(Trifluormethyl)selen(VI)‐Verbindungen, Synthese und Eigenschaften von Tetrafluor(trifluormethyl)selen‐halogeniden sowie Trifluormethanselenonaten

Abstract

Die Fluorierung von CF3SeF3 mit flüssigem Fluor bzw. AgF2 führt zu CF3SeF5 das thermisch in CF4 sowie SeF4 zerfällt und mit H2O zu CF4 und SeOF2 hydrolysiert. Durch Addition von ClF an CF3SeF3 entsteht CF3SeF4Cl, das sich hauptsächlich zu CF3Cl und SeF4 zersetzt. Die Hydrolyse liefert analog CF3Cl und SeOF2. Mit wäßr., gesättigter KMnO4 liefert CF3SeO2H in guter Ausbeute CF3SeO3K, aus dem die freie Säure mit 74proz. HClO4 erhalten wird. Sie läßt sich in wäßriger Lösung bis zu 90% anreichern und zerfällt bei weiterem Konzentrieren spontan zu CF4, COF2 und SeO2. Ihre Salze sind bei Raumtemperatur stabil und explodieren beim Erhitzen.

Chemistry Related to the Catalytic Cycle of the Antioxidant Ebselen

“…Selenonic acids in general have been little studied, but a few have been reported from the further oxidation of the corresponding seleninic acids. Several examples of such oxidations were achieved by using potassium permanganate, followed by perchloric acid to liberate the free selenonic acids from their potassium salts [88][89][90], while several salts of carbohydrate-derived selenonic acids were obtained by using dimethyldioxirane (DMDO) as the oxidant [91]. The selenonic acid derivative of selenocysteine has also been prepared and its x-ray crystal structure was determined [92].…”

Studies on the Properties of Organoselenium(IV) Fluorides and Azides

“…19 F NMR (CD 2 Cl 2 ): δ -94.8 (s, 1 J F-77Se ) 638.1 Hz). 77 (45), 2964 (59), 2910 (49), 2869 (41), 1594 (31), 1570 (12), 1462 (28), 1446 (27), 1382 (39), 1333 (16), 1303 (28), 1264 (29), 1236 (18), 1105 (20), 1062 (12), 1015 (21), 960 (15), 939 (11), 885 (37), 842 (13), 817 (11), 733 (100, νSeC), 650 (14), 606 (26), 520 (21), 488 (34,νSeF) (νSeF) vs cm -1 . 1 H NMR (CDCl 3 ): δ 7.13 (s, m-CH), 1.25-1.05(m).…”

“…19 F NMR (CDCl 3 ): δ -50.9 (s, 1 J F-77Se ) 608.2 Hz). 77 (23), 1459 (54), 1362 (26), 1330 (32), 1252 (18), 1218 (18), 1169 (26), 1153 (28), 1030 (27), 974 (20), 843 (33), 809 (41), 661 (27), 630 (19), 487 (30), 399 (33), 368 (40), 316 (25), 208 (27) cm -1 . IR (KBr): 3415 br, 3054 w, 2953 s, 2867 s, 2829 s, 2787 m, 2632 br, 2464 w, 2431 w, 2043 br, 1834 s, 1468 br, 1301 w, 1237 vs, 1174 w, 1120 w, 1097 w, 1017 s, 977 w, 951 w, 877 m, 839 m, 763 s, 617 m, 511 w, 472 m cm -1 .…”

“…For the Raman measurement, a solution (about 1 mL within three steps) was transferred into a glass NMR tube, and all volatile materials were removed in vacuo at -40 °C, yielding a colorless solid, which quickly decomposes upon warming to ambient temperature. Raman: 2941 (17), 2097 (16)/ 2026 (22, ν as,N3 ), 1216 (15), 1189 (9), 761 (5), 569 (3)/ 564 (6, ν SeC ), 403 (100, ν SeN ), 374 (18), 252 (27), 189 (35), 98 (20) cm -1 . 14 N NMR (CD 2 Cl 2 ): δ -136 (N β ), -190 (N γ ), -248 (N R , br).…”

“…The selenium azides known prior to this study are the ionic selenonium azides of the type [R 3 Se]N 3 (R = Me, Ph), the organoselenium(II) azides RSeN 3 (R = Ph, C 6 F 5 , Mes, 2,4,6-(CF 3 ) 3 C 6 H 2 , Mes*, 2,6-(Mes) 2 C 6 H 3 , 2-Me 2 NCH 2 C 6 H 4 ), of which only 2-Me 2 NCH 2 C 6 H 4 SeN 3 could be isolated at ambient temperature, and recently, also reported by us and others, the binary selenium(IV) azides Se(N 3 ) 4 , Se(N 3 ) 5 − , and Se(N 3 ) 6 2− . In the area of selenium(IV) fluorides of the type R 2 SeF 2 and RSeF 3 , several compounds were reported, – but up to now the only reported crystal structures are of the binary species SeF 4 , SeF 5 − , and SeF 6 2− , as well as of an organoselenium(VI) difluoride . In this contribution, we present a detailed study of organoselenium(IV) fluorides and azides with different substituents.…”