The ligating properties of 2,5-dimethoxy-1,4-benzoquinone, C8H8O4 1 towards metallic Lewis acids and organometallics in low oxidation states has been investigated. The title compound reacts with Group 4 tetrahalides to give adducts of formula MCl4(C8H8O4) (M = Ti 4a; M = Zr 4b) and (TiCl4)2(C8H8O4) 5. Moreover, bis-cyclopentadienyl derivatives of titanium() (TiCp2L2; L = CO, PMe3) and vanadium() (VCp2) react with 1 affording both 1 : 1 and 2 : 1 derivatives of general formula MCp2(C8H8O4) (M = Ti 10; M = V 7), (MCp2)2(C8H8O4) (M = Ti 11; M = V 6). The molecular structure of 6 has been determined by X-ray diffraction showing the presence of bimetallic units, with two [VCp2] fragments bonded to a quinonoid oxygen atom of a bridging 2,5-dimethoxy-1,4-benzenedialcoholato. The derivatives [(MCp2)2(C8H8O4)][BPh4]n (M = Ti, V; n = 1 12a, b; n = 2 12c, d) have been prepared by oxidation of (MCp2)2(C8H8O4) (M = Ti 11; M = V 6) with a stoichiometric amount of [FeCp2][BPh4]. The reaction of the vanadium derivative VCp2(C8H8O4) 7 with TiCl4 affords the heterobimetallic compound VCp2(C8H8O4)TiCl4 8. The magnetic properties of the 1 : 1 and 2 : 1 species are reported.
|Autori:||F. CALDERAZZO; U. ENGLERT; PAMPALONI G; V. PASSARELLI|
|Titolo:||Synthesis and characterization of mono- and bi-metallic derivatives of Groups 4 and 5 with 2,5-dimethoxy-1,4-benzoquinone|
|Anno del prodotto:||2001|
|Appare nelle tipologie:||1.1 Articolo in rivista|