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THE SYNTHESIS, REACTIVITY AND CHARACTERIZATION OF ORGANOMETALLICS OF TITANIUM, ZIRCONIUM AND HAFNIUM
Abstract
The thermal induced reactions of bis((eta)('5)-cyclopentadienyl)diphenyltitanium with several unsymmetrical acetylenes have been investigated. Acetylenes which vary widely in electronic and or steric properties were used to gain further insight in the thermolyses of bis((eta)('5)-cyclopentadienyl)diphenyltitanium with acetylenes. Analysis of the resulting isomeric benzotitanoles by ('1)H-NMR and chemical degradation techniques indicated that steric effects rather than electronic controlled the finial outcome of the reaction. Bis((eta)('5)-cyclopentadienyl) Group 4B diaryls {Cp(,2)MR(,2) (M = Ti, Zr, Hf) (R = C(,6)H(,5), p-CH(,3)C(,6)H(,4))} are photo-reactive. Unlike the thermal degradation of these materials the major organic product was the biaryl. Deuteration experiments indicated solvent participation during the photo-induced decomposition. An EPR study of the Group 4B diaryl metallocene derivatives indicated that a primary photo-process is homolytic cleavage of the metal-carbon linkage. Paramagnetic species, indicated by their EPR signals, and free organic radicals observed as a radical trap adduct were produced. These species can activate the carbon-hydrogen bonds of benzene and catalyzed the H/D exchange between molecular deuterium and benzene. The metal carbonyl compounds, Cp(,2)M(CO)(,2) (M = Ti, Zr, Hf), Ind(,2)M(CO)(,2) (M = Ti, Zr), Cp''CpM(CO)(,2) (M = Ti, zr, Hf) and Cp''(,2)M(CO)(,2) (M = Ti, Zr, Hf) were prepared in good yields under mild conditions (1 atm., 25(DEGREES)C) via the reductive carbonylation of the corresponding metallocene dichlorides complexes using mercuric chloride activated magnesium metal as a reducing agent.
Subject Area
Organic chemistry
Recommended Citation
MORIARTY, KEVIN JOSEPH, "THE SYNTHESIS, REACTIVITY AND CHARACTERIZATION OF ORGANOMETALLICS OF TITANIUM, ZIRCONIUM AND HAFNIUM" (1984). Doctoral Dissertations Available from Proquest. AAI8500106.
https://scholarworks.umass.edu/dissertations/AAI8500106