Crown ether complexes of titanium(IV) chloride and bromide and the structures of the hydrolysis products Ti2Cl6(mu-O)(18-crown-6)(2) and Ti4Cl8(mu-O)(4)(15-crown-5)(4)

Levason, William, Popham, Michael C., Reid, Gillian and Webster, Michael (2003) Crown ether complexes of titanium(IV) chloride and bromide and the structures of the hydrolysis products Ti2Cl6(mu-O)(18-crown-6)(2) and Ti4Cl8(mu-O)(4)(15-crown-5)(4). Dalton Transactions, (3), 291-294. (doi:10.1039/b210012f).

Abstract

The titanium(IV) complexes of 12-crown-4, 15-crown-5 and 18-crown-6 and of 1,4-dithia-7,10,13-trioxacyclopentadecane (L') of type [TiX4(eta(2)-L)] (X = Cl or Br, L = 15-crown-5 or 18-crown-6; X = Br, L = 12-crown-4) and [TiCl4(L')] have been prepared from TiX4 and the ligands in anhydrous toluene, and characterised by analysis, IR, UV-visible and H-1 NMR spectroscopy. Complexes with TiI4 do not form under similar conditions. The [TiCl4(L')] complex contains the thia-oxa-crown coordinated via sulfur to the titanium. The complexes are extremely readily hydrolysed and examples of the first two stages of the hydrolysis have been characterised by X-ray crystallography. These are the dimer [(18-crown-6)Cl3Ti(mu-O)TiCl3(18-crown-6)] which contains a single non-linear oxo-bridge linking two six-coordinate titanium centres also coordinated eta(2) to 18-crown-6 and to three (mer) chlorines. The second product is the tetrameric [{TiOCl2(15-crown-5)}(4)] in which there is an eight-membered ring composed of alternating Ti and O, each titanium also coordinated eta(2) to 15-crown-5 and two terminal (cis) chlorines.

This record has no associated files available for download.

Contributors

Author: William Levason

Author: Gillian Reid

Download statistics