The synthesis, characterization, and reactivity of some alkyne, vinylidene, and butatrienylidene complexes of ruthenium

Thesis/Dissertation · Thu Dec 31 23:00:00 EST 1992

OSTI ID:6974519

Lomprey, J R

Cumulene complexes of ruthenium were studied in regard to their preparation, characterization, and reactivity. This work is divided into two parts: first, a study of the alkyne to vinylidene isomerization on a ruthenium (II) center, and second the study of the synthesis of metal butatrienylidene complexes. The isomeric C[sub 2]H[sub 2] complexes [Ru([eta][sup 2]-HC[triple bond]CH) (PMe[sub 2]-Ph)[sub 2] (Cp)] [BF[sub 4]] and [Ru(C=CH[sub 2]) (PMe[sub 2]Ph)[sub 2](Cp)][BF[sub 4]] were prepared and structurally characterized, providing the first structural comparison of both C[sub 2]H[sub 2] isomers on identical mononuclear metal centers. While the isomerization of [RU([eta][sup 2]-HC[triple bond]CH) (PMe[sub 2]-Ph)[sub 2] (Cp)][BF[sub 4]] to [Ru(C=CH[sub 2]) (PMe[sub 2] Ph)[sub 2] (Cp)][BF[sub 4]] proceeds via an intramolecular, 1,2-hydride migration pathway as opposed to the hydrido-acetylide intermediates proposed by other investigators. The first examples of trapped butatrienylidenes have been prepared, several of which have been structurally characterized by X-ray methods. The alkynyl ketone complex [Ru[l brace]C[triple bond]CC(O)CMe[sub 2]H[r brace](PPh[sub 2])[sub 2](Cp)] reacted to form the trifluoroacetate-trapped butatrienylidene complex [Ru-[l brace]C[triple bond]CC(O[sub 2]CCF[sub 3])CMe[sub 2][r brace](PPh[sub 2])[sub 2](Cp)]. Reactivity patterns of [Ru[l brace]C[triple bond]CC(O[sub 2]CCF[sub 3])CMe[sub 2][r brace](PPh[sub 2])[sub 2](Cp)] suggest that it may be considered to be a tight ion pair of the trifluoroacetate anion and the butatrienylidene cation [Ru(C=C=C=CMe[sub 2])(PPh[sub 3])[sub 2] (CP)][sup +]. Contrary to expectations that hard nucleophiles will react at C[sub [alpha]] and soft nucleophilies at C[sub [beta]], both hard and soft nucleophilies react with [Ru-[l brace]C[triple bond]CC(O[sub 2]CCF[sub 3])CMe[sub 2][r brace](PPh[sub 2])[sub 2] (Cp)] at C[sub [gamma]].

• Research Organization: Kentucky Univ., Lexington, KY (United States)
• OSTI ID: 6974519
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACTIVATION ENERGY
ALKYNES
CHEMICAL PREPARATION
CHEMICAL PROPERTIES
CHEMICAL REACTIONS
COMPLEXES
ENERGY
HYDROCARBONS
ISOMERIZATION
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
RUTHENIUM COMPLEXES
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES