.poly.2020.114623
Supplementary material for: [https://doi.org/10.1016/j.poly.2020.114623]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4221
Synthesis and properties of the heterospin (S1 = S2 = 1/2) radical-ion salt bis(mesitylene)molybdenum(I) [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazolidyl
The authors are grateful to the Presidium of the Russian Academy of Sciences (Project 8.14), the Royal Society (RS International Joint Project 2010/R3), the Leverhulme Trust (Project IN-2012-094), the Siberian Branch of the Russian Academy of Sciences (Project 13), the Ministry of Education and Science of the Russian Federation (Project of Joint Laboratories of Siberian Branch of the Russian Academy of Sciences and National Research Universities), and the Russian Foundation for Basic Research (Projects 13-03-00072 and 15-03-03242) for financial support of various parts of this work. N.A.S. thanks the Council for Grants of the President of Russian Federation for postdoctoral scholarship (grant MK-4411.2015.3). B.E.B. is grateful for an EaStCHEM Hirst Academic Fellowship. A.V.Z. thanks the Foundation named after D. I. Mendeleev, Tomsk State University, for support of his work.Low-temperature interaction of [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole (1) with MoMes2 (Mes = mesitylene / 1,3,5-trimethylbenzene) in tetrahydrofuran gave the heterospin (S1 = S2 = 1/2) radical-ion salt [MoMes2]+[1]– (2) whose structure was confirmed by single-crystal X-ray diffraction (XRD). The structure revealed alternating layers of the cations and anions with the Mes ligands perpendicular, and the anions tilted by 45°, to the layer plane. At 300 K the effective magnetic moment of 2 is equal to 2.40 μB (theoretically expected 2.45 μB) and monotonically decreases with lowering of the temperature. In the temperature range 2−300 K, the molar magnetic susceptibility of 2 is well-described by the Curie-Weiss law with parameters C and θ equal to 0.78 cm3⋅K⋅mol–1 and −31.2 K, respectively. Overall, the magnetic behavior of 2 is similar to that of [CrTol2]+[1]– and [CrCp*2]+[1]–, i.e. changing the cation [MAr2]+ 3d atom M = Cr (Z = 24) with weak spin-orbit coupling (SOC) to a 4d atom M = Mo (Z = 42) with stronger SOC does not affect macroscopic magnetic properties of the salts. For the XRD structure of salt 2, parameters of the Heisenberg spin-Hamiltonian were calculated using the broken-symmetry DFT and CASSCF approaches, and the complex 3D magnetic structure with both the ferromagnetic (FM) and antiferromagnetic (AF) exchange interactions was revealed with the latter as dominating. Salt 2 is thermally unstable and slowly loses the Mes ligands upon storage at ambient temperature. Under the same reaction conditions, interaction of 1 with MoTol2 (Tol = toluene) proceeded with partial loss of the Tol ligands to afford diamagnetic product.PostprintPostprintPeer reviewe
Magnetic behavior of Co(II) chloride monocrystal with 1-allyltetrazole
Magnetic anisotropy of the single crystal of the
cobalt(ii) chloride complex with 1 allyltetrazole (alltz)
Co(alltz)Cl was studied. Types of magnetic ordering and easy and
hard magnetization axes were determined, their relationship with
crystallographic axes was established. The Co(alltz)Cl complex
is a weak ferromagnet with T K and possesses spontaneous
magnetization (4.5) = 1320 G cm mol.
Hysteresis effects, depending on the intensity of the magnetic field in
which the sample was cooled, were detected.
Key words. Molecular magnets, single crystal, cobalt(II),
tetrazole
Molecular magnets based on metal complexes with spin-labeled imidazoles
New heterospin systems based on Cu(II) and Mn(II)
complexes with spin-labeled imidazol-4-yl derivatives were synthesized.
Magneto-structural correlations inherent in their nature were investigated.
Key words. Nitroxides – metal complexes – structure – magnetic
properties
Structural peculiarities of phase transitions in heterospin systems
New heterospin complexes of metal
hexafluoroacetylacetonates with pyrazole-substituted nitronyl nitroxides
were synthesized and structurally characterized. For all compounds, detail
X-ray investigations (Smart Apex diffractometer, Bruker AXS) in the
temperature range 100-300 K were performed. It has been shown that the
temperature range of magnetic phase transition coincided with the the
temperature range of density changing. Movements of atoms in the course of
phase transitions have been analized.
Key words. Nitroxides – copper(II) complexes – structure – phase
transitio
Magnetic phenomena in nonrigid metal-nitroxide systems
For NiL heterospin bischelates, stereochemical
nonrigidity in solution has been found, which leads to solids with varying
structure and composition. While investigating the products of
Cu(hfac) interaction with spin-labeled pyrazole
4,4,5,5-tetramethyl-2-(1-methyl-1H-pyrazol-4-yl)-imidazoline-3-oxide-1-oxyl
we have isolated a family of heterospin compounds differing in the structure
and composition in the solid state. In synthetic systems, these compounds
often co-crystallize and must be separated mechanically. It is also shown
that minor variations in the structure of solid heterospin complexes
substantially change the magnetic properties of the compounds.
Key words. Nitroxides - metal complexes – structure - magnetic
properties
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