NEW HALOTUNGSTEN(- SYNTHESIS OF THE FIRST FLUOROTUNGSTEN(+VI) CARBYNECOMPLEX(VII) CARBYNES FORMED BY CHLORINATION OXIDATION )

Carbonyl carbyne complexes [L(R)CO)(2)W=C-p-tol], containing the tripo dal oxygen ligands L(R)(-)=[(C5H5)Co(P(O)R(2))(3)](-), R = OMe, (OPr)- Pr-i, are oxidised by iodobenzene dichloride (PhICl(2)) to yield the c hloro carbyne complexes [L(R)Cl(2)W=C-p-tol]. The reaction of the carb onyl carbyne complexes [L(R)CO)(2)Mo=C-p-tol] with PhICl(2) leads to t he molybdenum complexes [(L(OMe)MoCl(2)](2)] and [L(R)MoCl(4)], R = OM e, (OPr)-Pr-i. Treatment of [L(OMe)Cl(2)W=C-p-tol] with [Me(3)SnF] aff ords [L(OMe)F(2)W=C-p-tol], the first example of a Schrock carbyne com plex bearing fluoride ligands. In order to test the reactivity of the new fluoro carbyne complex, reactions with NaOEt and Me(3)SiNMe(2) hav e been performed. With NaOEt both fluoro ligands in [L(OMe)F(2)W=C-p-t ol] are substituted to yield [L(OMe)(OEt)(2)W=C-p-tol]. With Me(3)SiNM e(2) in toluene, [L(OMe)F(2)W=C-p-tol] reacts to yield the complex [L( OMe)F(NMe(2))W=C-p-tol]. When the reaction is performed in dichloromet hane, [L(OMe)Cl(NMe(2))W=C-p-tol] is isolated.