Cyclopentadienyl–diethylcarbamato derivatives of zirconium(IV) and hafnium(IV), [M(C5H5)(O2CNEt2)3]: synthesis and use as precursors for chemical implantation on a silica surface

Abstract

Reaction of Mg(C₅H₅)₂ with the homoleptic diethylcarbamato derivatives of zirconium(IV) or hafnium(IV), M(O₂CNEt₂)₄, gave the mixed cyclopentadienyl–diethylcarbamato complexes [M(C₅H₅)(O₂CNEt₂)₃]. These derivatives have also been obtained by reaction of Fe(O₂CNEt₂)₂ with M(C₅H₅)₄ in the appropriate stoichiometric ratio. The compound [Zr(C₅H₅)(O₂CNEt₂)₃] crystallizes in the space group P, Z = 2, a = 9.734(4), b = 10.234(2), c = 12.948(6) Å; α = 83.41(4), β = 86.13(4) and γ = 67.43(3)°. On reaction of [Zr(C₅H₅)(O₂CNEt₂)₃] with dehydrated silica, 1 mol of CO₂ per zirconium was evolved. The organometallic fragment Zr(C₅H₅)(O₂CNEt₂)₂ grafted on silica has been characterized by analytical methods and by CP MAS ¹³C NMR spectroscopy.