Synthesis and characterization of Ir(III) metallacycles derived from thiophene and related compounds: models for the hydrodesulfurization process

Simple item page
dc.contributor.authorGrieb, Arthur L.en
dc.contributor.committeechairMerola, Joseph S.en
dc.contributor.committeememberHanson, Brian E.en
dc.contributor.committeememberAnderson, Mark R.en
dc.contributor.departmentChemistryen
dc.date.accessioned2014-03-14T21:46:38Zen
dc.date.adate2009-09-29en
dc.date.available2014-03-14T21:46:38Zen
dc.date.issued1993-08-05en
dc.date.rdate2009-09-29en
dc.date.sdate2009-09-29en
dc.description.abstractResearchers use metal-thiophene complexes to mimic reactions which occur inside hydrodesulfurization (HDS) reactors. Information obtained from these model studies may often be applied to understanding the mechanisms involved with commercially used catalysts. Certain mechanisms¹ for HDS propose thiophene ring cleavage,forming a metallacycle, prior to hydrogenation of one double bond. There are, however, limited examples of complexes derived from C-S cleavage.<sup>2,3,4</sup> Thermal reactions of the iridium complex, [Ir(COD)(PMe<sub>3)3</sub>]Cl (COD=1,5- cyclooctadiene), with thiophene, thiazole, 4-methyl thiazole and 5-methyl thiazole yields the C-S addition metallacycles (Me₃P)₃Ir-(CH=CHCH=S)CI (I), \ (Me3P)3Ir-(CH=NCH=CHS)CI (II), (Me3P)3Ir-CCH=NC(CH3)=CHS)CI (III) and (Me3P)3Ir (CH=NCH=C(CH3)S)CI (IV), respectively. These compounds were characterized using the following methods: ¹H NMR, ¹³C NMR, ³¹P NMR, elemental analysis and single crystal x-ray diffraction. Following C-S addition to [Ir(COD)(PMe3)3]CI, nitrogen present in the thiazoles exhibit enhanced nucleophilicity. For exmnple, compounds II-IV react with methylene chloride to form dimers: CH2[NCR=CR'SIr(Cl)(PMe3)3CH]2. The above compounds are soluble in water and react with PF6 salts liberating the chloride atom from the Ir center. pKb measurements were recorded as well. This thesis describes the synthesis and examination of con1pounds I-IV as they may model the HDS process. Compounds II-IV represent the first examples of ring opened thiazole metallacycles with iridium.en
dc.description.degreeMaster of Scienceen
dc.format.extentv, 57 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-09292009-020335en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-09292009-020335/en
dc.identifier.urihttp://hdl.handle.net/10919/44946en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1993.G753.pdfen
dc.relation.isformatofOCLC# 29323336en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V855 1993.G753en
dc.subject.lcshFeed processingen
dc.subject.lcshPetroleum -- Refining -- Desulfurizationen
dc.subject.lcshThiophenesen
dc.titleSynthesis and characterization of Ir(III) metallacycles derived from thiophene and related compounds: models for the hydrodesulfurization processen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineChemistryen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
LD5655.V855_1993.G753.pdf
Size:
1.34 MB
Format:
Adobe Portable Document Format
Download

Collections

Masters Theses