Neste trabalho, os complexos tetrakis(ß-dicetonato) de terras-raras, (Q)[TR(&#946;-dicetonato)4 ] {(Q = Li+ , Na+ , K+ , (Et3 NH)+ , (Morf)+ , (TMPip)+ e (Diciclo)+ ); (TR3+ = Eu3+ , Gd3+ , Tb+ e Tm3+ ) e (&#946;-dicetonato = acac, dbm e tta), foram sintetizados, caracterizados e suas propriedades ópticas investigadas por meio de espectroscopia luminescente. Os dados de microanálises de CHN e titulação complexométrica evidenciaram a fórmula geral (Q)[TR(&#946;-dicetonato)4 ]. Os espectros de absorção na região do infravermelho indicaram o caráter anidro da maioria dos complexos, 3+ exceto para (Li)[TR(dbm))4 ].4H2 O, e que a coordenação dos &#946;-dicetonatos aos íons TR3+ ocorre através dos átomos de oxigênio dos grupos carbonila. Os difratogramas de raios-X (método do pó) evidenciam que os complexos com ligante acac e cátions derivados de metais alcalinos são mais cristalinos em relação aos compostos contendo bases nitrogenadas. O estudo fotoluminescente dos complexos (Q)[TR(&#946;-dicetonato)4] foi realizado a partir dos espectros de excitação e emissão registrados a 298 e 77K, e pela curva de decaimento luminescente. Os espectros de emissão dos compostos de Eu3+ , Tb3+ e Tm3+ apresentaram bandas finas características das transições intraconfiguracionais exibindo cores de emissão vermelha oriundas do íon Eu3+ (5 D0 7Fj J = 0-6), verde do íon Tb3+ (5D5 ? Fj, J = 6-0) e azul para do íon Tm3+ (1G4&#8594; 3H6 , e a 1G4&#8594;3 F4 ). Os desdobramentos e a intensidade das transições 5D0&#8594; 7Fj dos complexos de európio sugerem que este íon encontra-se em um ambiente químico D2d distorcido para C4v ou S4 . Com base nos dados espectrais foram determinados os parâmetros de intensidade experimentais (&#937;2, &#937;4 e &#937;6), os coeficientes de emissão radiativa (A<SUBrad) e não radiativa (A<SUBnrad) e a eficiência quântica de emissão experimental do nível 5D0 do íon Eu3+ (&#951;). Para os sistemas tetrakis contendo o ligante tta, o complexo com o contra-cátion (TMPip)+ apresentou o maior valor de &#9372 (42,1x10-20 cm-1) evidenciando um ambiente químico mais polarizável com o maior caráter covalente da ligação Eu3+ (&#946;-dicetonato). Os valores de eficiência quântica (&#951; ) do 5D0 , dos complexos tetrakis(&#946;-dicetonato) de Eu3+ , são altos quando comparados 0 com os compostos tris. Os complexos (Morf)[Eu(tta)4 ] e (TMPip)[Eu(tta)4 ] apresentaram os maiores valores de eficiência quântica &#951; = 88 e 92%, respectivamente. Portanto, estes complexos comportam-se como promissores dispositivos moleculares conversores de luz (DMCLs). A atribuição dos estados T dos ligantes acac, dbm e tta foram feitas a partir dos espectros de emissão dos complexos de gadolínio, (Q)[Gd(&#946;-dicetonato acac)4 ], registrados no estado estacionário e resolvido no tempo, a 77K. Os espectros de emissão dos complexos tetrakis, (Q)[Tm(acac)4] onde Q = Li+, Na+ e K apresentaram a transição 1G4&#8594; 3H6 bastante intensa, indicando a alta luminescência azul. Os espectros de emissão dos complexos tetrakis, (Q)[Tb(acac)4 ], Q = Li+ , Na+ e K+ mostram bandas de emissão finas características das transições 5D4&#8594;7Fj (J = 6-0) e não exibem as emissões originárias do ligante acac, indicando uma transferência de energia intramolecular 3+ eficiente do ligante acetilacetonato ao íon Tb3+ . Os dispositivos OLEDs, bicamada e tricamada, contendo os complexos tetrakis Li[Eu(dbm)4] e Li[Tb(acac)4], como camada emissora e transportadora de elétrons exibiram alta intensidade eletroluminescente vermelha e verde, oriundas das transições 5D0&#8594;7F0-4 e 5D4&#8594;7F6-0 dos íons Eu3+ e TbSUP>3+ , respectivamente. Os espectros triboluminescentes (TL) do complexo (TMPip)[Eu(tta)4 ] apresentam as transições intraconfiguracionais 5D0&#8594;7Fj (J = 0 a 4), com a transição hipersensível 5D0&#8594;7F2 proeminente na região de 612 nm. / This work reports the synthesis, characterization, spectroscopic properties of tetrakis(&#946;-diketonate) complexes of rare earths, (Q)[RE(&#946;-diketonate)4] {(Q+ = Li+, Na+, K+, (Et3NH)+, (Morf)+, (TMPip)+ and (Diciclo)+); (RE3+ = Eu3+, Gd3+, Tb+ and Tm3+) and (&$946;-diketonate = acac, dbm and tta)}. The elemental analysis of CHN and complexometric titration suggest the general formula (Q)[RE(&#946;-diketonate)4]. The infrared spectra indicated the anhydrous character of the complexes, except for (Li)[RE(dbm)4].4H2O, and the coordination between &$946;-diketonate ligands and RE3+ ions occurs through the oxygen atoms of carbonyl groups. The X-ray diffractograms (powder method) confirmed that the complexes with acac ligand and derived alkaline metals cations are more crystalline when compared with the complexes containing nitrogenated bases. The photoluminescence study of the (Q)[RE(&#946;-diketonate)4] complexes was performed through the excitation and emission spectra at 298 and 77K, and luminescence decay curves. The emission spectra of the Eu3+, Tb3+ and Tm3+ complexes displayed characteristic narrow bands arising from intraconfigurational transitions of trivalent rare earths ions and exhibited red color emission for the Eu3+ ion (5D0&#8594;7FJ, J = 0-6), green for the Tb3+ ion ( 5D4&#8594;7FJ, J = 6-0) and blue for the Tm3+ ion ( 1G4&#8594;3H6, and 1G4&#8594;3F4). The splitting and intensity of the 5D0&#8594;7FJ transitions of the europium complexes suggest the distortion of chemical environment around this Eu3+ ion from D2d to C4v or S4. Based on the spectroscopy data, the experimental intensity parameters (&#9372, &#937;4 e &#937;6), the coefficients of radioactive (Arad) and non-radioactive (Anrad) emissions and the quantum efficiency of experimental emission of the emitting 5D0 level of Eu3+ ion (&#951;) were determined. For tetrakis systems containing tta ligand, the complex with (TMPip)+ countercation presented the highest value of &#937;2 (42.1x10-20 cm-1), suggesting the presence of a highly polarizable chemical environment and consequently, indicating the highest covalent character of the Eu3+ - (&#946;-diketonate) bond. The values of quantum efficiency (&#951;) of the emitting 5D0 state of the tetrakis(&#946;-diketonate) complexes of Eu3+ were higher compared with those tris-complexes. The (Morf)[Eu(tta)4] and (TMPip)[Eu(tta)4] complexes presented highest values of quantum efficiency &#951; = 88 and 92%, respectively. Therefore, these complexes can act as potential candidates for Light Conversion Molecular Devices (LCMDs). The triplet states of the acac, dbm and tta ligands were determined from the emission spectra of gadolinium complexes, (Q)[Gd(&#946;-dicetonato acac)4], recorded by steady-state and time-resolved photoluminescence measurements, at 77K. The emission spectra of the tetrakis complexes, (Q)[Tm(acac)4] where Q+ = Li+, Na+ and K+ presented high intensity 1G4&#8594;3H6 transition, showing a intense blue luminescence. The emission spectra of tetrakis complexes, (Q)[Tb(acac)4], Q+ = Li+, Na+ e K+, exhibit characteristic narrow emission bands of the 5D4&#8594;7FJ (J = 6-0) transitions, however, the absent of the broaden band arising from the acac ligand suggests the efficient intramolecular energy transfer from the acetylacetonate ligand to Tb3+ ion. The double-layer and triple-layer OLEDs devices, containing Li[Eu(dbm)4] and Li[Tb(acac)4] tetrakis complexes as emitting layer and electron transport layer, exhibited high electroluminescent intensity with red and green emissions arising from the 5D0&#8594;7F0-4 and 5D4&#8594;7F6-0 transitions of Eu3+ and Tb3+ ions, respectively. The spectra of triboluminescence (TL) of the (TMPip)[Eu(tta)4] complex present intraconfigurational 5D0&#8594;7FJ transitions (J = 0 a 4), with the hypersensitive 5D0&#8594;7F2 transition prominent in the region around 612 nm.

O presente trabalho aborda a síntese, caracterização e estudo fotoluminescente dos complexos tetrakis(&#946;-dicetonatos) de terras raras (M)[TR(acac)4] (M+ = Li+, Na+ e K+; TR3+ = Eu3+, Gd3+, Tb3+ e Tm3+; acac- = acetilacetonato). Os dados de análise elementar evidenciam que os complexos são anidros. A espectroscopia de absorção da região do infravermelho mostra que o ligante acetilacetonato encontra-se coordenado ao íon terra rara via átomos de oxigênio. Os dados de análise térmica indicam que os complexos são termicamente estáveis até 150 °C e que são anidros. A difração de raios X demonstra que os complexos apresentam estrutura cristalina e não são isomorfos. O estado tripleto (T1) do ligante acac foi determinado com base no espectro de fosforescência do complexo (Na)[Gd(acac)4], o qual se encontra em torno de 25000 cm-1. Os espectros de emissão dos complexos (M)[Eu(acac))4] (M+ = Na+ e K+) exibiram picos finos característicos das transições intraconfiguracionais do íon Eu3+(5D0&#8594;7FJ; J = 0-6). Com base nos dados espectrais foram determinados os parâmetros de intensidade experimentais (&#937;2 e &#937;4), os coeficientes de emissão radiativa (Arad), não radiativa (Anrad) e a eficiência quântica de emissão (&#951;) para o nível 5D0 do Eu3+. Os valores dos parâmetros &#937;2 para os complexos com contracátions Na+ e K+ foram semelhantes (~23,5 10-20cm2), indicando que em ambos o íon Eu3+ encontra-se em um ambiente químico bastante polarizável. Os valores de eficiência quântica de emissão &#951; (Na+ = 72% e K+ = e 65% ) indicam que estes complexos atuam como Dispositivos Moleculares Conversores de Luz (DMCL\'s). Os espectros de emissão dos complexos (M)[Tb(acac)4] (M+ = Na+ e K+) apresentaram picos finos oriundos das transições intraconfiguracionais 5D4&#8594;7FJ (J = 6-0) do íon Tb3+ e eficiente transferência intramolecular de energia ligante - Tb3+. Os complexos (M)[Tm(acac)4] (M+ = Li+, Na+ e K+) apresentam nos espectros de emissão bandas finas correspondentes às transições 1G4&#8594;3H6, 1G4&#8594;3F4 e 1G4&#8594;3H5 do íon Tm3+. Não foi observada nesses espectros uma banda alargada originária da fosforescência do acac, indicando que a transferência intramolecular de energia para o íon Tm3+ é eficiente. A partir dos espectros de emissão dos complexos dos íons Eu3+, Tb3+ e Tm3+, foram determinadas as suas coordenadas no diagrama de cromaticidade CIE na região do vermelho, verde e azul, respectivamente, sugerindo potencial aplicação desses compostos em sistemas full-color. / This work covers the synthesis, characterization and photoluminescent study of the rare earths tetrakis¨&#946;-diketonate) complexes (M)[RE(acac)4] (M+ = Li+, Na+ and K+; RE3+ = Eu3+, Gd3+, Tb3+ and Tm3+; acac- = acetylacetonate). Data from elemental analysis shows that the complexes are anhydrous. The absorption spectroscopy in the infrared region shows that the acetylacetonate ligand is coordinated to the rare earth ion by the oxygen atoms. Thermal analysis data indicate that the complexes are thermally stable up to 150° C and that they are anhydrous. The X-ray powder diffraction demonstrates that the complex has crystalline structure and that they are not isomorphs. The first excited triplet state (T1) of the acetylacetonate ligand is determined based on the phosphorescence spectrum of the (Na)[Gd(acac)4] complex, which lies around 25000 cm-1. The emission spectra of the (M)[Eu(acac)4] (M+ = Na+ and K+) complexes showed the narrow peaks characteristic of the Eu3+ intraconfigurational transitions (5D0&#8594;7FJ; J = 0-6). Based on the spectral data, it was determined the experimental intensity parameters (&#937;2 and &#937;4), the coefficients of radiative (Arad) and non-radiative decay (Anrad) and the quantum efficiency (&#951;) of the 5D0 emitting level of the Eu3+ ion. The &#937;2 values of the complexes with Na+ and K+ countercations were similar (23.510-20 cm2), showing that in both cases the Eu3+ ion is in a very polarizable chemical environment. The quantum efficiency values &#951; (Na+ = 72% and K+ = 65%) indicate that these complexes may act as Light-Converting Molecular Devices (LCMD\'s). The emission spectra of (M)[Tb(acac)4] (M+ = Na+ and K+) complexes showed narrow peaks arising from 5D4&#8594;7FJ (J = 6-0) intraconfigurational transitions of Tb3+ ion, and also efficient ligand-Tb3+ intramolecular energy transfer. The (M) [Tm(acac)4] (M+ = Li+, Na+ and K+) complexes present narrow bands in its emission spectra corresponding to the transitions 1G4&#8594;3H6, 1G4&#8594;3F4 and 1G4&#8594;3H5 of Tm3+ ion. It was not observed in these spectra any broad band originated from the acac transitions, indicating an efficient intramolecular energy transfer from the ligand to the Tm3+ ion. Based on the emission spectra of the (M)[RE(acac)4] complexes, it was determined their coordinates on the CIE chromaticity diagram in the region of red (Eu3+), green (Tb3+) and blue (Tm3+), suggesting the potential application of these compounds in full-color systems.

Neste trabalho, os complexos tetrakis(ß-dicetonato) de terras-raras, (Q)[TR(&#946;-dicetonato)4 ] {(Q = Li+ , Na+ , K+ , (Et3 NH)+ , (Morf)+ , (TMPip)+ e (Diciclo)+ ); (TR3+ = Eu3+ , Gd3+ , Tb+ e Tm3+ ) e (&#946;-dicetonato = acac, dbm e tta), foram sintetizados, caracterizados e suas propriedades ópticas investigadas por meio de espectroscopia luminescente. Os dados de microanálises de CHN e titulação complexométrica evidenciaram a fórmula geral (Q)[TR(&#946;-dicetonato)4 ]. Os espectros de absorção na região do infravermelho indicaram o caráter anidro da maioria dos complexos, 3+ exceto para (Li)[TR(dbm))4 ].4H2 O, e que a coordenação dos &#946;-dicetonatos aos íons TR3+ ocorre através dos átomos de oxigênio dos grupos carbonila. Os difratogramas de raios-X (método do pó) evidenciam que os complexos com ligante acac e cátions derivados de metais alcalinos são mais cristalinos em relação aos compostos contendo bases nitrogenadas. O estudo fotoluminescente dos complexos (Q)[TR(&#946;-dicetonato)4] foi realizado a partir dos espectros de excitação e emissão registrados a 298 e 77K, e pela curva de decaimento luminescente. Os espectros de emissão dos compostos de Eu3+ , Tb3+ e Tm3+ apresentaram bandas finas características das transições intraconfiguracionais exibindo cores de emissão vermelha oriundas do íon Eu3+ (5 D0 7Fj J = 0-6), verde do íon Tb3+ (5D5 ? Fj, J = 6-0) e azul para do íon Tm3+ (1G4&#8594; 3H6 , e a 1G4&#8594;3 F4 ). Os desdobramentos e a intensidade das transições 5D0&#8594; 7Fj dos complexos de európio sugerem que este íon encontra-se em um ambiente químico D2d distorcido para C4v ou S4 . Com base nos dados espectrais foram determinados os parâmetros de intensidade experimentais (&#937;2, &#937;4 e &#937;6), os coeficientes de emissão radiativa (A<SUBrad) e não radiativa (A<SUBnrad) e a eficiência quântica de emissão experimental do nível 5D0 do íon Eu3+ (&#951;). Para os sistemas tetrakis contendo o ligante tta, o complexo com o contra-cátion (TMPip)+ apresentou o maior valor de &#9372 (42,1x10-20 cm-1) evidenciando um ambiente químico mais polarizável com o maior caráter covalente da ligação Eu3+ (&#946;-dicetonato). Os valores de eficiência quântica (&#951; ) do 5D0 , dos complexos tetrakis(&#946;-dicetonato) de Eu3+ , são altos quando comparados 0 com os compostos tris. Os complexos (Morf)[Eu(tta)4 ] e (TMPip)[Eu(tta)4 ] apresentaram os maiores valores de eficiência quântica &#951; = 88 e 92%, respectivamente. Portanto, estes complexos comportam-se como promissores dispositivos moleculares conversores de luz (DMCLs). A atribuição dos estados T dos ligantes acac, dbm e tta foram feitas a partir dos espectros de emissão dos complexos de gadolínio, (Q)[Gd(&#946;-dicetonato acac)4 ], registrados no estado estacionário e resolvido no tempo, a 77K. Os espectros de emissão dos complexos tetrakis, (Q)[Tm(acac)4] onde Q = Li+, Na+ e K apresentaram a transição 1G4&#8594; 3H6 bastante intensa, indicando a alta luminescência azul. Os espectros de emissão dos complexos tetrakis, (Q)[Tb(acac)4 ], Q = Li+ , Na+ e K+ mostram bandas de emissão finas características das transições 5D4&#8594;7Fj (J = 6-0) e não exibem as emissões originárias do ligante acac, indicando uma transferência de energia intramolecular 3+ eficiente do ligante acetilacetonato ao íon Tb3+ . Os dispositivos OLEDs, bicamada e tricamada, contendo os complexos tetrakis Li[Eu(dbm)4] e Li[Tb(acac)4], como camada emissora e transportadora de elétrons exibiram alta intensidade eletroluminescente vermelha e verde, oriundas das transições 5D0&#8594;7F0-4 e 5D4&#8594;7F6-0 dos íons Eu3+ e TbSUP>3+ , respectivamente. Os espectros triboluminescentes (TL) do complexo (TMPip)[Eu(tta)4 ] apresentam as transições intraconfiguracionais 5D0&#8594;7Fj (J = 0 a 4), com a transição hipersensível 5D0&#8594;7F2 proeminente na região de 612 nm. / This work reports the synthesis, characterization, spectroscopic properties of tetrakis(&#946;-diketonate) complexes of rare earths, (Q)[RE(&#946;-diketonate)4] {(Q+ = Li+, Na+, K+, (Et3NH)+, (Morf)+, (TMPip)+ and (Diciclo)+); (RE3+ = Eu3+, Gd3+, Tb+ and Tm3+) and (&$946;-diketonate = acac, dbm and tta)}. The elemental analysis of CHN and complexometric titration suggest the general formula (Q)[RE(&#946;-diketonate)4]. The infrared spectra indicated the anhydrous character of the complexes, except for (Li)[RE(dbm)4].4H2O, and the coordination between &$946;-diketonate ligands and RE3+ ions occurs through the oxygen atoms of carbonyl groups. The X-ray diffractograms (powder method) confirmed that the complexes with acac ligand and derived alkaline metals cations are more crystalline when compared with the complexes containing nitrogenated bases. The photoluminescence study of the (Q)[RE(&#946;-diketonate)4] complexes was performed through the excitation and emission spectra at 298 and 77K, and luminescence decay curves. The emission spectra of the Eu3+, Tb3+ and Tm3+ complexes displayed characteristic narrow bands arising from intraconfigurational transitions of trivalent rare earths ions and exhibited red color emission for the Eu3+ ion (5D0&#8594;7FJ, J = 0-6), green for the Tb3+ ion ( 5D4&#8594;7FJ, J = 6-0) and blue for the Tm3+ ion ( 1G4&#8594;3H6, and 1G4&#8594;3F4). The splitting and intensity of the 5D0&#8594;7FJ transitions of the europium complexes suggest the distortion of chemical environment around this Eu3+ ion from D2d to C4v or S4. Based on the spectroscopy data, the experimental intensity parameters (&#9372, &#937;4 e &#937;6), the coefficients of radioactive (Arad) and non-radioactive (Anrad) emissions and the quantum efficiency of experimental emission of the emitting 5D0 level of Eu3+ ion (&#951;) were determined. For tetrakis systems containing tta ligand, the complex with (TMPip)+ countercation presented the highest value of &#937;2 (42.1x10-20 cm-1), suggesting the presence of a highly polarizable chemical environment and consequently, indicating the highest covalent character of the Eu3+ - (&#946;-diketonate) bond. The values of quantum efficiency (&#951;) of the emitting 5D0 state of the tetrakis(&#946;-diketonate) complexes of Eu3+ were higher compared with those tris-complexes. The (Morf)[Eu(tta)4] and (TMPip)[Eu(tta)4] complexes presented highest values of quantum efficiency &#951; = 88 and 92%, respectively. Therefore, these complexes can act as potential candidates for Light Conversion Molecular Devices (LCMDs). The triplet states of the acac, dbm and tta ligands were determined from the emission spectra of gadolinium complexes, (Q)[Gd(&#946;-dicetonato acac)4], recorded by steady-state and time-resolved photoluminescence measurements, at 77K. The emission spectra of the tetrakis complexes, (Q)[Tm(acac)4] where Q+ = Li+, Na+ and K+ presented high intensity 1G4&#8594;3H6 transition, showing a intense blue luminescence. The emission spectra of tetrakis complexes, (Q)[Tb(acac)4], Q+ = Li+, Na+ e K+, exhibit characteristic narrow emission bands of the 5D4&#8594;7FJ (J = 6-0) transitions, however, the absent of the broaden band arising from the acac ligand suggests the efficient intramolecular energy transfer from the acetylacetonate ligand to Tb3+ ion. The double-layer and triple-layer OLEDs devices, containing Li[Eu(dbm)4] and Li[Tb(acac)4] tetrakis complexes as emitting layer and electron transport layer, exhibited high electroluminescent intensity with red and green emissions arising from the 5D0&#8594;7F0-4 and 5D4&#8594;7F6-0 transitions of Eu3+ and Tb3+ ions, respectively. The spectra of triboluminescence (TL) of the (TMPip)[Eu(tta)4] complex present intraconfigurational 5D0&#8594;7FJ transitions (J = 0 a 4), with the hypersensitive 5D0&#8594;7F2 transition prominent in the region around 612 nm.

O presente trabalho aborda a síntese, caracterização e estudo fotoluminescente dos complexos tetrakis(&#946;-dicetonatos) de terras raras (M)[TR(acac)4] (M+ = Li+, Na+ e K+; TR3+ = Eu3+, Gd3+, Tb3+ e Tm3+; acac- = acetilacetonato). Os dados de análise elementar evidenciam que os complexos são anidros. A espectroscopia de absorção da região do infravermelho mostra que o ligante acetilacetonato encontra-se coordenado ao íon terra rara via átomos de oxigênio. Os dados de análise térmica indicam que os complexos são termicamente estáveis até 150 °C e que são anidros. A difração de raios X demonstra que os complexos apresentam estrutura cristalina e não são isomorfos. O estado tripleto (T1) do ligante acac foi determinado com base no espectro de fosforescência do complexo (Na)[Gd(acac)4], o qual se encontra em torno de 25000 cm-1. Os espectros de emissão dos complexos (M)[Eu(acac))4] (M+ = Na+ e K+) exibiram picos finos característicos das transições intraconfiguracionais do íon Eu3+(5D0&#8594;7FJ; J = 0-6). Com base nos dados espectrais foram determinados os parâmetros de intensidade experimentais (&#937;2 e &#937;4), os coeficientes de emissão radiativa (Arad), não radiativa (Anrad) e a eficiência quântica de emissão (&#951;) para o nível 5D0 do Eu3+. Os valores dos parâmetros &#937;2 para os complexos com contracátions Na+ e K+ foram semelhantes (~23,5 10-20cm2), indicando que em ambos o íon Eu3+ encontra-se em um ambiente químico bastante polarizável. Os valores de eficiência quântica de emissão &#951; (Na+ = 72% e K+ = e 65% ) indicam que estes complexos atuam como Dispositivos Moleculares Conversores de Luz (DMCL\'s). Os espectros de emissão dos complexos (M)[Tb(acac)4] (M+ = Na+ e K+) apresentaram picos finos oriundos das transições intraconfiguracionais 5D4&#8594;7FJ (J = 6-0) do íon Tb3+ e eficiente transferência intramolecular de energia ligante - Tb3+. Os complexos (M)[Tm(acac)4] (M+ = Li+, Na+ e K+) apresentam nos espectros de emissão bandas finas correspondentes às transições 1G4&#8594;3H6, 1G4&#8594;3F4 e 1G4&#8594;3H5 do íon Tm3+. Não foi observada nesses espectros uma banda alargada originária da fosforescência do acac, indicando que a transferência intramolecular de energia para o íon Tm3+ é eficiente. A partir dos espectros de emissão dos complexos dos íons Eu3+, Tb3+ e Tm3+, foram determinadas as suas coordenadas no diagrama de cromaticidade CIE na região do vermelho, verde e azul, respectivamente, sugerindo potencial aplicação desses compostos em sistemas full-color. / This work covers the synthesis, characterization and photoluminescent study of the rare earths tetrakis¨&#946;-diketonate) complexes (M)[RE(acac)4] (M+ = Li+, Na+ and K+; RE3+ = Eu3+, Gd3+, Tb3+ and Tm3+; acac- = acetylacetonate). Data from elemental analysis shows that the complexes are anhydrous. The absorption spectroscopy in the infrared region shows that the acetylacetonate ligand is coordinated to the rare earth ion by the oxygen atoms. Thermal analysis data indicate that the complexes are thermally stable up to 150° C and that they are anhydrous. The X-ray powder diffraction demonstrates that the complex has crystalline structure and that they are not isomorphs. The first excited triplet state (T1) of the acetylacetonate ligand is determined based on the phosphorescence spectrum of the (Na)[Gd(acac)4] complex, which lies around 25000 cm-1. The emission spectra of the (M)[Eu(acac)4] (M+ = Na+ and K+) complexes showed the narrow peaks characteristic of the Eu3+ intraconfigurational transitions (5D0&#8594;7FJ; J = 0-6). Based on the spectral data, it was determined the experimental intensity parameters (&#937;2 and &#937;4), the coefficients of radiative (Arad) and non-radiative decay (Anrad) and the quantum efficiency (&#951;) of the 5D0 emitting level of the Eu3+ ion. The &#937;2 values of the complexes with Na+ and K+ countercations were similar (23.510-20 cm2), showing that in both cases the Eu3+ ion is in a very polarizable chemical environment. The quantum efficiency values &#951; (Na+ = 72% and K+ = 65%) indicate that these complexes may act as Light-Converting Molecular Devices (LCMD\'s). The emission spectra of (M)[Tb(acac)4] (M+ = Na+ and K+) complexes showed narrow peaks arising from 5D4&#8594;7FJ (J = 6-0) intraconfigurational transitions of Tb3+ ion, and also efficient ligand-Tb3+ intramolecular energy transfer. The (M) [Tm(acac)4] (M+ = Li+, Na+ and K+) complexes present narrow bands in its emission spectra corresponding to the transitions 1G4&#8594;3H6, 1G4&#8594;3F4 and 1G4&#8594;3H5 of Tm3+ ion. It was not observed in these spectra any broad band originated from the acac transitions, indicating an efficient intramolecular energy transfer from the ligand to the Tm3+ ion. Based on the emission spectra of the (M)[RE(acac)4] complexes, it was determined their coordinates on the CIE chromaticity diagram in the region of red (Eu3+), green (Tb3+) and blue (Tm3+), suggesting the potential application of these compounds in full-color systems.

Three new tetrakis [Rh2(PhNCOCH3)4·xNCR] (R = {2-CH3}C6H4 (x=2), R = {3-CH3}C6H4 (x=1), R = (3-CN)C6H4∞ (x=1)) complexes have been synthesized and characterized. These complexes were characterized by IR and 1H NMR spectroscopies and X-ray crystallography which solved with R1<0.05. [Rh2(PhNCOCH3)4·2NC{2-CH3}C6H4] was triclinic (a=9.79Å, b=14.79Å, c=16.36Å, α=103.84⁰, β=99.17⁰, γ=99.77⁰, P-1(#2), μCN=2227.78cm-1, Rh-Rh=2.42Å, N-C=1.13Å, 1.14Å, Rh-N=2.34Å, 2.35Å, Rh-N-C=151.6⁰, 152.5⁰, Rh-Rh-N=173.0⁰, 174.6⁰). [Rh2(PhNCOCH3)4·NC{3-CH3}C6H4] was triclinic (a=11.71Å, b=13.02Å, c=13.40Å, α=72.34⁰, β=66.78⁰, γ=82.74⁰, P-1(#2), μCN=2241.28cm-1, Rh-Rh=2.40Å, N-C=1.14Å, Rh-N=2.16Å, Rh-N-C=166.3⁰, Rh-Rh-N=175.9⁰). [Rh2(PhNCOCH3)4·2NC{3-CN}C6H4]∞ was triclinic (a=11.88Å, b=13.30Å, c=14.88Å, α=77.98⁰, β=74.61⁰, γ=65.48⁰, P-1(#2), μCN=2233.57cm-1, Rh-Rh=2.41Å, N-C=1.13Å, 1.13Å, Rh-N=2.18Å, 2.38Å, Rh-N-C=166.8⁰, 127.7⁰, Rh-Rh-N=178.4⁰, 175.4⁰). The bond distances, bond angles and bonding interactions (σ and π) are similar to the metal-carbene bond formed during carbenoid transformations catalyzed by dirhodium(II) compounds.

Nuclear magnetic resonance (NMR) spectroscopy has proven to be an invaluable tool for the modern chemist, despite being a relatively insensitive spectroscopic technique. However, it is precisely this insensitivity that limits characterization of low-receptivity nuclides, which make up the bulk of transition metal nuclides, in particular. In this work, high-fields were used to collect the first 61Ni solid-state NMR (SSNMR) spectra of diamagnetic nickel compounds, specifically, bis(1,5-cyclooctadiene)nickel(0) (Ni(cod)2), tetrakis(triphenylphosphite)nickel(0) (Ni[P(OPh)3]4), and tetrakis(triphenylphosphine)nickel(0) (Ni(PPh3)4). This was complemented by NMR study of the co-ordinated ligands and 61Ni density functional theory (DFT) computations. 61Ni SSNMR spectra of Ni(cod)2 were used to determine its isotropic chemical shift (δiso = 965 ± 10 ppm), span (Ω = 1700 ± 50 ppm), skew (κ = -0.15 ± 0.05), quadrupolar coupling constant (CQ = 2.0 ± 0.3 MHz), quadrupolar asymmetry parameter (η = 0.5 ± 0.2), and the relative orientation of the chemical shift and EFG tensors. Solution study of Ni(cod)2 saturated in C6D6 yielded a narrow 61Ni signal, and the temperature dependence of δiso(61Ni) was assessed (δiso being 936.5 ppm at 295 K). The solution is proposed as a secondary chemical shift reference for 61Ni NMR in lieu of the extremely toxic Ni(CO)4 primary reference. For Ni[P(OPh)3]4, 61Ni SSNMR was used to infer the presence of two distinct crystallographic sites and establish ranges for δ¬iso in the solid state, as well as an upper bound for CQ (3.5 MHz for both sites). For Ni(PPh3)4, fitting provided a δiso value of 515 ± 10 ppm, Ω of 50 ± 50 ppm, κ of 0.5 ± 0.5, CQ of 0.05 ± 0.01 MHz, and η of 0.0 ± 0.2. Ni(cod)2 was chosen for study as it is a ubiquitous source of nickel(0), used for both further synthesis of nickel(0) compounds and directly as a catalyst. The study of Ni[P(OPh)3]4 and Ni(PPh3)4 demonstrated the utility of 61Ni SSNMR given the lack of a previously reported crystal structure for both and the transient nature of Ni(PPh3)4 in solution. The work begins in Chapter 1 by introducing the interactions fundamental to NMR spectroscopy, before moving on to briefly review the field of transition metal nuclide NMR, the chemistry of nickel (with an emphasis on homogeneous catalysis with nickel(0)), and the literature with respect to nickel NMR up to this point. In Chapter 2, the theory and practice of NMR are explained, including solid-state NMR, as well as the basic principles of density functional theory NMR computations. The specific experimental and computational methods of this work are also introduced. Lastly, in Chapter 3 the results are discussed in the context of the concepts presented and literature reviewed, and highlight the use of 61Ni NMR as a means to gain novel information about the chemistry of the compounds studied.

The potential antimalarial and anticancer effect of molecules containing 1,10-phenanthroline skeleton has been suspected on several previous studies. It is why the goal of this project is to synthesize novel 1,10-phenanthrolines and cyclic analogs. The originality of this project is the synthesis way of these novel compounds. Indeed, these structures will be obtained through an original redox approach developed in the SMITH laboratory using the tetrakis(dimethylamino)ethylene (TDAE) reagent.      The TDAE is an electron rich organic molecule which is an effective reducing agent capable of generating an anion from halogenated derivatives under mild conditions via a single electron transfer (SET). From the different substrate we will work with, the TDAE will generate an anion which will be additioned on the 1,10-phenanthroline-5,6-dione. These different substrates will be aromatic and heterocyclic nitro-benzylic, and quinonic derivates as well as bromodifluoromethyl heteroarylated substrates. A one pot two step (reduction, dehydration) reaction will be done on these addition products, in order to obtain a cyclised product.        It is the first time we try these reactions on these kind on molecules, it is why this project needs a lot of optimization and that the yield obtained are medium or equal to zero. However, we observed that the addition reaction with TDAE worked with 4 substrates out of 6. We tried the cyclisation reaction on only one addition product and we think that after some improvement of the reaction conditions and the work-up, we will be able to obtain the product with a good yield. / Tidigare studier har indikerat att molekyler med 1,10-phenanthrolineskelett har en skyddande effekt mot malaria och cancer. Syftet med detta projekt är att syntetisera nya 1,10-phenanthrolinar och cykliska analoger. Framställningsmetoden som användes i denna studie har inte undersökts tidigare.    Föreningen skapades genom en originalmetod utnyttjande en redoxreaktion med hjälp av en TDAE-reagens. TDAE är en elektronrik organisk molekyl och fungerar som en effektiv reduktionsagent. Med hjälp av en enelektronöverföring (SET) kan en anjon framställas under milda förhållanden utifrån halogena derivat. Anjonen tillförs 1,10-phenanthroline-5,6-dione. De olika substraten är heteroaromatiska nitro-benzyliska och quinoniska derivat, samt bromodifluorometylheteroarylerade. Cykliska produkter erhölls genom en tvåstegsreaktion (reduktion, dehydratisering) genomförd i ett enda reaktionskärl.   Med detta projekt har dessa reaktioner för första gången testats på den här typen av molekyler. Det krävs mer optimering eftersom utbytena var låga till medelhöga. Utav sex möjliga substrat fungerade additionsreaktionen med TDAE med fyra stycken. I detta försök testades dock endast en cyklisk reaktion på additionsprodukten. Med ytterligare förbättringar av reaktionsvillkor och upparbetningar förväntas man kunna producera önskad produkt i gott utbyte.

During World War II, it was discovered that when lead was added to double-base propellants, it produced beneficial burn rate phenomena. Specifically, the propellant burn rate first increased unexpectedly at low pressures, then the burn rate became independent of pressure, followed lastly by “mesa burning” where the burn rate actually decreased with increasing pressure. This results in a beneficial negative feedback mechanism. Over the past 75 years, researchers have explored different lead complexes to achieve better propellant performance. However, over the last decade, research has shifted to finding an alternative to using lead as an additive to reduce toxicity. Until the attempts detailed herein, researchers had not, to our knowledge attempted to combine double-base propellant stabilizers with various metals to achieve these desired results. In doing so, we prepared two lead complexes, Tetrakis (µ3-(4-methyl-3-nitrophenyl imido lead (II))) 1, and Bis(dinitrophenyl imido lead(II)) 2, that were synthesized by reacting lead bis(trimethylsilyl)amide with a common double-base propellant stabilizer 2-nitrodiphenylamine (NDPA) and 4-methyl-3-nitroaniline. Both complexes formed from protolysis of the trimethylsilylamide ligand by the acidic proton of the amine, and crystallized from tetrahydrofuran (THF). Bomb calorimetry coupled with crystal density structure determined that 1 has a very high energy density of 74.1 MJ/L, more than three times the energy density of conventional nitroamine explosives, whereas 2 was lower at 38.2 MJ/L. The structure, charge and characterization of 1 and 2 are discussed. However, each complex is air sensitive making burn rate experimentation infeasible, so any possible changes to the propellant as an additive remained undetermined. Attempts to use of tin, zinc, or bismuth bis(trimethyl)amides in place of lead, were unsuccessfully characterized, although reactions were likely observed. / Chemistry

À ce jour, les seul dosimètres purement tridimensionnels (3D) sont basés sur la détection d’une propriété physique résultant d’une série de réactions chimiques radio-induites dans un volume de gel ou de plastique. Les études initiales ont généré beaucoup d’enthousiasme mais ces dosimètres 3D ne sont pas parvenus à une utilisation répandue dans les départements de radio-oncologie pour l’assurance-qualité 3D et la vérification de traitements complexes de radiothérapie moderne. Le temps et la complexité de la préparation de ces dosimètres 3D ne sont pas les raisons principales qui empêchent leur déploiement clinique. Ce sont plutôt leurs performances et la reproductibilité des mesures qui doivent être améliorées. Les plus étudiés et les plus utilisés parmi les différents types de dosimètres 3D sont les dosimètres à gels de polymère. De nombreuses compositions chimiques ont été proposées et testées pour la dosimétrie à gels de polymère. L’utilisation d’un antioxydant s’est révélée une découverte majeure dans le domaine puisque l’oxygène interfère avec le mécanisme de réponse des gels. Pourtant, un nombre croissant d’erreurs inexpliquées ont été rapportées dans les écrits et ont soulevé un doute sur la reproductibilité et la justesse des doses déterminées avec ces gels. Cette thèse a été entreprise pour étudier les sources radiochimiques d’erreurs dans les dosimètres à gels de polymère. Il était admis dans les écrits que l’utilisation d’un antioxydant permettait de contoumer tous les effets non-désirés de l’oxygène. Cette thèse démontre que cela était faux. Une méthodologie a été développée pour isoler l’effet de l’oxygène dans un gel de polymère contenant ou non un antioxydant. Les résultats ont révélé que la présence conjointe d’oxygène et d’antioxydant modifie la réponse du dosimètre. Indépendamment de la composition du dosimètre et de l’antioxydant, cet effet peut induire des erreurs dosimétriques significatives dans des mesures simples et dont les origines étaient difficilement appréciables en ignorant l’effet de l'oxygène et de l’antioxydant. Nos résultats nous permettent de postuler les réactions dominantes des antioxydants étudiés et leur devenir chimique au sein d’un gel de polymère sous irradiation. Puisque l’effet de l’oxygène et de l’antioxydant était négligé, plusieurs autres facteurs physico-chimiques faisaient l’objet d’hypothèse pour expliquer les erreurs observées. Ces facteurs incluent la compression des gels et des variations de propagation et de terminaison de la polymérisation reliées à la chaleur générée pendant la polymérisation. Des études détaillées de ces effets nous permettent de refuter ces hypothèses. Nos résultats nous permettent d’analyser, de catégoriser et de proposer des explications sur l’origine des erreurs dosimétriques recensées dans les écrits. Finalement, l’effet d’un antioxydant en particulier, le chlorure de tetrakis-(hydroxyméthyle) phosphonium (THPC), a été étudié en relation avec la structure du polymère formé dans un gel de polymère basé sur l’acrylamide. Le THPC est l’antioxydant le plus utilisé dans les différents dosimètres à gels de polymère. La spectroscopie FT-Raman et la microscopie électronique ont révélé que le THPC réagit avec les monomères pendant la polymérisation. Notre interprétation suggère un rôle important du THPC dans les variations de réponse à la dose dans les gels de polymère. La conclusion générale de cette thèse est que l’élimination chimique de l'oxygène par un antioxydant facilite grandement la préparation des dosimètres mais leur performance en est grandement altérée en comparaison avec des préparations dites anoxiques. L’oxygène demeure une source majeure d’erreur dans les dosimètres à gels de polymère.

Doctor of Philosophy / Department of Chemical Engineering / Keith L. Hohn / To characterize surface properties by current techniques, metal oxides typically have to be pre-treated at high temperature to remove surface absorbents. Therefore, a new low temperature method which can provide information on the surface chemistry is desired. In this work, the surface properties of metal oxide samples were studied by tetrakis(dimethylamino)ethylene (TDE) chemiluminescence (CL). This chemiluminescent method was also employed in probing the properties of reversed microemulsions. It was found that the emission intensity vs. reaction time curve (I[subscript]t) of catalyzed TDE CL on MgO was affected by the distributions and types of surface hydroxyl groups. Isolated hydroxyls with lower coordination were found to have higher catalytic reactivity for the emission of TDE CL. Although hydrogen bonded hydroxyls also catalyze the TDE oxidation reaction, the influence on the light emission was negative. Because the properties of surface hydroxyls are associated with specific orientations of adjacent ions, information on surface hydroxyls can provide information about some general surface characteristics of a metal oxide. When characterizing surface hydroxyls on Al[subscript]2O[subscript]3 by TDE CL, it was found that the catalytic reactivity of isolated hydroxyl groups is strongly associated with the stretching frequency of isolated hydroxyl. The stretching frequency of an isolated hydroxyl group is related to the modification of the adjacent ions and the coordination of the isolated hydroxyl. The results showed that the blue-shifts in the stretching frequencies of isolated hydroxyls led to increases in the catalytic reactivity of Al[subscript]2O[subscript]3 surfaces for the emission of TDE CL. TDE CL was further applied in characterizing the surfaces of other metal oxides and chemically grafted Al[subscript]2O[subscript]3. The results indicated that the isolated hydroxyl groups with fewer adjacent ions likely have higher affinity for the binding of grafting agents. Higher emission intensities were obtained from catalyzed TDE CL on metal oxides featuring higher percentages of isolated hydroxyls. The determination of a surfactant’s critical micellar concentration was accomplished by measuring the decay rate of the emission of TDE CL in a reversed microemulsion system. In this study, the CMC values of non-ionic and ionic surfactants were measured in different non-polar solvents.