Langmuir
Article
designed and synthesized a series of novel cationic gemini
surfactants with diethylammonium headgroups and a diamido
spacer. Scheme 1 shows the molecular structure and synthesis
General Procedure for the Synthesis of 6−9. N,N′-(Ethane-1,2-
diyl)bis(2-chloroacetamide) (20 mmol) and N,N-diethylalkane-1-
amine (44 mmol, 2.2 equiv) were dissolved in ethyl acetate (60
mL) and refluxed for 72 h. After the reaction mixture cooled to room
temperature, the white precipitate obtained was collected by filtration.
The crude product was washed with ethyl acetate, and it was
recrystallized from ethyl acetate/ethanol at least three times to
produce the final product as a white solid (∼60% yield).
Scheme 1
N,N′-((Ethane-1,2-diyl)bis(azanediyl))bis(2-oxoethane-2,1-diyl))-
bis(N,N-diethylde-can-1-aminium) Dichloride (6, Abbreviated as
C10). White powder crystals were obtained according to the general
1
procedure. Yield, 53%. H NMR (300 MHz, CD Cl): δ 0.85−0.90 (t,
3
6
H), 1.26−1.34 (m, 28 H), 1.46−1.51 (t, 12 H), 1.76 (m, 4 H), 3.36−
.39 (m, 4 H), 3.44 (s, 4 H), 3.51−3.67 (m, 8 H), 4.60 (s, 4 H), 9.90
3
(
s, 2 H). 13C NMR (300 MHz, CD Cl): 8.26, 14.03, 22.02, 22.56,
3
2
1
1
2
6
8
6.40, 28.96, 29.13, 29.29, 29.35, 31.74, 38.20, 55.42, 57.44, 59.27,
63.57. FTIR (KBr): v 3179, 3041, 2952, 2919, 2851, 1680, 1560,
−1
452, 1247, 722 cm . ESI−MS (P/ACE MDQ): m/z 284.4 ((M-
−
2+
− +
Cl ) /2), 603.5 (M-Cl ) . Anal. Calcd for C H N O Cl : C,
34
72
4
2
2
route of these gemini surfactants. Their surface and bulk
properties were investigated by surface tension, electrical
conductivity, fluorescence, viscosity, dynamic light scattering
3.82; H, 11.34; N, 8.76. Found (Vario EL III): C, 63.52; H, 11.13; N,
.86.
N,N′-((Ethane-1,2-diylbis(azanediyl))bis(2-oxoethane-2,1-diyl))-
(DLS), and transmission electron microscopy (TEM) measure-
bis(N,N-diethyldod-ecan-1-aminium) Dichloride (7, Abbreviated as
C12). White powder crystals were obtained according to the general
ments.
1
procedure. Yield, 55%. H NMR (300 MHz, CD Cl): δ 0.85−0.90 (t,
3
6
3
H), 1.25−1.34 (m, 36 H), 1.46−1.51 (t, 12 H), 1.76 (m, 4 H), 3.36−
EXPERIMENTAL SECTION
Materials. Ethylenediamine (AP), diethylamine (AP), chloracetyl
chloride (CP), 1-bromodecane (CP), 1-bromododecane (CP), 1-
bromotetradecane (CP), 1-bromohexadecane (CP), 1-bromooctade-
cane (CP), ethyl acetate (AP), dichloromethane (AP), and ethanol
■
.39 (m, 4 H), 3.43 (s, 4 H), 3.51−3.67 (m, 8 H), 4.59 (s, 4 H), 9.89
13
(s, 2 H). C NMR (300 MHz, CD Cl): 8.26, 14.06, 22.03, 22.61,
3
2
1
1
6
6.40, 28.98, 29.24, 29.36, 29.51, 31.83, 38.17, 55.42, 57.47, 59.27,
63.58. FTIR (KBr): v 3179, 3038, 2952, 2917, 2850, 1680, 1562,
468, 1453, 1248, 721 cm . ESI−MS: m/z 312.6 ((M-2Cl ) /2),
59.5 (M-Cl ) . Anal. Calcd for C H N O Cl : C, 65.58; H, 11.59;
−1
− 2+
(
AP) were purchased from Sinopharm Chemical Reagent Corpo-
− +
38
80
4
2
2
ration. Pyrene (AP) was purchased from Sigma-Aldrich and used as
received. Bidistilled water was used in all experiments (conductivity
was less than 1.3 μS·cm at 298.15 K).
N, 8.05. Found: C, 65.92; H, 11.99; N, 8.35.
N,N′-((Ethane-1,2-diylbis(azanediyl))bis(2-oxoethane-2,1-diyl))-
−1
bis(N,N-diethyltetr-adecan-1-aminium) Dichloride (8, Abbreviated
as C14). White powder crystals were obtained according to the general
Synthesis. N,N′-(Ethane-1,2-diyl)bis(2-chloroacetamide) (1). Di-
ethylamine (63.2 mmol, 3.8 g) in dichloromethane (20 mL) was added
dropwise to a stirred solution of chloracetyl chloride (132.8 mmol, 15
g) in dichloromethane (30 mL). The reaction mixture was stirred for 4
h at room temperature and then neutralized to a pH of ∼9 with NaOH
solution (6 M). The white precipitate was filtered out and
recrystallized from bidistillded water and ethanol, respectively, to
1
procedure. Yield, 58%. H NMR (300 MHz, CD Cl): δ 0.85−0.90 (t,
3
6
H), 1.25−1.34 (m, 44 H), 1.46−1.51 (t, 12 H), 1.76 (m, 4 H), 3.37
(
m, 4 H), 3.44 (s, 4 H), 3.54−3.65 (m, 8 H), 4.60 (s, 4 H), 9.89 (s, 2
13
H). C NMR (300 MHz, CD Cl): 8.23, 14.02, 22.01, 22.56, 26.36,
3
2
1
1
8.95, 29.22, 29.32, 29.46, 29.51, 31.78, 38.25, 55.41, 57.37, 59.26,
63.51. FTIR (KBr): v 3178, 3039, 2917, 2850, 1681, 1561, 1468,
453, 1247, 720 cm . ESI−MS: m/z 340.6 ((M-2Cl ) /2), 715.6
1
−1
− 2+
produce 1 as a white acerose crystal (4.5 g, 33.4% yield). H NMR
−
+
(
(
2
Varian Mercury-VX 300 MHz, (CD ) SO): δ 3.16−3.17 (t, 4H), 4.05
3
2
(M-Cl ) . Anal. Calcd for C H N O Cl : C, 67.07; H, 11.79; N,
42 88 4 2 2
s, 4H), 8.29 (s, 4H). FTIR (Nicolet 5700 FT-IR, KBr): v 3053, 3011,
7
.45. Found: C, 67.02; H, 11.90; N, 7.55.
N,N′-((Ethane-1,2-diylbis(azanediyl))bis(2-oxoethane-2,1-diyl))-
−1
953, 1654, 1544, 1428, 1404, 1263, 1230, 752 cm .
General Procedure for the Synthesis of 2−5. 1-Bromoalkane (0.15
bis(N,N-diethylhex-adecan-1-aminium) Dichloride (9, Abbreviated
as C16). White powder crystals were obtained according to the general
mol) and diethylamine (0.45 mol, 3 equiv) were dissolved in ethanol
1
(
100 mL) and refluxed for 24 h. The solvent was evaporated, and the
procedure. Yield, 64%. H NMR (300 MHz, CD Cl): δ 0.85−0.90 (t,
3
residue was poured in the NaOH solution (1 M, 200 mL) and stirred.
The solution was extracted with ethyl acetate (3 × 70 mL), and the
organic phase was dried over magnesium sulfate and filtered. The oily
yellow liquid was isolated after evaporation of the solution as the crude
product, which was distilled in vacuo to give the product as a colorless
oil (∼90% yield).
6 H), 1.25−1.34 (m, 52 H), 1.46−1.50 (t, 12 H), 1.76 (m, 4 H), 3.37
(m, 4 H), 3.43 (s, 4 H), 3.55−3.65 (m, 8 H), 4.60 (s, 4 H), 9.86 (s, 2
H). 13C NMR (300 MHz, CD Cl): 8.26, 14.03, 22.01, 22.58, 26.39,
3
28.96, 29.25, 29.35, 29.48, 29.55, 31.81, 38.23, 55.43, 57.41, 59.27,
163.51. FTIR (KBr): v 3179, 3038, 2952, 2917, 2850, 1680, 1562,
1468, 1453, 1248, 721 cm . ESI−MS: m/z 368.6 ((M-2Cl ) /2),
771.6 (M-Cl ) . Anal. Calcd for C H N O Cl : C, 68.36; H, 11.97;
−1
− 2+
−
+
N,N-Diethyldecan-1-amine (2). Yield, 90%. bp 110−111 °C/3
46 96 4 2 2
1
mmHg. H NMR (300 MHz, CD Cl): δ 0.85−0.90 (t, 3 H), 0.99−
1
2
N, 6.93. Found: C, 67.98; H, 11.90; N, 7.05.
3
.04 (t, 6 H), 1.26 (m, 14 H), 1.41−1.48 (m, 2 H), 2.37−2.42 (t, 2 H),
.48−2.55 (q, 4 H).
Methods. Surface Tension Measurement. The surface tension
was measured with a Fangrui tensiometer (type QBZY-2) using the
ring method. Techniques were followed to ensure that the ring and
glassware used in the measurements were scrupulously clean. To verify
that the ring and glassware were clean, the surface tension of bidistilled
water was measured regularly. Measurements were made in beakers
thermostatted by means of a constant-temperature bath (Fangrui
DC0506). Surface tensions from aged samples were obtained by
allowing solutions to stand in covered beakers for 48 h at room
temperature. Care was taken not to agitate the samples as they were
uncovered and placed in the tensiometer.
N,N-Diethyldodecan-1-amine (3). Yield, 93%. bp 132−133 °C/3
1
mmHg. H NMR (300 MHz, CD Cl): δ 0.85−0.90 (t, 3 H), 0.99−
1
2
3
.04 (t, 6 H), 1.26 (m, 18 H), 1.41−1.46 (m, 2 H), 2.37−2.42 (t, 2 H),
.48−2.55 (q, 4 H).
N,N-Diethyltetradecan-1-amine (4). Yield, 91%. bp 154−156 °C/3
1
mmHg. H NMR (300 MHz, CD Cl): δ 0.85−0.90 (t, 3 H), 0.99−
1
2
3
.04 (t, 6 H), 1.25 (m, 22 H), 1.41−1.45 (m, 2 H), 2.37−2.42 (t, 2 H),
.48−2.55 (q, 4 H).
N,N-Diethylhexadecan-1-amine (5). Yield, 91%. bp 170−171 °C/3
1
mmHg. H NMR (300 MHz, CD Cl): δ 0.85−0.90 (t, 3 H), 0.99−
1
2
Electrical Conductivity Measurement. The WTW conductivity
meter (model inoLab Cond730) was used to perform the experiments.
A 30 mL portion of bidistilled water was taken in a cell dipped in a
3
.04 (t, 6 H), 1.25 (m, 26 H), 1.41−1.44 (m, 2 H), 2.37−2.42 (t, 2 H),
.48−2.55 (q, 4 H).
1
1980
dx.doi.org/10.1021/la3011212 | Langmuir 2012, 28, 11979−11987