Реферат: The design and synthesis of novel charge-transfer (CT) complexes are of interest for fundamental chemistry and applications to materials science. In addition to the recently described first CT complex with both electron acceptor (A) and donor (D) groups belonging to the 1,2,5-thiadiazole series (1; A: 4-nitro-2,1,3-benzothiadiazole; D: 4-amino-2,1,3-benzothiadiazole), herein novel CT complexes 2 and 3 with 1,2,5-thiadiazoles as both A (4,6-dinitro-2,1,3-benzothiadiazole and [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole) and D (4-amino-2,1,3-benzothiadiazole) were synthesized. The series is completed by complex 4 with [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole as A and phenoxatellurine as D. Structures of complexes 2-4 were characterized by single-crystal X-ray diffraction (XRD), as well as solution and solid-state UV/Vis spectroscopy. Thermodynamics of their formation were obtained by density functional theory (DFT) calculations, their bonding situations were analyzed by quantum theory of atoms in molecules (QTAIM) calculations and dimer model energies of interactions quantified in the framework of the Hirshfeld surface (HS) analysis. With DFT calculations, the largest value of CT between D and A was found for complex 2, with 0.027 e in the XRD structure and 0.150 e in the optimized structure in MeCN. In the UV/Vis spectra, the lambda(max) of the CT bands of 2-4 varied in the range lambda = 517-705 nm. Model energy calculations for 1-4 revealed the importance of both dispersion interactions and hydrogen bonding between D and A as contributors to CT in the crystalline state. In an attempt to enlarge the CT value with bis[1,2,5-thiadiazolo][3,4-b; 3',4'-e]pyrazine as A and 4-amino-2,1,3-benzoselenadiazole as D, an unprecedented 1: 1 addition reaction was observed upon formation of a C-N bond between atom C7 of D and pyrazine atom N4 of A, accompanied by hydrogen atom transfer from C7 to another pyrazine atom N8 (compound 5). According to DFT calculations, the reaction is a multistep process featuring diradical intermediates and hydrogen atom intramolecular migration over four positions. Molecular and crystal structures of 5 (solvate with toluene) were elucidated by XRD and the crystal structure revealed a rather unusual porous framework.

Библиографическая ссылка: Chulanova E.A. , Pritchina E.A. , Malaspina L.A. , Grabowsky S. , Mostaghimi F. , Beckmann J. , Bagryanskaya I.Y. , Shakhova M.V. , Konstantinova L.S. , Rakitin O.A. , Gritsan N.P. , Zibarev A.V.
New Charge-Transfer Complexes with 1,2,5-Thiadiazoles as Both Electron Acceptors and Donors Featuring an Unprecedented Addition Reaction
Chemistry - A European Journal. 2017. V.23. N4. P.852-864. DOI: 10.1002/chem.201604121 WOS Scopus РИНЦ

Даты:

Опубликована online:	13 дек. 2016 г.
Опубликована в печати:	18 янв. 2017 г.

Идентификаторы:

Web of science	WOS:000395752500020
Scopus	2-s2.0-85006710509
РИНЦ	29469622
OpenAlex	W2566325408

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