Reactivity of carbon dioxide with organosamarium compounds and the synthesis and reactivity of solvent free organolanthanide metallocene cations | | Posted on:1999-10-07 | Degree:Ph.D | Type:Dissertation | | University:University of California, Irvine | Candidate:Seibel, Christopher Alan | Full Text:PDF | | GTID:1461390014969047 | Subject:Chemistry | | Abstract/Summary: | PDF Full Text Request | | The first part of this dissertation describes studies of the reactivity of organosamarium compounds with CO{dollar}sb2.{dollar} Two strategies for CO{dollar}sb2{dollar} activation were utilized: reduction using a Sm(II) organometallic reagent, namely ({dollar}rm Csb5Mesb5)sb2Sm(THF)sb2,{dollar} and insertion of CO{dollar}sb2{dollar} into Sm(III)-C and Sm(III)-N bonds.; Investigation of the chemical reduction of CO{dollar}sb2{dollar} utilizing the strongly reducing ({dollar}rm Csb5Mesb5)sb2Sm(THF)sb2{dollar} resulted in the direct reductive dimerization of CO{dollar}sb2{dollar} producing an oxalate dianion (({dollar}rm Osb2CCOsb2)rbracksp{lcub}2-{rcub}{dollar} in high yield. The analogous reaction with COS resulted in reductive disproportionation and produced the dithiocarbonate dianion, COS{dollar}sb2sp{lcub}2-{rcub}{dollar} and CO.; Once the reactivity of CO{dollar}sb2{dollar} with divalent organosamarium metallocenes was defined, the investigation of CO{dollar}sb2{dollar} insertion reactivity with trivalent organosamarium metallocenes was undertaken. The reaction of CO{dollar}sb2{dollar} with the bimetallic compound ({dollar}rm Csb5Mesb5)sb2Sm(mu{dollar}-{dollar}etasp1{lcub}:{rcub}etasp1{dollar}-{dollar}rm Nsb2Phsb2){dollar} resulted in the production of the asymmetric product ({dollar}rm Csb5Mesb5)sb2Smlbrack mu{dollar}-{dollar}etasp2{lcub}:{rcub}etasp1{dollar}-PhNN(CO{dollar}sb2{dollar})Ph) Sm({dollar}rm Csb5Mesb5)sb2{dollar}(THF) in high yield.; Further insertion chemistry of CO{dollar}sb2{dollar} with organosamarium compounds was demonstrated by clean insertion reactions with Sm-R bonds of monometallic ({dollar}rm Csb5Mesb5)sb2{dollar}Sm-R compounds (R = {dollar}rm Csb6Hsb5, CHsb2CHCHsb2Rspprime{dollar}). COS and CS{dollar}sb2{dollar} were also found to cleanly insert into the Sm-R bonds producing analogous products.; The second part of this dissertation describes the preparation and reactivity of solvent free lanthanide metallocene cations of general formula (({dollar}rm Csb5Mesb5)sb2Lnrbracklbrack BPhsb4rbrack.{dollar} Research was directed toward developing a solvent free samarium metallocene analogous to (({dollar}rm Csb5Mesb5)sb2Sm(THF)sb2rbracklbrack BPhsb4rbrack.{dollar} Reduction of AgBPh{dollar}sb4{dollar} by unsolvated divalent ({dollar}rm Csb5Mesb5)sb2Sm{dollar} in arene solvents was successful in generating (({dollar}rm Csb5Mesb5)sb2Smrbracklbrack BPhsb4rbrack.{dollar} The reaction of (({dollar}rm Csb5Mesb5)sb2Smrbracklbrack BPhsb4rbrack{dollar} with KC{dollar}sb4{dollar}Me{dollar}sb5{dollar} provided a new route to ({dollar}rm Csb5Mesb5)sb3Sm.{dollar}; New synthetic routes to (({dollar}rm Csb5Mesb5)sb2Lnrbracklbrack BPhsb4rbrack{dollar} which did not depend on divalent ({dollar}rm Csb5Mesb5)sb2Ln{dollar} were developed. Syntheses utilizing Ln(III) precursors were developed involving protonation reactions of ({dollar}rm Csb5Mesb5)sb2Ln(etasp3{dollar}-CH{dollar}sb2{dollar}CHCH{dollar}sb2{dollar}) with Et{dollar}sb3{dollar}NHBPh{dollar}sb4{dollar} in non-coordinating solvents to cleanly produce (({dollar}rm Csb5Mesb5)sb2Lnrbracklbrack BPhsb4rbrack.{dollar} The reaction of (({dollar}rm Csb5Mesb5)sb2Ndrbracklbrack BPhsb4rbrack{dollar} with KC{dollar}sb5{dollar}Me{dollar}sb5{dollar} produced ({dollar}rm Csb5Mesb5)sb3Nd{dollar} in sufficiently high quantities and purity to allow full characterization for the first time.; In order to fully utilize ({dollar}rm Csb5Mesb5)sb2Ln(etasp3{dollar}-CH{dollar}sb2{dollar}CHCH{dollar}sb2{dollar}) as a precursor to (({dollar}rm Csb5Mesb5)sb2Lnrbracklbrack BPhsb4rbrack,{dollar} a general large scale route to ({dollar}rm Csb5Mesb5)sb2Ln(etasp3{dollar}-CH{dollar}sb2{dollar}CHCH{dollar}sb2{dollar}) was developed utilizing Ln(III) starting materials. Reactions between ({dollar}rm Csb5Mesb5)sb2LnClsb2K(TH... | | Keywords/Search Tags: | {dollar}rm csb5mesb5, Organosamarium compounds, Reactivity, Solvent free, Sb2lnrbracklbrack bphsb4rbrack, Metallocene, Iii, Reaction | PDF Full Text Request | Related items |
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