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Quimica OrganicaJabones/tensioactivos/detergen
tes/soap
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Recordemos Acidos carboxilicos
Estructura de Lewis del acido formico
OC
H OH
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Propiedades fisicas de acidos carboxilicos
Acidos carboxilicos son polares:
OC
OH
CH3 ++++++++
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Carboxylic acids pueden formar puentes hidrogeno:
++++
++++
CH3 CO
O
HCH3C
O
OH
Propiedades fisicas de acidos carboxilicos
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Propiedades fsicas de los cidoscarboxilicos
Carboxylic acids also interact with water molecules by hydrogen
bonding through both the carboxyl oxygen and the hydroxyl
group.
H OH HO
H
HOH
HO
HOC
CH3 OH
H
HO
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Preparation of Carboxylic Acids
Oxidation of Primary Alcohols
CH3(CH2)5CH2OH H2CrO4 CH3(CH2)5COHO
HOCH2CH2CH2CH2OH HOCCH2CH2COHO O
KMnO4
1-heptanol heptanoic acid
1,4-butanediol butanedioic acid
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Acidity of Carboxylic AcidsAll carboxylic acids, whether soluble
or
insoluble in water, react quantitatively with NaOH, KOH, and
other strong bases to form salts
CO2H CO2 Na+ H2O + NaOH
benzoic acidlevemente soluble en agua(only slightly soluble in
H2O)
sodium benzoate soluble en agua(very soluble in water)
Acidity of Carboxylic AcidsCarboxylic acids solo reaccionan con
bases
debiles como el bicarbonato de sodio para formar sales
CO2 KCH OHCHO HCO2H
CO2 KCH OHCHO HCO2 Na
+ NaHCO3 + CO2 + H2O
potassium hydrogen tartrate (cream of tartar)
sodium bicarbonate (baking soda)
Baking powder: una mezcla de bicarbonato de sodio con tartrato
acido de potasio. Cuando se aade agua, la parte acida de la sal del
tartrato reacciona , y se libera dioxido de carbono.
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Derivatives of Carboxylic AcidsOC
R OCO
R
OC
R OR
OC
R NR
R
OC
R Clan acid chloride an anhydride
an ester an amide
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Reacciones de esteres
Hidrolisis Los Esteres son normalmente no-reactivos con
agua. Sin embargo, en presencia de acidos (aq. HCl
or H2SO4) o bases (NaOH or KOH), pueden hidrolizarse
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Hidrlisis Catalizada por cidos
El reverso de la esterificacin de Fischer:
OC
CH3 OCH2CH3
OC
CH3 OH
+ H2O
+ HOCH2CH3
H
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Base-Promoted Hidrolisis promovida por bases
Esta reacci es usada para la obtencion de obtencion de
jabonesjabones
OC
CH3 OCH2CH3
OC
CH3 O Na
+ NaOH
+ HOCH2CH3
H2O
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Mechanism of Saponification
Step One Nucleophilic addition of hydroxide anion:
OC
CH3 OCH2CH3
OHOCCH3 OCH2CH3OH
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Mechanism of Saponification
Step One Nucleophilic addition of hydroxide anion:
OC
CH3 OCH2CH3
OHOCCH3 OCH2CH3OH
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Mechanism of Saponification
Step Two Elimination of alkoxide anion:
OCCH3 OCH2CH3OH
OC
CH3 OH + OCH2CH3
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Mechanism of Saponification
Step Two Elimination of alkoxide anion:
OCCH3 OCH2CH3OH
OC
CH3 OH + OCH2CH3
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Mechanism of Saponification
Step Three Proton reorganization (acidbase reaction):
OC
CH3 O + HOCH2CH3
OC
CH3 OH + OCH2CH3
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Mechanism of Saponification
Step Three Proton reorganization (acidbase reaction):
OC
CH3 O + HOCH2CH3
OC
CH3 OH + OCH2CH3
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Ejemplo ProblemaComplete the following reaction:
OC
CH3 O
hydrolysis inaqueous acid
H3OOC
CH3 OHHO+
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Complete the following reaction:
OC
CH3 O
hydrolysis inaqueous acid
H3OOC
CH3 OHHO+
Ejemplo Problema
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Sample Problem
Complete the following reaction:
OCO
CH3CH2
OC
CH3 OCH2 saponification in
aqueous NaOH
OC
CH3 O NaNaOH H2O
2 + HOCH2CH2OH
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Sample Problem
Complete the following reaction:
OCO
CH3CH2
OC
CH3 OCH2 saponification in
aqueous NaOH
OC
CH3 O NaNaOH H2O
2 + HOCH2CH2OH
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Sample Problem
Complete the following reaction:
OCO
CH3CH2
OC
CH3 OCH2 saponification in
aqueous NaOH
OC
CH3 O NaNaOH H2O
2 + HOCH2CH2OH
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Soaps/ Jabones Sodium stearate/ estereato de Na:
ionic(hydrophilic)
hydrocarbon(hydrophobic)
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Soaps/ Jabones a partir de grasa
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Soap/JabonLa micela de Jabn:
Na
CO2
CO2
CO2
CO2
CO2O2C
O2C
O2C
O2C
O2C
O2C
CO2
O2C CO2
O2C
Na
Na
Na Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
H2OH2O
H2O
H2OH2O
H2O H2O
H2O
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Soap A soap micelle:
Na
CO2
CO2
CO2
CO2
CO2O2C
O2C
O2C
O2C
O2C
O2C
CO2
O2C CO2
O2C
Na
Na
Na Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
H2OH2O
H2O
H2OH2O
H2O H2O
H2O
Hidrofilica
Hidrofobica
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Soap A soap micelle:
Na
CO2
CO2
CO2
CO2
CO2O2C
O2C
O2C
O2C
O2C
O2C
CO2
O2C CO2
O2C
Na
Na
Na Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
H2OH2O
H2O
H2OH2O
H2O H2O
H2O
Mancha grasa
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Objetivo: Mejorar propiedades Objetivo: Mejorar propiedades
detersivasdetersivas del aguadel agua poca de sumerios (3000 a.c)
se usaba azufre jabonoso para cura de
enfermedades. Leblanc (1987) : Procedimiento para obtencion de
jabon a escala
industrial ( Quimica industrial de tensioactivos moderna) Siglos
XIX y XX se amplio la gama de derivados del jabon.
Crecimento del uso de fibras sinteticas ( celulosa;
acetatos,etc.). Gnter (BASF-1917): alquilacin y sulfonacin de
naftaleno; pero
el alquilnaftaleno sulfonato sin caracter tensiactivo
suficiente. Bertsch y col ( 1927): Mediante sulfatacin de un
alcohol graso
obtuvieron 1detergente sintetico..materias primas renovables?
Henkel(1932)
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LAS
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Algunas propiedades de los tensioactivos son:
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Clasificacin de los detergentes (tensioactivos):
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Ejemplo de formacion de un detergente anionico
H2SO4 cold
NaOH
OH
OSO3H
OSO
OO Na
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H2SO4 cold
NaOH
OH
OSO3H
OSO
OO Nahydrophilichydrophobic
Sodium dodecyl sulfate
Ejemplo de formacion de un detergente anionico
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Detergentes anionicos Alkyl benzene sulfonate detergents
(ABS)
Non-biodegradable
hydrophilichydrophobic S
O
OO Na
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