The tetrakis(triphenylphosphine)palladium-catalyzed cross coupling of 2-bromoindene or 2-bromo-4,7-dimethylindene with menthylmagnesium chloride gave the novel ligands 2-menthylindene (10) and 2-menthyl-4,7-dimethylindene (11) in 66 and 57% yields. These indenes were deprotonated with n-BuLi to give isolated indenyllithium complexes which were metalated with zirconium tetrachloride to give bis(2-menthylindenyl)zirconium dichloride ( 14) and bis(2-menthyl-4,7-dimethylindenyl)zirconium dichloride (15) in 40 and 66% yields. Both complexes formed as their single possible stereoisomer and were characterized by X-ray crystallography and MS, NMR, and IR spectroscopy. The variable-temperature 1 H NMR spectrum of bis(2-menthyl-4,7-dimethylindenyl)zirconium dichloride (15) showed that it interconverts with a rotational activation barrier of about 12.5 ( 0.5 kcal/mol, and that a 60:40 mixture of C 2 -symmetric diastereomeric conformations was present at -50 °C. The 1 H NMR spectrum of bis(2-menthylindenyl)zirconium dichloride ( 14) was invariant between -50 and +50 °C. Complexes 14 and 15 polymerized propene in the presence of methylaluminumoxane (MAO) and hydrogen (10 960 and 33 750 g PP/g Zr h, respectively). The molecular weights and stereoregularity of the polymers produced were low.

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The reactions of [Pt(triphos)(Cl)][Cl] (1) {triphos = bis[2-(diphenylphosphino)ethyl]phenylphosphine} with NaOC6H4-p-R, in the presence of NaPF6, yields the aryloxy complexes [Pt(triphos)(OC6H4-p-R)][PF6] (R = OMe (2a), Me (2b), H (2c), F (2d), Cl (2e)). Upon reaction of 2a−e with carbon monoxide at pressures from 10 to 134 psi in acetonitrile the (aryloxy)carbonyl complexes [Pt(triphos)(C(O)OC6H4-p-R)][PF6] (3a−e) were obtained. The molecular structure of [Pt(triphos)(C(O)OC6H4-p-Me)][PF6] (3b) was determined by X-ray diffraction. Complex 3b crystallized in the monoclinic space group P21/n (no. 14) with a = 10.797(1) Å , b = 19.927(3) Å, c = 19.113(2) Å, β = 98.07(1)°, V = 4071(2) Å3, and Z = 4. The structure was solved and refined to R = 0.035 and R w = 0.040 for 3958 reflections with I > 3σ(I). The kinetics of the carbonylation of 2a−e to form 3a−e were studied by 31P{1H} NMR. Rates of carbonylation exhibit a first order dependence on [CO], but are independent of the concentration of free aryloxide in solution. Rates of aryloxide ligand exchange were also found to be significantly faster than rates of carbonylation. The rates of carbonylation depend on the para-substituent of the aryloxy ligand and follow the order F (2d) > Me (2b) > OMe (2a). These observations are interpreted in terms of a carbonylation mechanism that proceeds via a migratory insertion pathway, rather than by nucleophilic attack at coordinated carbon monoxide by free or dissociated aryloxide.

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