Host-guest interactions between cyclodextrins and surfactants with functional groups at the end of the hydrophobic tail
Abstract
The aim of this work was to investigate the influence of the incorporation of substituents at the end of the hydrophobic tail on the binding of cationic surfactants to α-, β-, and -cyclodextrins. The equilibrium binding constants of the 1:1 inclusion complexes formed follow the trend K1(α-CD)>K1(β-CD)>>K1(-CD), which can be explained by considering the influence of the CD cavity volume on the host-guest interactions. From the comparison of the K1 values obtained for dodecyltriethylammonium bromide, DTEAB, to those estimated for the surfactants with the substituents, it was found that the incorporation of a phenoxy group at the end of the hydrocarbon tail does not affect K1, and the inclusion of a naphthoxy group has some influence on the association process, slightly diminishing K1. This makes evident the importance of the contribution of hydrophobic interactions to the binding, the length of the hydrophobic chain being the key factor determining K1. However, the presence of the aromatic rings does influence the location of the host and the guest in the inclusion complexes. The observed NOE interactions between the aromatic protons and the CD protons indicate that the aromatic rings are partially inserted within the host cavity, with the cyclodextrin remaining close to the aromatic rings, which could be partially intercalated in the host cavity. To the authors´ knowledge this is the first study on the association of cyclodextrins with monomeric surfactants incorporating substituents at the end of the hydrophobic tail
Full text
1
G aphical abs ac
In his wo k he in luence o he inco po a ion o a oma ic subs i uen s a he end o he
hyd ophobic ail on he binding o ca ionic su ac an s o cyclodex ins was s udied.
2
HOST-GUEST INTERACTIONS BETWEEN CYCLODEXTRINS AND
SURFACTANTS WITH FUNCTIONAL GROUPS AT THE END OF THE
HYDROPHOBIC TAIL
Vic o ia Isabel Ma ín, F ancisco José Os os, Manuel Angulo1, An onio Má quez, Pila
López-Co nejo, Manuel López-López2, Ana Te esa Ca mona3 and Ma ía Luisa Moyá*
Depa men o Physical Chemis y, Uni e si y o Se ille, C/ P o eso Ga cía González 1,
41012 Se ille. Spain. Tl . 34954557175. E-mail:moy[email p o ec ed]
1NMR Se ice, Uni e si y o Se ille, Apa ado 1203, E-41071 Se ille, Spain
2Depa men o Chemical Enginee ing, Physical Chemis y and Ma e ials Science, Facul y o
Expe imen al Sciences, Campus de El Ca men, A da. de las Fue zas A madas s/n, 21071
Huel a. Spain
3Depa men o O ganic Chemis y, Uni e si y o Se ille, C/P o eso Ga cía González 1,
41012 Se ille. Spain
Key wo ds: Su ac an s, cyclodex ins, inclusion complexes, a oma ic subs i uen s,
conduc i i y, NMR.
*Au ho o whom all co espondence should be di ec ed
3
Abs ac
The aim o his wo k was o in es iga e he in luence o he inco po a ion o
subs i uen s a he end o he hyd ophobic ail on he binding o ca ionic su ac an s o α-, β-,
and -cyclodex ins. The equilib ium binding cons an s o he 1:1 inclusion complexes o med
ollow he end K1(α-CD)>K1(β-CD)>>K1(-CD), which can be explained by conside ing he
in luence o he CD ca i y olume on he hos -gues in e ac ions. F om he compa ison o he
K1 alues ob ained o dodecyl ie hylammonium b omide, DTEAB, o hose es ima ed o he
su ac an s wi h he subs i uen s, i was ound ha he inco po a ion o a phenoxy g oup a he
end o he hyd oca bon ail does no a ec K1, and he inclusion o a naph hoxy g oup has
some in luence on he associa ion p ocess, sligh ly diminishing K1. This makes e iden he
impo ance o he con ibu ion o hyd ophobic in e ac ions o he binding, he leng h o he
hyd ophobic chain being he key ac o de e mining K1. Howe e , he p esence o he
a oma ic ings does in luence he loca ion o he hos and he gues in he inclusion
complexes. The obse ed NOE in e ac ions be ween he a oma ic p o ons and he CD p o ons
indica e ha he a oma ic ings a e pa ially inse ed wi hin he hos ca i y, wi h he
cyclodex in emaining close o he a oma ic ings, which could be pa ially in e cala ed in he
hos ca i y. To he au ho s´ knowledge his is he i s s udy on he associa ion o
cyclodex ins wi h monome ic su ac an s inco po a ing subs i uen s a he end o he
hyd ophobic ail.
1. In oduc ion
Cyclodex ins, CD, a e cyclic oligosaccha ides o med h ough (1-4) e he linkages
o glucopy anoside uni s [1,2]. The mos common CDs, -, -, and -CD, a e composed o
six, se en and eigh glucose uni s, espec i ely. CDs a e shaped like a unca ed cone wi h
in e nal ca i ies anging om 5 o 8 Å. The hyd oxyl unc ions a e o ien ed o he ex e io o
he ca i y, wi h he seconda y hyd oxyl g oups loca ed on he wide edge, and he p ima y
4
ones on he na ow edge. The C-H bonds on he ing and he nonbonding elec on pai s o he
glycosidic oxygen b idges poin inwa d. As a esul o his spa ial a angemen o he
unc ional g oups, he ca i y shows a ela i ely hyd ophobic cha ac e while he ex e nal
su aces a e hyd ophilic. This is esponsible o bo h hei wa e solubili y and hei abili y o
o m inclusion complexes wi h molecula gues s o sui able size. This capaci y o o m
inclusion complexes wi h a wide a ie y o molecules, oge he wi h he non- oxici y owa ds
humans, has been he basis o he CDs la ge ange o applica ions [3-9].
The unde s anding o he d i ing o ces in ol ed in he CD inclusion complex
o ma ion is undamen ally impo an no only in CD chemis y, bu also o sup amolecula
chemis y as a whole. In a ecen e iew Valen e and Söde man [10] poin ed ou ha
su ac an s a e ideal gues s o undamen al s udies on he complexa ion wi h CDs since bo h
hyd ophobic and hyd ophilic egions o he su ac an molecules can be sys ema ically a ied.
These au ho s examined he e ec o di e en su ac an a chi ec u es on he o ma ion o
inclusion complexes by conside ing he esul s ob ained by se e al au ho s o single ailed,
double ailed, gemini and bola o m su ac an s, wi h special emphasis on ca ionic su ac an s.
Howe e , o he au ho s´ knowledge, he in luence o he inco po a ion o a unc ional g oup
a he end o he hyd ophobic su ac an ail on he su ac an :CD in e ac ions has no been
in es iga ed. Wi h his in mind, he su ac an s ie hyl(1-phenoxydodecyl)ammonium
b omide (Phenoxy12) and ie hyl(2-naph hoxydodecyl)ammonium b omide (Naph hoxy12)
we e p epa ed in his wo k and hei in e ac ions wi h -, -, and -cyclodex ins s udied. In
o de o help he discussion o he esul s, he o ma ion o hos :gues complexes be ween
dodecyl ie hylammonium b omide (DTEAB) and CDs was also in es iga ed. Since he e is
no much in o ma ion abou su ac an s wi h unc ional g oups a he end o he hyd ophobic
ail in he li e a u e, a b ie discussion o he physicochemical p ope ies o Phenoxy12 and
5
Naph hoxy12 aqueous solu ions was done be o e conside ing he o ma ion o he inclusion
complexes.
N
CH2-CH3
B
( )11
DTEAB Phenoxy12
ON
B H
Naph hoxy12
( )11 CH2-CH3
CH2-CH3
CH2-CH3
ON
( )11 CH2-CH3
CH2-CH3
CH2-CH3
B
CH3
CH3-CH2
CH3-CH2
Scheme 1.- S uc u e o he su ac an s used in his wo k.
The esul s ob ained in his wo k will con ibu e o he unde s anding o he
su ac an :cyclodex in in e ac ions. This is impo an in ela ion o he wide ange o
applica ions o bo h CDs and su ac an s, which can be inc eased by aking ad an age o he
CD-su ac an complex o ma ion.
2. Expe imen al sec ion
2.1. Ma e ials and chemicals
Dodecyl yme hylammonium b omide, DTAB, was om Sigma-Ald ich. -, -, and
-cyclodex ins o he highes pu i y a ailable we e also pu chased om Ald ich (>99%
pu i y, acco ding o he manu ac u e ) and we e kep unde acuum. DTEAB was p epa ed in
a p e ious wo k [11] and i s syn hesis is b ie ly desc ibed in he Supplemen a y Ma e ial. The
p epa a ion o Phenoxy12 and Naph hoxy12 is desc ibed below. The su ac an s we e
cha ac e ized by 1H NMR, 13C NMR and elemen al analysis (CITIUS, Uni e si y o Se ille).
D2O was supplied by Sigma. Wa e was MilliQ ( esis i i y >18 M cm).
6
2.2. P epa a ion o he su ac an s
2.2.1. P epa a ion o Phenoxy12
The syn hesis o Phenoxy12 was pe o med acco ding o Scheme 2. S a ing om
comme cial 1,12-dib omo-dodecane, he phenoxy g oup, PhO, was in oduced a he end o
he a y alkyl chain by nucleophilic subs i u ion eac ion wi h sodium phenoxide in ace one,
hus gi ing compound 1 (12-b omo-1-phenoxydodecane) in 29% yield. Finally, a nucleophilic
displacemen eac ion wi h ace oni ile and ie hylamine ga e he compound 2 ( ie hyl(1-
phenoxydodecyl) ammonium b omide) in 75% yield. I s 1H NMR spec um indica ed he
appea ance o a iple and a qua e signals in eg a ing o nine and six p o ons, espec i ely,
co esponding o he new h ee e hyl g oups. P ocedu es o he p epa a ion o he su ac an
and in e media es a e desc ibed in de ail in Supplemen a y Ma e ial.
B (CH2)10B +PhONa ace one B (CH2)10 OPh
N(CH)10 OPh
B
ie hylamine
CH3CN
1
2
Scheme 2.- Syn hesis o Phenoxy12
2.2.2. P epa a ion o Naph hoxy12
The syn hesis o Naph hoxy12 was simila o ha o Phenoxy12, as i is shown in
Scheme 3. In his scheme he naph hoxy g oup is ep esen ed by NaphO. Comme cial 1,12-
dib omo-dodecane and sodium naph hoxide we e used in he nucleophilic subs i u ion
eac ion o ende compound 3 (12-b omo-1-naph hoxydodecane), in 52% yield. Finally, he
nucleophilic displacemen eac ion wi h ace oni ile and ie hylamine ga e he compound 4
( ie hyl(1-naph hoxydodecyl) ammonium b omide) in 97% yield. Simila ly o Phenoxy12,
7
+NaphONa ace one
B
ie hylamine
CH3CN
3
4
B B
10 NaphO B
10
NNaphO 10
Scheme 3.- Syn hesis o Naph hoxy12
1H NMR spec um o Naph hoxy12 indica ed he appea ance o a iple and a qua e signals
in eg a ing o nine and six p o ons, espec i ely, co esponding o he new h ee e hyl g oups.
P ocedu es o he p epa a ion o he su ac an s and in e media es a e also desc ibed in de ail
in Supplemen a y Ma e ial.
2.3. Me hods
2.3.1. Conduc i i y measu emen s
Conduc i i y was measu ed wi h a C ison GLP31 conduc ime e calib a ed wi h KCl
solu ions o he app op ia e concen a ion ange. The conduc ime e was connec ed o an
ex e nal wa e ci cula o (He o) and he whole sys em was placed in a oom in which he
empe a u e was kep cons an wi hin ±0.5 K. Tempe a u e was main ained a 3030.01 K.
Solu ions we e used wi hin 5 h a e p epa a ion. In a ypical expe imen a su ac an solu ion
was placed in he he mos a ed conduc i i y cell; hen, aliquo s o he CD solu ion, in he
p esence o he same su ac an concen a ion, we e added in a s epwise manne using a
p og ammable dispense C ison Bu e e 1S (0.1 L). The speci ic conduc i i y o he
solu ion was measu ed 10 min a e each addi ion, a e checking ha he speci ic
conduc i i y emained cons an wi h ime. Each expe imen was epea ed a leas wice.
The c i ical micella concen a ions o Phenoxy12 and Naph hoxy12 we e es ima ed
by means o conduc i i y measu emen s as desc ibed in e . 12.
8
2.3.2. Su ace ension measu emen s
Su ace ension was measu ed by a du Noüy ing me hod using a KSV 703 digi al
ensiome e (Finland) as desc ibed in e . 12.
2.3.3. NMR measu emen s
The NMR spec a we e pe o med in CITIUS (Resea ch Gene al Se ices o he
Uni e si y o Se ille). NMR samples we e p epa ed by dissol ing he co esponding amoun
o he su ac an and/o he CD in D2O ollowed by a b ie sonica ion. The solu ions we e
kep he mos a ed a 303 K o a leas 5 hou s be o e ca ying ou he NMR expe imen s.
NMR expe imen s we e eco ded on a B uke A ance III 500 MHz spec ome e (500.2 MHz
o 1H) equipped wi h a 5 mm TCI c yop obe ope a ing a 303 K. All 1H chemical shi s a e
e e enced o he esidual HDO signal se o 4.71 ppm [13].
Two-dimensional, 2D, o a ing ame nuclea O e hause e ec expe imen s we e
pe o med using he B uke s anda d pulse sequence (EASY-ROESY e sion [14]). 2048 x
256 da a poin s we e acqui ed wi h 16 ansien s pe inc emen and a elaxa ion delay o 1.5 s.
A mixing ime o 250 ms was used. Da a p ocessing was pe o med on a 1024 x 1024 da a
ma ix. Cosine-squa ed window unc ions we e used along F1 and F2.
3. Resul s and discussion
3.1. Physicochemical p ope ies o he Phenoxy12 and Naph hoxy12 aqueous solu ions
The c i ical micella concen a ion, cmc, and he micella ioniza ion deg ee, , o
Phenoxy12 and Naph hoxy12 in aqueous solu ions we e de e mined using conduc i i y
measu emen s. Figu e S1 (Supplemen a y Ma e ial) shows he dependence o he speci ic
conduc i i y on Phenoxy12 and on Naph hoxy12 concen a ions a 303 K. The Ca pena
me hod [15] was used in o de o ob ain he cmc and α alues om he expe imen al esul s.
These da a a e summa ized in Table 1, oge he wi h ha co esponding o DTEAB. The
Gibbs ene gy o micelliza ion, GoM, can be calcula ed by using eq. 1 [16]:
9
GoM= RT(2-α) ln cmc (1)
whe e cmc is exp essed in mole ac ion and R and T ha e hei usual meaning. GoM alues
a e lis ed in Table 1. Compa ison o he GoM alues ob ained o he h ee su ac an s shows
Table 1.-C i ical micella concen a ion, cmc, micella
ioniza ion deg ee, , and Gibbs ene gy o micelliza ion,
GoM, o he ca ionic su ac an s s udied in his wo k, a
303 K.
Su ac an
Cmc/mM
GoM/kJ
mol-1
DTEABa
14.30.4
0.350.02
-34.31.8
Phenoxy12b
3.70.2
0.400.03
-38.81.7
Naph hoxy12b
0.6410.015
0.430.03
-45.01.9
aRe . 11; bThis wo k.
ha he in oduc ion o a phenoxy and a naph hoxy g oup a he end o he su ac an
hyd ophobic ail subs an ially a o s micelliza ion. The expe imen al obse a ions can be
explained by aking in o accoun he ans e Gibbs ene gy con ibu ion, Go ans , o he Gibbs
ene gy o micelliza ion, GoM. Go ans conside s he ans e o he hyd ophobic su ac an
chains om he aqueous phase o he micella in e io and i is he d i ing o ce o he sel -
associa ion p ocess o su ac an s [17]. The su ac an s lis ed in Table 1 ha e a dodecyl
hyd ophobic chain and he co esponding Go ans con ibu ion would be he same o all o
hem. The 4- old and a 22- old diminu ion in he cmc, wi h espec o ha o DTEAB, caused
by he inco po a ion o a phenoxy g oup, C6H5O-, and o a naph hoxy g oup, C12H7O-, a he
end o he hyd ophobic ail can be a ionalized by conside ing he addi ional hyd ophobic
con ibu ion o Go ans due o he ans e o he C6H5O- and C12H7O- g oups in o he
micelles. The la ge di e ence ound be ween he cmc´s o Phenoxy12 and Naph hoxy12
could be accoun ed o by he di e en hyd ophobici y o hese wo a oma ic subs i uen s. As
an example, he loga i hm o he oc anol/wa e pa i i ion coe icien , logP, is 1.46 and 2.70
o phenol and naph hol, espec i ely [18].
16
o ien a ion o he su ac an , wi h he a oma ic moie y loca ed close o he na owe im o he
cyclodex in.
In e ac ions be ween he CD p o ons and he a oma ic su ac an p o ons a e obse ed
o Phenoxy12 and Naph hoxy12. Conside ing he ROESY spec a o he Phenoxy12
su ac an , one can see NOE in e ac ions be ween he a oma ic H1' and H2' p o ons (s onge
o H1') o he su ac an and p o ons o he cyclodex ins o -, -, and -CD. Fo
Naph hoxy12 (see Figu e 4S, Supplemen a y Ma e ial) NOE in e ac ions be ween he p o ons
H1', H3´, H4´, and H8´ (s onge o H1´and H3´) and p o ons o he CDs a e obse ed. These
indings poin ou ha in he o med inclusion complexes he cyclodex in emains close o
he a oma ic ings, which could be pa ially in e cala ed in he hos ca i y. They also
show he dynamic cha ac e o he inclusion complex o ma ion, which associa es and
dissocia es wi h a equency ha would depend, o a gi en gues , on he CD na u e. This
dynamic cha ac e could explain he eally in e es ing ac ha he in e ac ion be ween he CD
p o ons and all he a oma ic p o ons o Phenoxy12 is only obse ed in he case o -CD. This
cyclodex in has he la ges ca i y olume o he h ee CDs, which would make he
dissocia ion easie han o - and -CD, inc easing he p obabili y o in e ac ions be ween
he CD and he a oma ic p o ons. The es ima ed equilib ium binding cons an s ob ained in his
wo k suppo his assump ion (see below).
3.3. S oichiome y
P io o he calcula ion o he equilib ium binding cons an s o he inclusion
complexes, he binding s oichiome y o he CD:Su ac an hos -gues complexes has o be
es ima ed. In o de o do so Job´s me hod was used [26]. I is obse ed ha when CDs a e
added o an aqueous ionic su ac an solu ion, a cons an su ac an concen a ion, an inc ease
in CD concen a ion could esul in a dec ease in he expe imen al speci ic conduc i i y. This
dec ease can be asc ibed o he o ma ion o CD:Su ac an , CDS, inclusion complexes, which
17
ha e conside ably smalle ionic equi alen conduc i i y han hose o su ac an monome s
[27]. Fo his eason, conduc i i y measu emen s can be used in o de o ge in o ma ion
abou ionic su ac an s/CD in e ac ions. Figu e 3 shows some o he Job´s plo s ob ained o
he di e en su ac an s and cyclodex ins in es iga ed, whe e he dependence o
(κobs)× [CDT] on he CD mola ac ion was shown, obs being he expe imen al speci ic
conduc i i y. In all cases only 1:1 complexes, CDS, a e o med unde he wo king condi ions.
0.0 0.2 0.4 0.6 0.8 1.0
0
2
4
6
8
10
XCD
DTEAB:-CD
Maximum a XCD=0.50
a)
103x(obs[CDT] (mol m-4)
0.0 0.2 0.4 0.6 0.8 1.0
0
2
4
6
8
10
12
XCD
Phenoxy12:-CD
Maximum a XCD=0.50
103x(obs[CDT] (mol m-4)
b)
0.0 0.2 0.4 0.6 0.8 1.0
0.0
0.5
1.0
1.5
2.0
Naph hoxy12:-CD
XCD
Maximum a XCD=0.50
c)
103x(obs[CDT] (mol m-4)
Fig. 3.-Job´s plo s a 303 K. a)DTEAB:-CD; b)Phenoxy12:-CD; c)Naph hoxy12:β-CD.
3.4. Fo ma ion equilib ium cons an s o he inclusion complexes
The associa ion p ocess be ween he su ac an s and he cyclodex ins has been s udied
by a ying he CD concen a ion, o a cons an su ac an concen a ion lowe han he cmc.
18
The s abili y o he inclusion complexes can be desc ibed in e ms o he equilib ium binding
cons an s, K1. Fo a 1:1 complex K1 can be de ined as:
CD + S CDS K1=[CDS]
[CD ][S] (2)
F om he mass conse a ion law equa ions and aking in o accoun ha he expe imen al
speci ic conduc i i y is he sum o he con ibu ions coming om he su ac an ee ions, he
b omide coun e ions and he CDS inclusion complexes, he obse ed dec ease in he mola
conduc ance o he su ac an aqueous solu ions due o he addi ion o CD, obs, can be
exp essed as [28]:
ΔΛ𝑜𝑏𝑠 =Δ𝜆
2𝐾1[𝑆𝑇]{𝐾1([𝑆𝑇]+[𝐶𝐷𝑇])+
+1−((𝐾1 ([𝑆𝑇]+[𝐶𝐷𝑇])+1)2−4𝐾1
2 ([𝑆𝑇]+[𝐶𝐷𝑇]))1/2}
(3)
whe e, is he di e ence in he ionic conduc i i ies o he unassocia ed, S, and associa ed,
CDS, su ac an ions, and [ST] and [CDT] a e he o al su ac an and cyclodex in
concen a ions in he solu ions. Figu e 4 shows some examples o he dependence o obs on
he o al cyclodex in concen a ion. Eq. 3 was i ed o he expe imen al da a using a non-
linea leas -squa e algo i hm. Solid lines in Figu e 4 show he esul o he i ings. One can
see ha he ag eemen be ween he expe imen al and heo e ical da a is good. The alues o
he binding equilib ium cons an s, K1, ob ained om he i ings a e summa ized in Table 2.
Expe imen s wi h di e en su ac an concen a ions we e ca ied ou and he esul s showed
ha [ST] does no in luence he es ima ed K1 alue. The me hod was also checked by
de e mining K1 o he 1:1 inclusion complex o med be ween dodecyl ime hylammonium
b omide, DTAB, and -cyclodex in a 298 K. The K1 alue ob ained o his inclusion
complex was 1.9104 M-1, in good ag eemen wi h li e a u e da a [10]. K1 alues summa ized
in Table 2 a e he a e age o a leas ou di e en expe imen s.
19
0 1 2 3 4 5 6 7
0
1
2
3
4
5
a)
103[-CDT]
104obs(-1 m2 mol-1)
[Phenoxy12T]=2.0710-3 M
0 1 2 3 4 5
0
1
2
3
4
5
6b)
103[-CDT]
104obs(-1 m2 mol-1)
[Phenoxy12T]=1.7410-3 M
0 2 4 6 8 10 12 14
0
1
2
3
4
103[-CDT]
104obs(-1 m2 mol-1)
c)
[Phenoxy12]=1.7010-3 M
0.0 0.5 1.0 1.5 2.0 2.5 3.0
0
1
2
3
4
5
6
103[-CDT]
104obs(-1 m2 mol-1)
[Naph hoxy12T]=4.8510-4 M
d)
Fig. 4.-Dependence o obs on he o al cyclodex in concen a ion o he su ac an s
in es iga ed a 303 K. Solid lines show he i ing o he expe imen al da a by using eq. 3.
Table 2.- Values o equilib ium binding cons an ,
K1, es ima ed om he i ings o he obse ed
mola conduc ance a ia ions o he aqueous
su ac an solu ions upon inc easing he o al CD
concen a ion, by using eq. 3. T= 303 K.
Su ac an :CD
K1 (M-1)
DTEAB:-CD
(2.40.5) 104
DTEAB:-CD
(1.60.4)104
DTEAB:-CD
(3.80.3)102
Phenoxy12:-CD
(2.20.5)104
Phenoxy12:-CD
(1.30.2)104
Phenoxy12:-CD
(6.90.5)102
Naph hoxy12--CD
(2.90.7)104
Naph hoxy12--CD
(8.20.8)103
Naph hoxy12--CD
(4.02.2)102
I is wo h no ing ha he es ima ion o he equilib ium binding cons an s o he
inclusion complexes Naph hoxy12:CDs was ca ied ou in he p esence o [su ac an ]510-4
20
M, due o he low cmc o his su ac an (cmc=6.710-4 M). As a consequence, he p ecision
o he es ima ed K1 alues is poo , pa icula ly o he Naph hoxy12:-CD sys em.
The o ma ion equilib ium cons an s o he inclusion complexes can also be es ima ed
by using 1H NMR measu emen s. The e ec o micelliza ion in he chemical shi s o he
su ac an esonances has been a oided using a ixed su ac an concen a ion below he cmc.
The concen a ion o cyclodex in was a ied o ob ain di e en mola a ios
[CD]/[Su ac an ]. Rep esen a i e esul s o he 1H NMR spec a o he CD/su ac an
mix u es a e shown in Figu e 5 o he sys em Phenoxy12:-CD. The 1H NMR spec a o α-,
Cx=C2, C3, C4, C5, and C6
Fig. 5.- 1H NMR spec a o Phenoxy12:-CD solu ions in D2O a 303 K, wi h
[Phenoxy12]=2.05x10-3 M. a) [β-CD]=0 M; b) [β-CD]= 4.0x10-4 M; c) [β-CD]=2.0x10-3 M; d)
[β-CD]=4 x10-3 M; Mo e β-CD concen a ions we e in es iga ed bu he spec a a e no
included in he igu e o he sake o cla i y. T=303 K.
8
2'
3'
1
2
3
7
4
6
5
1
a)
b)
c)
d)
Cx
C1
21
β-, and -CD a e shown in Figu e S5 (Supplemen a y Ma e ial). Assuming ha he condi ion
o as exchange on he NMR ime scale applies, he measu ed equency is a weigh ed
a e age o he equencies in each si e, and he chemical shi can be used o measu e he
ex en in which he equilib ium is displaced [28]. The obse ed chemical shi , o a 1:1
inclusion complex is [10]:
δobs = XS δS +XSCDδSCD =(1−XSCD)δS+XSCDδSCD (4)
whe e XS=[S]/[ST] and XSCD=[SCD]/[ST]. In his case:
∆𝛿𝑜𝑏𝑠 = 𝛿𝑜𝑏𝑠 −𝛿𝑆= 𝑋𝑆𝐶𝐷(𝛿𝑆𝐶𝐷 −𝛿𝑆)= 𝑋𝑆𝐶𝐷∆𝛿𝑜 (5)
Fo a 1:1 inclusion complex, one can w i e [10]:
K1=[SCD]
[S][CD]=[SC]
([ST]−[SCD])([CDT]−[SCD]) =
=XSCD
(1−XSCD)([CDT]−XSCD[ST]) (6)
A e some algeb aic manipula ion and simpli ica ion [10]:
Δ𝛿𝑜𝑏𝑠 =Δδ0
2𝐾1[𝑆𝑇](𝐾1([𝑆𝑇]+[𝐶𝐷𝑇])+1−
−((𝐾1([𝑆𝑇]+[𝐶𝐷𝑇])+1)2−4𝐾1
2[𝑆𝑇][𝐶𝐷𝑇])1/2) (7)
Eq. 7 was i ed o he expe imen al da a using a non-linea leas -squa e algo i hm. Figu e 6
shows wo examples o he dependence o obs on he o al cyclodex in concen a ion o
some nuclei. The expe imen s we e done a leas wice o each su ac an -cyclodex in
sys em. Since hese measu emen s we e done in o de o check he eliabili y o he
equilib ium cons an s alues lis ed in Table 2, only β-cyclodex in was used. The equilib ium
cons an o he Naph hoxy12:CD complexes could no be calcula ed om 1H NMR
expe imen s because o he la ge e o s due o he low su ac an concen a ion p esen in he
deu e a ed solu ions. The alues o he binding equilib ium cons an s, K1, ob ained om
NMR measu emen s a e summa ized in Table 3. One can see ha he K1 alues lis ed in
Tables 2 and 3 a e in good ag eemen .
22
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
-0.04
-0.03
-0.02
-0.01
0.00
obs/ppm
H(5)
103x[-CDT]/M
a)
DTEAB:-CD
0 1 2 3 4 5
0.000
0.010
0.020
0.030
0.040
0.050
0.060
obs/ppm
H(3)
103x[-CDT]
b)
Phenoxy12--CD
Fig. 6.- Dependence o he chemical shi obs=obs-S on o al -cyclodex in concen a ion
o selec ed p o ons o he su ac an s. Solid lines a e he bes i o eq. 14.
Table 3.- Values o equilib ium binding cons an , K1, es ima ed om he
i ings o he obse ed chemical shi a ia ions o su ac an p o ons
upon inc easing he o al CD concen a ion, by using eq. 14. T= 303 K.
Su ac an :CD
[Su ac an T](M)
K1 (M-1)
DTEAB:β-CD
1.9510-3
(1.60.5) 104
Phenoxy12:β-CD
2.0510-3
(1.40.4)104
N
B
6
5
4
3
21
23
The expe imen al esul s ha e shown ha inclusion complexes a e o med be ween he
CDs and he su ac an s in es iga ed. A his poin , i is in e es ing o conside how hey a e
o med. The su ac an s a e qua e na y ammonium de i a i es, wi h iden ical ca ionic head
g oups and a hyd oca bon ail wi h wel e ca bon a oms. The olume o he -N(C2H5)3+ head
g oup is la ge and, besides, i is cha ged and o push i h ough he ela i ely non pola ca i y
o he CDs will be ene ge ically expensi e. As a consequence, i would be expec ed ha he
in e cala ion o he su ac an ail in o he hos ca i y occu ed as is shown in Figu e 7. The
Fig. 7.-Fo ma ion o he inclusion complexes
wo k o Lyon e al. [29] suppo ed his hypo hesis. These au ho s in es iga ed he o ma ion
o inclusion complexes be ween he bola o m su ac an s [(CH3)3N(CH2)nN(CH3)3]B 2 (n=8,
10, 12) and ((CH3)2E N(CH2)10NE (CH3)2)B 2, and α-CD. They ound ha he eplacemen o
one me hyl by an e hyl in each o he end g oups on he ((CH3)3N(CH2)10N(CH3)3)2+
su ac an esul s in a s ong dec ease in he equilib ium binding cons an . Replacemen s o
wo o all o he me hyls by e hyls p e en he o ma ion o he inclusion complexes e en
a e p olonged hea ing.
The geome ies o he a oma ic subs i uen s we e op imized wi h a RHF wa e unc ion using
6-81g(d) basis se wi h he Gaussian 09 sui o p og ams [30] and hei olumes we e
calcula ed. As is shown in Figu e 8, he bulk o he wo a oma ic subs i uen s pe mi s he
inse ion o he hyd ophobic ail in o he hos ca i y o ei he -, - o -CD o o m he
inclusion complexes. Figu e 7 shows ha wo possible inclusion complexes could be o med
due o he unca ed cone shape o he CD molecule. Only in he case o he α-CD:Phenoxy12
24
sys em, he ROESY spec um sugges s ha he su ac an is p e e en ially o ien ed wi h he
a oma ic moie y loca ed close o he na owe im o he cyclodex in. The expe imen al da a
would gi e in o ma ion abou he a e age equilib ium binding cons an .
Fig. 8.- Some s uc u al in o ma ion abou he hos molecules and he wo a oma ic
subs i uen s.
The d i ing o ces leading o he o ma ion o CD:Su ac an inclusion complexes
include elec os a ic in e ac ions, an de Waals in e ac ions, hyd ophobic in e ac ions,
hyd ogen bonding, elease o con o ma ional s ain o he CD, exclusion o ca i y-bound
high-ene gy wa e om he CD ca i y and cha ge- ans e in e ac ions [31]. Tables 2 and 3
show ha he equilib ium binding cons an s ollow he end K1(α-CD)>K1(β-CD)>>K1(-
CD). These obse a ions can be explained by conside ing he olume o he cyclodex in
ca i y (α-CD(V=174 Å3 [32]), β-CD (V=270 Å3 [32]) and -CD(V=472 Å3 [32]), and aking
in o accoun ha he smalle he ca i y is, he s onge he su ac an -CD in e ac ions will be
[10, 33-36]. Due o en halpy-en opy compensa ion, elease o con o ma ional s ain and
exclusion o ca i y-bound high-ene gy wa e do no usually play an impo an ole in he
complex o ma ion. Van de Waals in e ac ions and hyd ophobic in e ac ions cons i u e he
majo d i ing o ces o cyclodex in complexa ion, oge he wi h elec os a ic in e ac ions
and hyd ogen bonding. This is in ag eemen wi h he no subs an ial e ec s o he subs i uen s
25
on K1. One can see ha he inco po a ion o a phenoxy g oup, C6H5-O-, a he end o he
dodecyl chain does no signi ican ly a ec he binding o he su ac an molecules o he h ee
CDs in es iga ed. On he o he hand, he p esence o a naph hoxy g oup, C10H7-O-, makes he
associa ion o he su ac an o he α-CD somewha s onge , whe eas he associa ion o he β-
CD is made a li le weake . The binding o Naph hoxy12 o -CD also seems o be weake ,
al hough he la ge expe imen al e o s do no pe mi o each any conclusion. This makes
clea ha he hyd oca bon chain leng h is he key s uc u al su ac an ea u e de e mining he
s abili y o he inclusion complexes in es iga ed, which can be aken as e idence o he
impo ance o he hyd ophobic in e ac ions con ibu ion o he binding [10, 31]. A simila
esul was ound by o he au ho s in he s udy o inclusion complexes o med be ween
anionic, ca ionic and non-ionic su ac an homologs and cyclodex ins [10, 37, 38]. The
p esence o he a oma ic ings a he end o he hyd ophobic ail does no subs an ially a ec
K1, howe e , i does in luence he loca ion o he hos and he gues in he inclusion
complexes. The obse ed NOE in e ac ions be ween he a oma ic p o ons and he CD p o ons
indica e ha he a oma ic ings a e pa ially inse ed wi hin he hos ca i y, wi h he
mac ocycle p e e en ially loca ed a he end o he hyd oca bon ail o he su ac an , in
con as wi h he s uc u e o he inclusion complexes o med wi h DTEAB. I was also ound
han in he case o he phenoxy subs i uen , he pa e n o in e molecula NOEs obse ed
sugges s a speci ic o ien a ion o he su ac an in he inclusion complex o med wi h α-CD,
wi h he a oma ic moie y loca ed close o he na owe im o he cyclodex in.
4. Conclusions
In he s udy o he complexa ion be ween cyclodex ins and su ac an s he in luence
o se e al ac o s in he s abili y o he hos -gues complexes has been in es iga ed. The
e ec s on he o ma ion o he inclusion complexes o changing he size o he hos ca i y
[10, 33-36, 39], he hyd ophobic chain leng h o he su ac an [10, 37, 38], he na u e o he
32
ension, calo ime y, and molecula dynamics o cyclodex ins wi h a non-ionic
su ac an . J. Phys. Chem. B 111 (2008) 4383-4392.
[36] S. M. Gho eishi, M. Behpou , M. Goles aneh, S udy o he inclusion complex
o ma ion be ween a ca ionic su ac an , wo cyclodex ins and a d ug. J. Incl.
Phenom. Mac ocycl. Chem. 62 (2008) 279-284.
[37] M. Benko, R. Tabajdi, Z. Ki aly 976The modynamics o o ma ion o b-cyclodex in
inclusion complexes wi h ou se ies o su ac an homologs. J. The m. Anal. Calo im.
112 (2013) 969-976.
[38] A. Pe ek, M. K ajnc, A. Pe ek S udy o hos -gues in e ac ion be ween -cyclodex in
and alkyl ime hylammonium b omides in wa e . J. Incl. Phenom. Ma ocycl. Chem.
86 (2016) 221-229.
[39] S. K. Meh a, K. K. Bhasin, S. Dham, M. L. Singla, Micella beha io o aqueous o
dodecyldime hyle hylammonium b omide, dodecyl ime hylammonium chlo ide and
e adecyl ime hylammonium chlo ide in he p esence o -, -, HP--, and -
cyclodex ins. J. Colloid In e ace Sci. 321 (2008) 442-451.
[40] X. Du, X. Chen, W. Lu, J. Hou, Spec socopic s udy on binding beha io s o di e en
s uc u al nonionic su ac an s o cyclodex ins. J. Colloid In e ace Sci. 274 (200)
645-651.
[41] D. Ondo, Calo ime ic s udy on he in e ac ion o didecyldime hylammonium and
decyl ime hylammonium ca ions wi h na i e cyclodex ins in wa e . J. Chem.
The modynamics 97 (2016) 235-243.
[42] E. Alami, S. A. Alami, J. Eas oe, I. G illo, R. K. Heenan, In e ac ions be ween a
nonionic gemini su ac an and cyclodex ins in es iga ed by small-angle neu on
sca e ing. J. Colloid In e ace Sci. 255 (2002) 346-356.
33
[43] Ch. Zhou, D. Wang, M. Cao, Y. Chen. Z. Liu, Ch. Wu, H. Xu, S. Wang, Y. Wang,
Sel -agg ega ion, an ibac e ial ac i i y, and mildness o cyclodex in/ca ionic ime ic
su ac an complexes. ACS Appl. Ma e . In e aces 8 (2016) 30811-30823.
[44] M. Qui oga, M. Pa ajó, P. Rod íguez-Da on e, L. ga cía-Río, Kine ic s udy o
[2]pseudo o axane o ma ion wi h an asyme ical ead. Langmui 32 (2016) 6367-
6375.
[45] V. I. Ma ín, B. Sa ión, M. López-López, P. López-Co nejo, I. Robina, M. L. Moyá,
Re e sibili y o he in e ac ions be ween a no el su ac an de i ed om lysine and
biomolecules. Colloids Su . B 135 (2015) 346-356.
[46] Gonzalez-Pe ez A, Dias RS, Nylande T, Lindman B. Cyclodex in–su ac an
complex: a new ou e in DNA decompac ion. Biomac omolecules 9 (2008) 772-775.
[47] Ca ls ed J, Gonzalez-Pe ez A, Ala o e-Meda M, Dias RS, Lindman B. Release o
DNA om su ac an complexes induced by 2-hyd oxyp opyl-be a-cyclodex in. In .
J. Biol. Mac omol. 46 (2010) 153–8.
[48] Gonzalez-Pe ez A, Ca ls ed J, Dias RS, Lindman B. Cyclodex ins in DNA
decompac ion. Colloid Su . B 76 (2010) 20–7.
[49] Ca ls ed J, Lundbe g D, Dias RS, Lindman B. Condensa ion and decondensa ion o
DNA by ca ionic su ac an , spe mine, o ca ionic su ac an –cyclodex inmix u es:
mac oscopic phase beha io , agg ega e p ope ies, and dissolu ion mechanisms.
Langmui 28 (2012) 7976–89.
[50] A. J. Ki by, P. Camille i, J. F. B. N Engbe s, M. C. Fei e s, R. J. M. Nol e, O.
Söde man, M. Be gsma, P. C. Bell, M. L. Fielden, C. L. Ga cía Rod íguez, P. Guda ,
A. K eme , C. McG ego , C. Pe in, G. Ronsin, M. C. P. an Eijk, Gemini su ac an s:
New syn he ic ec o s o gene ans ec ion. Angew. Chem. In . ed. 42 (2003) 1448-
1457.
34
Figu e cap ions
Figu e 1.- Concen a ion dependence o 1H NMR spec um o Phenoxy12, in D2O, on
su ac an concen a ion. a) [Phenoxy12]=2.00x10-3 M; b) [Phenoxy12]= 0.010M. T=303 K.
Figu e 2.- ROESY spec a o D2O solu ions con aining [Phenoxy12]=2.0510-3 M and
[CD]=2.0010-3 M a 303 K. a) α-CD; b)β-CD; c)-CD.
Figu e 3.-Job´s plo s a 303 K. a)DTEAB:-CD; b)Phenoxy12:-CD; c)Naph hoxy12:β-CD.
Figu e 4.-Dependence o obs on he o al cyclodex in concen a ion o he su ac an s
in es iga ed a 303 K. Solid lines show he i ing o he expe imen al da a by using eq. 3.
Figu e 5.- 1H NMR spec a o Phenoxy12:-CD solu ions in D2O a 303 K, wi h
[Phenoxy12]=2.05x10-3 M. a) [β-CD]=0 M; b) [β-CD]= 4.0x10-4 M; c) [β-CD]=2.0x10-3 M; d)
[β-CD]=4 x10-3 M; Mo e β-CD concen a ions we e in es iga ed bu he spec a a e no
included in he igu e o he sake o cla i y. T=303 K.
Figu e 6.- Dependence o he chemical shi obs=obs-S on o al -cyclodex in
concen a ion o selec ed p o ons o he su ac an s. Solid lines a e he bes i o eq. 14.
Figu e 7.-Fo ma ion o he inclusion complexes
Figu e 8.- Some s uc u al in o ma ion abou he hos molecules and he wo a oma ic
subs i uen s.
35
Tables
Table 1.-C i ical micella concen a ion, cmc, micella
ioniza ion deg ee, , and Gibbs ene gy o micelliza ion,
GoM, o he ca ionic su ac an s s udied in his wo k, a
303 K.
Su ac an
Cmc/mM
GoM/kJ
mol-1
DTEABa
14.30.4
0.350.02
-34.31.8
Phenoxy12b
3.70.2
0.400.03
-38.81.7
Naph hoxy12b
0.6410.015
0.430.03
-45.01.9
aRe . 11; bThis wo k.
Table 2.- Values o equilib ium binding cons an ,
K1, es ima ed om he i ings o he obse ed
mola conduc ance a ia ions o he aqueous
su ac an solu ions upon inc easing he o al CD
concen a ion, by using eq. 3. T= 303 K.
Su ac an :CD
K1 (M-1)
DTEAB:-CD
(2.40.5) 104
DTEAB:-CD
(1.60.4)104
DTEAB:-CD
(3.80.3)102
Phenoxy12:-CD
(2.20.5)104
Phenoxy12:-CD
(1.30.2)104
Phenoxy12:-CD
(6.90.5)102
Naph hoxy12--CD
(2.90.7)104
Naph hoxy12--CD
(8.20.8)103
Naph hoxy12--CD
(4.02.2)102
Table 3.- Values o equilib ium binding cons an , K1, es ima ed om he
i ings o he obse ed chemical shi a ia ions o su ac an p o ons
upon inc easing he o al CD concen a ion, by using eq. 14. T= 303 K.
Su ac an :CD
[Su ac an T](M)
K1 (M-1)
DTEAB:β-CD
1.9510-3
(1.60.5) 104
Phenoxy12:β-CD
2.0510-3
(1.40.4)104
36
SUPPLEMENTARY MATERIAL
HOST-GUEST INTERACTIONS BETWEEN CYCLODEXTRINS AND
SURFACTANTS WITH FUNCTIONAL GROUPS AT THE END OF THE
HYDROPHOBIC TAIL
Vic o ia Isabel Ma ín,a F ancisco José Os os, Manuel Angulo,b An onio Má quez,a
Pila López-Co nejo,a Manuel López-López,c Ana Te esa Ca mona,d and Ma ía Luisa
Moyáa*
aDepa men de Química Física, Uni e sidad de Se illa, C/ P o eso Ga cía González 1,
41012 Se illa. Spain. Tl . 34954557175 Fax: 34954557174 E-mail: [email protected]
bSe icio de RMN, Uni e sidad de Se illa, Apa ado 1203, E-41071 Se illa, Spain
cDepa men o Chemical Enginee ing, Physical Chemis y and Ma e ial Science, Facul y o
Expe imen al Sciences, Campus El Ca men, A da. De las Fue zas A madas s/n, 21071
Huel a,.Spain
dDepa men o O ganic Chemis y, Uni e si y o Se ille, C/P o eso Ga cía González 1,
41012 Se ille. Spain
*Au ho o whom all co espondence should be di ec ed.
37
P epa a ion o dodecyl ie hylammonium b omide, DTEAB
The DTEAB was p epa ed in a p e ious wo k ( e .11) ollowing he me hod o Guo e
al. (J. Polym. Sci. A 2009, 47, 434-449). B ie ly, s oichiome ic amoun s o 1-
b omododecane and ie ylamine we e hea ed, unde e lux, in ace one o 20 h a 75ºC. The
c ude p oduc was ec ys allized 5 imes om ace one and washed wi h e he . The p oduc
was ob ained as a whi e solid (26.7%). The pu i y o DTEAB was checked by NMR
measu emen s and mass spec ome y.
Expe imen al p ocedu es o ie hyl(1-phenoxydodecyl)ammonium b omide,
Phenoxy12 and ie hyl(2-naph hoxydodecyl)ammonium b omide, Naph hoxy12.
Gene al echniques. The cha ac e iza ion o he compound was pe o med by i s spec al
da a. 1H and 13C-NMR spec a we e ob ained o solu ions in D2O on a B uke A ance III 500
MHz spec ome e (500.2 MHz o 1H) equipped wi h a 5 mm TCI c yop obe ope a ing a
303 K. All 1H NMR chemical shi s a e e e enced o he esidual HDO signal se o 4.71
ppm; J alues a e gi en in Hz and δ in ppm. The NMR spec a o all compounds we e
pe o med in CITIUS (Resea ch Gene al Se ice o he Uni e si y o Se ille). The
comple ion o he eac ions we e moni o ed by TLC (silica gel HF254 (Me ck) hexane and
DCM:MeOH=3:1) wi h de ec ion by UV ligh and cha ing wi h Pancaldi. Elemen al analysis
o he su ac an was also ca ied ou .
12-B omo-1-phenoxydodecane (1)
A solu ion o 1,12-dib omo-dodecane (1g, 3.05 mmoles) and sodium phenola e (0.71g,
6.12 mmol) in d y ace one (70 mL), was s i ed unde A and hea ed a 62 °C o 30 min and
hen concen a ed o d yness a educed p essu e. The esidue was dissol ed in
dichlo ome hane and ex ac ed successi ely wi h wa e (4x15 mL). The o ganic phase was
d ied wi h Na2SO4 and concen a ed o d yness unde educed p essu e. The esidue was
pu i ied using column ch oma og aphy wi h silica gel and hexane. P oduc 1 was ob ained as
a whi e amo phous solid (0.3 g, 29%).
T ie hyl(1-phenoxydodecyl)ammonium b omide (2), Phenoxy12
A solu ion o 12-b omo-1-phenoxydodecane (0.246g, 0.79 mmol) and ie hylamine
(2.5mL, 17.9 mmol) in ace oni ile (19 mL), was s i ed unde A and hea ed a 90 °C o 1
day. The p og ess o he eac ion was con olled by TLC (DCM:MeOH=3:1). The eac ion
mix u e was hen concen a ed o d yness a educed p essu e. Subsequen ly, 10 ml o hexane
was added and he mix u e was s i ed o 15 min and hen il e ed unde acuum ( his
38
p ocedu e was epea ed h ee imes). P oduc 2 was ob ained as a whi e amo phous solid (0.24
g, 75%).
1H RMN (500 MHz, D2O): (ppm)=7.45 ( , 2H, Ph), 7.15-7.07 (m, 3H, Ph), 4.16 ( , 2H, Ph-
O-CH2-(CH2)11), 3.36-3.26 (m, 6H, N+(CH2)3(CH3)3), 3.21-3.13 (m, 2H, CH2-
N+(CH2)3(CH3)3), 1.88-1.79 (m, 2H, Ph-O-CH2-CH2), 1.76-1.66(m, 2H, CH2-CH2-
N+(CH2)3(CH3)3), 1.56-1.47 (m, 2H, Ph-O-(CH2)2-CH2), 1.47-1.34 (m, 14H, (CH2)7), 1.31 ( ,
9H, 3J = 7 Hz, N+(CH2)3(CH3)3).
13C RMN (75.4 MHz, CDCl3): δ (ppm) = 157.1, 129.24, 127.65, 123.63, 118.7, 106.7
(Ph), 67.9 (Ph-O-CH2-(CH2)11), 56.5 (CH2-N+(CH2)3(CH3)3), 52.7 (N+(CH2)3(CH3)3), 29.6,
26.4, (Ph-O-CH2-(CH2)9), 21.3(CH2-CH2-N+(CH2)3(CH3)3, N+(CH2)3(CH3)3)
12-B omo-1-naph hoxydodecane (3)
A solu ion o 1,12-dib omo-dodecane (2g, 6.10 mmoles) and sodium naph hola e
(2.03g, 12.19 mmol) in d y ace one (140 mL), was s i ed unde A and hea ed a 65 °C o 30
min and hen concen a ed o d yness a educed p essu e. The esidue was pu i ied using
column ch oma og aphy wi h silica gel and cyclohexane. P oduc 1 was ob ained as a whi e
amo phous solid (2.11 g, 52.26%).
T ie hyl(2-naph hoxydodecyl)ammonium b omide (4), Naph hoxy12
A solu ion o 12-b omo-1-naph hoxydodecane (0.640g, 1.64 mmol) and ie hylamine
(2.73mL, 19.62 mmol) in ace oni ile (50 mL), was s i ed unde A and hea ed a 90 °C o 1
day. The p og ess o he eac ion was con olled by TLC (DCM:MeOH=3:1). The eac ion
mix u e was hen concen a ed o d yness a educed p essu e. Subsequen ly, 10 ml o cold
cyclohexane was added and he mix u e was s i ed o 30 min and hen il e ed unde
acuum ( his p ocedu e was epea ed h ee imes). P oduc 2 was ob ained as a whi e
amo phous solid (0.624 g, 97.43%).
1H NMR (500 MHz, D2O, 303 K): (ppm)=7.38 (m, 2H, Naph), 7.05 (m, 1H, Naph), 7.02 (m,
2H, Naph), 4.09 ( , 2H, Naph-O-CH2-, 6.5 Hz), 3.23 (q, 6H, N+(CH2CH3)3, 7.3 Hz), 3.10 (m,
2H, -CH2-N+(CH2CH3)3), 1.76 (m, 2H, Naph-O-CH2-CH2-), 1.63 (m, 2H, -CH2-CH2-N+-),
1.44 (m, 2H, Naph-O-(CH2)2-CH2-), 1.38-1.26 (m, 14H, -(CH2)7-(CH2)2-N+-), 1.23 (b , 9H, -
N+(CH2CH3)3).
13C NMR (75.4 MHz, CDCl3): δ= 134.72 (C4’, C5’and C8’), 129.40-127.72 (C4’, C5’and
C8’), 126.79-126.41 (C6'), 123.58 (C7’), 119.12 (C1’ and C3’), 106.68 (C1’and C3’) 68.12
(C8), 57.74 (C3), 53.74 (C2), 29.59-29.25 (C7, C6 and C5), 26.60-26.19 (C6 and C5),
22.23(C4), 8.27 (C1).
39
0.0 0.5 1.0 1.5 2.0
0
20
40
60
80
100
120
cmc = 6.41x10-4 M
= 0.43
103x[Naph hoxy12]/M
/S cm-1
T=303 K
b)
Figu e S1.- Dependence o he speci ic conduc i i y, /S cm-1, on su ac an concen a ion.
a)Phenoxy12; b)Naph hoxy12. T=303 K. The solid lines co espond o he Ca pena i ings.
103x[Phenoxy12]/M
02468
0
100
200
300
400
500
/S cm-1
cmc=3.7x10-3 M
=0.40
T=303 K
a)
40
-8 -7 -6 -5 -4
44
48
52
56
60
exc=1.64x10-6 mol m-2
Amin=99x10-20 m2
ln([Phenoxy12]/M)
mN m-1
Figu e S2.- Dependence o he su ace ension, , on ln([Phenoxy12). T=303 K.
41
Figu e S3.- Concen a ion dependence o 1H NMR spec um o Naph hoxy12, in D2O, on
su ac an concen a ion. a) [Naph hoxy12]=5.00x10-4 M; b) [Naph hoxy12]=1.00x10-3 M.
T=303 K.
b)
a)