Synthesis and Structure of Polyoxoanion Supported Organorhodium (I) and Organoiridium (I) Complexes

Main, Deborah Jean

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Description

Title

Synthesis and Structure of Polyoxoanion Supported Organorhodium (I) and Organoiridium (I) Complexes

Author(s)

Main, Deborah Jean

Issue Date

1987

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Chemistry, Inorganic

Abstract

• The iridium 1,5-cyclooctadiene Nb$\sb2$W$\sb4$O$\sb \sp{4-}$ adduct $\{\lbrack({\rm C\sb8H\sb )Ir\rbrack\sb5(Nb\sb2W\sb4O\sb )}\sb2\}\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb3$ (1) has been prepared by reaction of 2.5 eg of $\lbrack{\rm Ir(C\sb8H\sb )(NCCH\sb3)\sb2\rbrack PF\sb6}$ with (Nb$\sb2$W$\sb4$O$\sb )\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb4.$ NMR and IR data suggests the anion of 1 is isostructural with the anion of $\{\lbrack({\rm C\sb7H\sb8)Rh\rbrack\sb{5}(Nb\sb2W\sb4O\sb })\sb2\}\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb3$ (2) reported previously. In 1, two Nb$\sb2$W$\sb4$O$\sb \sp{4-}$ anions act as pentadentate bridging ligands in which both terminal and bridging oxygens are utilized to bind five (C$\sb8$H$\sb $)Ir$\sp+$ units. Reaction of compound 1 with 3 eq of (Nb$\sb2$W$\sb4$O$\sb )\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb4$ in acetonitrile followed by addition of 1 eq of acetic acid results in the formation of $\{\lbrack({\rm C\sb8H\sb )Ir\rbrack\sb2H(Nb\sb2W\sb4O\sb })\sb2\}\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb5$ (3). In the anion of 3, one two-coordinate proton and two four-coordinate (C$\sb8$H$\sb $)Ir$\sp+$ units link together the two Nb$\sb2$W$\sb4$O$\sb \sp{4-}$ anions. The ONb$\sb2$ and ONb oxygens are utilized in binding to the proton and (C$\sb8$H$\sb $)Ir$\sp+$ units respectively. Reaction of $\lbrack{\rm Ir(C\sb8H\sb )(NCCH\sb3)\sb2\rbrack PF}\sb6$ with (P$\sb3$O$\sb9)\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb3$ in methylene chloride has resulted in isolation of $\{\lbrack({\rm C\sb8H\sb )Ir\rbrack(P\sb3O\sb9})\}\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb2$ (4a). The P$\sb3$O$\sb9\sp{3-}$ anion is bound to iridium in a tridentate fashion making the coordination geometry around Ir$\sp{\rm I}$ approximately square pyramidal.
• The metal dicarbonyl polyoxoanion adducts $\{\lbrack({\rm CO)\sb2Rh\rbrack\sb5(Nb\sb2W\sb4O\sb })\sb2\}\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb3$ (8), $\{\lbrack({\rm CO)\sb2Rh\rbrack\sb3(Nb\sb2W\sb4O\sb })\sb2\}\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb5$ (9), $\{\lbrack({\rm CO)\sb2Ir\rbrack\sb2H(Nb\sb2W\sb4O\sb })\sb2\}\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb5$ (10), and $\{\lbrack({\rm CO)\sb2Ir\rbrack(P\sb3O\sb9)\}\lbrack(C\sb6H\sb5)\sb3PNP(C\sb6H}\sb5)\sb3\rbrack\sb2$ (11) have been prepared and characterized. Compounds 8, 10, and 11 are synthesized by carbonylation of their respective diene analogs, whereas compound 9 is prepared from (Rh(CO)$\sb2$Cl) $\sb2$ and (Nb$\sb2$W$\sb4$O$\sb )\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb4.$ Based on IR and NMR data, compounds 8, 10, and 11 exhibit the same anion structures as their respective diene analogs.
• The novel reaction of $\{\lbrack({\rm C\sb8H\sb )Ir\rbrack(P\sb3O\sb9})\}\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb2$ (4a) with dioxygen is reported. In 1,2-dichloroethane at 55-60$\sp\circ$, dioxygen reacts with 4a to form $\{\lbrack(\eta\sp1,\eta\sp3{\rm C\sb8H\sb OH)Ir\rbrack(P\sb3O\sb9})\}\lbrack(n$-C$\sb4$H$\sb9)\sb4$N) $\sb2$ (13). A single crystal X-ray diffraction study of 13 shows the Ir$\sp{\rm III}$ atom to be bonded to three oxygens of the P$\sb3$O$\sb9\sp{3-}$ ligand and to four carbons of the C$\sb8$H$\sb $OH ring, making the coordination geometry around iridium octahedral if the allyl function is regarded as occupying two coordination sites. (Abstract shortened with permission of author.)

Graduation Semester

1987

Type of Resource

text

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