Coordination of Halide and Chalcogenolate Anions to Heavier 1,2,5-Chalcogenadiazoles: Experiment and Theory
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- 作者：Nikolay A. Semenov ; Anton V. Lonchakov ; Nikolay A. Pushkarevsky ; Elizaveta A. Suturina ; Valery V. Korolev ; Enno Lork ; Vladimir G. Vasiliev ; Sergey N. Konchenko ; Jens Beckmann ; Nina P. Gritsan ; Andrey V. Zibarev
- 刊名：Organometallics
- 出版年：2014
- 出版时间：August 25, 2014
- 年：2014
- 卷：33
- 期：16
- 页码：4302-4314
- 全文大小：603K
- ISSN：1520-6041
文摘
New products of coordination of anions X鈥?/sup> (X = F, I, PhS) to the Te atom of 3,4-dicyano-1,2,5-telluradiazole (1) were synthesized in high yields and characterized by X-ray diffraction (XRD) as the salts [(Me2N)3S]+[1-F]鈭?/sup> (9), [K(18-crown-6)]+[1-I]鈭?/sup> (10), and [K(18-crown-6)]+[1-SPh]鈭?/sup>路THF (11), respectively. In the crystal lattice of 10, I atoms are bridging between two Te atoms. The bonding situation in anions of the salts 9鈥?b>11 and some other adducts of 1,2,5-chalcogenadiazoles (chalcogen = S, Se, Te) and anions X鈥?/sup> (X = F, Cl, Br, I, PhS) was studied using DFT, QTAIM, and NBO calculations, for 9鈥?b>11 in combination with UV鈥搗is, IR/Raman, and MS-ESI techniques. In all cases, the nature of the coordinate bond is negative hyperconjugation involving the transfer of electron density from X鈥?/sup> to the heterocycles. The energy of the bonding interaction varies in a range from 鈭?0 kcal mol鈥? comparable with energies of weak chemical bonds (e.g., internal N鈥揘 bond in organic azides) to 鈭?6 kcal mol鈥?/b>1 comparable with an energy of the C鈥揅 covalent bonds. The thermodynamics of the anions鈥?coordination to 1 and their Se and S congeners was also studied by quantum chemical calculations. The general character of this reaction and favorable thermodynamics in the case of heavier chalcogens (Se, Te) were established. Comparison with available data on acyclic analogues, i.e. the chalcogen diimines RN鈺怷鈺怤R, reveals that they also coordinate various anions but in addition reactions across X鈺怤 (X = S, Se, Te) double bonds. Attempts to prepare the anion [1-TePh]鈭?/sup> led to disintegration of 1. The only unambiguously identified product was a rather rare tellurocyanate that was characterized by XRD and elemental analysis as the salt [K(18-crown-6)]+[TeCN]鈭?/sup> (13).