http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
formation and characterization of ionic transition metal carbonyl cluster fragments by ion-molecule reactions
The formation and characterization of ionic transition metal carbonyl cluster fragments by ion-molecle reactions is presented for the Cr(CO)6, Fe(CO)5, Co(CO)3(NO), and Ni(CO)4 systems as well as the heteronuclear co(CO)3(NO)/ Ni(CO)4, Co(CO)3(NO)/Fe(CO)5, and Ni(CO)4/Fe(CO)5 systems. The ionic cluster fragments formed in the Cr(CO)6, Fe(CO)5, Co(CO)3(NO), and Ni(CO)4 systems are characterized in terms of their coordination unsaturation. The definition of coordination unsaturation of the ionic cluster fragments progresses from the metal-to-ligand ratio to the electron deficiency model. A general relationship emerges between reactivity and electron deficiency. Insight into the bond order and Lewis acidity /basicity of the ionic cluster fragments can also be obtained from the electron deficiency model. A detailed analysis of these systems reveals that the sequence leading to cluster formation can be explained using the CVMO model developed by Lauher. The ion-molecule chemistry of the heteronuclear ionic cluster fragments of the Co(CO)3(NO)/Ni(CO)4, Ni(CO)4/ Fe(CO)5, and Co(CO)3(NO)/Fe(CO)5 systems are examined to further probe the relationship between the CVMO model and the sequence of reaction of relationship between the CVMO model and the sequence of reaction of the ionic cluster fragments. The ionic cluster fragments formed in the heteronuclear systems containing Fe(CO)5 appear to follow the bonding patterns found in the heterometallic systems containing Fe(CO)4^-2. The relationship between reactivity and coordination unsaturation is further tested by ligand exchange studies with molecular oxygen. Ionic cluster fragments which are coordinatively unsaturated readily react with O2 by displacement of carbonyl ligands. The coordinatively saturated ionic cluster fragments having high bond orders are unreactive toward O2.
Includes bibliographical references (leaves 160-165).