Synthesis and crystal structural characterization of two new 3,5-disubstituted 4-amino-1,2,4- triazoles

Article abstract of DOI:10.1515/hc-2014-0079

Two new asymmetrical 3-(p-R-phenyl)-4-amino- 5-(2-pyridyl)-1,2,4-triazoles (3a, R = CH₃ and 3b, R = OCH₃) were synthesized with a yield of 58% and 69%, respectively. The compounds 3a and 3b were characterized with FT-IR, ¹

Full text of DOI:10.1515/hc-2014-0079

Heterocycl. Commun. 2014; 20(4): 201–206
Xin He, Bin Li, Lang Chen, Xuan Shen and Dun-Ru Zhu*
Synthesis and crystal structural characterization
of two new 3,5-disubstituted 4-amino-1,2,4-
triazoles
Abstract: Two new asymmetrical 3-(p-R-phenyl)-4-amino- the asymmetrical 3,5-disubstituted 4-amino-1,2,4-triazoles
5-(2-pyridyl)-1,2,4-triazoles (3a, R ꢀ= ꢀ CH3 and 3b, R ꢀ= ꢀ OCH3) remain largely unexplored. As a continuation of our inves-
were synthesized with a yield of 58% and 69%, respec- tigation on substituted 4-amino-1,2,4-triazoles [19, 20], in
tively. The compounds 3a and 3b were characterized with this article, we present synthesis of two new asymmetrical
1
FT-IR, H NMR, ESI-MS spectra, and elemental analysis. 3,5-disubstituted 4-amino-1,2,4-triazoles, namely 3-(p-R-
Additionally, their molecular and crystal structures were phenyl)-4-amino-5-(2-pyridyl)-1,2,4-triazoles 3a (R ꢀ= ꢀ CH3)
determined by single crystal X-ray analysis.
and 3b (R ꢀ= ꢀ OCH3) (Scheme 1). Compounds 3a and 3b were
characterized by FT-IR, 1H NMR, ESI-MS spectra, elemen-
Keywords: 4-amino-1,2,4-triazole; crystal structure; hydra- tal analysis, and single crystal X-ray diffraction. For the
zine; synthesis.
purpose of comparison, a known homologous compound,
3c (R ꢀ= ꢀ Cl), is also discussed [21].
DOI 10.1515/hc-2014-0079
Received May 6, 2014; accepted May 27, 2014; previously published
online July 3, 2014
Results and discussion
Synthesis of 3,4,5-trisubstituted 1,2,4-triazoles has recently
been reviewed [22]. In general, there are three types of
methods reported for the preparation of 3,4,5-trisubsti-
tuted 1,2,4-triazoles [23]. One of these methods was chosen
for the synthesis of our target compounds – 3,5-disubsti-
tuted 4-amino-1,2,4-triazoles 3a–c. Compounds 3a,b are
new and synthesis of 3c has been previously published
[21].
N-(p-R-phenylcarbonyl)-N′-(2-pyridylcarbonyl)hydra-
zines 1a–c were obtained in a yield of 81%, 79%, and 82%,
respectively, by stirring pyridine-2-carbonylhydrazine
with the corresponding benzoyl chloride in anhydrous
pyridine at ambient temperature [24]. Then, 1,4-dichloro-
1-(2-pyridyl)-4-(p-R-phenyl)-2,3-diaza-1,3-butadienes 2a–c
were obtained by stirring 1 with thionyl chloride in dried
toluene with the respective yield of 68%, 69%, and 72%
[25]. Finally, the cyclization reaction of 2a,b with anhy-
drous hydrazine conducted at 120°C for 12 h produced
3a,b with a yield of 58% and 69%, respectively. Synthesis
of the known compound 3c in a 47% yield has previously
been reported [21].
Introduction
During the past five decades, substituted 1,2,4-triazoles
have aroused wide interest because of their anti-inflam-
matory, antitumor, fungicide, and herbicide properties [1].
Substituted 1,2,4-triazoles and their derivatives are also
useful ligands in coordination chemistry due to their rich
and versatile coordination modes [2–4]. In addition, some
iron(II) complexes containing substituted 1,2,4-triazoles
possess fascinating spin crossover properties which can
be applied as molecular-based electronics, displays, and
switching materials [5–10].
Recently, a series of symmetrical and asymmetrical
3,5-disubstituted 1,2,4-triazoles have been successfully
prepared by our group [11–18] and others [3, 8]. However,
*Corresponding author: Dun-Ru Zhu, College of Chemistry and
Chemical Engineering, State Key Laboratory of Materials-oriented
Chemical Engineering, Nanjing Tech University, Nanjing 210009,
P.R. China, e-mail: zhudr@njtech.edu.cn
Xin He, Bin Li, Lang Chen and Xuan Shen: College of Chemistry and
Chemical Engineering, State Key Laboratory of Materials-oriented
Chemical Engineering, Nanjing Tech University, Nanjing 210009,
P.R. China
New compounds 3a,b were characterized by FT-IR,
1H NMR, ESI-MS, and elemental analysis. The molecular
structures of 3a,b were also confirmed by X-ray crystal-
lography (Table 1). Single crystals of 3a and 3b suitable
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ꢁꢁꢁꢂ
202ꢀ
ꢀX. He et al.: Two new 3,5-disubstituted 4-amino-1,2,4-triazoles
Cl
Table 2ꢀSelected bond lengths (Å) and angles (°) for 3a,b.
O
C
O
C
C
R
R
O
NHNH2
NHNH
3a
ꢀ
3b
C
O
N
N
N1-C5
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
1.338(2)ꢃ
1.372(2)ꢃ
1.419(2)ꢃ
1.508(3)ꢃ
1.338(2)ꢃ
108.2(1)ꢃ
118.6(2)ꢃ
106.2(1)ꢃ
124.8(2)ꢃ
121.7(2)ꢃ
N1-C5
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
1.332(4)
1.365(4)
1.407(4)
1.361(4)
1.324(4)
107.9(2)
118.8(2)
105.5(3)
124.3(2)
118.4(3)
1a-c
N2-N3
N2-N3
Cl
Cl
N4-N5
C11-C14
N1-C1
N4-N5
O1-C11
N1-C1
C
N N C
SOCl2
NH2NH2
toluene
120°C, 12 h
N
C6-N2-N3
C6-C5-N1
C7-N4-C6
N5-N4-C7
C6-N2-N3
C6-C5-N1
C7-N4-C6
N5-N4-C7
2a-c
R
NH2
N
R
a: R = Me
b: R = OMe
c: R = Cl
C10-C11-C14ꢃ
C11-O1-C14 ꢃ
N
N
N
3a-c
for X-ray diffraction study were obtained upon slow con-
centration of ethanol solution at ambient temperature.
The crystal structure of 3c has been previously published
Scheme 1ꢀSynthesis of 3,5-disubstituted 4-amino-1,2,4-triazoles
3a–c.
Table 1ꢀCrystallographic data for 3a–c.
Compound
ꢀ
3a
ꢀ
3b
ꢀ
3c [21]
Empirical formula
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
C14H13N5
251.29
Triclinic
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
C14H13N5O
267.29
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
C13H10N5Cl
271.71
Formula weight
Crystal system
Triclinic
Monoclinic
C2/c
Space group
P1
̅
P1̅
a (Å)
6.2709(10)
7.0252(12)
14.572(2)
86.277(2)
84.922(2)
72.728(2)
610.09(17)
2
6.183(10)
7.245(12)
14.77(2)
76.816(17)
85.501(18)
73.507(18)
617.7(17)
2
28.68(7)
6.041(16)
14.68(4)
90.00
b (Å)
c (Å)
α (°)
β (°)
103.90(3)
90.00
γ (°)
V (Å3)
2470(11)
8
Z
Dc (gꢀ⋅ ꢀcm-3)
1.368
1.437
1.462
μ (mm-1)
0.088
0.097
0.302
F (000)
264
280
1120
Crystal size (mm)
θ Range
0.24 ꢀ× ꢀ 0.16 ꢀ× ꢀ 0.10 ꢃ
0.14 ꢀ× ꢀ 0.10 ꢀ× ꢀ 0.06 ꢃ
0.16 ꢀ× ꢀ 0.12 ꢀ× ꢀ 0.10
1.46–25.00
8203
1.40–25.00
ꢃ
ꢃ
1.42–25.00
ꢃ
ꢃ
Reflections collected
Independent reflections
4295
4277
2125 [Rint ꢀ= ꢀ 0.0174]ꢃ
2128 [Rint ꢀ= ꢀ 0.0184]ꢃ
2175 [Rint ꢀ= ꢀ 0.0757]
1436
2175/3/178
1.071
0.0682/0.1834
0.1027/0.1985
0.801, -0.280
Reflections observed [Iꢀ> ꢀ2σ(I)]ꢃ
1607
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
1817
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
Data/restraints/parameters
Goodness-of-fit on F2
R/wR [Iꢀ> ꢀ2σ(I)]
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
2125/3/180
1.067
2128/4/188
1.095
0.0449/0.1234
0.0624/0.1324
0.227, -0.221
0.0594/0.1852
0.0675/0.1897
0.397, -0.377
R/wR (all data)
Max., Min. Δρ (eꢀ⋅ ꢀÅ-3)
Note: data of 3c are given for comparison.
Figure 1ꢀViews of 3a and 3b showing the atom-numbering scheme. Hydrogen atoms are omitted for clarity.
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Table 3ꢀThe interplanar angles (°) for 3a,b.
[21]. The crystal structures of 3a,b with an atom-labeling
scheme are shown in Figure 1, and selected bond lengths
and bond angles are listed in Table 2. The X-ray crystal-
lography analysis indicates that both 3a and 3b crystallize
Compoundꢀ
Py/Trzꢀ
CH3-Ph/Trzꢀ
CH3O-Ph/Trz
3a
3b
ꢃ
ꢃ
2.0(1)ꢃ
7.1(1)ꢃ
30.2(1)ꢃ
ꢃ
30.9(1)
̅
in the triclinic space group Pꢀ1, which is different from the
Table 4ꢀThe hydrogen bonds, C-H···π and π···π interactions (Å, °) in 3a,b.
Compoundꢀ
D-H···A
ꢀ
d(D-H)/Åꢀ
d(H···A)/Åꢀ
d(D···A)/Åꢀ
∠D-H···A/°
3a
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
C1v-H1Av···N5
C4-H4A···N2i
N5-H5A···N1
N5-H5B···N2ii
ꢃ
ꢃ
ꢃ
ꢃ
0.93ꢃ
0.93ꢃ
0.89ꢃ
0.88ꢃ
0.96ꢃ
2.70ꢃ
2.82ꢃ
3.420(2)ꢃ
3.394(2)ꢃ
2.908(2)ꢃ
3.106(2)ꢃ
3.656(2)ꢃ
ꢃ
135
121
142
137
128
2.15ꢃ
2.41ꢃ
2.98ꢃ
C14-H14C···π (C8-C13)iii ꢃ
π···π interaction
π (Py) ···π (Trz)iv
C1viii-H1Aviii···N5
C2vi-H2Avi···O1
N5-H5B···N1
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
cent···cent (Å)
3.687(2)
2.76ꢃ
Dihedral angle (°)
ꢃ
1.9
124
168
131
126
3b
0.93ꢃ
0.93ꢃ
0.85ꢃ
0.96ꢃ
3.378(6)ꢃ
3.533(6)ꢃ
2.902(5)ꢃ
3.927(5)ꢃ
2.62ꢃ
2.27ꢃ
C14-H14A···π (C8-C13)viiꢃ
3.29ꢃ
Symmetry codes: (i) -x, 1-y, 2-z; (ii) 1+x, y, z; (iii) 2-x, -y, 1-z; (iv) 1-x, -y, 2-z; (v) 2-x, -y, 2-z; (vi) x, y-1, 1+z; (vii) 2-x, -1-y, 2-z; (viii) 2-x, -y, 1-z.
Figure 2ꢀView of the crystal packing for 3a showing hydrogen bonds, C-H···π and π···π interactions.
Figure 3ꢀView of the crystal packing for 3b showing hydrogen bonds and C-H···π interactions.
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204ꢀ
N-(p-Methoxyphenylcarbonyl)-N′-(2-pyridylcarbonyl)hydrazine
(1b)ꢁYield 79%; mp 154–156°C (lit. mp 153–155°C [22]); IR: 3285, 3021,
2964, 1703, 1642, 1610, 1566, 1508, 1488, 1303, 1260, 1026, 998 cm-1; 1H
NMR: δ 3.88 (3H, s, CH3), 7.19 (2H, d, J ꢀ= ꢀ 8 Hz, ArH), 7.65 (1H, dd, J1 ꢀ= ꢀ 5
Hz, J2 ꢀ= ꢀ 2 Hz, PyH), 8.05–8.09 (3H, m, PyH, ArH), 8.25 (1H, d, J ꢀ= ꢀ 8 Hz,
PyH), 8.80 (1H, d, J ꢀ= ꢀ 5 Hz, PyH), 10.51 (1H, s, NH), 10.53 (1H, s, NH).
Anal. Calcd for C14H13N3O3: C, 61.99; H, 4.83; N, 15.49. Found: C, 61.82;
H, 4.71; N, 15.77.
homologous compound 3c (C2/c). The central 1,2,4-triazole
in 3a is oriented at interplanar angles of 2.0(1)° and 30.2(1)°
with respect to the pyridyl ring and the p-methylphenyl
ring, respectively. Similarly, the central 1,2,4-triazole ring
in 3b is oriented at interplanar angles of 7.1(1)° and 30.9(1)°
with respect to the pyridyl ring and the p-methoxyphenyl
ring, respectively (Table 3). In addition, the N atom of the
pyridyl group is oriented towards the amino group on the
N4 position in both 3a and 3b. This feature is similar to
that of the related substituted 4-amino-1,2,4-triazoles com-
pounds [19, 20]. The bond lengths and bond angles of 3a
and 3b are similar and in normal ranges [23, 26, 27]. The
hydrogen bonds, a C-H···π interaction and a non-bonding
π···π interaction in these compounds are given in Table 4.
These interactions stabilize the crystal packing of 3a and
3b. The crystal packing diagrams of 3a and 3b are shown
in Figures 2 and 3, respectively.
N-(p-Chlorophenylcarbonyl)-N′-(2-pyridylcarbonyl)hydrazine
(1c)ꢁYield 82%; mp 179–181°C; IR: 3177, 3007, 1688, 1642, 1597, 1570,
1513, 1488, 1334, 1092, 1016, 844 cm-1; 1H NMR: δ 7.62 (2H, d, J ꢀ= ꢀ 8 Hz,
ArH), 7.68 (1H, dd, J1 ꢀ= ꢀ 5 Hz, J2 ꢀ= ꢀ 2 Hz, PyH), 7.94 (2H, d, J ꢀ= ꢀ 8 Hz, ArH),
8.05 (2H, m, PyH), 8.72 (1H, d, J ꢀ= ꢀ 5 Hz, PyH), 10.63 (1H, s, NH), 10.67
(1H, s, NH). Anal. Calcd for C13H10N3O2Cl: C, 56.64; H, 3.66; N, 15.24.
Found: C, 56.42; H, 3.54; N, 15.39.
Preparation of 1,4-dichloro-1-(2-pyridyl)-4-
(p-R-phenyl)-2,3-diaza-1,3-butadienes 2a–c
A solution of thionyl chloride (5 mL) in anhydrous toluene (10 mL)
was added dropwise to a stirred solution of 1 (16 mmol) in anhydrous
toluene (50 mL). The mixture was heated under reflux for 8 h at 120°C
and then the solvent was removed under reduced pressure. The resi-
due was crystallized from ethanol to give 2 as colorless crystals.
Experimental
Melting points were determined on an X-4 digital microscope melt-
ing-point apparatus (Beijing) and are uncorrected. FT-IR spectra
were recorded on a Nicolet 380 FT-IR instrument using KBr disks. 1H
NMR spectra were measured on a Bruker AM 500 MHz spectrometer
at ambient temperature in DMSO-d6 for 1 and 2 but in CDCl3 for 3.
Electrospray ionization mass spectra (ESI-MS) were recorded on an
LCQ ADVANTAGE MAX mass spectrometer. The spray voltage, the
capillary voltage, and the capillary temperature were 4 kV, 40 V,
and 260°C, respectively. Elemental analyses were carried out with a
Thermo Finnigan Flash 1112A elemental analyzer. All chemicals were
of analytical grade and used as received. Toluene was freshly dis-
tilled from Na/benzophenone, whereas pyridine was distilled over
NaOH. Pyridine-2-carbonylhydrazine was prepared according to a
previously reported method [23].
1,4-Dichloro-1-(2-pyridyl)-4-(p-methylphenyl)-2,3-diaza-1,3-
butadiene (2a)ꢁYield 68%; mp 156–158°C; IR: 3054, 2993, 1613,
1
1588, 1556, 1494, 1458, 1443, 1247, 1183, 1079, 824, 743, 728 cm-1; H
NMR: δ 2.45 (3H, s, CH3), 7.32–7.34 (2H, d, J ꢀ= ꢀ 8 Hz, ArH), 7.47 (1H, dd,
J1 ꢀ= ꢀ 5 Hz, J2 ꢀ= ꢀ 2 Hz, PyH), 7.85 (1H, m, PyH), 8.09 (2H, d, J ꢀ= ꢀ 7 Hz, ArH),
8.32 (1H, d, J ꢀ= ꢀ 8 Hz, PyH), 8.72 (1H, d, J ꢀ= ꢀ 5 Hz, PyH). Anal. Calcd for
C14H11N3Cl2: C, 57.55; H, 3.79; N, 14.38. Found: C, 57.31; H, 3.43; N, 14.49.
1,4-Dichloro-1-(2-pyridyl)-4-(p-methoxyphenyl)-2,3-diaza-1,3-
butadiene (2b)ꢁYield 69%; mp 152–154°C; IR: 3052, 2978, 1615, 1585,
1498, 1458, 1443, 1268, 1176, 1085, 1019, 832, 790, 741 cm-1; 1H NMR: δ
3.85 (3H, s, CH3), 7.02 (2H, d, J ꢀ= ꢀ 8 Hz, ArH), 7.45 (1H, dd, J1 ꢀ= ꢀ 5 Hz, J2 ꢀ= ꢀ
2 Hz, PyH), 7.83 (1H, m, PyH), 8.14 (2H, d, J ꢀ= ꢀ 8 Hz, ArH), 8.31 (1H, d,
J ꢀ= ꢀ 8 Hz, PyH), 8.61 (1H, d, J ꢀ= ꢀ 5 Hz, PyH). Anal. Calcd for C14H11N3Cl2O:
C, 54.57; H, 3.60; N, 13.64. Found: C, 54.36; H, 3.45; N, 13.41.
Preparation of N-(p-R-phenylcarbonyl)-N′-(2-
pyridylcarbonyl)hydrazines 1a–c
1,4-Dichloro-1-(2-pyridyl)-4-(p-chlorophenyl)-2,3-diaza-1,3-buta-
diene (2c)ꢁ Yield 72%; mp 146–148°C; IR: 1605, 1586, 1553, 1479,
1463, 1442, 1275, 1151, 1090, 835, 794, 731 cm-1; 1H NMR: δ 7.45 (1H, dd,
J1 ꢀ= ꢀ 5 Hz, J2 ꢀ= ꢀ 2 Hz, PyH), 7.50 (2H, d, J ꢀ= ꢀ 8 Hz, ArH), 7.92 (1H, m, PyH),
8.16 (2H, d, J ꢀ= ꢀ 8 Hz, ArH), 8.32 (1H, d, J ꢀ= ꢀ 8 Hz, PyH), 8.82 (1H, d, J ꢀ= ꢀ 5
Hz, PyH). Anal. Calcd for C13H8N3Cl3: C, 49.95; H, 2.58; N, 13.44. Found:
C, 49.66; H, 2.32; N, 13.68.
A suspension of the corresponding p-substituted benzoyl chloride
(48 mmol) in anhydrous pyridine (10 mL) was added dropwise to a
stirred solution of pyridine-2-carbonylhydrazine (5.49 g, 40 mmol) in
dichloromethane (80 mL) at 0°C. The mixture was stirred for 8 h at
ambient temperature and then poured into 80 mL of ice water. The
resultant precipitate was filtered, dried in vacuo, and crystallized
from anhydrous ethanol to give 1a–c as a white solid.
N-(p-Methylphenylcarbonyl)-N′-(2-pyridylcarbonyl)hydrazine
(1a)ꢁYield 81%; mp 182–184°C; IR: 3189, 3010, 2922, 1674, 1633, 1607,
1500, 1280, 1114, 836, 743 cm-1; 1H NMR: δ 2.44 (3H, s, CH3), 7.13 (2H, d,
J ꢀ= ꢀ 8 Hz, ArH), 7.54 (1H, dd, J1 ꢀ= ꢀ 5 Hz, J2 ꢀ= ꢀ 2 Hz, PyH), 8.01–8.05 (3H,
Preparation of 3-(p-R-phenyl)-4-amino-5-(2-
pyridyl)-1,2,4-triazoles 3a–c
m, PyH, ArH), 8.20 (1H, d, J ꢀ= ꢀ 8 Hz, PyH), 8.63 (1H, d, J ꢀ= ꢀ 5 Hz, PyH), A mixture of 2 (2 mmol) and anhydrous hydrazine (2 mL) was sealed
10.48 (1H, s, NH), 10.51 (1H, s, NH). Anal. Calcd for C14H13N3O2: C, 65.87; in a 25 mL Teflon-lined stainless steel reactor and heated for 12 h at
H, 5.13; N, 16.46. Found: C, 65.73; H, 5.31; N, 16.67.
120°C and then cooled to ambient temperature. The precipitate was
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drous ethanol to give 3 as colorless crystals.
3-(p-Methylphenyl)-4-amino-5-(2-pyridyl)-1,2,4-triazole
(3a)ꢁYield 58%; mp 205–207°C; IR: 3345, 3272, 3193, 1640, 1591, 1472,
1422, 1284, 1151, 1034, 993, 961, 818, 786, 728, 696, 583 cm-1; 1H NMR: δ
2.42 (3H, s, CH3), 6.45 (2H, br, NH2), 7.30 (2H, d, J ꢀ= ꢀ 9 Hz, ArH), 7.36 (1H,
dd, J1 ꢀ= ꢀ 5 Hz, J2 ꢀ= ꢀ 2 Hz, PyH), 7.85 (1H, m, PyH), 8.08 (2H, d, J ꢀ= ꢀ 9 Hz,
ArH), 8.36 (1H, d, J ꢀ= ꢀ 7 Hz, PyH), 8.62 (1H, d, J ꢀ= ꢀ 5 Hz, PyH); ESI-MS:
m/z 252.25 (M+H)+. Anal. Calcd for C14H13N5: C, 66.92; H, 5.21; N, 27.87.
Found: C, 66.76; H, 5.05; N, 27.99.
[7] van Koningsbruggen, P. J. Special classes of iron(II) azole spin
crossover compounds. Top. Curr. Chem. 2004, 233, 123–149.
[8] Kitchen, J. A.; Brooker, S. Spin crossover in iron(II) complexes
of 3,5-di(2-pyridyl)-1,2,4-triazoles and 3,5-di(2-pyridyl)-1,2,4-
triazolates. Coord. Chem. Rev. 2008, 252, 2072–2092.
[9] Malcolm, A. H. Structure: function relationships in molecular
spin-crossover complexes. Chem. Soc. Rev. 2011, 40, 4119–
4142.
[10] Shen, G. P.; Qi, L.; Wang, L.; Xu, Y.; Jiang, J. J.; Zhu, D.; Liu, X.
Q.; You, X. Spin-crossover in a trans-[FeL2(NCS)2] family (L ꢀ= ꢀ
triaryltriazole): remote substituent effects on spin transition
modes and temperature. J. Chem. Soc. Dalton. Trans. 2013, 42,
10144–10152.
3-(p-Methoxyphenyl)-4-amino-5-(2-pyridyl)-1,2,4-triazole
(3b)ꢁYield 69%; mp 194–195°C; IR: 3342, 3278, 3157, 2993, 2833, 1611,
1582, 1488, 1441, 1247, 1188, 1035, 972, 840, 737, 696, 594 cm-1; 1H NMR:
δ 3.86 (3H, s, CH3), 6.44 (2H, br, NH2), 6.99 (2H, d, J ꢀ= ꢀ 9 Hz, ArH), 7.35
(1H, dd, J1 ꢀ= ꢀ 5 Hz, J2 ꢀ= ꢀ 2 Hz, PyH), 7.84 (1H, m, PyH), 8.14 (2H, d, J ꢀ= ꢀ 9
Hz, ArH), 8.32 (1H, d, J ꢀ= ꢀ 7 Hz, PyH), 8.61 (1H, d, J ꢀ= ꢀ 5 Hz, PyH); ESI-
MS: m/z 268.3 (M+H)+. Anal. Calcd for C14H13N5O: C, 62.91; H, 4.90; N,
26.20. Found: C, 62.74; H, 4.78; N, 26.31.
3-(p-Chlorophenyl)-4-amino-5-(2-pyridyl)-1,2,4-triazole
(3c)ꢁSee reference [21].
Single-crystal X-ray diffraction analysis of 3a and 3bꢁThe single
crystals of 3a and 3b were selected for lattice parameter determina-
tion and collection of intensity data at 296 K on a Bruker SMART CCD
diffractometer with a detector distance of 5 cm and frame exposure
time of 10 s using a graphite-monochromated Mo-Kα (λ ꢀ= ꢀ 0.71073 Å)
radiation. The structures were solved by direct methods and refined
on F2 by full-matrix least squares procedures using SHELXTL sof-
ware [28]. All non-hydrogen atoms were anisotropically refined.
The H atoms were placed on calculated positions (C-H 0.96 Å) and
assigned isotropic thermal parameters riding on their parent atoms;
the H atoms of -NH2 were located from difference Fourier maps and
refined isotropically. Details on crystal data of 3a and 3b are sum-
marized in Table 1.
[11] Zhu, D. R.; Song, Y.; Xu, Y.; Zhang, Y.; Raj, S. S. S.; Fun, H. K.;
You, X. Z. Syntheses, crystal structures and properties of the
novel Co(II) and Ni(II) complexes with 4-(p-methylphenyl)-3,5-
bis(pyridin-2-yl)-1,2,4-triazole. Polyhedron 2000, 19, 2019–
2025.
[12] Zhu, D. R.; Xu, Y.; Zhang, Y.; Wang, T. W.; You, X. Z. 4-Phenyl-
3,5-bis(2-pyridyl)-4H-1,2,4-triazole. Acta Crystallogr. 2000,
C56, 895–896.
[13] Zhu, D.; Xu, Y.; Mei, Y.; Shi, Y.; Tu, C.; You, X. Crystal and molec-
ular structure of a novel complex [Mn(MOBPT)(H2O)2(NCS)2]
(MOBPT ꢀ= ꢀ 4-(p-methoxyphenyl)-3,5-bis(pyridin-2-yl)-1,2,4-
triazole). J. Mol. Struct. 2001, 559, 119–125.
[14] Zhou, J.; Yang, J.; Qi, L.; Shen, X.; Zhu, D.; Xu, Y.; Song, Y.
Synthesis, crystal structure and magnetic property of the novel
dinuclear nickel(II) complex with 4-(p-methoxyphenyl)-3,5-
bis(pyridine-2-yl)-1,2,4-triazole. Transition Met. Chem. 2007,
32, 711–715.
CCDC 983076 (3a) and 983077 (3b) contain the supplementary
crystallographic data for this article. These data can be obtained free
of charge from the Cambridge Crystallographic Data Centre via www.
ccdc.cam.ac.uk/data_request/cif.
[15] Yang, J.; Bao, W. W.; Ren, X. M.; Xu, Y.; Shen, X.; Zhu, D. R.
Synthesis, crystal structure, and magnetism of a dinuclear
nickel(II) complex [Ni2(MOBPT)2(N3)4]ꢀ⋅ ꢀ2H2O. J. Coord. Chem.
2009, 62, 1809–1816.
Acknowledgments: This work was funded by the National
Natural Science Foundation of China (nos. 20771059,
21171093).
[16] Chen, L.; Cheng, H. M.; Jiang, J. J.; Shen, X.; Zhu, D. R. Synthe-
sis, crystal structure and thermal stability of [CuL2(ClO4)2] (L ꢀ= ꢀ
3-(p-bromophenyl)-4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-
triazole). Chinese J. Inorg. Chem. 2012, 28, 381–385.
[17] Lu, W.; Zhu, D. R.; Xu, Y.; Cheng, H. M.; Zhao, J.; Shen, X.
Syntheses and crystal structures of two novel Cu(II)
and Co(II) complexes with 3-methyl-4-(p-bromophenyl)
-5-(2-pyridyl)-1,2,4-triazole. Struct. Chem. 2010, 21, 237–244.
[18] Zhao, J.; Cheng, H. M.; Shen, G. P.; Xu, Y.; Zhu, D. R. Syntheses,
crystal structures, and spectral properties of Mn(II) and Co(II)
complexes with 3-(p-chlorophenyl)-4-(p-methylphenyl)-5-(2-
pyridyl)-1,2,4-triazole. J. Coord. Chem. 2011, 64, 942–951.
[19] Shen, G. P.; Jiang, J. J.; Sun, F.; Shen, X.; Zhu, D. R.; Liu, X. Q.
Syntheses, crystal structures, and spectral characterization of
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