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1.
Single crystals of (NMe4)(HF2) were obtained during attempted recrystallization of NMe4F from fluoroolefin. X‐ray diffraction data show that (NMe4)(HF2) crystallizes in the orthorhombic space group Pmmn with unit cell dimensions a = 6.535(2), b = 8.688(3), and c = 5.333(2) Å. The symmetric and virtually linear HF2 anions exhibit a short F···F distance of 2.256(2) Å. The both crystal structures of (NMe4)(H2F3) (orthorhombic, Pbca, a = 8.509(1), b = 11.273(2), and c = 14.880(2) Å) and CsH2F3 (orthorhombic, P212121, a = 7.345(3), b = 9.126(4), and c = 11.444(4) Å) contain dihydrogentrifluoride anions, H2F3?, which have a bent shape and F···F distances of 2.30‐2.34Å. 相似文献
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Olga N. Vysochanskaya Dr. Victor A. Brotsman Dr. Alexey A. Goryunkov Dr. Christian G. Feiler Prof. Dr. Sergey I. Troyanov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(11):2338-2341
The carbon cage of buckminsterfullerene Ih-C60, which obeys the Isolated-Pentagon Rule (IPR), can be transformed to non-IPR cages in the course of high-temperature chlorination of C60 or C60Cl30 with SbCl5. The non-IPR chloro derivatives were isolated chromatographically (HPLC) and characterized crystallographically as 1809C60Cl16, 1810C60Cl24, and 1805C60Cl24, which contain, respectively two, four, and four pairs of fused pentagons in the carbon cage. High-temperature trifluoromethylation of the chlorination products with CF3I afforded a non-IPR CF3 derivative, 1807C60(CF3)12, which contains four pairs of fused pentagons in the carbon cage. Addition patterns of non-IPR chloro and CF3 derivatives were compared and discussed in terms of the formation of stabilizing local substructures on fullerene cages. A detailed scheme of the experimentally confirmed non-IPR C60 isomers obtained by Stone–Wales cage transformations is presented. 相似文献
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Natalia A. Romanova Maria A. Fritz Dr. Kaichin Chang Dr. Nadezhda B. Tamm Dr. Alexey A. Goryunkov Prof. Lev N. Sidorov Dr. Chuanbao Chen Prof. Shangfeng Yang Prof. Erhard Kemnitz Prof. Sergey I. Troyanov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(35):11707-11716
Trifluoromethylation of a higher fullerene mixture with CF3I was performed in ampoules at 550 °C. HPLC separation followed by crystal growth and X‐ray diffraction study resulted in the structure elucidation of nine CF3 derivatives of D2d‐C84 (isomer 23). The molecular structures of C84(23)(CF3)4, C84(23)(CF3)8, C84(23)(CF3)10, C84(23)(CF3)12, two isomers of C84(23)(CF3)14, two isomers of C84(23)(CF3)16, and C84(23)(CF3)18 were discussed in terms of their addition patterns and the relative formation energies. Extensive theoretical DFT calculations were performed to identify the most stable molecular structures. It was found that the addition of CF3 groups to the C84(23) fullerene is governed by two main rules: no additions in positions of triple hexagon junctions and predominantly para additions in C6(CF3)2 hexagons on the fullerene cage. The only exception with an isolated CF3 group in C84(23)(CF3)12 is discussed in more detail. 相似文献
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Nataliya A. Samoylova Nikita M. Belov Victor A. Brotsman Dr. Ilya N. Ioffe Dr. Natalia S. Lukonina Dr. Vitaliy Yu. Markov Dr. Adrian Ruff Alexey V. Rybalchenko Paul Schuler Olesya O. Semivrazhskaya Prof. Dr. Bernd Speiser Prof. Dr. Sergey I. Troyanov Prof. Dr. Tatiana V. Magdesieva Dr. Alexey A. Goryunkov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(52):17969-17979
Novel difluoromethylenated [70]fullerene derivatives, C70(CF2)n (n=1–3), were obtained by the reaction of C70 with sodium difluorochloroacetate. Two major products, isomeric C70(CF2) mono‐adducts with [6,6]‐open and [6,6]‐closed configurations, were isolated and their homofullerene and methanofullerene structures were reliably determined by a variety of methods that included X‐ray analysis and high‐level spectroscopic techniques. The [6,6]‐open isomer of C70(CF2) constitutes the first homofullerene example of a non‐hetero [70]fullerene derivative in which functionalisation involves the most reactive bond in the polar region of the cage. Voltammetric estimation of the electron affinity of the C70(CF2) isomers showed that it is substantially higher for the [6,6]‐open isomer (the 70‐electron π‐conjugated system is retained) than the [6,6]‐closed form, the latter being similar to the electron affinity of pristine C70. In situ ESR spectroelectrochemical investigation of the C70(CF2) radical anions and DFT calculations of the hyperfine coupling constants provide evidence for the first example of an inter‐conversion between the [6,6]‐closed and [6,6]‐open forms of a cage‐modified fullerene driven by an electrochemical one‐electron transfer. Thus, [6,6]‐closed C70(CF2) constitutes an interesting example of a redox‐switchable fullerene derivative. 相似文献
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Structures of Chlorinated Fullerenes,IPR C96Cl20 and Non‐classical C94Cl28 and C92Cl32: Evidence of the Existence of Three New Isomers of C96 下载免费PDF全文
Prof. Dr. Shangfeng Yang Tao Wei Song Wang Dr. Ilya N. Ioffe Prof. Dr. Erhard Kemnitz Prof. Dr. Sergey I. Troyanov 《化学:亚洲杂志》2014,9(11):3102-3105
Chlorination of various HPLC fractions of C96 with a mixture of VCl4 and SbCl5 at 340–360 °C and single‐crystal X‐ray diffraction study of the products led to the identification of three new IPR isomers of C96. The C96(175) isomer forms a stable chloride, C96(175)Cl20, while chlorides of two other new isomers, C96(114) and C96(80), undergo cage shrinkage yielding C94(NC1)Cl28 and C96(NC2)Cl32 with non‐classical (NC) cages. These two NC chlorides contain, respectively, one and two heptagons flanked by pairs of fused pentagons and are stabilized by chlorine attachment to the emerging pentagon–pentagon junctions. Thus, the number of the experimentally confirmed C96 isomers has reached nine, which corroborates the empirical rule that the C6n fullerenes exhibit particularly rich isomerism. 相似文献
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Transalkylation of Higher Trifluoromethylated Fullerenes with C70: A Pathway to New Addition Patterns of C70(CF3)8 下载免费PDF全文
Nikita M. Belov Marina G. Apenova Alexey V. Rybalchenko Eugenia V. Borkovskaya Dr. Natalia S. Lukonina Dr. Alexey A. Goryunkov Dr. Ilya N. Ioffe Prof. Dr. Sergey I. Troyanov Prof. Dr. Lev N. Sidorov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(4):1126-1133
We report three new isomers of C70(CF3)8, structurally related to p7mp‐C70(CF3)10, that are inaccessible by direct trifluoromethylation, but can be easily identified among the products of the transalkylation of higher trifluoromethylfullerenes with C70. The reported compounds are characterized by UV/Vis, 1 D and 2 D COSY 19F NMR spectroscopy, and DFT calculations. A rather unusual addition pattern is observed in p6,i‐C70(CF3)8 in which one addend is attached remotely from the others; polarization of the adjacent unsaturated bonds by the addend makes the molecule readily oxidizable. 相似文献
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