Abstract
Addition of one equiv of water to Mo(CAr)[OCMe(CF(3))(2)](3)(1,2-dimethoxyethane) (2, Ar = o-(OMe)C(6)H(4)) in the presence of PPhMe(2) leads to formation of Mo(O)(CHAr)[OCMe(CF(3))(2)](2)(PPhMe(2)) (3(PPhMe(2))) in 34% yield. Addition of one equiv of water alone to 2 produces the dimeric alkylidyne hydroxide complex, {Mo(CAr)[OCMe(CF(3))(2)](2)(μ-OH)}(2)(dme) (4(dme)) in which each bridging hydroxide proton points toward an oxygen atom in an arylmethoxy group. Addition of PMe(3) to 4(dme) gives the alkylidene oxo complex, (3(PMe(3))), an analogue of 3(PPhMe(2)) (95% conversion, 66% isolated). Treatment of 3(PMe(3)) with two equiv of HCl gave Mo(O)(CHAr)Cl(2)(PMe(3)) (5), which upon addition of LiO-2,6-(2,4,6-i-Pr(3)C(6)H(2))(2)C(6)H(3) (LiOHIPT) gave Mo(O)(CHAr)(OHIPT)Cl(PMe(3)) (6). Compound 6 in the presence of B(C(6)F(5))(3) will initiate the ring-opening metathesis polymerization of cyclooctene, 5,6-dicarbomethoxynorbornadiene (DCMNBD), and rac-5,6-dicarbomethoxynorbornene (DCMNBE), and the homocoupling of 1-decene to 9-octadecene. The poly(DCMNBD) has a cis,syndiotactic structure, whereas poly(DCMNBE) has a cis,syndiotactic,alt structure. X-ray structures were obtained for 3(PPhMe(2)), 4(dme), and 6.