Mary K. S. Batista

Bis(pentamethylene)urea complexes of the lanthanide nitrates: synthesis, characterization, properties

Lanthanide nitrate complexes of bis(pentamethylene)urea (BPMU) with general formula Ln(NO 3 ) 3 3BPMU, where Ln: La, Nd, Sm, Eu, Ho and Er have been prepared and characterized based on CHN elemental analyses, lanthanide titration with EDTA, molar conductivity, spectroscopic data and thermal studies. The infrared spectra show that ligands (BPMU) are bonded through the carbonyl oxygen, nitrate counter-ions are bidentate linked to the central ions. The structure of the neodymium complex was determined. The crystal is monoclinic, P2 1/c , Z = 4, with the following parameters: a = 10.148(1) A, b = 21.879(2), c = 19.154(2) A, β = 104.11(1)°, V = 4124.3(7) A 3 . The polyhedron is a distorted tricapped trigonal prism, coordination number nine.

Propriedades espectroscópicas e parâmetros ópticos-eletrônicos dos complexos Ln(NO3)3.2DTPO.4H2O (Ln = Nd e Er)

Complexes with the composition Ln(NO3)3.2DTPO.4H2O (Ln = Nd and Er) were synthesized and characterized by infrared and visible absorption spectra (solid state and solution). The results of the absorption spectra in the solid state suggest that metal-ligand bonds are essentially electrostatic in all complexes. The absorption spectra of the nitrate salt solution presented smaller values of the oscillator strength when compared to the spectra of the complexes in the same solvent.

Avaliação dos parâmetros ópticos-eletrônicos do íon Nd3+nos compostos Nd(TMS)3.9H2O e Nd(TMS)(3)5BPMU.2H2O em solução

Electronic systems when submitted to an electrical field of electromagnetic radiation, acquire induced dipole moment, modifying the distribution of charge and distortion the molecular geometry. In this paper, electronic polarizability when evaluated for the Nd(TMS)3.9H2O and Nd(TMS)35BPMU.2H2O, were TMS = trifluorometanessulfonate and BPMU = bis(pentametileno)ureia, in methanol and acetonitrile solutions from the electronic absorption spectra. When the solvent is acetonitrile the distribution on electronic cloud showed greater values in the compounds.

Parâmetros cinéticos da degradação térmica de complexos entre percloratos de terras raras com lactama

Complexes of rare earth perchlorates with 2-azacyclononanone (AZA) were synthesized (molar ratio 1:8) by reaction of hydrated perchlorates in ethanol and triethlylorthoformate by a vapor diffusion method and they were characterized by complexometric analyses with EDTA, CHN microanalytical procedures, IR absorption spectra, thermogravimetry in air and N2 atmosphere and differential scanning calorimetry (DSC) in the N2 atmosphere. The theoretical kinetic study was carried out using the QBASIC program inputting the TG data.