80
B. Liu et al. / Journal of Molecular Structure 825 (2006) 79–86
(2),
[Cd3(L)6(H2O)6](ClO4)6Æ2H2OÆ2DMFÆ2EtOH
(3),
tion of 0.2 mmol Mn(ClO4)2 (about 52 mg) yielding yellow
[Zn3(L)8(H2O)4](BF4)4(SiF6)Æ2EtOHÆ12H2O (4), were syn-
thesized and the crystal structures, magnetic, semicon-
ducting and fluorescent properties were characterized.
suspension. The suspension was filtered and the filtrate was
placed to naturally evaporate. The orange block crystals
were isolated by slow evaporation of the aqueous solution
at room temperature for a couple of weeks. Yield on L:
53 mg, 43%. Elemental analysis (%), Found (calcd): C,
31.42(31.39); H, 2.92(2.96); N, 13.68(13.73). IR data (in
KBr, cmꢀ1): 3433 (s), 3125 (m), 2975 (m), 2896 (w), 1616
(s), 1544 (w), 1496 (w), 1462 (w), 1382 (w), 1301 (w),
1207 (m), 1113 (s), 1090 (s), 1012 (m), 1000 (m), 870 (m),
781 (m), 650 (m), 625 (m), 458 (w).
2. Experimental section
2.1. General
All chemicals were used as purchased without further
purification except that (m-phenol)-1,2,4-triazole (L) was
prepared by literature methods [6] with some modifica-
tions of prolonging the reaction time at 170 ꢁC to
enhance the yield. ZnSiF6 and Zn(BF4)2 were prepared
by Zn2(OH)2CO3 reacting with H2SiF6 and HBF4,
respectively. Mn(ClO4)2, Cd(ClO4)2 were, respectively,
obtained from HClO4 reacting with MnCO3 and
Cd2(OH)2CO3. Ni2(OH)2CO3 reacted with HBF4 to syn-
thesize Ni(BF4)2. The IR spectra were recorded on a Nic-
olet Magna 750 FT-IR spectrometer with KBr pellets in
the range 4000–400 cmꢀ1 and elemental analyses of C, H
and N were carried out on a Vario EL III elemental ana-
lyzer. The electronic emission and excitation spectra
recorded at room temperature were obtained on an Edin-
burgh FL/FS 920 TCSPC fluorescence spectrophotome-
ter at room temperature with excitation and emission
slit at 5.0 nm, increment 1.0 nm and integration time
0.1 s. Optical diffuse reflectance spectra were measured
at room temperature with a Lambda 35 UV–vis spectro-
photometer. Variable-temperature, solid-state direct cur-
rent (DC) magnetic susceptibility data down to 2 K
were collected on a Quantum Design PPMS60000 mag-
netometer in our institute. Diamagnetic corrections were
applied to the observed paramagnetic susceptibilities
using Pascal’s constants.
2.2.3. Synthesis of [Ni3(L)6(H2O)6](BF4)6Æ4DMF (2)
The 10 mL aqueous solution of Ni(BF4)2 (about 46 mg,
0.2 mmol) was added dropwise to a solution of (m-phenol)-
1,2,4-triazole (64 mg, 0.4 mmol) in a minimum of water.
The reaction mixture was stirred at room temperature for
6 h producing green precipitate. The green precipitate
was filtered, washed with water and ethanol in turn and
added to DMF. Evaporation of DMF solution yielded
green prismatic crystals suitable for X-ray diffraction. Yield
on L: 52 mg, 38%. Elemental analysis (%), Found (calcd):
34.89(34.91); H, 3.95(4.00); N, 14.97(14.93). IR data (in
KBr, cmꢀ1): 3410 (s), 2974 (m), 2927 (m), 1629 (m), 1455
(w), 1381 (w), 1326 (w), 1271 (w), 1089 (s), 1050 (s), 881
(s), 804 (s), 669 (w), 433 (w).
2.2.4. Synthesis of [Cd3(L)6(H2O)6](ClO4)6Æ2H2OÆ
2DMFÆ2EtOH (3)
To a stirring aqueous solution (10 mL) containing (m-
phenol)-1,2,4-triazole (64 mg, 0.4 mmol) was added drop-
wise an aqueous solution of Cd(ClO4)2 (about 62 mg,
0.2 mmol). The resulting yellow mixture was filtered,
washed with water and added to mixture of DMF and
EtOH (v/v, 10:5). The yellow prismatic crystals suitable
for X-ray diffraction studies were obtained by slow evapo-
ration of the solution at room temperature for several
weeks. Yield on L: 42 mg, 27%. Elemental analysis (%),
Found (calcd): 30.55(30.51); H, 3.75(3.71); N,
12.31(12.27). IR data (in KBr, cmꢀ1): 3435 (s), 3121 (m),
2977 (m), 2898 (w), 1616 (s), 1542 (w), 1492 (w), 1460
(w), 1380 (w), 1303 (w), 1205 (m), 1089 (s), 1010 (m),
1005 (m), 871 (m), 781 (m), 652 (m), 623 (m), 457 (w).
2.2. Synthesis
2.2.1. Synthesis of (m-phenol)-1,2,4-triazole (L)
The reaction was carried out by heating the dif-
ormylhydrazine (6 mmol, 0.56 g) with m-amino-phenol
(6 mmol, 0.53 g) at 443 K for three days. The orange prod-
uct was purified by recrystallization from ethanol. Yield
based on m-amino-phenol: 0.79 g, 82%. Elemental analysis
(%), Found (calcd): C, 59.80 (59.62); H, 4.45(4.38); N,
26.07 (25.90) Scheme 1.
2.2.5. Synthesis of [Zn3(L)8(H2O)4](BF4)4(SiF6)Æ
2EtOHÆ12H2O (4)
A 20 mL aqueous solution of (m-phenol)-1,2,4-triazole
(96 mg, 0.6 mmol) was added to mixture of aqueous solu-
tion containing Zn(BF4)2 (24 mg, 0.1 mmol) and ZnSiF6
(20 mg, 0.1 mmol) yielding a yellow suspension. The yellow
suspension was filtered and the filtrate was placed to natu-
rally evaporate. The orange prismatic crystals were isolated
by slow evaporation of the solution at room temperature
for several weeks. Yield on L: 38 mg, 22%. Elemental anal-
ysis (%), Found (calcd): 34.72(34.68); H, 4.25(4.28); N,
14.32(14.27). IR data (in KBr, cmꢀ1): 3433 (s), 3125 (m),
2975 (m), 2896 (w), 1616 (s), 1544 (w), 1496 (w), 1462
2.2.2. Synthesis of [Mn3(L)6(H2O)6](ClO4)6 (1)
To a solution of (m-phenol)-1,2,4-triazole (64 mg,
0.4 mmol) in a minimum of water was added aqueous solu-
OH
H2N
OH
O
O
N
N
443 K
hydrothermal
N
HC HNNH CH
+
Scheme 1. The synthesis of (m-phenol)-1,2,4-triazole.