Alkoxides as ancillary ligands in organolanthanide chemistry. Synthesis of, reactivity of, and olefin polymerization by the [mu]-hydride-[mu]-alkyl compounds [Y(C[sub 5]Me[sub 5])(OC[sub 6]H[sub 3][sup t]Bu[sub 2])][sub 2]([mu]-H) ([mu]-alkyl)

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Organometallics; (United States)

DOI:https://doi.org/10.1021/om00013a017· OSTI ID:5042248

Schaverien, C J ^[1]

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1. Koninklijke/Shell-Lab., Amsterdam (Netherlands)

Reaction of Y(C[sub 5]Me[sub 5])(OAr)[sub 2] (2; OAr = 0.2,6-C[sub 6]H[sub 3][sup t]Bu[sub 2]) with MCH(SiMe[sub 3])[sub 2] (M = Li, K) affords Y(C[sub 5]Me[sub 5])(OAr)[l brace]CH(SiMe[sub 3])[sub 2][r brace] (3), which on subsequent hydrogenation (20 bar, 25[degree]C) gives the [mu]-H dimer [YC[sub 5]Me[sub 5](OAr)([mu]-H)][sub 2] (4). Terminal olefins H[sub 2]C=CHR (R = H, Me, Et, n-Bu) react regiospecifically and irreversibly with 4 to give the [mu]-n-alkyl species trans-[Y(C[sub 5]Me[sub 5])(OAr)][sub 2]([mu]-H)([mu]-CH[sub 2] CH[sub 2]R) (R = H (5), Me (6), Et (7), n-Bu (8)), respectively. Reaction of [Y(C[sub 5]Me[sub 5])(OAr)([mu]-D)][sub 2] (4-D) (prepared from 3 and D[sub 2]) with propene yields selectively only trans-[Y(C[sub 5]Me[sub 5])(OAr)][sub 2]([mu]-D)([mu]-CH[sub 2]C HDMe) (6-D), confirming the nonreversibility of olefin insertion. Compounds 4-8 polymerize ethene and are single-component catalysts for the polymerization of [alpha]-olefins and nonconjugated dienes. Dissolution of 4 in neat 1-hexene (to give 8 in situ) results in slow polymerization to yield poly(1-hexene) with M[sub w] = 15 700 and M[sub w]/M[sub n] = 1.67. 4 cyclopolymerizes neat 1,5-hexadiene to poly(methylene-1,3-cyclopentanediyl) rather than promotes cyclization to methylenecyclopentane. The [mu]-alkyls 5-8 show diastereotopic [alpha]-CH[sub 3] resonances, implying idealized C[sub 2], rather than C[sub 2v] geometry, which indicates a mutually trans geometry for the attendant C[sub 5]Me[sub 5] and OAr ligands. In 6, exchange of the two diastereotopic C[sub [alpha]]H[sub 2] hydrogens by inversion at Y([mu]-C[sub 5])Y occurs with [Delta]G* = 11.1 [+-] 0.5 kcal mol[sup [minus]1] ([minus]25[degree]C), and tert-butyl group equilibation on the same phenoxide occurs with [Delta]G* = 9.0 [+-] 0.5 kcal mol[sup [minus]1] ([minus]93[degree]C). 60 refs., 1 fig., 2 tabs.

• OSTI ID: 5042248
• Journal Information: Organometallics; (United States), Journal Name: Organometallics; (United States) Vol. 13:1; ISSN ORGND7; ISSN 0276-7333
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
ALKENES
ALKOXIDES
AROMATICS
CATALYSTS
CHEMICAL REACTIONS
HYDROCARBONS
HYDROGENATION
LIGANDS
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
POLYMERIZATION
RESONANCE
SYNTHESIS
THERMODYNAMICS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS