Go to  Advanced Search

Pyrazolyl ligands in mixed metal complexes

Show simple item record

dc.contributor.author Onyiriuka, Emmanuel C.
dc.date.accessioned 2010-08-07T14:25:29Z
dc.date.available 2010-08-07T14:25:29Z
dc.date.copyright 1986 en
dc.date.issued 2010-08-07T14:25:29Z
dc.identifier.uri http://hdl.handle.net/2429/27178
dc.description.abstract The anions LMo(CO)₃⁻ (L = MeGapz₃ or MeGa(3,5-Me₂pz)₃) have been isolated as the Na⁺, Et₄N⁺ or HAsPh₃⁺ salts and the solution structures of the Na⁺ salts in THF have been defined by analysis of the v[sub CO] ir spectra. Ion-pair interaction of the LMo(CO)₃⁻ anion with Na⁺cation in THF solution is apparent from the spectroscopic evidence obtained. The MeGapz₃Mo(CO)₃ ⁻anion reacted with HCl or EtBr to give the seven-coordinate [MeGapz₃]-Mo(CO)₃R (R = H or Et) complexes. However, with Mel or PhCOCl complexes of the type [MeGapz₃]Mo(CO)₂(n₂-COR) (R = Me or Ph) were obtained. The reactions of the LMo(CO)₃⁻ ions (L = MeGapz₃ HBpz₃ or Me₂Gapz(0-CH₂CH₂NMe₂)) with a variety of transition metal halide species have yielded complexes with transition metal-transition metal bonds. The X-ray crystal structures of two such complexes [MeGapz₃]Mo(CO)₃Cu(PPh₃) and [MeGapz₃]Mo-(CO)₃Rh(PPh₃)₂ have been determined. The former complex provides a rare example of a 3:3:1, or capped octahedral structure, with a short (mean) Mo-Cu distance of 2.513(9)Å. The latter compound displays one terminal and two bridging CO ligands and a Mo-Rh distance of 2.6066(5)Å. Transition metal-group 14 (Si, Ge or Sn) element bonded complexes of the type [MeGapz₃]Mo(CO) ₃M'Y (Y = Me₃ or Ph₃, M' = Ge or Sn; Y = Me₃, M' = Si; Y = Me₂Cl, M' = Sn) have been prepared from the reaction of the MeGapz₃Mo(CO)₃anion with the appropriate organo-group 14 chloride. In all the complexes, direct Mo-M' (M' = Si, Ge or Sn) single bonds are featured. The [MeGapz₃]Mo(CO) ₃SnMe₂Cl complex shows an interesting solution behaviour in which a transition from a 3:4, or piano stool structure, to a 3:3:1, or capped octahedral arrangement, is thought to occur. The 3:3:1 structure has been demonstrated in the solid state for the [MeGapz₃]Mo(CO)₃SnPh₃ compound by means of a crystal structure determination. The 'Mo-SnPh₃' and the 'Mo-Cu' compounds discussed in this work are the first examples of such complexes incorporating either the MeGapz₃⁻, HBpz₃⁻ or C₅H₅⁻ ligands in which the 3:3:1 arrangement has been demonstrated unequivocally. The novel tridentate unsymmetric ligands Me₂GapzO(C₅H₃N)CH₂NMe₂⁻ (L[sub a]⁻) and Me₂GapzO(C₉H₆N)⁻ (L[sub q]⁻) have been prepared and numerous transition metal compounds containing these ligands synthesized. The compounds L[sub a] M(CO)₃(M = Mn or Re) are the first examples of transition metal carbonyl complexes in which both the fac and mer arrangements of the unsymmetric ligand about the central metal have been found to co-exist in solution. The square planar rhodium(I) complex, L[sub q]Rh(CO) has been shown to add Mel oxidatively, followed by facile methyl migration reaction to produce the five-coordinate Rh(III) acetyl derivative, L[sub q]Rh(COMe)I. In contrast, the reaction of L[sub a]Rh(CO) with Mel, led to the six-coordinate Rh(III) oxidative addition product, L[sub a]Rh(Me)(I)CO. en
dc.language.iso eng en
dc.publisher University of British Columbia en
dc.relation.ispartofseries UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/] en
dc.title Pyrazolyl ligands in mixed metal complexes en
dc.type Electronic Thesis or Dissertation en
dc.degree.name Doctor of Philosophy - PhD en
dc.degree.discipline Chemistry en
dc.degree.grantor University of British Columbia en
dc.degree.campus UBCV en
dc.description.scholarlevel Graduate en

Files in this item

Files Size Format Description   View
UBC_1986_A1 O59_4.pdf 11.80Mb Adobe Portable Document Format   View/Open

This item appears in the following Collection(s)

Show simple item record

All items in cIRcle are protected by copyright, with all rights reserved.

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893