Organometall‐Oxide — Höhervalente Derivate der d‐Metall‐Säuren, 6. Tris(3,5‐dimethyl‐1‐pyrazolyl)boranato‐substituierte Alkyl(dioxo)1‐, Methylenphosphoranyl(dioxo)1‐ und s1‐Allyl(dioxo)1‐Komplexe des Molybdäns und Wolframs

Abstract

Organometallic Oxo Complexes — Highervalent Derivatives of the d‐Metal Acids, 6. — Hydrotris(3,5‐dimethyl‐1‐pyrazolyl)borato‐Substituted Alkyl(dioxo)1‐, Methylenephosphoranyl(dioxo)1‐, and s̀1‐Allyl(dioxo) Complexes of Molybdenum and Tungsten Tp*MoO 2 Cl ( 1 ) and Tp*WO 2 Cl ( 2 ) [Tp* = κ 3 1‐HB(3,5‐Me 2 pz) 3 ] react with trimethyl aluminium to form the corresponding dioxo(methyl) complexes Tp*MO 2 (CH 3 ), MMo ( 3 ), W ( 4 ). An X‐ray crystal structure analysis of 3 is performed. The less oxidizing tungsten complex 2 is alkylated by Grignard reagents to yield alkyl complexes of the type Tp*WO 2 R 5–7 [RCH 2 SiMe 3 , CH 2 t Bu and CH 2 C(Me)Ph 2 ] and the s̀1‐2‐methallyl complex Tp*WO 2 (CH 2 CMeCH 2 ) 8 . Reactions of 2 with methylenephorphoranes R 3 PCH 2 (R i Pr, Ph) give transylidation products Tp*WO 2 (CHP i Pr 3 ) ( 9 ) and Tp*WO 2 (CH‐PPh 3 ) ( 10 ). Hydrolysis of 10 leads to a trioxotungstate [Tp*WO 3 ] – ( 11 ), stabilized by a hydroxyphosphonium cation.