Heterospin π-Heterocyclic Radical-Anion Salt: Synthesis, Structure, and Magnetic Properties of Decamethylchromocenium [1,2,5]Thiadiazolo[3,4-c][1,2,5]thiadiazolidyl

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• 作者：Nikolay A. Semenov ; Nikolay A. Pushkarevsky ; Anton V. Lonchakov ; Artem S. Bogomyakov ; Elena A. Pritchina ; Elizaveta A. Suturina ; Nina P. Gritsan ; Sergey N. Konchenko ; Ruediger Mews ; Victor I. Ovcharen
• 刊名：Inorganic Chemistry
• 出版年：2010
• 出版时间：August 16, 2010
• 年：2010
• 卷：49
• 期：16
• 页码：7558-7564
• 全文大小：898K
• 年卷期：v.49,no.16(August 16, 2010)
• ISSN：1520-510X

文摘

Decamethylchromocene, Cr^II(η⁵-C₅(CH₃)₅)₂ (2), readily reduced [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole (1) in a tetrahydrofuran solvent at ambient temperature with the formation of radical-anion salt [2]⁺[1]⁻ (3) isolated in 97% yield. The heterospin salt 3 ([2]⁺, S = ³/₂; [1]⁻, S = ¹/₂) was characterized by single-crystal X-ray diffraction as well as magnetic susceptibility measurements in the temperature range 2−300 K. The experimental data together with theoretical analysis of the salt’s magnetic structure within the CASSCF and spin-unrestricted broken-symmetry (BS) density functional theory (DFT) approaches revealed antiferromagnetic (AF) interactions in the crystalline 3: significant between anions [1]⁻, weak between cations [2]⁺, and very weak between [1]⁻ and [2]⁺. Experimental temperature dependences of the magnetic susceptibility and the effective magnetic moment of 3 were very well reproduced in the assumption of the AF-coupled [1]⁻···[1]⁻ (J₁ = −40 ± 9 cm⁻¹) and [2]⁺···[2]⁺ (J₂ = −0.58 ± 0.03 cm⁻¹) pairs. The experimental J₁ value is in reasonable agreement with the value calculated using BS UB3LYP/6-31+G(d) (−61 cm⁻¹) and CASSCF(10,10)/6-31+G(d) (−15.3 cm⁻¹) approaches. The experimental J₂ value is also in agreement with that calculated using the BS DFT approach (−0.33 cm⁻¹).