PROTONATION EQUILIBRIA OF L-DOPA AND 1,10 PHENONTHROLINE IN PROPYLENE GLYCOL-WATER MIXTURES

Protonation equilibria of L-Dopa and 1,10 phenonthroline have been studied in varying concentrations (0-60% v/v) of propylene glycol-water mixtures maintaining an ionic strength of 0.16 mol dm-3 at 303 K using pH metric method. The protonation constants have been calculated with the computer program...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	RAMA RAJU,B, SANTHEE DEVI,K V, PADMAJA,N, NAGESWARA RAO,G
Lenguaje:	English
Publicado:	Sociedad Chilena de Química 2011
Materias:	Protonation equilibria propylene glycol L-Dopa 1,10-Phenanthroline
Acceso en línea:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072011000400004
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:scielo:S0717-97072011000400004
record_format	dspace
spelling	oai:scielo:S0717-970720110004000042012-03-06PROTONATION EQUILIBRIA OF L-DOPA AND 1,10 PHENONTHROLINE IN PROPYLENE GLYCOL-WATER MIXTURESRAMA RAJU,BSANTHEE DEVI,K VPADMAJA,NNAGESWARA RAO,G Protonation equilibria propylene glycol L-Dopa 1,10-Phenanthroline Protonation equilibria of L-Dopa and 1,10 phenonthroline have been studied in varying concentrations (0-60% v/v) of propylene glycol-water mixtures maintaining an ionic strength of 0.16 mol dm-3 at 303 K using pH metric method. The protonation constants have been calculated with the computer program MINIQUAD75 and the best fit models are arrived at based on statistical grounds employing crystallographic R factor, χ2 , skewness and kurtosis. Dopa has three dissociable protons and one amino group which associate with proton. It exists as LH4+ at low pH and gets deprotonated with the formation of LH3, LH2- and LH2- successively with increase in pH. Phen forms LH2(2+) at low pH and gets deprotonated with the formation of LH+ and L with increase in pH. Secondary formation functions confirm the existence of 3 and 2 protonation equilibria for dopa and phen, respectively. The linear increase of log values of protonation constants of Dopa with decreasing dielectric constant of PG-water mixtures indicates the dominance of electrostatic forces in the protonation-deprotonation equilibria. Phen exhibits non-linear trend indicating the dominance of non-electrostatic forces.info:eu-repo/semantics/openAccessSociedad Chilena de QuímicaJournal of the Chilean Chemical Society v.56 n.4 20112011-12-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072011000400004en10.4067/S0717-97072011000400004
institution	Scielo Chile
collection	Scielo Chile
language	English
topic	Protonation equilibria propylene glycol L-Dopa 1,10-Phenanthroline
spellingShingle	Protonation equilibria propylene glycol L-Dopa 1,10-Phenanthroline RAMA RAJU,B SANTHEE DEVI,K V PADMAJA,N NAGESWARA RAO,G PROTONATION EQUILIBRIA OF L-DOPA AND 1,10 PHENONTHROLINE IN PROPYLENE GLYCOL-WATER MIXTURES
description	Protonation equilibria of L-Dopa and 1,10 phenonthroline have been studied in varying concentrations (0-60% v/v) of propylene glycol-water mixtures maintaining an ionic strength of 0.16 mol dm-3 at 303 K using pH metric method. The protonation constants have been calculated with the computer program MINIQUAD75 and the best fit models are arrived at based on statistical grounds employing crystallographic R factor, χ2 , skewness and kurtosis. Dopa has three dissociable protons and one amino group which associate with proton. It exists as LH4+ at low pH and gets deprotonated with the formation of LH3, LH2- and LH2- successively with increase in pH. Phen forms LH2(2+) at low pH and gets deprotonated with the formation of LH+ and L with increase in pH. Secondary formation functions confirm the existence of 3 and 2 protonation equilibria for dopa and phen, respectively. The linear increase of log values of protonation constants of Dopa with decreasing dielectric constant of PG-water mixtures indicates the dominance of electrostatic forces in the protonation-deprotonation equilibria. Phen exhibits non-linear trend indicating the dominance of non-electrostatic forces.
author	RAMA RAJU,B SANTHEE DEVI,K V PADMAJA,N NAGESWARA RAO,G
author_facet	RAMA RAJU,B SANTHEE DEVI,K V PADMAJA,N NAGESWARA RAO,G
author_sort	RAMA RAJU,B
title	PROTONATION EQUILIBRIA OF L-DOPA AND 1,10 PHENONTHROLINE IN PROPYLENE GLYCOL-WATER MIXTURES
title_short	PROTONATION EQUILIBRIA OF L-DOPA AND 1,10 PHENONTHROLINE IN PROPYLENE GLYCOL-WATER MIXTURES
title_full	PROTONATION EQUILIBRIA OF L-DOPA AND 1,10 PHENONTHROLINE IN PROPYLENE GLYCOL-WATER MIXTURES
title_fullStr	PROTONATION EQUILIBRIA OF L-DOPA AND 1,10 PHENONTHROLINE IN PROPYLENE GLYCOL-WATER MIXTURES
title_full_unstemmed	PROTONATION EQUILIBRIA OF L-DOPA AND 1,10 PHENONTHROLINE IN PROPYLENE GLYCOL-WATER MIXTURES
title_sort	protonation equilibria of l-dopa and 1,10 phenonthroline in propylene glycol-water mixtures
publisher	Sociedad Chilena de Química
publishDate	2011
url	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072011000400004
work_keys_str_mv	AT ramarajub protonationequilibriaofldopaand110phenonthrolineinpropyleneglycolwatermixtures AT santheedevikv protonationequilibriaofldopaand110phenonthrolineinpropyleneglycolwatermixtures AT padmajan protonationequilibriaofldopaand110phenonthrolineinpropyleneglycolwatermixtures AT nageswararaog protonationequilibriaofldopaand110phenonthrolineinpropyleneglycolwatermixtures
_version_	1718445453750566912

PROTONATION EQUILIBRIA OF L-DOPA AND 1,10 PHENONTHROLINE IN PROPYLENE GLYCOL-WATER MIXTURES

Ejemplares similares