1236036-62-6Relevant articles and documents
Preparation and reactivity of mono- and dinuclear derivatives of niobium and tantalum pentahalides with alkyl aryl ethers
Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
, p. 767 - 774 (2010)
The niobium and tantalum pentahalides MX5 (X = F, Cl) react with a series of bifunctional alkyl aryl ethers in a 2:1 ratio, resulting in formation of the dinuclear species (MX5)2[μ- κ2-(O-O)] [2a-h, 3a-d; O-O = 1,4-(OMe)2C 6H4, 1,4-(OMe)2-2,5C6H 2F2, 1,3-(OMe)2C6H4, PhO(CH2)2OPh]. The mononuclear complexes MX5(L) [L = κ1-1,4-(OMe)2C6H4, X = F, M = Nb, 4a; L = κ2-1,3-(OMe)2C6H 4, X = Cl, M = Ta, 4c; L = MeOC6H5, X = F, M = Nb, 4d; L = MeOC6H5, X = Cl, M = Nb, 4e] have been prepared, by 1:1 molar reactions of MX5 with the appropriate reactant. Alternatively, NbCl5[κ1-1,4-(OMe) 2C6H4] (4b) has been obtained upon addition of acetone to (NbCl5)2-[μ-κ2-1,4-(OMe) 2C6H4] (2b). The aryloxide complexes TaBr 4[κ1-OC6H4(4-OMe)] (5a), NbCl4[κ1-OC6H3(Me)(4-OEt)] (5b) and TaX4[K2-OC6H4(2-OMe)] (X = Cl, 7a; X = Br, 7b) form an admixture with equimolar amounts of alkyl halide by addition of dialkoxyarenes to MX5 (X = Cl, Br), as result of room-temperature C-O bond cleavage. Differently, the ionic species [MF 4(κ2-O-O)2][M2F11] [O-O = 1,2-(OMe)2C6H4, M = Nb, 6a; O-O = 1,2-(OMe)2C6H4, M = Ta, 6b; O-O = 1,2,4(OMe)3C6H3, M = Nb, 6c] are produced cleanly by treating oriho-dimethoxyarenes with MF5 in the opportune stoichiometry. All the products described herein were obtained selectively in good to excellent yields and were characterized by spectroscopic and analytical techniques. Moreover, the molecular structure of 2b was elucidated by an X-ray diffraction study.
