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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
841

Mononuclear and dinuclear complexes of rhodium and iridium: pyrazole complexes and pyrazolyl bridged dimers

Bailey, James Arthur 22 June 2018 (has links)
A series of mononuclear complexes of general formula [M(η5-C5Me5)Cl3-n(pzH)n](n-1)+ (n = 1,2) has been prepared as a result of an investigation of the reactivity of pyrazole with rhodium and iridium cyclopentadienyl and pentamethyl-cyclopentadienyl precursors. These complexes are discussed in terms of the dynamic processes that are exhibited in the 1H NMR experiment and in terms of their use as precursors to dimeric species. Dinuclear complexes of formula [M(η5-C5R5)Cl(μ-pz)]2 containing pyrazolyl bridges have been prepared from the mononuclear compounds and from the chloro-bridged dimers of formula [M(η5-C5R5)Cl2]2 by treatment with triethylamine, but not from the dipyrazole iridium cation [Ir(η5-C5Me5)Cl(pzH)2]+ 26 which has been found to be unreactive to this type of symmetrical dimer formation: the low reactivity is attributed to a relative non-lability of the pyrazole groups. The dimeric complexes have been shown to undergo a core conformational change upon chemical reduction or halide abstraction. The chair conformation of the pyrazolyl bridged complex [Rh(η5-C5ME5)Cl(μ-pz)]2 38 has been proven crystallographically. Chloride abstraction from 38 yields the binuclear product [(Rh(η5-C5ME5)(μ-pz))2(μ-Cl)]BF4 46 which is bridged by two pyrazolyl and one chloride ligand and has been structurally characterized by X-ray diffraction to contain a boat conformation for the pyrazolyl framework. Reduction of either 38 or the C5H5 analogue 40 results in the metal-metal bonded dinuclear complexes [Rh(η5-C5ME5)(μ-pz)]2 48 and 49. The C5H5 complex 49 has been crystallographically determined to possess the boat conformation. The reactivity of the metal-metal bonded products has been investigated: one and two fragment addition is discussed and a number of oxidative addition products have been structurally characterized. The mononuclear dipyrazole iridium cation 26 which contains non-labile pyrazole groups is utilized to prepare mixed-metal and mixed-oxidation state dimers with the formula [Ir(η5-C5Me5)Cl(μ-pz)MLn]. The synthesis and potential for further investigation of these complexes is discussed. / Graduate
842

Estudo da cinetica do pertecnetato nas glandulas parotidas e submaxilares em individuos normais

VILLALOBOS, JOSEFA P. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:29:32Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:56Z (GMT). No. of bitstreams: 1 01045.pdf: 1054911 bytes, checksum: df544356c8a7508645752932c9940b7f (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
843

Controle analitico dos processos de separacao de zirconio e hafnio

IHA, CHIEKO 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:30:54Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:10Z (GMT). No. of bitstreams: 1 01372.pdf: 1371976 bytes, checksum: 5d7884919c9499eae4d722ce6eb5d692 (MD5) / Dissertacao (Mestrado) - IPEN / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
844

Comportamento eletroquimico do zinco-zincato em meio de NaOH .A influencia do benzotriazol e dos ions cloreto, benzoato e silicato sobre o sistema Zn/OH-

PESSINE, ELISABETE J. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:31:48Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:07Z (GMT). No. of bitstreams: 1 02680.pdf: 7799956 bytes, checksum: 0fb7a1e9771367df25180514680a23d0 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Química - Universidade de São Paulo - IQ/USP
845

Estudos de descontaminacao zirconio-hafnio por particao no sistema tri-n-butilfosfato-varsol-acido nitrico-agua

CORREA, HELENO S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:25:16Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:09Z (GMT). No. of bitstreams: 1 00793.pdf: 5041844 bytes, checksum: 90d6f5341ec43beca948e2d6b17c2409 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP
846

Efeito da radiacao neutronica na recuperacao e recristalizacao do niobio policristalino

MONTEIRO, WALDEMAR A. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:24:34Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:09Z (GMT). No. of bitstreams: 1 00035.pdf: 1568343 bytes, checksum: d24b78db5e62e038d8e29fb63959c300 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Fisica, Universidade de Sao Paulo - IF/USP
847

Estudos espectroscopicos de fluoperovskitas dopadas com ions de metais de transicao

MARTINS, EVELY 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:38:08Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:43Z (GMT). No. of bitstreams: 1 05650.pdf: 11452261 bytes, checksum: ebbc39f29ed2ce2849bf7f8bc188fac7 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP / FAPESP:93/03991-2
848

Separacao de uranio, molibdenio e vanadio, em meio Sulfurico, por extracao com alamina 336

FLOH, BERTHA 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:24:47Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:05Z (GMT). No. of bitstreams: 1 00285.pdf: 1290882 bytes, checksum: 5969506d48a13aafc8dd3c7558145254 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP
849

Estudos para a determinacao de Itrio por analise por ativacao em presenca de lantanidios .Aplicacao da tecnica da subestequiometria

SILVA, DEBORAH I.T. da 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:26:02Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:50Z (GMT). No. of bitstreams: 1 00378.pdf: 987505 bytes, checksum: b6587927b6c5975dc6119eb53714b845 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Energia Atomica - IEA
850

Efeitos de baixas doses de radiacao gama de cobalto-60 sobre sementes de feijao, arroz e rabanete

KIKUCHI, OLIVIA K. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:32:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:29Z (GMT). No. of bitstreams: 1 01537.pdf: 1505528 bytes, checksum: 79b06b0cf173671eeb859566744153c3 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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