Synthesis, electrochemistry, and photophysical properties of pyrazolino[60]fullerene-1,8-naphthalimide fluorescent derivatives

Article abstract of DOI:10.1016/j.tet.2012.08.031

A series of pyrazolino[60]fullerene-1,8-naphthalimide (Pz[60]-NI) fluorescent derivatives were synthesized in one pot by a [3+2] dipolar cycloaddition between C₆₀ and functionalized hydrazones in good yield. In contrast with 4-aziridino[60]fullerene-1,8-naphtalimide dyads, Pz[60]-NI derivatives present stronger fluorescence intensity. Electrochemical study revealed that Pz[60]-NI presents better electron accepting character than the parent C₆₀. The natural bond orbital of the dyads were calculated using density functional theory method and found that the sp3 nitrogen atom in the pyrazoline ring plays a key role in the charge transfer process.

Full text of DOI:10.1016/j.tet.2012.08.031

Tetrahedron 68 (2012) 8924e8930
Contents lists available at SciVerse ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Synthesis, electrochemistry, and photophysical properties of pyrazolino[60]
fullerenee1,8-naphthalimide fluorescent derivatives
,
c
,
b
b
a
a
c,
*
Beiqiong Lu a, Jianmin Zhang a
, Jia Li , Jianhua Yao , Minjian Wang , Yuanhai Zou , Shizheng Zhu
**
a Department of Chemistry, School of Science, Shanghai University, No. 99, Shangda Road, Shanghai 200444, China
b Department of Computer Chemistry and Chemoinformatics, Shanghai Institute of Organic Chemistry, Shanghai 200032, PR China
c Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 25 May 2012
Received in revised form 2 August 2012
Accepted 10 August 2012
Available online 16 August 2012
A series of pyrazolino[60]fullerenee1,8-naphthalimide (Pz[60]eNI) fluorescent derivatives were syn-
thesized in one pot by a [3þ2] dipolar cycloaddition between C60 and functionalized hydrazones in good
yield. In contrast with 4-aziridino[60]fullerenee1,8-naphtalimide dyads, Pz[60]eNI derivatives present
stronger fluorescence intensity. Electrochemical study revealed that Pz[60]eNI presents better electron
accepting character than the parent C60. The natural bond orbital of the dyads were calculated using
density functional theory method and found that the sp3 nitrogen atom in the pyrazoline ring plays a key
role in the charge transfer process.
Keywords:
Fullerene C60
Electrochemical
Photophysical
Chemical calculation
Pyrazoline
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
cells built with PzC60 derivatives have a better efficiency than those
constructed with [6,6]-phenyl-C61-butyric acid methyl ester
The construction of artificial photosynthetic models to mimic
natural photosynthesis through the design of covalently linked
electron-donor and -acceptor moieties is an area of great interest. The
interest lies in the development of efficient organic solar cells1 and
other areas of nanotechnology, such as photonics or sensors.2 Fuller-
ene C60 is an excellent electron acceptor,3 its visible light absorption
allows energy transfer (EN) and electron transfer (ET) in fullerene-
donor dyads.4 These systems can undergo efficient photoinduced
electron transfer (PET) processes to give long-lived radical-ion pairs.2
Fullerene-fused pentagonal heterocyclic rings, such as full-
eroindolines,5 fullerene-fused lactones,6 and pyrazolo-fullerenes
have been the focus of intense research. For example, pyrazolo-
fullerenes (PzC60) derivatives have recently been used to link elec-
troactive groups to the C60 cage and the products showed efficient
PET processes.7 It has been shown that the lone-pair electron of the
pyrazoline sp3 nitrogen atom is able to afford PET to the C60 cage.8
Thus, the Pz moiety acts as an intermediary in the PET process
from the donor unit present in the organic addend.9 Interestingly,
recent studies on organic photovoltaic cells10 constructed with
donor polymers and fullerene derivatives as acceptors indicate that
(PCBM), highlighting the interest of these compounds.
We have reported the synthesis of 4-aziridino[60]full-
erenee1,8-naphthalimide under microwave irradiation.11 It is well
known that the naphthalimide usually exhibits strong fluorescence
on irradiation, which usually acts as supermolecular moieties for
the study of PET processes12 and fluorescence switcher.13 To our
knowledge, the incorporation of bischromophore (pyrazoline and
naphthalimide) within C60 has rarely been studied. Herein, we
present the synthesis, electrochemical properties and molecular
* Corresponding author. Tel.: þ86 021 5492 5185; fax: þ86 021 6416 6128
** Corresponding author. Tel./fax: þ86 021 6613 3801; e-mail addresses:
lubeiqiong@163.com (B. Lu), jmzhang@shu.edu.cn (J. Zhang), zhusz@mail.sioc.ac.cn
(S. Zhu).
0040-4020/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2012.08.031

B. Lu et al. / Tetrahedron 68 (2012) 8924e8930
8925
Table 1
orbital calculations of pyrazolino[60]fullerenee1,8-naphtalimide
Optimization of reaction conditions of C60 with 3c
derivatives (Pz[60]eNI) and the first comparative study of the
photophysical properties of pyrazolo- (4aee) and azir-
idinoefullerene (5) derivatives. The compound 5 is N-dodecyl-4-
aziridinofullerenee1,8-naphthalimide that was reported by our
group.11
Entry Mole Solvent
ratioa
Temperature Time Yieldb Isolated Recovered
(ꢀC)
(min) (%) yield (%) C60 (%)
1
2
3
4
5
6
7c
8
9
1:1:1 Benzene RT
1:1:3 Benzene RT
2:2:1 Benzene RT
2:2:1 Toluene RT
50
50
50
50
50
50
30
30
30
55
80
82
66
80
85
61
76
68
8
19
21
15
8
23
9
16
10
80
74
72
75
84
74
76
73
75
2:2:1 o-DCB
RT
2. Results and discussion
2.1. Synthesis
2:2:1 Benzene 40
2:2:1 Benzene 40
2:2:1 Benzene 60
2:2:1 Benzene 80
The hydrazones 3 were prepared according to the literature
method,14 which was then tried to be introduced to the C60 skeleton
by a [3þ2] dipolar cycloaddition reaction (Scheme 1).15 As listed in
Table 1, the reaction of hydrazone 3c with C60 was chosen as
a model reaction to screen the optimized reactions. Initial experi-
ment was performed using PhI(OAc)2 (Iodobenzene diacetate) as
additive and the reaction was carried out at room temperature in
various solvents with various mole ratios of 3c:PhI(OAc)2:C60. It
was found that the yield of product 4c could be improved by in-
creasing the amount of 3c and PhI(OAc)2 or C60 (entries 2 and 3).
Further increasing the amount of 3c and PhI(OAc)2 had a negligible
effect on the product yield. The temperature can affect the yield of
productdwhen temperature was raised to 40 ꢀC in benzene, the
yield improved to 85%. However, when the reaction mixture was
refluxed in benzene, the yield dropped to 68%. Other solvents, such
as toluene and o-DCB were also evaluated in various temperatures
(entries 4 and 5). [hydroxyl(tosyloxy)iodo]benzene (HTIB) was used
as additive to mediate the reaction, but the yield was smaller than
that when PhI(OAc)2 was used (entry 7). After optimizations, the
best reaction conditions for the preparation of Pz[60]eNI were
ascertained as 1 equiv of C60, 2 equiv 3, 2 equiv PhI(OAc)2 in ben-
zene at 40 ꢀC under nitrogen atmosphere (entry 6).
RT: room temperature.
a
Mole ratio refers to 3c:PhI(OAc)2:C60.
Isolated yield based on the reacted C60
Two equiv of HTIB was used as additive.
b
.
c
Table 2
Preparation of various Pz[60]eNI derivatives
Entry
Ar of
Product 4a
Yieldb
(%)
Isolated
yield (%)
Recovered
C60 (%)
reactant 3
1
C6H5
4a
4b
4c
4d
4e
4f
4g
4h
4i
81
83
85
70
67
83
85
86
82
80
66
24
21
23
22
21
23
27
29
24
25
22
68
75
74
68
69
72
65
66
70
69
67
2
C6F5
3
4
5
6
4-NO2C6H4
4-Me2NC6H4
4-EtOC6H4
4-FC6H4
7
8
9
10
11
4-ClC6H4
4-BrC6H4
2,4-2FC6H3
4-CNC6H4
4-OHCC6H4
4j
4k
a
Mole ratio refers to 3: PhI(OAc)2:C60¼2:2:1; under nitrogen atmosphere; all
reactions were performed in benzene at 40 ꢀC.
b
Isolated yield based on the reacted C60
.
2H) and 7.52e7.55 (m, 3H) for the phenyl ring and five singlets at
9.14, 8.74, 8.66, 8.27, and 7.83 ppm for the NI moiety. 4.17 (t, 2H),
1.72e1.73 (m, 2H), 1.25 (s, 18H), and 0.87 (m, 3H) belong to the alkyl
group (C12H25ꢁ). The observed signals in the 13C NMR spectra were
in agreement with the proposed structures, showing that PzC60eNI
derivatives were [6,6]-closed isomers. In the 13C NMR spectrum of
4a there were 37 peaks in the range of 119e164 ppm due to the sp2
carbons of the C60 skeleton, NI moiety and phenyl ring. Two peaks
at about 60.42 and 58.50 ppm for the two sp3 carbons of the C60
.
Scheme 1. Preparation of Pz[60]eNI derivatives.
The two peaks at 163.80 and 164.14 were attributed to the two C]
O, one peak at 147.67 ppm was related to the C]N carbon atom.
Having established suitable reaction conditions, a serious of Pz
[60]eNI derivatives 4 were prepared. As shown in Table 2, most
examined substrates 3 provided good yields of 70e86%, except 4e
and 4k with 67% and 66% yields, respectively.
The structures of the Pz[60]eNI products 4aek were established
by spectroscopic methods (UVevis, FTIR, 1H, 19F, 13C NMR, and ESI
mass). The mass spectra of the product 4 exhibited the expected
[MꢁH]ꢁ peaks matching the calculated molecular weights. The 1H
NMR spectra of 4 in CDCl3 exhibited similar signals to the hydra-
zones 3 and were shifted slightly to the downfield. The 1H NMR
spectrum of 4a displayed one doublet and one multiplet at 8.33 (d,
2.2. UVevis spectra
The UVevis spectra of dyads 3(a,b,e), 4(a,b,e) and 5 in CHCl3 at
room temperature are shown in Fig. 1. The UVevis spectra of
4(a,b,e) and 5 were similardtwo main absorption peaks appearing
at about 254 and 326 nm. Both of them were the characteristic of
the C60 moiety. A peak at 390 nm was observed in 5, which attri-
butes to NI moiety. The most distinct difference of 3(a,b,e) was the
main absorption peak at 420e460 nm, which attributes to NI
moiety. Moreover, the intensity of this peak was varying from 3a

8926
B. Lu et al. / Tetrahedron 68 (2012) 8924e8930
4a
4b
4e
3a
3b
3e
5
2.4. Electrochemical examinations
The results of the cyclic voltammetry (CV) studies are summa-
rized in Table 3. In Fig. 3 product 4e show a quasi-reversible elec-
trochemical behavior with four one-electron reduction waves
corresponding to the reduction of the C60 moiety and the organic
addend hydrazones 3. Dyads 4(aed) showed similar shape to the
4e. In this case, the first reduction potential values exhibit an anodic
shift (80 mV for 4c and 60 mV for 4b), in comparison with the
parent C60. Especially, when the substituent R on the phenyl ring
was more electron-withdrawing, the first reduction potentials shift
to more positive values. We attributed this shift to the electro-
negative character of the nitrogen atom linked to the C60 core.
1.2
0.8
0.4
0.0
300
400
500
Therefore, dyads 4 present better acceptor ability than parent C60
.
Wavelength (nm)
An irreversible oxidation wave at around 0.58 V, corresponding to
the oxidation of the hydrazones 3, was also observed.
Fig. 1. UVevis spectra of 3(a,b,e), 4(a,b,e) and 5 in CHCl3 solutions at room temper-
ature (c¼7ꢂ10ꢁ6 mol/L).
Table 3
Redox potentials of organofullerenes 4(aee) and 3(aee)
and 3e to 3b, as the increasing of electronic deficiency of the sub-
stituent R. While in 4(a,b,e) this peak disappeared, the observation
suggests that the UVevis spectra of 4(a,b,e) are more likely to be
the characteristic of C60 than that of NI moiety.
Compound
Red4/V
Red3/V
Red2/V
Red1/V
Ox1/V
C60
4a
3a
4b
3b
4c
3c
4d
3d
4e
3e
ꢁ2.55
ꢁ2.26
ꢁ2.27
ꢁ2.28
ꢁ2.40
ꢁ2.17
ꢁ2.31
ꢁ2.28
ꢁ2.07
ꢁ2.05
ꢁ1.59
ꢁ1.58
ꢁ1.61
ꢁ1.55
ꢁ1.58
ꢁ1.52
ꢁ1.59
ꢁ1.55
ꢁ1.61
ꢁ1.61
ꢁ1.66
ꢁ1.12
ꢁ1.08
0.57
0.55
0.54
0.60
0.53
0.64
0.55
0.68
0.63
0.67
ꢁ1.90
ꢁ1.94
ꢁ1.87
ꢁ1.06
ꢁ1.04
ꢁ1.08
ꢁ1.10
2.3. Fluorescence spectra
Fluorescence spectra of corresponding hydrazones 3(a,b,e),
4(a,b,e), and 5 were measured in CHCl3, as shown in Fig. 2. The
fluorescence peaks of 4(a,b,e) were observed at 430e440 nm while
the peak of 5, appearing at 495 nm, was similar to the appended
donor NI moiety’s emission band. The fluorescence intensity of 5
was decreased approximately 12-folds than that of 4a. The C]N
double bonds and sp3 nitrogen atom of pyrazoline ring make
charge transmitting easier than aziridine ring, so we inferred that
pyrazoline ring acts as a better bridge than aziridine ring in terms of
a PET process. The fluorescence peaks of hydrazones were observed
at 493e537 nm and as the increasing of electronic deficiency of the
substituent R, the fluorescence intensities were varying consider-
ably from 3a and 3e to 3b. The fluorescence peak for 4(a,b,e) were
blue-shifted by 60e100 nm relative to the corresponding hydra-
zones, and the fluorescence intensities of 4 were significantly
quenched. On one hand, the new formed pyrazoline ring blocked
charge transferring and changed conjugation system, On the other
hand, a charge-transfer interaction in the excited state between the
C60 moiety and the appended donor NI moiety. As the electronic
deficiency of the substituent increased, the fluorescence intensity
of dyads 4 became weaker (i.e., 4e>4b).
ꢁ1.89
ꢁ2.06
ꢁ2.35
4.0x10-5
4e
2.0x10-5
0.0
red 1
-2.0x10-5
-4.0x10-5
-6.0x10-5
-8.0x10-5
-1.0x10-4
red 2
red 3
red 4
-2
-1
0
1
2
E
/ V
red
Fig. 3. Cyclic voltammogram of product 4e.
700
2.5. Molecular orbital calculations
4a
600
4b
To observe an insight into the molecular structures, theoretical
calculations within density functional theory (DFT) framework
were performed at the B3LYP/6-31G level.16,17 The optimized
structures of 4a and 4b are shown in Fig. 4. For 4a and 4b, the two
4e
500
3a
3b
3e
400
5
300
200
100
0
400
500
600
Wavelength (nm)
Fig. 2. Fluorescence spectra of 3(a,b,e), 4(a,b,e) and 5 solutions in CHCl3 at room
temperature (c¼7.0ꢂ10ꢁ6 mol/L).
Fig. 4. Fully optimized structures of 4a and 4b.

B. Lu et al. / Tetrahedron 68 (2012) 8924e8930
8927
donor moieties are aligned in an L-shape with an angle of approx-
imately 90ꢀ between the two units. The center-to-center distances
(Rcc) between C60 and the donor entities were estimated to be
ꢀ
8.006 and 8.036 A for 4a and 4b, respectively. In 4a, the NI moiety
was twisted by 47.7ꢀ with respect to the pyrazoline ring, whereas
the phenyl group was twisted by 53.8ꢀ. In 4b, the NI moiety was
twisted by 50.5ꢀ with respect to the pyrazoline ring, whereas the
pentafluorophenyl was twisted by 86.9ꢀ.
The highest occupied molecular orbital (HOMO) and lowest
unoccupied molecular orbital (LUMO) of 4a and 4b are shown in
Fig. 5. The electron density of the HOMO was found to be delo-
calized among the NI moiety and pyrazoline ring, whereas the
electron density of the LUMO was located in the C60 cage. These
results suggest the existence of charge-separated states having
a structure like (NI)Pzþ¼C60ꢁ.18 The electron was localized on the
C60 sphere, and the radical cation was delocalized along the NI
moiety and Pz groups.
Fig. 6. The model of dyads 3(a,b) and 4(a,b) for NBO calculation.
Table 5
The atomic charge of dyads 3(a,b) and 4(a,b)a,b
NBO
Dyads
3a
4a
0.222
0.031
0.286
ꢁ0.279
ꢁ0.214
0.220
D
4a,3ac
3b
0.141
4b
0.232
D4b,3b
NI
0.108
0.008
0.284
ꢁ0.395
ꢁ0.249
0.011
0.113
0.023
0.002
0.115
0.034
0.209
0.009
0.090
0.047
0.011
0.099
0.038
0.223
0.015
Phenyl
Alkinyl
N4
N5
C6
C11
C12
H9
ꢁ0.080
ꢁ0.032
0.285
0.297
ꢁ0.381
ꢁ0.208
ꢁ0.035
ꢁ0.187
0.197
ꢁ0.282
ꢁ0.169
0.187
ꢁ0.100
ꢁ0.091
ꢁ0.172
0.207
0.190
ꢁ0.016
0.185
ꢁ0.019
0.397
0.400
H10
0.193
0.220
C44
C45
ꢁ0.111
0.111
ꢁ0.111
0.111
C6eN4
N5eN4
C6eC11
N5eC12
0.406
0.145
0.111
ꢁ0.456
0.499
0.064
0.300
ꢁ0.405
0.093
ꢁ0.081
0.051
0.346
0.173
0.152
ꢁ0.405
0.470
0.052
0.360
ꢁ0.355
0.124
ꢁ0.121
0.050
0.189
0.208
a
In 4a and 4b the C44 and C45 represent two sp3 carbon atom of C60
.
b
c
The NBO of parent C60 is zero.
D4a,3a represent the difference value between 4a and 3a.
These evidences indicated that charges in 4b were transmitted to
the pentafluorophenyl and C60 moiety that enhanced the charge-
transfer interaction in the excited state; thus, the fluorescence in-
tensity of 4b was weaker than that of 4a. This result was confirmed
by fluorescence spectra.
Fig. 5. The HOMO and LUMO of 4a and 4b.
As shown in Table 4, the HOMO energy levels of 4aee are higher
in energy relative to parent C60 (ꢁ9.48 eV). The LUMO energy levels
of these systems 4aee are lower than that of C60 (ꢁ2.88 eV). Con-
sequently, these systems present a small HOMOeLUMO gap, en-
abling an easier electron-transfer process, particularly in the case of
4d (5.41 eV).To explain the charge transfer process, the natural
bond orbital (NBO) of 3(a,b) and 4(a,b) were calculated. Fig. 6
represents the model of dyads 3(a,b) and 4(a,b). The results are
summarized in Table 5, which show that after hydrazones 3 fused
with C60, the positive charges of NI moiety were significantly in-
creased. In Pz groups, the positive charges of N5 increased to 0.034
for 4a and 0.038 for 4b, while the positive charges of C6 increased
0.209 for 4a and 0.223 for 4b. We inferred that the sp3 nitrogen
atom of N5 had stronger charge transmission ability than C6;
therefore, NI moiety donated more charges to the C60 moiety than
to substituted aryl. Moreover, the fluorescence intensity and atomic
charges behaved certain correlation. In Table 5, the positive charges
of C6 and C11 increased, especially when the substituted aryl was
pentafluorophenyl, 4b acquired more positive charges than 4a.
3. Conclusion
Pz[60]eNI fluorescent derivatives functionalized with various
substituents have been synthesized in one pot via a [3þ2] dipolar
cycloaddition between C60 and corresponding hydrazone. In this
study, Pz[60]eNI provided a better fluorescence property than 4-
aziridino[60]fullerenee1,8-naphthalimide (5); pyrazoline ring
acted as a better bridge than aziridine in the PET processes. Elec-
trochemical study revealed that Pz[60]eNI anodically shifted first
reduction potential in comparison with the parent C60, which in-
dicated that Pz[60]eNI possess a better electron acceptor character
than that of the parent C60. Theoretical calculations were used to
obtain optimized structures as well as spatial distributions of the
HOMO and LUMO levels of the dyads 4(a,b). The results suggest the
existence of charge-separated states and the gap of HOMOeLUMO
in 4aee were smaller than that in the parent C60, which enables an
easier electron-transfer process. The NBO of the dyads 4(a,b) were
calculated and it was found that the sp3 nitrogen atom in the pyr-
azoline ring plays a key role in the charge transfer process.
Table 4
The LUMO and HOMO energies and LUMOeHOMO energy gaps (Eg) were calculated
by PM3 level
Compound
EHOMO (eV)
ELUMO (eV)
Eg (eV)
4. Experimental section
4.1. General remarks
C60
4a
4b
4c
4d
4e
ꢁ9.48
ꢁ9.16
ꢁ9.28
ꢁ9.34
ꢁ8.65
ꢁ9.13
ꢁ2.88
ꢁ3.28
ꢁ3.39
ꢁ3.46
ꢁ3.23
ꢁ3.25
6.59
5.87
5.88
5.87
5.41
5.87
C60 was purchased from Wuhan University with 99% purity.
Carbon disulfide, benzene, and toluene were used in AR quality.

8928
B. Lu et al. / Tetrahedron 68 (2012) 8924e8930
Thin layer chromatography (TLC) was performed on a silica gel. All
melting points were taken with a WRS-1 digital melting point ap-
paratus made by Shanghai physical instrument factory (SPOIF),
China. 1H, 13C, and 19F NMR spectra were recorded on Bruker AV-
500 spectrometer. Chemical shifts for 1H NMR spectra were re-
ported in parts per million downfield from TMS, chemical shifts for
13C NMR spectra were reported in ppm relative to internal chlo-
573.3 ([M]þ, 4); 553.3 ([MꢁF]þ, 100); HRMS: calcd for
C31H33N3O2Fþ51 [MþH]þ 574.2502; found 574.2487.
4.2.1.3. N-Dodecyl-4-(4-nitrobenzylimino)amino-1,8-
naphthalimide (3c). Yield: 87%; mp 160e162 ꢀC; IR (KBr) nmax
(cmꢁ1): 3448, 2923, 2851, 1692, 1641,1586, 1389, 1339, 1278, 1241,
1124, 1104, 776; 1H NMR (500 MHz, CDCl3,
d): 8.95 (s, 1H, NH),
roform (
d
77.2 ppm for 13C), and chemical shifts for 19F NMR spectra
8.63 (d, J¼8.5 Hz, 1H), 8.60 (d, J¼8.5 Hz, 1H), 8.31 (d, J¼8.5 Hz,
2H), 8.20 (d, J¼8.5 Hz, 1H), 8.11 (s, 1H), 7.93 (d, J¼7.5 Hz, 2H), 7.87
(d, J¼7.5 Hz, 1H), 7.72e7.74 (m, 1H), 4.16 (s, 2H), 1.73 (s, 2H), 1.24
were reported in ppm downfield from internal fluorotrichloro-
methane (CFCl3). The terms m, s, d, t, q refer to multiple, singlet,
doublet, triplet, and quarter, respectively. Infrared spectra (IR) were
recorded with an AVATAR 370 FTIR spectrometer; the absorbance
frequencies were given at maximum of intensity in cmꢁ1. High-
resolution mass spectra were obtained with MicroMass Q-Tof Mi-
cro LC/MS and IonSpec 4.7 Tesla FTMS spectrometer. UVevis ab-
sorption spectra were recorded on CRAY-100 spectrophotometer.
Fluorescence measurements were carried out with PerkineElmer
LS55 in a solution of 10ꢁ6 mol/L. Electrochemical measurements
were performed using a Base 2000 CV system electrochemical
analyzer. Cyclic voltammetric measurements were carried out in o-
dichlorobenzene/acetonitrile (4:1) containing 0.1 M n-Bu4NPF6 as
a supporting electrolyte, using a Pt working electrode (4¼1 mm)
with ferrocene, and a vitreous carbon rod counter electrode, scan
rate: 100 mV/s.
(s, 18H), 0.87 (s, 3H); 13C NMR (125 MHz, CDCl3,
d): 164.33, 163.92,
148.12, 143.88, 140.14, 139.55, 133.49, 131.30, 130.50, 129.51,
127.31, 125.77, 124.97, 124.11, 123.58, 119.01, 114.72, 109.10, 58.51,
40.47, 31.93, 29.63, 29.58, 29.42, 29.36, 28.20, 27.20, 22.70, 18.45,
14.13; EIMS (70 eV) m/z: 528.3 ([M]þ, 38); 379.3 ([C24H31N2O2]þ,
100); HRMS: calcd for C31H37N4Oþ41 [MþH]þ 529.2823; found
529.2809.
4.2.1.4. N-Dodecyl-4-(4-N,N dimethylaminobenzylimino)amino-
1,8-naphthalimide (3d). Yield: 86%; mp 194e196 ꢀC; IR (KBr) nmax
(cmꢁ1): 3444, 3317, 3264, 2920, 2850, 1638, 1636, 1612, 1570, 1389,
1352, 1104, 775; 1H NMR (500 MHz, CDCl3,
d
): 8.60 (d, J¼8 Hz, 1H),
8.54 (d, J¼8 Hz,1H), 8.20 (d, J¼8 Hz,1H), 7.99 (s,1H), 7.77 (d, J¼8 Hz,
1H), 7.65 (d, J¼9 Hz, 3H), 6.80 (s, 2H), 4.16 (t, J¼7 Hz, 2H), 3.05 (s,
6H), 1.69e1.75 (m, 2H), 1.24 (s, 18H), 0.87 (t, J¼7 Hz, 3H); 13C NMR
4.2. Synthesis
(125 MHz, CDCl3, d): 164.10, 163.95, 146.82, 133.94, 131.08, 129.69,
128.54, 125.66, 125.07, 123.25, 118.74, 111.02, 107.91, 40.73, 40.37,
40.10, 34.88, 31.93, 29.66, 29.60, 29.45, 29.37, 28.24, 27.24, 22.70,
18.44, 14.13; EIMS (70 eV) m/z: 526.4 ([M]þ, 100); HRMS: calcd for
C33H42N4O2Naþ1 [MþNaþH]þ 549.3185; found 549.3200.
4.2.1. Preparation of hydrazones. 1 was prepared according to the
published literature,12 which served as the starting material for
further synthesis. 2-Dodecyl-6-hydrazinyl-1H-benzo isoquinoline-
1,3(2H)-dione (1). Yield 89%. 1H NMR (CDCl3,
d): 8.61 (d, J¼6.4 Hz,
1H), 8.55 (d, J¼8.0 Hz, 1H), 8.04 (d, J¼7.6 Hz, 1H), 7.67 (d, J¼7.2 Hz,
2H), 6.58 (s, 1H), 4.17 (s, 2H), 3.51(s, 2H), 1.49e1.71(m, 20H), 0.97
(s, 3H).
4.2.1.5. N-Dodecyl-4-(4-ethyloxybenzylimino)amino-1,8-
naphthalimide (3e). Yield: 88%; mp>200 ꢀC; IR (KBr) nmax (cmꢁ1):
3443, 3270, 2921, 2851, 1687, 1641, 1572, 1390, 1354, 1246, 1113,
1102, 775; 1H NMR (500 MHz, CDCl3 d): 8.60 (d, J¼7 Hz,1H), 8.56 (d,
J¼8.5 Hz, 1H), 8.17e8.20 (m, 1H), 8.02 (s, 1H), 7.83 (d, J¼8.5 Hz, 1H),
7.80 (d, J¼8.5 Hz, 1H), 7.71 (d, J¼8.5 Hz, 2H), 6.95e6.99 (m, 3H),
4.14e4.17 (m, 2H), 4.07e4.11 (m, 2H), 1.71e1.74 (m, 2H), 1.40e1.42
(m, 3H), 1.25 (s, 18H), 0.87e0.89 (m, 3H); 13C NMR (125 MHz, CDCl3,
A solution of the corresponding aldehyde 2aek (1.1 mmol),
hydrazine 1 (1 mmol) and two drops of acetic acid in 20 mL of
ethanol was heated under reflux for 1e2 h. The mixture was cooled
to room temperature, filtered and the solid was recrystallized from
acetone and ethanol mixture (4:1, v/v) to afford hydrazones 3.
d): 164.54, 164.07, 145.19, 143.22, 133.91, 131.08, 129.63, 128.60,
4.2.1.1. N-Dodecyl-4-(benzylimino)amino-1,8-naphthalimide
(3a). Yield: 89%; mp 173e175 ꢀC; IR (KBr) nmax (cmꢁ1): 3441, 3266,
2922, 2851, 1702, 1690, 1661, 1586, 1390, 1355, 1241, 1112, 777, 753;
126.49, 125.34, 125.14, 123.34, 118.70, 114.87, 112.91, 108.09, 63.66,
40.38, 31.93, 31.43, 30.20, 29.71, 29.64, 29.44, 29.36, 28.23, 27.23,
22.70, 14.78, 14.13; EIMS (70 eV) m/z: 527.4 ([M]þ, 100); HRMS:
calcd for C33H42N3Oþ3 1 [MþH]þ 528.3226; found 528.3220.
1H NMR (500 MHz, CDCl3,
d
): 8.69 (s, 1H，NH), 8.62 (d, J¼7 Hz, 1H),
8.58 (d, J¼8.5 Hz, 1H), 8.20 (d, J¼8.5 Hz, 1H), 8.07 (s, 1H), 7.84 (d,
J¼8.5 Hz, 1H), 7.78 (d, J¼8.5 Hz, 2H), 7.69 (t, J¼8.5 Hz, 1H), 7.41e7.47
(m, 3H), 4.16 (t, J¼7.5 Hz, 2H),1.69e1.75 (m, 2H),1.24e1.35 (m,18H),
4.2.1.6. N-Dodecyl-4-(4-fluorobenzylimino)amino-1,8-
naphthalimide (3f). Yield: 85%; mp 157e159 ꢀC; IR (KBr) nmax
(cmꢁ1): 3439, 2955, 2923, 2852, 1694, 1635, 1588, 1575, 1509, 1390,
0.87 (t, J¼7.5 Hz, 3H); 13C NMR (125 MHz, CDCl3,
d): 164.34, 163.90,
142.97, 133.82, 131.16, 129.97, 128.91, 127.04, 125.33, 125.22, 108.44,
40.41, 31.94, 29.67, 29.65, 29.60, 29.45, 29.37, 28.23, 28.10, 27.23,
22.71, 14.15; EIMS (70 eV) m/z: 483.3 ([M]þ, 100); HRMS: calcd for
C31H38N3Oþ2 1 [MþH]þ 484.2968; found 484.2958.
1355, 1237, 1112, 775; 1H NMR (CDCl3):
d 8.67 (s, 1H, NH), 8.62 (d,
J¼7 Hz,1H), 8.57 (d, J¼8.5 Hz,1H), 8.18 (d, J¼8.5 Hz,1H), 8.04 (s,1H),
7.81 (d, J¼8.5 Hz, 1H), 7.75e7.78 (m, 2H), 7.69 (t, J¼8.5 Hz, 1H), 7.15
(t, J¼8.5 Hz, 2H), 4.16 (t, J¼7.5 Hz, 2H), 1.69e1.76 (m, 2H), 1.25 (s,
18H), 0.87 (t, J¼7 Hz, 3H); 19F NMR(470 MHz, CDCl3,
d):
4.2.1.2. N-Dodecyl-4-(pentafluorobenzylimino)amino-1,8-
naphthalimide (3b). Yield: 87%; mp 145e146 ꢀC; IR (KBr) nmax
(cmꢁ1): 3446, 3266, 2921, 2850, 1702, 1691, 1660, 1572, 1519, 1493,
ꢁ109.97eꢁ110.01 (m, 1F); EIMS (70 eV) m/z: 501.4 ([M]þ, 89); 122.1
([C7H5FN]þ, 100); HRMS: calcd for C31H37N3O2Fþ1 [MþH]þ
502.2883; found 502.2864.
1388, 1357, 1345, 1249, 1231, 966, 779; 1H NMR (500 MHz, CDCl3,
d):
9.03 (s, 1H, NH), 8.62 (d, J¼7.5 Hz, 1H), 8.55e8.57 (m, 1H), 8.24 (d,
J¼8 Hz, 1H), 8.11 (s, 1H), 7.79 (d, J¼8.5 Hz, 1H), 7.71 (t, J¼8 Hz, 1H),
4.15 (t, J¼8 Hz, 2H), 1.70e1.73 (m, 2H), 1.24 (s, 18H), 0.87e0.89 (m,
4.2.1.7. N-Dodecyl-4-(4-chlorobenzylimino)amino-1,8-
naphthalimide (3g). Yield: 90%; mp 173e174 ꢀC; IR (KBr) nmax
(cmꢁ1): 3451, 3280, 2922, 2850, 1693, 1636, 1577, 1389, 1352, 1114,
3H); 19F NMR (470 MHz, CDCl3,
d
): ꢁ141.81eꢁ141.87 (m, 2F),
1093, 774; 1H NMR (CDCl3,
d
): 8.61 (d, J¼7 Hz, 1H), 8.56 (d, J¼8.5 Hz,
ꢁ152.40eꢁ152.48 (m, 1F), ꢁ161.53eꢁ161.63 (m, 2F); 13C NMR
1H), 8.19 (d, J¼8.5 Hz, 1H), 8.03 (s, 1H), 7.81 (d, J¼8.5 Hz, 1H),
7.67e7.72 (m, 3H), 7.42 (d, J¼8.5 Hz, 2H), 4.16 (t, J¼7.5 Hz, 2H),
1.69e1.76 (m, 2H), 1.24 (s, 18H), 0.87 (t, J¼7 Hz, 3H); EIMS (70 eV)
m/z: 517.3 ([M]þ, 74); 379.3 ([C24H31N2O2]þ, 100); HRMS: calcd for
C31H37N3O2Clþ1 [MþH]þ 518.2557; found 518.2568.
(125 MHz, CDCl3, d): 164.34, 163.65, 143.69, 133.53, 133.23, 131.27,
131.10, 130.66, 130.20, 129.46, 128.09, 125.78, 125.17, 123.53, 123.20,
122.34, 118.97, 114.95, 109.28, 40.66, 31.93, 29.63, 29.56, 29.43,
29.37, 28.20, 28.10, 27.21, 27.14, 22.70, 14.13; EIMS (70 eV) m/z:

B. Lu et al. / Tetrahedron 68 (2012) 8924e8930
8929
4.2.1.8. N-Dodecyl-4-(4-bromobenzylimino)amino-1,8-
naphthalimide (3h). Yield: 86%; mp 171e172 ꢀC; IR (KBr) nmax
(cmꢁ1): 3451, 3279, 2922, 2849, 1692, 1636, 1577, 1389, 1353, 1114,
4.2.2.2. 10-(N-Dodecyl-1,8-naphthalimidyl)-30-(2,3,4,5,6-
pentafluorophenyl)pyrazolino-[60]fullerene (4b). Brown solid, Yield:
36.8 mg (21%, 83% based on reacted C60); IR (KBr) nmax (cmꢁ1):
3445, 2961, 2921, 2850,1701, 1662, 1494, 1261, 1098, 1022, 801, 526;
775; 1H NMR (CDCl3,
d): 8.72 (s, 1H, NH), 8.56e8.62 (m, 2H), 8.18 (d,
J¼8.5 Hz, 1H), 8.02 (s, 1H), 7.81 (d, J¼8.5 Hz, 1H), 7.57e7.69 (m, 5H),
4.15e4.16 (m, 2H), 1.71e1.72 (m, 2H), 1.24 (s, 18H), 0.87e0.89 (m,
3H); EIMS (70 eV) m/z: 561.2 ([M]þ, 79); 379.3 ([C24H31N2O2]þ,
100); HRMS: calcd for C31H37N3O2Brþ1 [MþH]þ 562.2067; found
562.2063.
1H NMR (500 MHz, CDCl3,
d
): 9.10 (d, J¼8.5 Hz, 1H), 8.75 (d,
J¼7.5 Hz, 1H), 8.69 (d, J¼6.5 Hz, 1H), 8.25 (d, J¼8 Hz, 1H), 7.89 (t,
J¼8.5 Hz, 1H), 4.17 (t, J¼7.5 Hz, 2H), 1.70e1.76 (m, 2H), 1.25 (s, 18H),
0.86 (t, J¼7 Hz, 3H); 19F NMR (470 MHz, CDCl3,
d):
ꢁ135.99eꢁ136.03 (m, 2F), ꢁ148.70eꢁ148.79 (m, 1F);
ꢁ159.07eꢁ159.17 (m, 2F); 13C NMR (125 MHz, CDCl3,
d): 164.03,
4.2.1.9. N-Dodecyl-4-(2,4-difluorobenzylimino)amino-1,8-
naphthalimide(3i). Yield: 86%; mp 152e154 ꢀC; IR (KBr) nmax
(cmꢁ1): 3450, 3282, 2923, 2852, 1689, 1637, 1613, 1574, 1389, 1354,
163.61, 147.79, 147.31, 146.38, 146.09, 145.99, 145.61, 145.51, 145.43,
145.27, 144.70, 144.35, 144.28, 144.03, 143.17, 142.90, 142.81, 142.28,
142.15, 141.97, 141.02, 137.89, 136.30, 131.96, 131.31, 129.81, 128.24,
127.50, 126.81, 125.31, 123.26, 122.34, 92.28, 58.51, 40.69, 34.54,
31.93, 30.19, 29.72, 29.57, 29.36, 28.16, 27.19, 22.70, 18.46, 14.15; ESI-
MS: calcd for C91H30F5N3O2: 1292.22; found 1292.32 [(MꢁH)ꢁ].
1116, 776; 1H NMR (CDCl3,
d
): 8.89 (s, 1H, NH), 8.61 (d, J¼7 Hz, 1H),
8.56 (d, J¼8.5 Hz, 1H), 8.27 (s, 1H), 8.21 (d, J¼8.5 Hz, 1H), 8.11 (dd,
J¼8.5,15.5 Hz,1H), 7.79 (d, J¼8.5 Hz,1H), 7.69 (t, J¼8 Hz,1H), 6.99 (t,
J¼8.5 Hz, 1H), 6.85e6.89 (m, 1H), 4.16 (t, J¼7.5 Hz, 2H), 1.69e1.75
(m, 2H), 1.24 (s, 18H), 0.87 (t, J¼7 Hz, 3H); 19F NMR(470 MHz, CDCl3,
4.2.2.3. 10-(N-Dodecyl-1,8-naphthalimidyl)-30-(4-nitrophenyl)
pyrazolino[60]fullerene (4c). Brown solid, Yield: 27.5 mg (23%, 85%
based on reacted C60); IR (KBr) nmax (cmꢁ1): 3443, 2960, 2919, 2848,
1699, 1659, 1583, 1338, 1261, 1101, 1025, 849, 802, 526; 1H NMR
d
): ꢁ106.52eꢁ106.57 (m, 1F), e117.24eꢁ117.29 (m, 1F); EIMS
(70 eV) m/z: 519.2 ([M]þ, 44); 365.3 ([C24H30NO2]þ, 100); HRMS:
calcd for C31H36N3O2Fþ2 1 [MþH]þ 520.2788; found 520.2770.
(500 MHz, CDCl3,
d
): 9.02 (d, J¼9 Hz, 1H), 8.74 (d, J¼8 Hz, 1H), 8.69
4.2.1.10. N-Dodecyl-4-(4-nitrilebenzylimino)amino-1,8-
naphthalimide (3j). Yield: 89%; mp 189e191 ꢀC; IR (KBr) nmax
(cmꢁ1): 3441, 2921, 2851, 2222, 1692, 1648, 1576, 1388, 1358, 1241,
(d, J¼7 Hz, 1H), 8.60 (d, J¼9 Hz, 2H), 8.40 (d, J¼9 Hz, 2H), 8.27 (d,
J¼8 Hz, 1H), 7.87 (t, J¼8 Hz, 1H), 4.18 (t, J¼7.5 Hz, 2H), 1.72e1.74 (m,
2H), 1.25 (s, 18H), 0.85e0.87 (m, 3H); 13C NMR (125 MHz, CDCl3,
d):
1120, 1102, 775; 1H NMR (CDCl3,
d
): 9.07 (s, 1H, NH), 8.56e8.61 (m,
163.97, 163.58, 148.01, 147.71, 147.33, 146.46, 146.33, 146.10, 146.07,
145.94, 145.66, 145.52, 145.44, 145.34, 145.27, 144.84, 144.22, 144.16,
144.12, 143.16, 143.02, 142.42, 142.21, 140.51, 138.38, 135.96, 131.97,
131.24, 130.12, 129.11, 127.54, 124.26, 123.34, 122.43, 112.97, 93.51,
80.34, 40.70, 31.94, 29.72, 29.67, 29.63, 29.58, 29.41, 29.38, 28.17,
27.19, 22.71, 14.15; ESI-MS: calcd for C91H34N4O4: 1247.27; found
1247.28 ([MꢁH]ꢁ).
2H), 8.19e8.24 (m, 1H), 8.08 (s, 1H), 7.82e7.86 (m, 2H), 7.69e7.77
(m, 4H), 4.15e4.18 (m, 2H), 1.70e1.73 (m, 2H), 1.24 (s, 18H),
0.87e0.89 (m, 3H); EIMS (70 eV) m/z: 508.2 ([M]þ, 38); 379.3
([C24H31N2O2]þ, 100); HRMS: calcd for C32H37N4Oþ2 1 [MþH]þ
509.2909; found 509.2911.
4.2.1.11. N-Dodecyl-4-(4-formylbenzylimino)amino-1,8-
naphthalimide (3k). Yield: 85%; mp 144e146 ꢀC; IR (KBr) nmax
(cmꢁ1): 3451, 3312, 2923, 2851, 1690, 1643, 1579, 1548, 1390, 1355,
4 . 2 . 2 . 4 . 1 0- ( N - D o d e c yl - 1, 8 - n a p h t h a l i m i d yl ) - 3 0- ( 4 -
dimethylaminophenyl)pyrazolino-[60]fullerene (4d). Brown solid,
Yield: 27.8 mg (22%, 70% based on reacted C60); IR (KBr) nmax
(cmꢁ1): 3438, 2959, 2923, 2850, 1700, 1664, 1602, 1589, 1376, 1351,
1260, 1118, 1099, 1020, 804, 775; 1H NMR (CDCl3,
d): 10.06 (s, 1H),
8.92 (s, 1H, NH), 8.63 (d, J¼7 Hz, 1H), 8.59 (d, J¼8.5 Hz, 1H), 8.22 (d,
J¼8.5 Hz, 1H), 8.11 (s, 1H), 7.94 (dd, J¼8.5, 16 Hz, 4H), 7.87 (d,
J¼8.5 Hz, 1H), 7.71 (t, J¼8.5 Hz, 1H), 4.16 (t, J¼8 Hz, 2H), 1.70e1.76
(m, 2H), 1.25 (s, 18H), 0.87e0.89 (m, 3H); EIMS (70 eV) m/z: 511.3
([M]þ, 91); 379.2 ([C24H31N2O2]þ, 100); HRMS: calcd for
C32H38N3Oþ3 1 [MþH]þ 512.2904; found 512.2907.
1261, 1173, 1096, 1021, 803, 594; 1H NMR (500 MHz, CDCl3,
d): 9.16
(d, J¼8 Hz, 1H), 8.70 (d, J¼9 Hz, 2H), 7.97e7.99 (m, 3H), 7.89 (t,
J¼8 Hz, 1H), 6.73 (d, J¼9 Hz, 2H), 4.17 (t, J¼7.5 Hz, 2H), 3.13 (s, 6H),
1.74e1.77 (m, 2H), 1.25 (s, 18H), 0.86e0.88 (m, 3H); ESI-MS: calcd
for C93H40N4O2: 1245.34; found 1244.84 ([MꢁH]ꢁ).
4.2.2. Typical procedure for the synthesis of fulleropyrazolines.
Under nitrogen atmosphere a mixture of C60 (72 mg, 0.1 mmol),
hydrazones 3 (0.2 mmol), and PhI(OAc)2 (64 mg, 0.2 mmol) was
dissolved in 40 mL of benzene and stirred at 40 ꢀC for a desired
time. The solvent was then evaporated in vacuo and the residue was
separated on a silica gel column using CS2 or CS2etoluene as the
eluent to afford unreacted C60 and adduct 4.
4.2.2.5. 10-(N-Dodecyl-1,8-naphthalimidyl)-30-(4-ethyoxylphenyl)
pyrazolino[60]fullerene (4e). Brown solid, Yield: 25.9 mg (21%, 67%
based on reacted C60); IR (KBr) nmax (cmꢁ1): 3459, 2962, 2923, 2852,
1699, 1659, 1587, 1494, 1461, 1400, 1261, 1096, 1021, 801, 702, 526;
1H NMR (500 MHz, CDCl3,
d
): 9.16 (d, J¼8.5 Hz, 1H), 8.74 (d,
J¼7.5 Hz, 1H), 8.65 (d, J¼7.5 Hz, 1H), 8.25e8.28 (m, 3H), 7.81 (t,
J¼7.5 Hz, 1H), 7.54 (d, J¼8.5 Hz, 2H), 4.18 (t, J¼7 Hz, 2H), 4.12(q,
J¼3 Hz, 2H), 1.72e1.75 (m, 2H), 1.41e1.43 (m, 3H), 1.26 (s, 18H),
4.2.2.1. 10-(N-Dodecyl-1,8-naphthalimidyl)-30-(phenyl)pyrazolino
[60]fullerene (4a). Brown solid, Yield: 29.2 mg (24%, 81% based on
reacted C60); IR (KBr) nmax (cmꢁ1): 3449, 2963, 2924, 2848, 1699,
1657, 1494, 1460, 1413, 1261, 1096, 1021, 865, 801, 702, 525; 1H NMR
0.87e0.88 (m, 3H); 13C NMR (125 MHz, CDCl3,
d): 164.16, 163.78,
147.64, 147.45, 146.39, 146.05, 145.83, 145.59, 145.50, 145.39, 145.20,
144.39, 144.17, 143.14, 142.92, 142.40, 142.11, 140.39, 139.75, 136.39,
135.94, 134.36, 132.01, 131.45, 129.98, 129.75, 129.04, 127.83, 126.99,
126.75, 125.31, 124.09, 123.11, 119.12, 114.73, 92.89, 81.48, 63.92,
58.47, 40.65, 34.88, 34.53, 31.44, 30.20, 29.66, 29.36, 28.17, 27.20,
22.70, 18.43, 14.79, 14.13; ESI-MS: calcd for C93H39N3O3: 1246.32;
found 1246.14 ([MꢁH]ꢁ).
(500 MHz, CDCl3,
d
): 9.14 (d, J¼8 Hz, 1H), 8.74 (d, J¼8 Hz, 1H), 8.66
(d, J¼7.5 Hz, 1H), 8.33 (d, J¼7.5 Hz, 2H), 8.27 (d, J¼8 Hz, 1H), 7.83 (t,
J¼8 Hz, 1H), 7.52e7.55 (m, 3H), 4.17 (t, J¼7.5 Hz, 2H), 1.72e1.73 (m,
2H), 1.25 (s, 18H), 0.87e0.89 (m, 3H); 13C NMR (125 MHz, CDCl3,
d):
164.14, 163.80, 147.67, 147.24, 146.91, 146.40, 146.26, 146.01, 145.85,
145.59, 145.27, 144.97, 144.36, 144.26, 144.15, 143.15, 142.93, 142.41,
142.26, 142.13, 142.11, 141.88, 140.42, 138.54, 136.41, 135.96, 131.88,
130.01, 129.96, 129.04, 128.88, 127.11, 126.87, 124.48, 123.99, 123.15,
119.11, 60.42, 58.50, 40.65, 34.88, 31.92, 31.44, 30.19, 29.63, 29.16,
28.16, 27.19, 22.69, 18.44, 14.15; ESI-MS: calcd for C91H35N3O2:
1202.27; found 1201.95 [(MꢁH)ꢁ].
4.2.2.6. 10-(N-Dodecyl-1,8-naphthalimidyl)-30-(4-fluorophenyl)
pyrazolino[60]fullerene (4f). Brown solid, Yield: 28.3 mg (23%, 83%
based on reacted C60); IR (KBr) nmax (cmꢁ1): 3449, 2962, 2919, 2849,
1699, 1659, 1587, 1350, 1261, 1096, 1023, 802, 526; 1H NMR
(500 MHz, CDCl3,
d): 9.11 (d, J¼8.5 Hz, 1H), 8.73 (d, J¼8 Hz, 1H), 8.66
(d, J¼7 Hz, 1H), 8.60(d, J¼8 Hz, 1H), 8.31e8.34 (m, 2H), 8.25 (d,

8930
B. Lu et al. / Tetrahedron 68 (2012) 8924e8930
J¼8 Hz, 1H), 8.21 (d, J¼8 Hz, 1H), 7.82 (t, J¼8 Hz, 1H), 4.17 (t,
J¼7.5 Hz, 2H), 1.71e1.74 (m, 2H), 1.25 (s, 18H), 0.87e0.88 (m, 3H);
8.74 (d, J¼8 Hz, 1H), 8.68 (dd, J¼1, 7 Hz, 1H), 8.57 (d, J¼8 Hz, 2H),
8.28 (d, J¼8 Hz, 1H), 8.05 (d, J¼8 Hz, 2H), 7.86 (t, J¼8 Hz, 1H), 4.18 (t,
J¼7.5 Hz, 2H), 1.70e1.75 (m, 2H), 1.25 (s, 18H), 0.86e0.87 (m, 3H);
ESI-MS: calcd for C92H35N3O3: 1230.28; found 1230.39 ([MꢁH]ꢁ).
19F NMR(470 MHz, CDCl3,
d
): ꢁ109.87eꢁ109.93 (m, 1F); ESI-MS:
calcd for C91H34FN3O2: 1220.26; found 1220.37 ([MꢁH]ꢁ).
4.2.2.7. 10-(N-Dodecyl-1,8-naphthalimidyl)-30-(4-chlorophenyl)
pyrazolino[60]fullerene (4g). Brown solid, Yield: 33.6 mg (27%, 85%
based on reacted C60); IR (KBr) nmax (cmꢁ1): 3451, 2919, 2848, 1699,
1659, 1585, 1384, 1351, 1260, 1094, 804, 783, 526; 1H NMR
Acknowledgements
This work was supported by the National Natural Science
Foundation of China (Nos. 20972092, 21032006, 21072216); MOST
(2011BAE06B05). The authors thank the instrumental analysis &
research center of Shanghai University and Dr. Hongmei Deng, High
Performance Computing and Data Center, Shanghai Advanced Re-
search Institute, Chinese Academy of Sciences.
(500 MHz, CDCl3,
d): 9.09 (d, J¼8.5 Hz,1H), 8.73 (d, J¼8 Hz,1H), 8.66
(d, J¼7.5 Hz, 1H), 8.29 (d, J¼9 Hz, 2H), 8.25 (d, J¼8 Hz, 1H), 7.83 (t,
J¼7.5 Hz, 1H), 7.52 (d, J¼9 Hz, 2H), 4.17 (t, J¼7.5 Hz, 2H), 1.71e1.74
(m, 2H), 1.24e1.26 (m, 18H), 0.85e0.87 (m, 3H); ESI-MS: calcd for
C91H34ClN3O2: 1236.72; found 1236.45 ([MꢁH]e).
4.2.2.8. 10-(N-Dodecyl-1,8-naphthalimidyl)-30-(4-bromophenyl)
pyrazolino[60]fullerene (4h). Brown solid, Yield: 37.4 mg (29%, 86%
based on reacted C60); IR (KBr) nmax (cmꢁ1): 3446, 2919, 2848, 1699,
1659, 1584, 1384, 1351, 1260, 1235, 1098, 1074, 822, 782, 526; 1H
Supplementary data
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.tet.2012.08.031.
NMR (500 MHz, CDCl3,
d): 9.09 (d, J¼8.5 Hz, 1H), 8.73 (d, J¼8 Hz,
1H), 8.66 (d, J¼7.5 Hz, 1H), 8.23 (t, J¼9 Hz, 3H), 7.83 (t, J¼8 Hz, 1H),
7.68 (d, J¼8.5 Hz, 2H), 4.17 (t, J¼7.5 Hz, 2H), 1.70e1.76 (m, 2H), 1.25
(s, 18H), 0.83e0.86 (m, 3H); ESI-MS: calcd for C91H34BrN3O2:
1281.17; found 1281.33 ([MꢁH]ꢁ).
References and notes
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3442, 2962, 2922, 2850,1698,1658,1587, 1261,1096, 1022, 866, 801,
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8.74 (d, J¼7.5 Hz, 1H), 8.66 (d, J¼6.5 Hz, 1H), 8.61 (dd, J¼1, 7 Hz, 1H),
8.27 (d, J¼7.5 Hz, 1H), 8.21 (d, J¼7.5 Hz, 1H), 7.95 (dd, J¼8.5, 14.5 Hz,
1H), 7.86 (t, J¼7.5 Hz, 1H), 4.15e4.18 (m, 2H), 1.70e1.74 (m, 2H), 1.25
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d):
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(125 MHz, CDCl3, d): 164.24, 163.73, 147.71, 147.24, 146.71, 146.37,
146.04, 145.93, 145.50, 145.38, 145.25, 144.37, 144.21, 144.06, 143.21,
143.14, 142.88, 142.29, 142.23, 142.18, 142.05, 141.92, 140.75, 139.77,
136.29, 133.85, 131.90, 131.60, 131.20, 129.82, 128.18, 126.94, 123.14,
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pyrazolino[60]fullerene (4j). Brown solid, Yield: 30.4 mg (25%, 80%
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(eCN), 1701, 1661, 1587,1352, 1236, 1102, 784, 527; 1H NMR
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(500 MHz, CDCl3,
d
): 9.03 (d, J¼8.5 Hz, 1H), 8.73 (d, J¼7.5 Hz, 1H),
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7.86 (t, J¼8 Hz, 1H), 7.83 (d, J¼8.5 Hz, 2H), 4.17(t, J¼7.5 Hz, 2H),
1.71e1.73 (m, 2H), 1.25 (s, 18H), 0.83e0.85 (m, 3H); 13C NMR
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(125 MHz, CDCl3, d): 164.00, 163.61, 147.71, 147.33, 146.46, 146.32,
146.08,145.92,145.64,145.53,145.48,145.34,145.27,144.95,144.24,
143.64, 143.23, 142.91, 142.41, 142.28, 142.18, 142.04, 141.92, 140.50,
140.03, 136.67, 136.53, 135.94, 132.73, 131.95, 130.10, 128.91, 127.47,
123.30,122.33,112.97, 93.44, 40.70, 31.93, 29.66, 29.64, 29.57, 29.40,
29.36, 29.07, 28.16, 27.18, 22.70, 14.15; ESI-MS: calcd for
C92H34N4O2: 1227.28; found 1226.07 ([MꢁH]ꢁ).
4.2.2.11. 10-(N-Dodecyl-1,8-naphthalimidyl)-30-(4-formylphenyl)
pyrazolino[60]fullerene (4k). Brown solid, Yield: 26.8 mg (22%, 66%
based on reacted C60); IR (KBr) nmax (cmꢁ1): 3443, 2954, 2921, 2850,
1700, 1659, 1585, 1462, 1356, 1261, 1100, 1027, 804, 784, 526; 1H
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NMR (500 MHz, CDCl3,
d): 10.10 (s, 1H), 9.07 (dd, J¼1, 8.5 Hz, 1H),