The spectrophotometric determination of the pka of pyrrolidinedithiocarbamic and piperidinedithiocarbamic acids, based on diode array measurements
A spectrophotometric method, based on the use of a diode array spectrophotometer, is proposed in order to determine the pKa of pyrrolidinedithiocarbamic (HPyr-I) and piperidinodithiocarbamic (HPip-II) acids. The high speed of data acquisition of the equipment made it possible to minimize the problem of acid decomposition. The values obtained were 3.10(I) and 3.51(II) in I = 0.50 mol L-1 (NaClO4) at 25.0 °C, and are consistent with the acid decomposition mechanism. A discussion is presented based on the shape of the compound spectra in acidic and basic media and their relation to the order of the pKa values for I and II.
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| Main Authors: | , |
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| Format: | Digital revista |
| Language: | English |
| Published: |
Sociedade Brasileira de Química
1997
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| Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531997000100010 |
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