Files in this item

FilesDescriptionFormat

application/pdf

9114327.pdf (4MB)
(no description provided)PDF

Description

 Title: Studies of the mechanism of oxygen atom transfer from molecular oxygen to iridium-coordinated cyclooctadiene Author(s): Lockledge, Scott Potter Doctoral Committee Chair(s): Klemperer, Walter G. Department / Program: Chemistry Discipline: Chemistry Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: Ph.D. Genre: Dissertation Subject(s): Chemistry, Inorganic Abstract: The cyclooctadiene complex ((C$\sb8$H$\sb{12}$)Ir(P$\sb3$O$\sb9$)) ((n-C$\sb4$H$\sb9$)$\sb4$N) $\sb2$, a, reacted in solution at ambient temperature with O$\sb2$ to form ((C$\sb8$H$\sb{11}$OH)Ir(P$\sb3$O$\sb9$)) ((n-C$\sb4$H$\sb9$)$\sb4$N) $\sb2$, f. Sealed tube $\sp{31}$P NMR spectroscopic experiments established the presence of three additional species in this reaction and the relationship between them. One of these intermediates, the oxametallacyclobutane complex ((C$\sb8$H$\sb{12}$O)Ir(P$\sb3$O$\sb9$)) ((n-C$\sb4$H$\sb9$)$\sb4$N) $\sb2$, e, was isolated and structurally characterized. Pseudo-octahedral coordination geometry at the Ir(III) center is defined by three terminal (P$\sb3$O$\sb9$)$\sp{3-}$ oxygen atoms, an olefinic C=C bond, and the carbon and oxygen atoms of an oxametallacyclobutane ring. The structures a and e are related by insertion of an O atom into a C-Ir bond of a. The structures of e and f are related by proton transfer from the allylic carbon of e to the oxygen atom of the oxametallacyclobutane ring. Oxygen uptake experiments indicated that both atoms of O$\sb2$ are incorporated into a molecule of a.Two other species were observed by $\sp{13}$C and $\sp{31}$P NMR spectroscopy and structures for these complexes are proposed. On the basis of these observations, a mechanism is proposed detailing the incorporation of the oxygen atoms from O$\sb{2}$ into a and its subsequent reactivity. Issue Date: 1990 Type: Text Language: English URI: http://hdl.handle.net/2142/21894 Rights Information: Copyright 1990 Lockledge, Scott Potter Date Available in IDEALS: 2011-05-07 Identifier in Online Catalog: AAI9114327 OCLC Identifier: (UMI)AAI9114327
﻿