New organolanthanide complexes containing a σ-bonded 1,3-dithiane. Crystal structures of [M(C5H4But)2(C4H7S2-1,3)]·LiCl·2thf (M = Lu or Y; thf = tetrahydrofuran)

Abstract

New complexes of Y and Lu have been synthesized and fully characterized by single-crystal X-ray analysis: [M(C₅H₄Bu^t)₂(C₄H₇S₂-1,3)]·LiCl·2thf (M = Lu 1 or Y 2, thf = tetrahydrofuran). Both complexes crystallize from pentane at 0 °C. The crystal of 1 has space group P with a= 11.489(4), b= 14.438(6), c= 20.217(4)Å, α= 94.16(3), β= 89.76(2) and γ= 97.58(3)°. Least-square refinements based on 5881 reflections [l > 2.0σ(I)] converged to a final R= 0.072. Complex 2 crystallizes in orthorhombic unit cell and space group Pbca with a= 14.744(6), b= 21.148(7) and c= 21.472(6)Å. Least-squares refinement based on 1570 reflections [l > 2.0σ(I)] converged to a final R= 0.081. The complexes contain the anion of 1,3-dithiane included into a pentagonal co-ordination ring formed by M (Lu or Y), C, S, Li and Cl atoms. 1,3-Dithiane is σ bonded to the metal (Y or Lu) through the 2-carbon atom. Proton and ¹³C NMR spectra suggest high conformational stability of the 1,3-dithiane ring in solution at room temperature. The complexes react with protonic acids such as water, NH(SiMe₃)₂ and HCCPh releasing free 1,3-dithiane and forming corresponding cyclopentadienyl derivatives.