Post on 28-Apr-2023
ORIGINAL ARTICLE
Surfactants Based on Bis-Galactobenzimidazolones: Synthesis,Self-Assembly and Ion Sensing Properties
L. Lakhrissi • N. Hassan • B. Lakhrissi •
M. Massoui • E. M. Essassi • J. M. Ruso •
C. Solans • C. Rodriguez- Abreu
Received: 1 December 2010 / Accepted: 22 February 2011 / Published online: 15 March 2011
� AOCS 2011
Abstract A series of new non-ionic amphiphiles based
on bis-galactobenzimidazolones have been synthesized by
grafting alkyl bis-benzimidazolone units as hydrophobic
tails on hydroxypropyloxygalacto-pyranose moieties as
hydrophilic heads. Their surface and self-aggregation
properties in water were evaluated. The compounds show
very low critical micellar concentrations (CMCs) that
decrease with increasing chain length; values for the
minimal area per molecule at the interface (Amin) follow
the same trend. The synthesized compounds also form
hexagonal liquid crystals in water for a certain range of
hydrophobic tail lengths. On the other hand, the new am-
phiphiles show characteristic UV–Vis absorption and
fluorescence emission bands associated with the benzimi-
dazolone moiety. The fluorescence emission is quenched
with a certain degree of selectivity by cations, due to their
strong affinity towards the benzimidazolone group, which
shows ion complexation properties. Hence, the reported
new amphiphiles are candidates as self-assembling
chemosensors. The quenching efficiency and also ion
sensing sensitivity is higher in the monomeric state as
compared to the micellar state. The fluorescence emission
intensity is higher for compounds with a shorter alkyl
chain.
Keywords Bis-benzimidazolones � D-Galactose �Surfactant synthesis � Non-ionic surfactants � Surface
properties � Fluorescence probe spectroscopy
Introduction
Sugar-based surfactants, with their low toxicity and
excellent biodegradability, i.e. reduced environmental
impact, offer an attractive alternative to more conventional
non-ionic surfactants such as poly(ethyleneoxide) alkyl
ethers[1]. Moreover, they show performance properties
which are exploited in microbiology and biotechnology
[2–4], and have potential pharmaceutical and biomedical
applications [5–7]. Sugar surfactants are made from
renewable resources and are increasingly used in washing
agents [8], cosmetics [9, 10], and drug carriers [11, 12].
The influence of structural changes on the physical prop-
erties of this family of surfactants has been studied in
several reports [1, 13–15].
Electronic supplementary material The online version of thisarticle (doi:10.1007/s11743-011-1262-7) contains supplementarymaterial, which is available to authorized users.
L. Lakhrissi � B. Lakhrissi
Laboratoire d’Agroressources et Genie des Procedes,
Faculte des Sciences, Universite Ibn Tofaıl,
Kenitra, Morocco
L. Lakhrissi � M. Massoui � E. M. Essassi
Laboratoire de Chimie Heterocyclique,
Faculte des Sciences, Universite Mohamed V,
Rabat, Morocco
N. Hassan � J. M. Ruso
Soft Matter and Molecular Biophysics Group,
Department of Applied Physics, University of Santiago de
Compostela, 15782 Santiago de Compostela, Spain
C. Solans � C. Rodriguez- Abreu
Institut de Quımica Avancada de Catalunya (IQAC),
Consejo Superior de Investigaciones Cientıficas (CSIC),
Jordi Girona, 18-26, 08034 Barcelona, Spain
C. Rodriguez- Abreu (&)
International Iberian Nanotechnology Laboratory,
Av. Mestre Jose Veiga, 4715-310 Braga, Portugal
e-mail: crodriguez@inl.int
123
J Surfact Deterg (2011) 14:487–495
DOI 10.1007/s11743-011-1262-7
On the other hand, benzimidazolones are important
heterocyclic components of various products with phar-
maceutical and biological importance [16–19]. They also
present chelating and complexation properties [20], and
show a characteristic UV absorption band and fluorescence
emission [21, 22]. Hence, they can act as intrinsic
chemosensor molecules in which the donor atoms for
substrate complexation are a part of the fluorophore [23,
24]; the interaction between the bound substrate and the
fluorophore leads directly to the modification of its emis-
sion properties. However, the low solubility in water is
a drawback, therefore designing benzimidazolone-based
hydrosoluble chemosensors is an interesting goal [25].
They could attract an additional interest if they would have
amphiphilic nature and therefore form self assemblies in
solution or on substrates [23].
In a continuation of our previous work in this area
[26–29], we have synthesized a series of new non-ionic
amphiphiles based on bis-galactobenzimidazolone (see
Fig. 1a), which was prepared by grafting the 6-O-[2,3-ep-
oxypropyl]-1,2:3,4-di-O-isopropylidene-a–galactopyranose
group on the N-3 nitrogen atom of two benzimidazolone
units that are linked by an alkyloxypropylene group in the
same conditions as described earlier [29], following by
the deprotection of diacetonide galactopyranose moiety
[28–31]. The new synthesis route is easier and involves
fewer steps than the previously reported one [29].
Additionally, we evaluated surface and self-aggregation
properties in water by several techniques such as surface
tension, fluorescent probe spectroscopy, and polarized
optical microscopy. The ion complexing properties of the
synthesized compounds were studied by UV–Vis and
fluorescence spectroscopy.
Experimental
Chemical Analysis
Thin-layer chromatography (TLC) was performed on Silica
Gel 60 F254 (E. Merck) plates with visualization by UV
light (254 nm) and/or charring with the vanillin–H2SO4
reagent. Column chromatography was performed using
230–400 mesh E Merck silica gel. Melting points were
determined on an automatic electrothermal IA 9200 digital
melting point apparatus in capillary tubes and are uncor-
rected. Optical rotations, for solutions in chloroform or
methanol, were measured with a digital polarimeter JAS-
CO model DIP-370, using a sodium lamp at 25 �C.1H-NMR spectra were recorded on a Bruker 300 WB
spectrometer at 300 MHz, and 13C-NMR spectra were
recorded at 75 MHz for solutions in CDCl3 or Me2SO-d6.
Chemical shifts are given as d values with reference to
tetramethylsilane (TMS) as internal standard. Analytical
TLC was performed on Merck aluminium backed silica
gel (Silica Gel F254); spots were visualized in UV light.
Column chromatography was performed on silica gel
(60 mesh, Matrix) by elution with hexane–acetone or
acetone–methanol mixtures.
Synthesis
All chemicals were purchased from Aldrich or Acros
(France). All solvents were distilled before use. The
compound N,N0-1,3-Bis-[N-3-(6-deoxy-3-O-methyl-D-glu-
copyranose-6-yl)-2-oxo-benzimidazole-1-yl)]-2-dodecyloxy
propane, abbreviated as LBC12, was synthesized as reported
in a previous paper [29].
Fig. 1 Structures of
(I) N,N0-1,3-bis-[N-3-(6-
(20-hydroxypropyloxy)-
D-galactopyranos-6-yl)-
2-oxobenzimidazol-1-yl)]-
2-alkyloxypropanes (4a-c) and
(II) N,N- 1,3-Bis-[N-3-
(6-deoxy-3-O-methyl-D-
glucopyranos-6-yl)-2-
oxobenzimidazol-1-yl)]-
2-dodecyloxypropane
(compound LBC12)
488 J Surfact Deterg (2011) 14:487–495
123
1,3-N,N0-bis-[2-oxobenzimidazol-1-yl]-2-alkyloxypro-
panes 1a-c were synthesized in three steps. The first one is
the condensation of N-isopropenylbenzimidazolone [20]
with epichlorohydrin in a toluene-DMSO mixture in the
presence of potassium carbonate. The second step is the
alkylation of the free OH group by n-bromoalkanes in a
toluene-DMSO mixture and potassium hydroxide [29].
Subsequent N-3 deprotection in a cold acid medium [20]
afforded the corresponding compounds 1a–c.
6-O-[2,3-epoxypropyl]-1,2:3,4-di-O-isopropylidene-a-
D-galactopyranose 2 was synthesized by adopting the
modified Koll’s method [32] which consists of the reaction
of 1,2:3,4-di-O-isopropylidene-a-D-galactopyranose [33]
with epichlorohydrin in the presence of sodium hydroxide
and in Toluene-DMSO mixture as solvent.
N,N0-1,3-Bis-[N-3-(6-(20-hydroxypropyloxy)-1,2:3,4-di-
O-isopropylidene-a-D-galactopyranos-6-yl)-2-oxobenzimid
azol-1-yl)]-2-alkyloxypropanes 3a–c were synthesized
following Scheme 1, by condensing the 1,3-N,N0-bis-[2-
oxobenzimidazol-1-yl]-2-alkyloxypropanes 1a–c [29] units
with activate galactopyranose 2 in the presence of potas-
sium carbonate and in pure DMSO as solvent [28, 29].
In order to give a hydrophilic character to the molecules
obtained 3a–c, they were treated with a mixture of triflu-
oroacetic acid–water (9:1, v/v) at room temperature
[29–31]. The precipitates obtained were purified by chro-
matography with a mixture of acetone-methanol (1:1, v/v)
to give N,N0-1,3-bis-[N-3-(6-(20-hydroxypropyloxy)-D-ga-
lactopyranos-6-yl)-2-oxobenzimidazol-1-yl)]-2-alkyloxy-
propanes 4a–c as white solids.
Physical constants are given in Tables 1 and 2 as a
function of n, which is the number of carbon atoms in the
n-alkyl chain.
Surface and Self-Aggregation Properties
The surface tension of surfactant solutions was measured
by the Wilhelmy plate method with a Kruss K12
tensiometer at 25 �C. The samples were left to rest for
several hours to reach equilibrium. Consecutive measure-
ments were performed until surface tension data was con-
stant with time. From the graphical plots of surface tension
against logarithm of surfactant concentration the values of
critical micelle concentration (CMC) were obtained.
UV–Vis and Fluorescence Spectroscopy
UV–Vis spectra at 25 �C were measured using a Varian
Cary UV–Visible spectrophotometer whereas steady state
fluorescence was measured at 25 �C using a Varian Cary
Eclipse spectrophotometer. Both instruments were equip-
ped with a temperature-controlled sample holder. Samples
were placed in 1-cm path length quartz cuvettes. Pyrene
was excited at a wavelength of 335 nm and the emission
Scheme 1 Synthesis method
Table 1 Physicochemical constants of compounds 4a–c and their
precursors 3a–c
Product Yield
(%)
Mp ( �C) Molecular
formula½a�26
D ðc ¼ 1:0Þ a/b
Molecular
weight
3a (n = 10) 88.0 68–70 C57H84N4O17 -60.2�a –
1097.29
3b (n = 12) 84.4 62–64 C59H88N4O17 -60.3�a –
1125.35
3c (n = 14) 79.1 58–60 C61H92N4O17 -59.6�a –
1153.40
4a (n = 10) 90.1 120–122 C51H76N4O17 20.4�b 3/4
1017.16
4b (n = 12) 88.0 116–118 C53H80N4O17 20.2�b 5/6
1045.22
4c (n = 14) 86.1 96–98 C55H84N4O17 20.8�b 3/4
1073.27
a In CHCl3b In CH3OH
J Surfact Deterg (2011) 14:487–495 489
123
intensity from 350 to 600 nm was recorded. On the other
hand, fluorescence emission spectra of synthesized com-
pounds (without pyrene) were collected using an excitation
wavelength of 280 nm.
Aqueous solutions of copper, magnesium and sodium
nitrate were used during spectrophotometric titrations. For
experiments with copper nitrate, the pH remained between
5.2 and 6 in the experiments.
Microscopy
Samples placed in glass slides were observed at 25 �C
under a polarized light microscope (Leica Reichert Polyvar
2) equipped with a hot stage (Mettler FP82HT) and a CCD
camera.
Results and Discussion
Surface and Self-Aggregation Properties
The synthesized bis-galactobenzimidazolones 4a–c are
soluble in water. The plot of surface tension versus loga-
rithm of surfactant concentration of compound 4b (alkyl
chain length n = 12) is presented in Fig. 2. Plots corre-
sponding to compounds 4a and 4c (n = 10 and n = 14,
respectively) showed the same features, with clear breaks
in the data trends (see supplementary information, Fig. S1),
which is a typical behavior for surfactants and evidences
their capacity to decrease the surface tension as well as to
form micellar aggregates in aqueous media. The Critical
Micellar Concentrations (CMC) values derived from those
breaks are very low and the surface tension values at the
CMC, namely, the effectiveness of surface tension reduc-
tion, are around, 40 mN/m (see Table 3).
As in the case of other amphiphiles [34], experimental
points for CMC follow approximately an equation of the
form log CMC = a - b�n; a and b be are constants and n is
the alkyl chain length. For the present series of compounds,
Table 2 NMR spectroscopic data of compounds 3a in CDCl3 and 4a in DMSO-d6
Compound Galactosyl moiety Oxo-benzimidazolyl Alkyl chain Propyloxy moiety Hydroxypropyl moiety moiety moiety
3a (n = 10) H1: 5.45 (d, 2H, J1,2 = 5.00) Harom : 7.00-7.28 CH3ω : 0.87(t, 3H) OCH: 4.10 (m ,1H) OCH2: 3.44 (m,2H)
H2: 4.32 (dd, 2H, J2,3 = 2.40) (m, 8H) CH2ω−1 : 1.03(sext, 2H) NCH2: 3.95 (m, 4H) CHOH: 4.25 (m,2H)
H3: 4.60 (dd, 2H, J3,4 = 8.00) 7CH2 : 1.05-1.55(m,14H) NCH2: 3.95(dd, 1H) H4: 4.24 (dd, 2H, J4,5 = 1.70) OCH2
α : 3.35 (t, 2H) J1,2 = 5.5 4.30 (dd, 1H) H5: 3.96 (m, 2H, J5,6a = 6.60) H6a : 3.68 (dd, 4H, J6,6 = 10.10) Jω,ω−1 = 7.2 H6b: 3.54(dd, 4H, J5,6b = 4.20) Jα,β = 6.4 CH3iso: 1.24 -1.46 (4s, 12H) OH: 2.12 (s, 2H)
3a (n = 10) C1: 96.2 C2=O: 155.1 CH3ω: 14.1 NCH2: 43.6 OCH2: 72.3;72.5
C2: 70.4 C4,C7:108.4;108.5; CH2ω−1: 22.6 OCH: 76.5 CHOH: 69.0;69.2
C3: 70.6 108.6;109.3 5CH2 : 29.3-31.8 NCH2: 44.3;44.4 C4: 71.1 C5,C6:121.3;121.5 CH2
γ : 25.7 C5: 66.7;66.7 C8,C9:129.5;129.8 CH2
β : 29.6C6: 71.4 ΟCH2
α : 71.3 (CH3)2: 26.2;26.5
Ciso: 111.7 4a (n = 10) C1α : 92.7 C2α=O: 153.8 CH3
ω: 13.9 NCH2: 43.1 OCH2: 72.8;72.9 C1β: 97.4 C2β=O: 153.9 CH2
ω−1: 22.1 OCH: 76.1 CHOH:69.2;69;3 C2, C3, C4, C5 : 68.4 − 83.1 C4,C7:108.2;108.5 5CH2: 28.6 - 31.2 NCH2: 44.3;44.4 C-6 : 70.1 C5,C6:120.6;120.8 CH2
γ : 25.0 C8,C9:129.4;129.5 CH2
β: 29.2 129.7;129.8 ΟCH2
α : 70.8
Fig. 2 Surface tension (squares) and ratio of intensities of first and
third peaks in pyrene fluorescence spectrum (I1/I3, circles) as a
function of surfactant concentration (25 �C) for compound 4b(n = 12). The lines serve to indicate the break for each set of data
490 J Surfact Deterg (2011) 14:487–495
123
b (&0.06) is quite small when compared to other surfac-
tants [34], indicating that the effect of increasing the
hydrophobic chain length on the aggregation tendency is
less marked.
The surface excess concentration (Cmax) corresponding
to the maximum concentration of surfactant adsorbed at
the saturated liquid/air interface, in mol/cm2, is obtained
from the Gibbs equation for non-ionic surfactants, Cmax =
-(dc/dlnC)/(RT), where (dc/dlnC) is the slope of the sub-
micellar region of the plot of surface tension against loga-
rithm of surfactant concentration, R = 8.31 J.mol-1. K-1
and T is the temperature in K. From the surface excess
values, the area occupied per molecule of surfactant
adsorbed at the air/liquid interface (Amin), expressed in A2,
is obtained according to Amin = 1016/NA Cmax where NA is
the Avogadro’s number and Cmax is the surface excess
concentration.
The Cmax and Amin values obtained (Table 3) are of the
same order as those of alcohol ethoxylates with an average
number of ethylene oxide units of 6–8 [34, 35], and very
close to LBC12 homologue series (see Fig. 1) with alkyl
chain lengths in the range n = 10–14 [29]. The values of
effective surface area per molecule at the interface (Amin)
follow the typical decreasing trend with increasing hydro-
phobic tail length.
Pyrene is a fluorescent probe sensitive to the polarity of
the microenvironment, which is proportional to the ratio of
the first and third peaks in the probe emission spectrum
(I1/I3). As a result, it has been widely used for the deter-
mination of the CMC. Figure 2 shows the results on
fluorescence probe spectroscopy for compound 4b (alkyl
chain length n = 12). Plots corresponding to compounds
4a and 4c (n = 10 and n = 14, respectively) exhibited the
same features (see supplementary information, Fig. S2),
with clear breaks signalling a change in the microenvi-
ronment surrounding pyrene at the onset of aggregate
formation. As can be seen in Table 3, the values of CMC
derived from the breaks in I1/I3 data are in agreement with
those derived from surface tension measurements.
Amphiphilic compounds usually form lyotropic liquid
crystals in water. The small amount of surfactant available
from the synthesis reported here made it difficult to prepare
well mixed, concentrated samples in water with a precise
surfactant concentration. In such a case it is common to use
the water penetration method to detect qualitatively the
liquid crystal formation. Samples of the compounds 4a–c
were examined by means of polarized optical microscopy.
As it can be seen in Fig. 3, when putting the synthesized
compounds in contact with water, they form liquid crystals
with hexagonal grainy optical texture for alkyl chain lengths
of 10 and 12 carbons. For 14 carbons, clear liquid crystal
optical textures could not be observed; birefringence seems
to be produced by crystals of insoluble solid. The compound
LBC12, with a similar structure, also forms hexagonal
liquid crystals in water, as reported in a previous article [29].
Ion Complexation
We tried first to characterize the ion complexation
properties of the synthesized compounds by UV–Vis
Table 3 Physicochemical parameters of compounds 4a–c
Product Chain
length, nCMC from surface
tension (mM)
CMC from
fluorescence (mM)
cCMC
(mN/m)
Cmax 9 1010
(mol/cm2)
Amin (A2)
4a 10 0.0025 0.0024 38 2.7 (3 and 2.3) 60 (55 and 70)
4b 12 0.0016 0.0016 44 2.9 (3.2 and 2.5) 57 (52 and 66)
4c 14 0.0014 0.0013 41 3.4 (3.7 and 3.4) 48 (45 and 48)
Values of Cmax and Amin for alcohol ethoxylates with an average number of ethylene oxide units of 6 and 8 and the same alkyl chain length of
compounds 4a–c are shown between brackets and in italics (data taken from Refs. [34, 35])
Fig. 3 Images of optical polarized microscopy (25 �C) for compounds 4a–c (a) n = 10 (b) n = 12 (c) n = 14. The compounds were put in
contact with water (black region in the image) for the observation
J Surfact Deterg (2011) 14:487–495 491
123
spectrometry. UV spectra can be found in the supplemen-
tary information (Figs. S3 and S4). In the absence of Cu2?,
the spectra of 4b and LBC12 compounds show a single
absorption band with a maximum at 282 nm; compounds
4a and 4c show the same spectral features. The position of
the characteristic band is almost the same as that of
benzimidazolone in organic polar solvents such as ethanol
and acetonitrile [21]. Upon addition of Cu2?, Mg2? or
Na?, a slight bathochromic (red) shift was observed for the
282 nm band, and a new (overlapped) band seems to
develop; from deconvolution of the spectra, the maximum
of this band is estimated to be around 300–302 nm, almost
in the same position of that found for neat cation (nitrate)
solutions. The band remained even after subtraction of
cation background, but results are not conclusive con-
cerning the effect of ion complexation on UV–Vis spectra,
particularly because the 302 nm band could not be
detected at cation concentrations within the same order of
magnitude of that of the synthesized compounds in the
experiments.
Fluorescence spectroscopy is known to be an analysis
technique much more sensitive than UV–Vis spectrometry.
Fluorescence emission spectra of compounds 4b upon
titration with Cu2? are shown in Fig. 4. Neat 4a–c aqueous
solutions (0.005 mM) show a single emission band at
312 nm, similar to benzimidazolone in organic polar sol-
vents such as ethanol and acetonitrile [21]; this spectral
feature is not changed by Cu2? addition, but the fluores-
cence intensity at the maximum decreases, i.e. there is a
cation-induced quenching. Cation affinity of the imidazole
group is determined by its complexing properties. The
quenching process is induced by coordination of cations
either directly to donor atoms of the fluorophore or to
chelating groups covalently attached to the latter [36].
Particularly, Cu2? has a high thermodynamic affinity for
typical N,O-chelate ligands and fast metal-to-ligand bind-
ing kinetics [37].
As can be observed in Fig. 5, fluorescence intensity
quenching follows the Stern–Volmer relationship [38, 39],
Io/I = 1 ? KSV [Q], where Io and I are the fluorescence
intensities in the absence and in the presence of quencher,
respectively, [Q] is the quencher concentration and KSV is
the Stern–Volmer quenching constant (other Stern–Volmer
plots can be found in the supplementary information,
Figs. S5 and S6); K is a measure of the quenching effi-
ciency. Results points to a diffusion-controlled quenching
process. KSV values for 4b and LBC12 (both with the same
alkyl chain length) decrease in the order Mg2?[Cu2?[Na?
(see Table 4). Ionic radii of Mg2? and Cu2? are very similar
and both are lower than that of Na?, hence, the relationship
between ionic radius and KSV is not straightforward. KSV
values for Cu2? as quencher are higher for LBC12 when
compared to 4b, the latter having a bulkier group sur-
rounding the benzimidazolone moiety. Therefore, steric
effects might be playing a role. It should be mentioned here
that other cations, such as Ca2? and Pb2? were also found to
induce fluorescence quenching of the compound 4b.
Concerning the effect of amphiphile concentration, KSV
for Cu2? increases from 0.1532 to 1.0141 mM-1 when 4b
concentration is decreased from 0.005 mM (micellar state)
280 300 320 340 360 380 400
I(A
.U.)
Wavelength (nm)
0 mM
6 mM
Fig. 4 Fluorescence spectra (25 �C) for different Cu2? concentra-
tions in aqueous solutions of compound 4b. The surfactant concen-
tration is kept at 0.005 mM. Cu2? concentrations are varied from 0 to
6 mM in 1 mM steps
Fig. 5 Stern-Volmer plot for surfactants LBC12 and 4b (both with
the same alkyl chain length) with Cu2? as quencher (25 �C). Io and
I are the fluorescence intensities in the absence and in the presence of
quencher, respectively. The surfactant concentration is fixed at
0.005 mM. The position of fluorescence maxima remains constant
at 312 nm
Table 4 Values for of Stern–Volmer constants (KSV) in mM-1 for
different cations as quenchers (25 �C)
Surfactant Mg2? Cu2? Na?
4b 0.1922 0.1532 0.1098
LBC12 0.3106 0.2762 0.2510
The surfactant concentration is fixed at 0.005 mM
492 J Surfact Deterg (2011) 14:487–495
123
to 0.0005 mM (monomer state); hence, the quenching
efficiency and also ion sensitivity is improved at low am-
phiphile concentration. This tendency has been reported
before for associating polymers [40], and was attributed not
only to stoichiometry but also to aggregation-related
effects [40].
On the other hand, the alkyl chain length has practically
no effect on KSV for Cu2? as quencher. Nevertheless, there
are differences in the fluorescence intensity as a function of
4a–c concentration in neat solutions (no cation added): the
shorter the alkyl chain, the stronger the emission intensity.
This effect was found for certain alkyl substituted fluoro-
phores [41], and was attributed to changes in chain confor-
mation that affect fluorescent properties. The fluorescence
intensity in the absence of cations (see supplementary
information, Fig. S7) increased linearly with concentration
of compounds 4a–c with no apparent discontinuity or step-
like fluorescence enhancement in the vicinity of the CMC,
contrary to that observed for another fluorescent amphiphile
[42]. The position of the fluorescence intensity maximum
also remained invariable below and above the CMC. This
fact might be attributed to the location of the fluorescent
moiety near the hydrophilic group, which remains highly
solvated below and above the CMC, namely, the slight
change in microenvironment, if any, cannot be detected by
fluorimetry.
Conclusions
The synthesized bis-galactobenzimidazolones are soluble
in water and form micellar aggregates at very low con-
centration. Their surface properties are similar to some
ethoxylated nonionic surfactants. The synthesized com-
pounds are also capable of forming lyotropic liquid crystals
within a certain range of alkyl chain lengths. Moreover,
they show UV–Vis absorption and fluorescence emission
properties; the latter can be used for ion sensing as the
fluorescence is quenched by cations that form complexes
with the benzimidazolone moiety. Hence, the reported new
amphiphiles are promising as self-assembling chemosen-
sors. The quenching efficiency is higher in the monomer
state as compared to the micellar state. It was also found
that the emission intensity increased with decreasing alkyl
chain length.
Acknowledgments This work was supported by CNRST-CSIC
project (2007MA0055). The ‘‘Ministere Marocain de l’Enseignement
Superieur’’ is gratefully acknowledged. C.R-A is also grateful to the
Ministerio de Ciencia e Innovacion, Spain (Project CTQ2008-01979/
BQU) for research funding. J.M.R and N. H. thank Direccion Xeral de
Promocion Cientıfica e Tecnologica del sistema Universitario de
Galicia for their financial support.
References
1. Rodrıguez-Abreu C, Aramaki K, Tanaka Y, Lopez-Quintela MA,
Ishitobi M, Kunieda H (2005) Wormlike micelles and micro-
emulsions in aqueous mixtures of sucrose esters and nonionic
cosurfactants. J Colloid Interf Sci 291:560–569
2. Rauter AP, Lucas S, Almeida T, Sacoto D, Ribeiro V, Justino J,
Neves A, Silva FV, Oliveira MC, Ferreira MJ, Santos M-S,
Barbosa E (2005) Synthesis, surface active and antimicrobial
properties of new alkyl 2, 6-dideoxy-l-arabino-hexopyranosides.
Carbohydr Res 340:191–201
3. Van Hamme JD, Singh A, Ward OP (2006) Physiological
aspects: part 1 in a series of papers devoted to surfactants in
microbiology and biotechnology. Biotechnol Adv 24:604–620
4. Singh A, Van Hamme JD, Ward OP (2007) Surfactants in
microbiology and biotechnology: Part 2. Application aspects.
Biotechnol Adv 25:99–121
5. Ro _zycka-Roszak B, Jurczak B, Wilk KA (2007) Effects of non-
ionic sugar surfactants on the phase transition of DPPC mem-
branes. Thermochim Acta 453:27–30
6. Ren X, Mao X, Cao L, Xue K, Si L, Qiu J, Schimmer AD, Li G
(2009) Nonionic surfactants are strong inhibitors of cytochrome
P450 3A biotransformation activity in vitro and in vivo. Eur J
Pharm Sci 36:401–411
7. Jiao J (2008) Polyoxyethylated nonionic surfactants and their
applications in topical ocular drug delivery. Adv Drug Deliver
Rev 60:1663–1673
8. Tracy DJ, Ruoxin L, Yang JY (1999) Nonionic Gemini surfac-
tants having multiple hydrophobic and hydrophilic sugar groups.
US Patent 5863886
9. Bais D, Trevisan A, Lapasin R, Partal P, Gallegos C (2005)
Rheological characterization of polysaccharide-surfactant matri-
ces for cosmetic O/W emulsions. J Colloid Interf Sci
290:546–556
10. Ahsan F, Arnold JJ, Meezan E, Pillion DJ (2003) Sucrose
cocoate, a component of cosmetic preparations, enhances nasal
and ocular peptide absorption. Int J Pharm 251:195–203
11. Uchegbu IF, Vyas SP (1998) Non-ionic surfactant based vesicles
(niosomes) in drug delivery. Int J Pharm 172:33–70
12. Wu D-Q, Lu B, Chang C, Chen C-S, Wang T, Zhang Y-Y, Cheng
S-X, Jiang X-J, Zhang X-Z, Zhuo R-X (2009) Galactosylated
fluorescent labeled micelles as a liver targeting drug carrier.
Biomaterials 30:1363–1371
13. Nakamura N, Yamaguchi Y, Hakansson B, Olsson U, Tagawa T,
Kunieda H (1999) Formation of microemulsion and liquid crystal
in biocompatible sucrose alkanoate systems. J Disper Sci Technol
20:535–557
14. Stradner A, Mayer B, Sottmann T, Hermetter A, Glatter O (1999)
Sugar surfactant-based solutions as host systems for enzyme
activity measurements. J Phys Chem B 103:6680–6689
15. Castro MJL, Kovensky J, Fernandez-Cirelli A (2002) New family
of nonionic gemini surfactants. Determination and analysis of
interfacial properties. Langmuir 18:2477–2482
16. Terefenko EA, Kern J, Fensome A, Wrobel J, Zhu Y, Cohen J,
Winneker R, Zhang Z, Zhang P (2005) SAR studies of 6-aryl-1,
3-dihydrobenzimidazol-2-ones as progesterone receptor antago-
nists. Bioorg Med Chem Lett 15:3600–3603
17. Monforte AM, Rao A, Logoteta P, Ferro S, De Luca L, Barreca
ML, Iraci N, Maga G, De Clercq E, Pannecouque C, Chimirri A
(2008) Novel N1-substituted 1,3-dihydro-2H-benzimidazol-
2-ones as potent non-nucleoside reverse transcriptase inhibitors.
Bioorg Med Chem 16:7429–7435
19. Li S-K, Ji Z-Q, Zhang J-W, Guo Z-Y, Wu W-J (2010) Synthesis
of 1-Acyl-3-isopropenylbenzimidazolone derivatives and their
J Surfact Deterg (2011) 14:487–495 493
123
activity against Botrytis cinerea. J Agric Food Chem
58:2668–2672
20. Meth-Cohn O, Smith DI (1982) N-bridged heterocycles. Part
5.a,x-bis-(2-oxobenzimidazolinyl)-alkanes and -ethers as selec-
tive ligands for group-1 and -2 metals, J Chem Soc Perkin I
261–270
21. Lazar Z, Benali B, Elblidi K, Zenkouar M, Lakhrissi B, Massoui
M, Kabouchi B, Cazeau-Dubroca C (2003) Photophysical study
of benzimidazolone and its derivative molecules in solution.
J Mol Liq 106(1):89–95
22. Benali B, Lazar Z, Elblidi K, Lakhrissi B, Massoui M, Elassyry
A, Cazeau-Dubroca C (2006) Solvatochromic effect on photo-
physical properties of benzimidazolone. J Mol Liq 128:42–45
23. Mancin F, Rampazzo E, Tecilla P, Tonellato U (2006) Self-
assembled fluorescent chemosensors. Chem Eur J 12:1844–1854
24. El Majzoub A, Cadiou C, Dechamps-Olivier I, Chuburu F,
Aplincourt M, Tinant B (2009) Mono- and bis-N-functionalised
cyclen with benzimidazolylmethyl pendant arms: sensitive and
selective fluorescent probes for zinc and copper ions. Inorg Chim
Acta 362:1169–1178
25. Pina F, Bernardo MA, Garcıa-Espana E (2000) Fluorescent
chemosensors containing polyamine receptors. Eur J Inorg Chem
2143–2157
26. Lakhrissi B, Ejjiyar S, Massoui M, Comelles F, Garcia MT,
Ribosa I, Azemar N, Solans C (2002) Surface and self-aggrega-
tion properties of bis-benzimidazolone derivatives of D-glucose.
Jorn Com Esp Deterg 32:365–373
27. Lakhrissi L, Lakhrissi B, Lakhrissi M, Massoui M, Essassi EM,
Solans C, Azemar N, Morales D, Comelles F (2007) Synthesis
and evaluation of surfactants properties of new amphiphile and
bolaamphiphile derivatives of bis-glucobenzimidazolones. Jorn
Com Esp Deterg 37:347–353
28. Lakhrissi B, Benksim A, Massoui M, Essassi EM, Lequart V,
Joly N, Beaupere D, Wadouachi A, Martin P (2008) Towards the
synthesis of new benzimidazolone derivatives with surfactant
properties. Brahim Lakhrissi. Carbohydr Res 343:421–433
29. Lakhrissi B, Lakhrissi L, Massoui M, Essassi EM, Comelles F,
Esquena J, Solans C, Rodriguez-Abreu C (2010) Surface and self-
aggregation properties of bis-benzimidazolones derivatives of
D-glucose. J Surfact Deterg 13:329–338
30. Goueth PY, Ronco G, Villa P (1994) Synthesis of novel
bis(glycosyl) ethers as bolaamphiphile surfactants. J Carbohydr
Chem 13:679–696
31. Lakhrissi B, Essassi EM, Massoui M, Goethals G, Lequart V,
Monflier E, Cecchelli R, Martin P (2004) Synthesis and amphi-
philic behavior of N, N-bis-glucosyl-1,5-benzodiazepin-2,
4-dione. J Carbohydr Chem 23:389–401
32. Koll P, Saak W, Pohl S, Steiner B, Miroslav Koos M (1994)
Preparation and crystal and molecular structure of 6-O-[(2S)-2,
3-epoxypropyl]-1,2:3,4-di-O-isopropylidene-a-D galacto-pyra-
nose. Pyranoid ring conformation in 1,2:3,4-di-O-isopropylidene
galactopyranose and related systems. Carbohyd Res 265:237–248
33. Baggett N, Buck KW, Foster AB, Jefferis R, Rees BH, Webber
JM (1965) Aspects of stereochemistry. Part XIX. Isopropylidene
derivatives of some polyhydric alcohols. Observations on the
hydrolytic behaviour and migration of cyclic ketals. J Chem Soc
3382–3387
34. Rosen MJ (1989) Surfactant and interfacial phenomena, 2nd edn.
Wiley, New York
35. Lu JR, Thomas RK, Penfold J (2000) Surfactant layers at the air/
water interface: structure and composition. Adv Colloid Interf Sci
143–304
36. Fabbrizzi L, Licchelli M, Pallavicini P, Perotti A, Taglietti A,
Sacchi D (1996) Fluorescent sensors for transition metals based
on electron-transfer and energy-transfer mechanisms. Chem Eur J
2:75–82
37. Zhou LL, Sun H, Zhang XH, Wu SK (2005) An effective fluo-
rescent chemosensor for the detection of copper(II). Spectrochim
Acta A 61:61–65
38. Stern O, Volrner M (1919) The fading time of fluorescence.
Z Phys 20:183–188
39. Lakowicz JR, Weber G (1973) Quenching of fluorescence by
oxygen. Probe for structural fluctuations in macromolecules.
Biochemistry 12:4161–4170
40. Tan C, Pinto MR, Schanze KS (2002) Photophysics, aggregation
and amplified quenching of a water-soluble poly(phenylene eth-
ynylene). Chem Commun 446–447
41. Pu S, Li M, Fan C, Liu G, Shen L (2009) Synthesis and the
optoelectronic properties of diarylethene derivatives having
benzothiophene and n-alkyl thiophene units. J Mol Struct
919:100–111
42. Iwunze MO, Lambert M, Silversmith EF (1997) Characterization
of fluorescent surfactant aggregates by fluorimetric and viscosi-
metric techniques. Monatsh Chem 128:585–592
Author Biographies
L. Lakhrissi studied chemistry at the Mohamed V University of
Rabat (Morocco) and then at the Ibn Tofaıl University of Kenitra
(Morocco). She is now a Ph.D. candidate in organic synthesis and
surfactant properties, at the Mohamed V University of Rabat
(Morocco).
N. Hassan studied chemistry at the University of Chile (Santiago-
Chile) and she is currently a Ph.D. candidate in Science and
Technology of Materials at the University of Santiago de Compostela
(Spain).
B. Lakhrissi studied chemistry at the Henri Poincare University of
Nancy (France) and obtained his Ph.D. in organic and analytic
chemistry from the same University in 1988. Since 1989 he has been
an assistant professor at the Ibn Tofaıl University in Kenitra
(Morocco). He obtained his state doctorate thesis in organic chemistry
from Ibn Tofaıl University of Kenitra (Morocco) in 2003 and since
then he has been a professor at that university. Since 2005 he has also
been Director of the Agro resources and Process Engineering
Laboratory. His areas of scientific activity are organic synthesis,
surfactant properties and complexant systems.
M. Massoui studied chemistry at the Picardie University of Amiens
(France) and received his doctorate in Organic Chemistry from the
same University in 1985. Since then he has been Professor at Ibn
Tofaıl University in Kenitra (Morocco). He was also Director of the
Agro resources and Process Engineering Laboratory. His area of
scientific activity is the organic synthesis and the chemistry of
glucids.
E. M. Essassi studied chemistry at the Mohamed V University of
Rabat (Morocco) and received his doctorate in Organic Chemistry
from the University of Montpellier (France) in 1977. He then joined
the University Mohammed V in Rabat and was promoted to Professor
in 1981. Professor Essassi is currently Director of the Heterocyclic
Organic Chemistry Laboratory. In 2006 he was named a member of
Hassan II Academy of Science and Technology. His area of scientific
activity is organic synthesis.
J. M. Ruso is an associate professor at the University of Santiago de
Compostela. He received his Ph.D. (1998) from the University of
Santiago de Compostela. He was a visiting researcher at the
494 J Surfact Deterg (2011) 14:487–495
123
University of Manchester, Columbia University and Universidad
Nacional del Sur. His research focuses on design and characterization
of mesoporous materials, nanotechnology, self assembled supramo-
lecular structures and physicochemical characterization of proteins
and protein aggregates.
C. Solans is a researcher at the Institute for Advanced Chemistry of
Catalonia of the Spanish Council for Scientific Research (CSIC) in
Barcelona, Spain. She received a B.Sc. degree in Chemistry (1970)
from the University of Barcelona (Spain) an M.Sc. degree in
Chemistry (1980) from the University of Missouri-Rolla (U.S.A.)
and a Ph.D. in Chemistry (1983) from the University of Sevilla
(Spain). Her current research interests include surfactant phase
behavior and their application to emulsification processes by low-
energy methods, detergency, solubilization and synthesis of materials.
C. Rodriguez-Abreu received his B.Sc. and M.Sc. in Chemical
Engineering from the University of Los Andes (Venezuela) and
obtained his Ph.D. in engineering from the Yokohama National
University (Japan) in 2001. After working as an associate professor at
the University of Los Andes (Venezuela) and as a research fellow at
Yokohama National University (Japan), University of Santiago de
Compostela (Spain), and the Institute for Advanced Chemistry of
Catalonia (IQAC)-Spanish Council of Scientific Research (CSIC), he
joined the International Iberian Nanotechnology Laboratory in 2010.
His area of scientific activity is the physical-chemistry of amphiphilic
systems, and their application in the synthesis of nanomaterials.
J Surfact Deterg (2011) 14:487–495 495
123