Synthesis of N,N-dialkylcarbamato complexes of Group 4 metals (Ti, Zr, Hf) by the metal chloride–NHR<sub>2</sub>–CO<sub>2</sub>system (R = Et or Pr<sup>i</sup>): crystal and molecular structure of [Hf(O<sub>2</sub>CNPr<sup>i</sup><sub>2</sub>)<sub>4</sub>]
作者:Fausto Calderazzo、Sandra Ianelli、Guido Pampaloni、Giancarlo Pelizzi、Martin Sperrle
DOI:10.1039/dt9910000693
日期:——
The compounds [M(O2CNR2)4] (M = Ti, Zr or Hf; R = Et or Pr) have been prepared by treating the corresponding metal tetrachloride with CO2-NHR2 in toluene. The structure of [Hf(O2CNPr2i)4] has been solved by X-ray diffraction methods. Crystal data: monoclinic, space group P2(1)/c, a = 12.756(3), b = 22.131(9), c = 14.548(5) angstrom, beta = 113.03(2)-degrees and Z = 4. It consists of monomeric units, the hafnium atom being surrounded by the eight oxygen atoms of the four N,N-diisopropylcarbamato groups in a slightly distorted dodecahedral arrangement. By reaction with anhydrous hydrogen halides HX (X = Cl, Br or l) the hexahalogenometalate(iv) anions, [MX6]2-, as the diethylammonium derivatives, have been obtained in high yields. The redox reaction between [Ti(O2CNEt2)4] and [V(eta-C5Me5)2] gives the titanium(III) and vanadium(III) complexes [Ti(O2CNEt2)3}n] and [V(eta-C5Me5)2(O2CNEt2)], respectively.