Full title: Preparation of N(SeCl)2+X- (X = SbCl6 or FeCl4), F3CCSeNSeCCF3+SbCl6-, F3CCSeNSeCCF3, F3CCSeNSeCCF3 and F3CCSeSeC(CF3)C(CF3)SeSeCCF3. Electron diffraction study of F3CCSeSeCCF3 and crystal structure of the eight-membered heterocycle F3CCSeSeC(CF3)C(CF3)SeSeCCF3. The salts N(SeCl)2 +SbCl6- 1 and N(SeCl)2 +FeCl4- 2 were synthesized by reaction of SeCl3 + X-(X = SbCl6 or FeCl) with N(SiMe3)3; 1 was also formed by reaction of Se2NCl3 with SbCl5. Reaction of 1 with SnCl2 and F3CCCCF3 led to the formation of F3CCSeNSeCCF3 + SbCl6- 3. In this reaction the Se2N + cation is a likely intermediate because SnCl2 seems to be essential for chloride abstraction in the first reaction step to generate Se2N+ in situ which then adds F3CCCCF3 to yield 3. Compound 3 is a useful building block to generate selenium compounds such as F3CCSeNSeCCF3 4, F3CCSeSeCCF3 5 and F3CCSeSeC(CF3)C(CF3)SeSeCCF3 6. The heterocycle 5 was shown by electron diffraction to have an approximately planar four-membered ring structure. The structure of compound 6 was determined by X-ray crystallography: orthorhombic, space group Pbca, a = 10.1920(21), b = 13.0615(20) and c = 22.050(5) Å. In order to rationalize the structures of 5 and the cation F3CCSeNSeCCF3+, ab initio calculations were made on model compounds in which the CF3 groups were replaced by a fluorine atom (i.e. FCSeSeCF for 5and FCSeNSeCF+ for the cation in 3). In addition, mass spectrometric experiments were performed in order to examine the structures and stabilities of the unligated cation F3CCSeNSeCCF3 + as well as its neutral counterpart. The existence of the neutral radical 4 was established by means of neutralization-reionization mass spectrometry.
|Number of pages||8|
|Journal||Journal of the Chemical Society, Dalton Transactions|
|Publication status||Published - Dec 1 1994|
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