A novel sulfur-nitrogen 蟺-heterocyclic radical anion, (6H-1,2,3-benzodithiazol-6-ylidene)malononitrilidyl, and its homo- and heterospin salts

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• 作者：Alexander Yu. Makarov^a ; Elena A. Chulanova^b ; ^c ; Nikolay A. Semenov^a ; Nikolay A. Pushkarevsky^c ; ^d ; Anton V. Lonchakov^b ; Artem S. Bogomyakov^e ; Irina G. Irtegova^a ; Nadezhda V. Vasilieva^a ; Enno Lork^f ; Nina P. Gritsan^b ; ^g ; ^{gritsan@kinetics.nsc.ru" class="auth_mail} ; Sergey N. Konchenko^c ; ^d ; Victor I. Ovcharenko^e ; Andrey V. Zibarev^a ; ^g ; ^{zibarev@nioch.nsc.ru" class="auth_mail}
• 关键词：Radical anions ; Sulfur&ndash ; nitrogen heterocycles ; X-ray diffraction ; EPR spectroscopy ; DFT calculations ; Cyclic voltammetry ; Magnetic properties
• 刊名：Polyhedron
• 出版年：18 April, 2014
• 年：2014
• 卷：72
• 期：Complete
• 页码：43-49
• 全文大小：1230 K

文摘

(6H-1,2,3-Benzodithiazol-6-ylidene)malononitrile (4) was electrochemically and chemically reduced with tetrakis(dimethylamino)ethylene (TDAE) and CrTol₂ into the title radical anion (5). The electrochemically generated 5 and its salts [TDAE]²⁺[5]₂ (7) and [CrTol₂]⁺ [5] (8) were characterized by solution EPR in combination with UV-Vis spectroscopy. Salts 7 and 8 were isolated and characterized by elemental analysis and solid-state EPR, and 8 by magnetic measurements in the temperature range 2-300 K. The value of the effective magnetic moment of the salt 8 at 300 K, 渭_eff = 1.64 渭_B, indicates 蟺-dimerization of 5 in the solid state. For the molar magnetic susceptibility 蠂 of 8, the temperature dependences of 蠂T and 1/蠂 in the range 2-300 K can be approximated by the Curie-Weiss law with the Curie-Weiss constant C and temperature T_c equal to 0.33 卤 0.01 cm³ K mol^鈭? and 鈭?.0 卤 0.1 K, respectively. In the mean-field approximation, the effective value of the exchange interaction of [CrTol₂]⁺ with its neighboring cations can be estimated as zJ = 鈭?.4 褋m^鈭?. All the experimental results were supported by DFT calculations.