Nucleophilic attack on eta/sup 2/-acyls of zirconium. The synthesis and reactivity of zirconium ketone complexes
The reaction of Cp/sub 2/ZrMe/sub 2/ with the eta/sup 2/-acyl complex, Cp/sub 2/Zr(C(O)Me)(/sup +/-OC)Mo(CO)/sub 2/Cp, produced the bridging ketone complex 4. The nucleophilic Ar-CH/sub 3/ added 1,2 across the C-O bond of the acyl group to generate an acetone ligand which was coordinated through the ketone oxygen to one Zr center and through both the ketone carbon and oxygen to the other Zr center. The crystal structure of 4 was reported. Ancillary ligand effects were investigated on the susceptibility of zirconocene eta/sup 2/-acyls to attack by Cp/sub 2/ZrMe/sub 2/, and on the ability of zirconocene methyl complexes to act as nucleophiles. Nucleophilic attack by Cp/sub 2/ZrMe/sub 2/ at the carbon of a eta/sup 2/-acyl was favored by the presence of a strong sigma-donor with limited ..pi..-donor ability. Methyl transfer from a zirconocene methyl complex was favored by the presence of similar ancillary substitution. Reactions of standard organometallic nucleophiles with zirconium eta/sup 2/-acyls was investigated as a route to new ketone complexes. The presence of ..cap alpha..-protons on the acyl group resulted in its deprotonation to known ketene complexes. The absence of ..cap alpha..-protons on the acyl group permitted the use of RLi reagents to synthesize new zirconium ketone complexes. The reactivity of complex 4 towards insertion, radical addition and attack by nucleophilic and electrophilic reagents was investigated. The crystal structure of the product of CO insertion into the ketone ligand was reported.
- Research Organization:
- Colorado State Univ., Fort Collins (USA)
- OSTI ID:
- 6886135
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
KETONES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
ORGANOMETALLIC COMPOUNDS
ZIRCONIUM COMPLEXES
ACYL RADICALS
CARBONYLS
LIGANDS
COMPLEXES
ORGANIC COMPOUNDS
RADICALS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties