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,

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• 作者：Nikolay A. Pushkarevsky ; Nikolay A. Semenov ; Alexey A. Dmitriev ; Natalia V. Kuratieva ; Artem S. Bogomyakov ; Irina G. Irtegova ; Nadezhda V. Vasilieva ; Bela E. Bode ; Nina P. Gritsan ; Lidia S. Konstantinova ; J. Derek Woollins ; Oleg A. Rakitin ; Sergey N. Konchenko ; Victor I. Ovcharenko ; Andrey V. Zibarev
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：July 20, 2015
• 年：2015
• 卷：54
• 期：14
• 页码：7007-7013
• 全文大小：397K
• ISSN：1520-510X

文摘

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]^{鈭?/sup> (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掳, to the layer plane. At 300 K the effective magnetic moment of 2 is equal to 2.40 渭_B (theoretically expected 2.45 渭_B) and monotonically decreases with lowering of the temperature. In the temperature range 2鈥?00 K, the molar magnetic susceptibility of 2 is well-described by the Curie鈥揥eiss law with parameters C and 胃 equal to 0.78 cm3 K mol鈥? and 鈭?1.2 K, respectively. Overall, the magnetic behavior of 2 is similar to that of [CrTol₂]+[1]鈭?/sup> and [CrCp*₂]+[1]鈭?/sup>, i.e., changing the cation [MAr₂]+ 3d atom M = Cr (Z = 24) with weak spin鈥搊rbit 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.}