Syntheses and chemistry of hypervalent cyclo-R4Sb4, cyclo-(RSbE)n [R = 2-(Me2NCH2)C6H4, E = O, S] and precursors

Autor: Opris, Laura M., Silvestru, Anca, Silvestru, Cristian, Breunig, Hans J., Lork, Enno
Zdroj: Dalton Transactions; 2004, Vol. 2004 Issue: 21 p3575-3585, 11p
Abstrakt: The cyclostibane R4Sb4 (1) (R = 2-(Me2NCH2)C6H4) was synthesized by reduction of RSbCl2 with Mg in THF or with Na in liquid NH3. The reaction of 1 with [W(CO)5(THF)] gives the stibinidene complex RSb[W(CO)5]2 (2). RSbCl2 and (RSbCl)2E [E = O (6), E = S (8)] react with KOH or Na2S in toluene/water to give the heterocycles (RSbE)n [E = O, n = 3 (3); E = S, n = 2 (4)]. The chalcogeno-bridged compounds of the type (RSbCl)2E [E = O (6), E = S (8)] were synthesized by reaction of RSbCl2 with KOH or Na2S in toluene/water, but also by reaction of RSbCl2 with the heterocycles (RSbE)n. The compounds (RSbI)2O (7) and (RSbBr)2S (9) were prepared via halogen-exchange reactions between (RSbCl)2E and NaI (E = O) or KBr (E = S) or by reactions between RSbI2 and KOH or RSbBr2 and Na2S. The reaction of cyclo-(RSbS)2 with W(CO)5(THF) in THF results in trapping of the cis isomer in cyclo-(RSbS)2[W(CO)5] (5). The solution behaviour of the compounds was investigated by 1H and 13C NMR spectroscopy. The molecular structures of compounds 1–7 and 9 were determined by single-crystal X-ray diffraction.
Databáze: Supplemental Index