A TRIS-(MU-2-I) FACE-SHARING DIZIRCONIUM(III) COMPLEX, [1,4-ZR2I7(PET3)2]- - THE 1ST SUCH DIZIRCONIUM SPECIES

We report here the first example of a [1,4-Zr2X7L2]- species, in the c ompound [NBu4][Zr2I7(PEts)2]. It was prepared by reduction of ZrI by H Sn(n-Bu)3 followed by addition of [NBu4]I and PEt3, all reagents being used in the correct stoichiometric ratio. The yield was c. 17%. X-ray crystallography showed that the anion is a face-sharing bioctahedron with a Zr-Zr distance of 3.171(3) angstrom and it is concluded that th ere is a Zr-Zr sigma bond. The compound forms monoclinic crystals in s pace group P2(1)/m (No. 11) with a = 11.577(1), b = 12.808(1), c = 16. 860(1) angstrom, beta = 98.78(1)-degrees, V = 2470.6(6) angstrom3 and Z = 2. With 167 parameters refined on 1603 reflections having F2>3sigm a(F2) the final R factors were R=6.14% and R(w) = 7.37%.