Thallium(I) derivatives of monocyclopentadienylbis(arene-1,2-dithiolato)titanium, Tl[Ti(?5-C5HnMe5-n)-(S 2C6H3R)2 (1-6; n = 0, 4 or 5; R = H or Me), have been synthesised and isolated in yields of 31-65% from reactions of the corresponding trichloromonocyclopentadienyltitanium reagents, Ti(?5-C5HnMe5-n)Cl3 and thallium salts of the benzene- 1,2-dithiol or toluene-3,4-dithiol in tetrahydrofuran. Reaction between Tl[Ti(?5-C5Me5)(1,2-S2C 6H4)2] and bis(triphenylphosphine)iminium chloride, [N(PPh3)2]Cl, has also afforded the derivative [N(PPh3)2][Ti(?5-C5Me 5)(1,2-S2C6H4)2] 7. Products have been characterised by elemental analysis, NMR, IR and mass spectroscopy, and by X-ray diffraction. The structure of 7, in the crystalline state as a tris(dichloromethane) solvate, comprises an ionic lattice containing discrete [Ti(?5-C5Me5)(1,2-S2C 6H4)2]- anions of four-legged piano stool geometry with two chelating benzene-1,2-dithiolate ligands folded along the S ? S axis in exo and endo conformations, respectively, relative to the cyclopentadienyl ring. The crystal structure of Tl[Ti(?5-C5Me5)(S2C 6H4)2] 1 contains two forms of the anion [Ti(?5-C5Me5)(S2C 6H4)]- in endolendo and endolexo conformations, respectively, which are unsymmetrically co-ordinated to the TlI cations. A TlI ion is connected by two Tl-S bonds to endo dithiolate ligands of each anion and there is also one Tl-S interaction between pairs of endolendo and endolexo forms. Additional weaker Tl ? S interactions to the TlI ions generate a linked chain of dimeric units. In solution, NMR spectra suggest a more symmetrical structure for all derivatives but shifts in resonances support the retention of co-ordinate links between the cyclopentadienylbis(arene-1,2-dithiolato)titanium anion and TlI.
|Number of pages||6|
|Journal||Journal of the Chemical Society, Dalton Transactions|
|Publication status||Published - 21 May 1998|