The reactions of dialkyl sulfones [R2SO2: R = Me (a), Et (b), Ph (c), R2 = -(CH2)4- (d)J with the metal tetrachlorides of Group 4 [MCl4,: M = Ti (1), Zr(2), Hf (3)] give different products mainly depending on the sulfone/M molar ratio. Compounds of formula [M2Cl8(R2SO2)2] [M = Ti, R2 = -(CH2)4- (1d); M = Zr, R = Et (2b), R = Ph (2c)] and [MCl4(R2SO2)2 (sulfone/M = 2) [M = Ti, R = Me (1aa); M = Zr, R = Me (2aa), R = Ph (2cc), R2 = -(CH2)4- (2dd); M = Hf, R = Me (3aa), R2 = -(CH2)4- (3dd)] have been obtained. By X-ray diffraction methods the dinuclear titanium and zirconium adducts, [Ti 2Cl8(μ-sulfolane-O,O′)2] (Id) and [Zr2Cl8(μ-Ph2SO2-O,O') 2] (2c) have been established to contain bridging sulfone and hexacoordinated metal centres, while the mononuclear zirconium complex [ZrCl4(Me2SO2)2] (2aa) has cis-monodentate sulfones in a slightly distorted octahedral geometry. The reaction between TiCl4 and sulfolane (tetrahydrothiophene 1,1-dioxide) in SOCl2 affords the 1:1 adduct independent of the sulfone/Ti molar ratio. Ligand-exchange and inter-conversion between mononuclear and dinuclear species have been observed by NMR, while the spectral features of the SO2 moiety have been assigned by IR- and Raman spectroscopies.
|Autori:||BIAGINI P; CALDERAZZO F; MARCHETTI F; PAMPALONI G; RAMELLO S; SALVALAGGIO M; SANTI R; SPERA S|
|Titolo:||Mono- and dinuclear complexes of sulfones with the tetrachlorides of group 4|
|Anno del prodotto:||2004|
|Digital Object Identifier (DOI):||10.1039/b405871b|
|Appare nelle tipologie:||1.1 Articolo in rivista|