Made available in DSpace on 2015-05-14T13:21:07Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2772098 bytes, checksum: 3c1518599ff53c3339b74cffefd4da7a (MD5) Previous issue date: 2010-09-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work were synthesized, characterized and studied experimentally and theoretically, the compounds of general formula [MX3 (L)], where M = Sb or Bi, X = Cl, Br, L = 2,2'-bipyridine (Bpy), 1,10-phenanthroline (Phen). The synthesized compounds were characterized by elemental analysis (C, H, N, Cl and Br), thermal analysis (TG / DTA) and absorption spectroscopy in the infrared region. The results of elemental analysis suggest a stoichiometry of 1:1 salt / ligand in agreement with the stoichiometry suggested by thermogravimetric analysis. The infrared data of the ligands when compared with those of the adducts indicate a strengthening of the CC bonds, CN the aromatic ring with the coordination.The Thermochemical parameters were obtained experimentally by solution calorimetry. The enthalpy of reaction, acid-Lewis base, determined by calorimetry indicate the strongest basic character of Phen compared to metals. Enthalpies of metal-nitrogen bond follows the order of bonding strength: [BiBr3(Phen)] > [SbCl3(Phen)] > [BiBr3(Bpy)] > [SbCl3(Bpy)]. The theoretical studies were aimed to the structural properties and thermochemistry in the gas phase, through the semi-empirical PM3 method. The results of the calculations predict a geometry type distorted square pyramidal for all the adducts studied, indicating the strong influence of the lone pair of electrons of metals over distance of bond metal-nitrogen. Dipole moments are calculated in the range 10-14D, suggesting a large polar character of the compounds studied. / Nesse trabalho foram sintetizados, caracterizados e estudados experimentalmente e teoricamente, os compostos de formula geral [MX3(L)], onde M = Sb ou Bi; X= Cl, Br; L= 2,2 -bipiridina (Bpy) , 1,10-fenantrolina (Phen). Os compostos sintetizados foram caracterizados por análise elementar (C,H,N,Cl e Br), análise térmica (TG/DTA) e espectroscopia de absorção na região do infravermelho. Os resultados da analise elementar sugerem uma estequiometria de 1:1 sal/ligante em concordância com a estequiometria sugerida pela análise termogravimétrica. Os dados de infravermelho dos ligantes quando comparados com os do adutos indicam um fortalecimento das ligações CC,CN do anel aromático com a coordenação. Os parâmetros termoquímicos foram obtidos experimentalmente por calorimetria em solução. As entalpias de reação, ácido-base de Lewis, determinadas por calorimetria indicam o maior caráter básico da Phen frente aos metais estudados. Das entalpias de ligação metal-nitrogênio segue a ordem de força de ligação: [BiBr3(Phen)] > [SbCl3(Phen)] > [BiBr3(Bpy)] ] > [SbCl3(Bpy)]. Os estudos teóricos foram realizados visando as propriedades estruturais e termoquímicas em fase gasosa, através do método sem-empírico PM3. Os resultados dos cálculos predizem uma geometria do tipo pirâmide de base quadrada distorcida para todos os adutos estudados, indicando a forte influência do par de elétrons isolado dos metais sobre as distâncias de ligação metal-nitrogênio. Os momentos de dipolo calculados estão na faixa 10-14D, sugerindo um elevado caráter polar dos compostos estudados.

Interference effects of co-generated hydrides of arsenic, antimony, bismuth and selenium on trapping behavior of selenium or antimony hydrides (analytes) within iridium modified, transversely heated graphite tube atomizer (THGA) was investigated. A twin-channel hydride generation system was used for independent separate generation and introduction of analyte and interferent hydrides, i.e. in simultaneous and/or sequential analyte-interferent and interferent-analyte mode of operation. Influence of the analyte and modifier mass, interferent amount, trapping temperature and composition of the gaseous phase was studied. A simple approach for elimination of mutual interference effects by modification of the gaseous phase with oxygen in substoichiometric ratio to chemically generated hydrogen is proposed and suppression of these interference effects is demonstrated. A hypothesis on mechanism of trapping and mutual interference effects is drawn.