Early transition metal complexes with pi donor ligands and their reaction with alkynes.

Persistent Link:
http://hdl.handle.net/10150/186222
Title:
Early transition metal complexes with pi donor ligands and their reaction with alkynes.
Author:
Chao, Yuan-Wei.
Issue Date:
1993
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
A one step procedure for the preparation of new group 5 amido halides M(NEt₂)ₓCl₅₋ₓ (x = 1, 2, 3), imido halides M(=NAr)Cl₃(L)₂, and group 4 and 5 phenoxide halides. These complexes are obtained easily from the metal halides and trimethylsilyl reagents such as Me₃SiNR₂, Me₃SiNHAr, and Me₃SiOAr. The dimeric amides [M(NEt₂)₂Cl₃]₂ (M = Nb, Ta), the dimeric imide [Ta(=NAr)Cl₃(NH₂Ar)]₂, and the polymeric imide [Ta(=NAr)Cl₃(NH₂Ar)](n) are also prepared in a single step. The use of Me₃SiNR₂ and Me₃SiOAr compounds as amidation and alkoxylation reagents can be extended to prepare the alkoxide amides Ta(NEt₂)(OAr)Cl₃(OEt₂), Ta(NEt₂)(OAr)₂Cl₂(OEt₂), and Ta(OAr)(OAr')Cl₃(OEt₂). When these complexes are reduced using 2 equiv of NaHg in the presence of the appropriate alkyne, the d² alkyne adducts or cycloadducts of the form (alkyne)Ta(NEt₂)(m)X(3-m) (m = 1, 2), (alkyne)Ta(=NAr)X(py)₂, and (R₃CC=CHCH=CCR₃))Ta(=NAr)X(py)₂ (X = OAr, Cl), and (η⁶-C₆Et₆)Ta(OAr)Cl₂, (η⁶-C₆Me₆)Ta(OAr')Cl, (R₃CC=CHCH=CCR₃)Ta(OAr)Cl₂, and (alkyne)Nb(DIPP)₃ are formed. CpTa(NEt₂)₂Cl₂ (Cp = C₅H₅⁻) forms from the reaction of Ta(NEt₂)₂Cl₃(OEt₂) and NaCp. A low yield of [CpTa(NEt₂)₂H₂]₂ is isolated from CpTa(NEt₂)₂Cl₂ and 2 equiv of LiNHAr. The reaction of Ta(NEt₂)₂Cl₃(OEt₂) with various equiv of LiNHAr provides the mono(imido) complex Ta(=NAr)(NEt₂)Cl₂(L)₂, bis(imido) complex Ta(=NAr)₂Cl(py)₂, and tris(imido)complexes [Ta(=NAr)₃(NHAr)]⁻. The analogous complexes of niobium, [Nb(=NAr)(NEt₂)Cl₂(NHEt₂)]₂, Nb(=NAr)₂Cl(py)₂, and [Nb(=NAr)₃(NHAr)]⁻ are prepared from [Nb(NEt₂)₂Cl₃]₂ by a parallel procedure. Preliminary results, not always reproducible, for the syntheses of Li[Ta(=NAr)₃(py)] are also reported. The reaction of MCl₄ (M = Zr, Hf) with 4 equiv of LiNHAr in the presence of donor solvents provides the imido complexes M(=NAr)(NHAr)₂(L)₂.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Dissertations, Academic.; Chemistry, Inorganic.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Wigley, David E.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleEarly transition metal complexes with pi donor ligands and their reaction with alkynes.en_US
dc.creatorChao, Yuan-Wei.en_US
dc.contributor.authorChao, Yuan-Wei.en_US
dc.date.issued1993en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractA one step procedure for the preparation of new group 5 amido halides M(NEt₂)ₓCl₅₋ₓ (x = 1, 2, 3), imido halides M(=NAr)Cl₃(L)₂, and group 4 and 5 phenoxide halides. These complexes are obtained easily from the metal halides and trimethylsilyl reagents such as Me₃SiNR₂, Me₃SiNHAr, and Me₃SiOAr. The dimeric amides [M(NEt₂)₂Cl₃]₂ (M = Nb, Ta), the dimeric imide [Ta(=NAr)Cl₃(NH₂Ar)]₂, and the polymeric imide [Ta(=NAr)Cl₃(NH₂Ar)](n) are also prepared in a single step. The use of Me₃SiNR₂ and Me₃SiOAr compounds as amidation and alkoxylation reagents can be extended to prepare the alkoxide amides Ta(NEt₂)(OAr)Cl₃(OEt₂), Ta(NEt₂)(OAr)₂Cl₂(OEt₂), and Ta(OAr)(OAr')Cl₃(OEt₂). When these complexes are reduced using 2 equiv of NaHg in the presence of the appropriate alkyne, the d² alkyne adducts or cycloadducts of the form (alkyne)Ta(NEt₂)(m)X(3-m) (m = 1, 2), (alkyne)Ta(=NAr)X(py)₂, and (R₃CC=CHCH=CCR₃))Ta(=NAr)X(py)₂ (X = OAr, Cl), and (η⁶-C₆Et₆)Ta(OAr)Cl₂, (η⁶-C₆Me₆)Ta(OAr')Cl, (R₃CC=CHCH=CCR₃)Ta(OAr)Cl₂, and (alkyne)Nb(DIPP)₃ are formed. CpTa(NEt₂)₂Cl₂ (Cp = C₅H₅⁻) forms from the reaction of Ta(NEt₂)₂Cl₃(OEt₂) and NaCp. A low yield of [CpTa(NEt₂)₂H₂]₂ is isolated from CpTa(NEt₂)₂Cl₂ and 2 equiv of LiNHAr. The reaction of Ta(NEt₂)₂Cl₃(OEt₂) with various equiv of LiNHAr provides the mono(imido) complex Ta(=NAr)(NEt₂)Cl₂(L)₂, bis(imido) complex Ta(=NAr)₂Cl(py)₂, and tris(imido)complexes [Ta(=NAr)₃(NHAr)]⁻. The analogous complexes of niobium, [Nb(=NAr)(NEt₂)Cl₂(NHEt₂)]₂, Nb(=NAr)₂Cl(py)₂, and [Nb(=NAr)₃(NHAr)]⁻ are prepared from [Nb(NEt₂)₂Cl₃]₂ by a parallel procedure. Preliminary results, not always reproducible, for the syntheses of Li[Ta(=NAr)₃(py)] are also reported. The reaction of MCl₄ (M = Zr, Hf) with 4 equiv of LiNHAr in the presence of donor solvents provides the imido complexes M(=NAr)(NHAr)₂(L)₂.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectDissertations, Academic.en_US
dc.subjectChemistry, Inorganic.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairWigley, David E.en_US
dc.contributor.committeememberFeltham, Robert D.en_US
dc.contributor.committeememberEnemark, John H.en_US
dc.contributor.committeememberLichtenberger, Dennis L.-
dc.contributor.committeememberBates, Robert B.-
dc.identifier.proquest9322732en_US
dc.identifier.oclc716272441en_US
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