In recent years numerous complexes have been reported in which olefins were chelated to transition metals.Ever since the generally regarded first olefin complex, Zeise's salt (32) KPt(C2H43, the interest in this field of organometallic chemistry has expanded to several families of olefinic ligands and metals like palladium(II), platinum(II) copper(I), silver(I), and more recently vanadium and titanium
The nature of the bonding of olefins to metal atoms seemed to involved the interaction between pi electrons in the unsaturated molecule and the hybrid orbitals of the metal rather than a localized sigma bonds between the metal atom and a particular carbon atom. The metal was complexed to a hydrocarbon which possessed a surplus of electrons. The direct overlap of a sigma orbital of the metal anad the p-orbital of the carbon atom formed a sigma type bond. The ligand carbon atom donated a surplus bonding pi-p electrons to a vacant sigma orbital of the metal while at the same time the excess negative charge was released back to the olefin from from a pi-d orbital of the metal to an empty antibonding pi-p orbital of the carbon atom. Dewar (9) illustrated this point by molecular orbital diagram. (See figure B) [see PDF file for Formula] The metal to olefin bond consisted of two parts: (a) overlap of the pi electron density of the olefin with sigma type acceptor orbital on the metal atom and (b) a "back-bonding" resulting from the flow of electron density from filled metal dxy or other dπ - pπ hybrid orbitals into antibonding orbital on the carbon atom. A schematic diagram of platinum olefin complexes can be shown as: [see PDF file for Formula]
It was the intention of this research to increase our understanding of these stable diolefin complexes. In particular, the occurrence of rearrangement upon complexation of certain ligands to most likely a more stable configuration posed an interesting project. They syntheses of diolefin complexes provided an establishment of good technique and verification of reported data.
The program of study was concentrated on the complexation of cyclic diolefins with primarily palladium(II) and platinum(II) chloride.
| Identifer | oai:union.ndltd.org:pacific.edu/oai:scholarlycommons.pacific.edu:uop_etds-2669 |
| Date | 01 January 1968 |
| Creators | Chinn, Donald Y. |
| Publisher | Scholarly Commons |
| Source Sets | University of the Pacific |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | University of the Pacific Theses and Dissertations |
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