Publication Date

2011-06-06

Availability

Open access

Embargo Period

2011-06-06

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Chemistry (Arts and Sciences)

Date of Defense

2011-06-03

First Committee Member

Burjor Captain

Second Committee Member

Francisco Raymo

Third Committee Member

Roger LeBlanc

Fourth Committee Member

Barbara Noziere

Abstract

The reactivity of bulky ligands with various transition metal complexes was studied to better understand the nature of organometallic electronic unsaturation and the role this plays in small molecule activation. A bulky stannyl hydride, tBu3SnH, was synthesized by a revised procedure that is far more facile and reproducible. This sterically encumbered ligand was shown to oxidatively add to a broad range of transition metal complexes, particularly those displaying carbonyl ligands, in greatly differing manners. Reaction of tBu3SnH with Ni(COD)2 and tBuNC was found to yield the mononuclear complex Ni(SntBu3)2(tBuNC)3. This compound possesses photochemical reactivity, most likely attributable to the massive steric bulk surrounding the Ni center, and generates electronically unsaturated metal centered radicals upon photolysis. This complex and its photochemical products were studied from both experimental and spectroscopic aspects. The stable organic radical TEMPO was also reacted with Ni(COD)2 to afford the unsaturated square planar complex Ni(TEMPO)2 which was studied both experimentally and spectroscopically. This deceivingly simple compound displays a wide spectrum of complicated reactivity and small molecule activation which may be utilized in future catalysis.

Keywords

Catalysis; Nickel; Tin; Photolysis; Radical TEMPO

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