In:
European Journal of Inorganic Chemistry, Wiley, Vol. 2004, No. 6 ( 2004-03), p. 1175-1182
Abstract:
The title compound [(μ‐CH 2 )(ZrCp 2 Me) 2 ] ( 4 ) was prepared by the reaction of [Cp 2 Zr(Cl)Me] ( 6 ) with CH 2 (MgBr) 2 ( 5 ) or (CH 2 Mg) n ( 7 ). It had been expected that the carbon atom bridging the two zirconium atoms of 4 might be a candidate for a planar tetracoordinate carbon atom, but the X‐ray crystal structures of two different modifications (crystals 1 and 2) showed it to be non‐planar; however, the widened Zr−C−Zr angle of 132.7(1) and 134.0(3)°, respectively, and an unsymmetrical coordination of the central μ‐CH 2 group (average: Zr1−CH 2 2.225 Å, Zr2−CH 2 2.242 Å) indicates a tendency towards planarity. While 4 is relatively stable in THF solution, it disproportionates in toluene solution to give the 1,3‐dizirconacyclobutane (Cp 2 ZrCH 2 ) 2 ( 8 ) and [Cp 2 ZrMe 2 ] ( 9 ), especially in the presence of magnesium salts; a tentative mechanism is presented. Reaction of 4 with B(C 6 F 5 ) 3 yielded the methyl‐bridged cationic complex 17 , which, on treatment with trityl chloride, was transformed into the corresponding chloro complex 18 ; the latter was characterized by an X‐ray crystal structure determination. With THF and tetrahydrothiophene, 17 formed the unsymmetrical adducts 19a and 19b , respectively; NMR spectroscopic data revealed dynamic symmetrization due to methyl‐group exchange at 280 and 213 K, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Type of Medium:
Online Resource
ISSN:
1434-1948
,
1099-0682
DOI:
10.1002/ejic.v2004:6
DOI:
10.1002/ejic.200300754
Language:
English
Publisher:
Wiley
Publication Date:
2004
detail.hit.zdb_id:
1475009-0
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