SciELO - Scientific Electronic Library Online

 
vol.12 número4Alkamides and phenethyl derivatives from Aristolochia gehrtiiReaction of diphenylcyclopropenone with N-acylamidine derivatives. Synthetic and mechanistic implications índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Journal of the Brazilian Chemical Society

versão impressa ISSN 0103-5053

Resumo

ANTUNES, Patrícia A.; BREVIGLIERI, Susete T.; CHIERICE, Gilberto O.  e  CAVALHEIRO, Éder T. G.. Solution and solid state thermal stability of morpholinedithiocarbamates. J. Braz. Chem. Soc. [online]. 2001, vol.12, n.4, pp. 473-480. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532001000400005.

Thermogravimetric and differential scanning calorimetric investigation of the thermal behavior of NH4+, Mn2+, Co2+, Ni2+ e Cu2+ morpholinedithiocarbamates were performed under nitrogen and air atmospheres in order to investigate the effect, in the thermal decomposition, of the presence of an oxygen as the heteroatom in the amine ring. Decomposition products were identified by their X-ray diffraction patterns. Metal sulfites and oxides were the major residues under nitrogen and air atmospheres, respectively. Spectrophotometric measurements were used to estimate the pKa =3.56 for the morpholinedithiocarbamic acid at 0.50 mol dm-3 ionic strength (NaClO4) at 25.0 °C and kinetic parameters of decomposition at different pH values (klim = 0.14 ± 0.04 s-1 e t½ lim = 5.3 ± 1.2 s).

Palavras-chave : morpholinedithiocarbamates; thermogravimetry; differential scanning calorimetry; decomposition rate constant.

        · resumo em Português     · texto em Inglês     · pdf em Inglês