Browsing by Author "Haines, Raymond J"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Open Access
    Ligand-bridged dinuclear carbonyl compounds of rutheniun and osmium
    (2008) Mushonga, Paul; Moss, John R; Haines, Raymond J
    Ligand-bridged dinuc1ear carbonyl compounds of ruthenium and osmium have been successfully prepared and characterised by various analytical and spectroscopic techniques. X-ray crystal structures have been determined for the osmium complexes [OS2(CO)4(p-02CCsH4FeCsHs)2L2] {L = PPh3 (102), py (103)}. Some of the complexes were then investigated for their catalytic activity in the oxidation of cyc10hexane and octane. In this work, hydrogen peroxide was used as an oxidant and acetonitrile as the solvent. A higher selectivity for the alcohol products over the ketones was observed. The average ratio of alcohols to ketones was found to be 4.56 and 1.76 for cyc10hexane and octane respectively. The complexes [OS2(CO)6(p-02CMeh] (4) [Ru(CO)2(p-02CMe)2]n (86), [Ru2( CO )4(p-02CMe )(p-dppm h] [PF 6] (117) and [Ru2( CO)4(p -( 02CMe h(MeCN)2] (118), were tested as homogeneous catalysts for the isomerisation of terminal alkenes. Complex 4 was inactive while the complex 118 gave a 100 % conversion. It is proposed that the catalysis proceeded via the displacement of one acetonitrile ligand from the metal centre providing a vacant site onto which the substrate coordinated. The redox behaviour of the four complexes [Ru2(CO)2(p-COh(
  • Thumbnail Image
    Item
    Open Access
    Studies directed towards the synthesis of metal-containing ketones
    (1977) Davidowitz, Bette; Cragg, G M L; Haines, Raymond J
    The photochemistry of organometallic compounds is receiving increasing attention in the current literature, but as yet, little work has been reported on the photochemistry of metal-containing ketones. The objective of the work reported in this thesis was the synthesis of ligands for the formation of suitable metal-containing ketones. The initial studies were directed at the preparation of β- and ϒ-hydroxyketones by a variety of methods, but the major effort was later concentrated on the synthesis of phosphorus derivatives of o-hydroxyphenyl alkyl ketones . The reaction of o-hydroxyphenyl alkyl ketones with phosphorus trichloride afforded 2-chloro- 1,3,2-dioxaphosphorinans which were readily converted to the corresponding 2-alkoxy derivatives by reaction with various alcohols. Extension of the study to acteylacetone indicated that an analogous reaction occurs to give highly labile products. This part of the work has been accepted for publication in Chemical Communications. The reaction of o-hydroxyphenyl alkyl ketones with other phosphorus halides, such as dichlorophenyl phosphine and chlorodiphenylphosphine, has also been investigated. Reaction of the former reagent with o-hydroxyacetophenone gave a crystalline phosphorus-containing derivative; spectroscopic evidence indicates that this compound possesses an unusual structure and it is currently being studied by X-ray crystallography.