Degree Type
Dissertation
Date of Award
2001
Degree Name
Doctor of Philosophy
Department
Chemistry
First Advisor
Robert J. Angelici
Abstract
This dissertation presents an overview of synthesis and chemical reactivity of a novel diruthenium complex (eta5-C5H 3)2(SiMe2)2Ru2(CO) 4 (1) and its derivatives. Complex 1H +, [(eta5-C5H3)2(SiMe 2)2Ru2(CO)4(mu-H)]+, with a protonated Ru-Ru bond, is deprotonated only very slowly (hours or days) by basic amines and phosphines although the proton in 1H + is acidic thermodynamically. This remarkable kinetic inertness of the bridging proton allows primary and secondary amines to react with 1H+ by attacking the CO ligand to give a formamide and the CO-substituted ruthenium complex (eta5-C5H 3)2(SiMe2)2Ru2(NHR 1R2)(CO)3. We have demonstrated that a CO ligand in the protonated complex (eta5-C5H3) 2(SiMe2)2Ru2(CO)4(mu-H)] + (1H+-) is the site of reaction with amines because of the high electrophilicity of the CO ligands and the low kinetic acidity of the bridging hydride---a unique combination of kinetic properties that are not found in the Fe and Os analogs. On the other hand, I-, RS- and phosphines add at one of the Ru centers in 1H+, resulting in cleavage of the Ru-H-Ru bond. The final type of addition to 1H + is that exhibited by MeO- and F- , which results in cleavage of Si-C(cyclopentadienyl) bonds. Except for the reaction with F-, all of these types of reactions depend on the presence of the proton on the Ru-Ru bond. The unprotonated (eta 5-C5H3)2(SiMe2)2 Ru2(CO)4 (1) undergoes no reactions with these nucleophiles (except F-) under the mild room temperature conditions of these studies. The protonated diruthenium alkene complexes (eta5-C5H3)2 (SiMe2)2Ru2(CO)3(eta 2-CH2=CH-R)(mu-H)]+ react with a variety of nucleophiles to give hydrofunctionalized alkenes with predominantly Markovnikov regioselectivity. The dinuclear ruthenium complex (eta5-C 5H3)2(SiMe2)2Ru2(CO) 4 (1) is a precursor for the synthesis of a variety of new dinuclear ruthenium complexes, in which the bridging (eta5-C 5H3)2(SiMe2)2 ligand controls the geometry of the final product. Thus, complex 1 reacts with diphenylacetylene to form a series of the unusual ruthenacarbocyclic complexes as major products.
DOI
https://doi.org/10.31274/rtd-180813-12518
Publisher
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu
Copyright Owner
Maxim V. Ovchinnikov
Copyright Date
2001
Language
en
Proquest ID
AAI3016736
File Format
application/pdf
File Size
144 pages
Recommended Citation
Ovchinnikov, Maxim V., "Synthesis and reactions of organometallic complexes featuring a doubly-linked dicyclopentadienyl ligand " (2001). Retrospective Theses and Dissertations. 1071.
https://lib.dr.iastate.edu/rtd/1071