P. Zhu et al. / Polyhedron 131 (2017) 52–58
53
synthesized according to the reported literature [25]. The Elemen-
tal analyses of the C, H and N were measured by the Perkin–Elmer
2400 CHN elemental analyzer. Infrared Spectrum (IR) was obtained
from the Alpha Centaurt FT/IR spectrometer with KBr pellets. The
XRD pattern was scanned by the Rigaku D/MAX 2500 V XRD
in Table 1 and Table S12. The CCDC reference number of com-
pounds 1 and 2 is 1495425 and 1495426.
3. Results and discussion
diffractometer with Cu Ka radiation. The diffuse reflectance spec-
Single-crystal X-ray diffraction analysis shows that the
supramolecular frameworks of compounds 1 and 2 exhibit the dif-
tra were scanned on T9 spectrometer, and the UVꢁVis spectra
were recorded on a 756 CRT spectrophotometer.
ferent helical structure. According to the bond valence sum calcu-
P
lation [27], S = exp[ꢁ(R ꢁ Ro)/B] (S = bond valence, R = bond
length), all Mo atoms are in the full oxidation state. To balance
the charge, the protons are added and compounds are formulated
as [Ag6(btp)(pyttz)6ꢀ(HSiMo12O40)2]ꢀ4H2O for 1 and [Ag2(pyttz)4-
ꢀ(H2SiMo12O40)2]ꢀ(TMA)2ꢀ4H2O for 2. The parallel experiments have
indicated that the use of TMAH species was necessary for the iso-
lation of the compounds 1 and 2, although it was not involved in
the final structures in 1. If not, compounds 1 and 2 cannot be
isolated.
2.2. Synthesis of [Ag6(btp)(pyttz)6ꢀ(HSiMo12O40)2]ꢀ4H2O (1)
a-H4[SiMo12O40], (300 mg, 0.16 mmol), AgNO3 (150 mg,
0.88 mmol), pyttz ligand (80 mg, 0.54 mmol), tetramethylammo-
nium hydroxide (TMAH) (0.20 mmol) were dissolved in distilled
water (10 mL) with stirring for 2 h at room temperature, and pH
value was adjusted to ca. 2.16 by 1 mol Lꢁ1 HCl. The resulting solu-
tion was transferred and sealed in a 20 mL Teflon-lined stainless
steel reactor and heated at 170 °C for 5 days. After the autoclave
was cooled to room temperature at 10 °C h-1, the blue block crystal
suitable for X-ray crystallography were obtained, and then washed
with distilled water and air-dried (yield: 32% based on Ag). Ele-
3.1. Structure and Topological analysis of compound 1
mental analysis: Anal. Calcd for
C68H62Ag6Si2Mo24N50O84
4ꢁ
Compound 1 is consisted of two [SiMo12O40
]
clusters (abbr.
(5929.6): C 13.77, H 1.05 and N 11.81%; Found C 13.64; H 1.23
and N 11.78%. IR (KBr pellet, cmꢁ1): 3497 (w), 3105 (w), 1641
(s), 951 (s), 904 (s), 791 (s), 628 (w), 623 (w), 508 (w).
SiMo12), six Ag+ ions, six pyttz ligands, one btp ligand and four
water molecules in Fig. S1 (supporting information). There are
three crystallography independent Ag+ ions (Ag1, Ag2 and Ag3)
with three kinds of coordination modes in Fig. S2 (supporting
information): Ag1 exhibits screwy pyramidal geometry coordi-
nated with four N atoms from two pyttz ligands and one O atom
from the SiMo12 clusters; Ag2 adopts triangular pyramid geometry
completed by three N atoms from one pyttz ligand and one btp
ligand and one O atom from the SiMo12 clusters; Ag3 shows trian-
gle geometry completed by three N atoms from two pyttz ligands.
In turn, the SiMo12 clusters as two-connected inorganic ligands
2.3. Synthesis of [Ag2(pyttz)4ꢀ(H2SiMo12O40)2]ꢀ(TMA)2ꢀ4H2O (2)
The preparation of 2 was similar to that of compound 1, except
that the pH values was adjusted 3.54. The light yellow block crystal
of 2 (yield: 43% based on Ag) was successfully isolated. Elemental
analysis: Anal. Calcd for
C44H64Ag2Si2Mo24N30O84 (4931.7): C
10.72, H 1.31 and N 8.52%; Found C 10.57; H 1.46 and N 8.46%.
IR (KBr pellet, cmꢁ1): 3312 (w), 3231 (w), 1640 (s), 1482 (s),
1234 (s), 956 (s), 906 (s), 795 (s), 631 (w), 505 (w).
Table 1
2.4. Catalytic synthesis of acetylsalicylic acid
Crystallographic and structural refinement data for 1 and 2.
Compound
Compound 1
Compound 2
Salicylic acid (1.5 g, 10.86 mmol) was transferred to a clean, dry
three-necked flask with the volume of 50 mL. The acetic anhydride
Chemical formula
CCDC no.
C
68H62Ag6Si2Mo24N50O84 C44H64Ag2Si2Mo24N30O84
1495425
5929.6
293(2)
0.71069
triclinic
1495426
4931.7
293(2)
(3.0 mL) and compounds (40 mg, 0.0067 mmol for
1
or
Formula weight
Temperature (K)
Wavelength (Å)
Crystal system
Space group
a (Å)
0.0081 mmol for 2) were dispersed in the three-necked flask,
respectively. The reaction was carried out in water bath (75–
90 °C) for 60 min. At 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 and
60 min, the sample (10 mL) was taken out from the flask and diluted
with PBS buffer solution for UV–Vis analysis. According to ultravio-
let two-wavelength isoabsorption spectrophotometry (A = A1 + A2),
the content of salicylic acid (SA) and acetylsalicylic Acid (ASP) were
detected, which the high reliability, accuracy of the detection tech-
nology had been proved (ESIy and Eqs. (1) and (2).
0.71069
triclinic
ꢀ
ꢀ
P1
P1
12.174(5)
12.766(5)
23.329(5)
93.590(5)
90.790(5)
110.640(5)
3384(2)
11.7027(3)
13.3019(6)
19.2198(6)
92.951(3)
99.439(2)
93.295(3)
2940.88(18)
1
b (Å)
c (Å)
a
(°)
b (°)
c
(°)
V (Å3)
CSA ¼ 39:8586A297 ꢁ 1:5328A270 ꢁ 0:7647
ð1Þ
Z
q
l
1
(g cmꢁ3
(mmꢁ1
)
)
3.124
5.646
2804.0
2.782
5.808
2336.0
CASP ¼ 387:7989A270 ꢁ 87:7713A297 ꢁ 6:5271
ð2Þ
F(000)
h (°)
3.235–25.000
16491
3.41–25.000
22404
Reflections collected
2.5. X-ray Crystallographic measurements
Independent reflections
11904 (0.0234)
10333 (0.0267)
(Rint
)
Crystallographic data for compounds were collected on the Agi-
lent Technology Eos Dual system with Mo radiation
Data/restraints/
parameters
11904/33/1054
1.061
10333/43/877
1.093
K
a
Goodness-of-fit on F2
(k = 0.71069 Å) at room temperature. The structure of compounds
was solved by the direct method and refined full-matrix last
squares on F2 through the SHELXTL and WINGX software package
[26]. All non-hydrogen atoms were refined anostropically and the
ISOR, DELU and SIMU command was used to refine some APD
and NPD atoms the bond length between some atoms in 1 and 2.
The crystal data and selected bond lengths and angles are listed
Final R indices [I > 2
R indices (all data)
r
(I)] R1 = 0.0426, wR2 = 0.0938 R1 = 0.0667, wR2 = 0.1822
R1 = 0.0568, wR2 = 0.1014 R1 = 0.0846, wR2 = 0.2077
Largest diff. peak and
3.136 and ꢁ1.434
2.756 and ꢁ2.274
hole (e Åꢁ3
)
P
P
P
P
aR1
=
||F0|| ꢁ |Fc||/ |F0|. bwR2 = { [w(F02 ꢁ Fc2)2]/ [w(F02)2]}1/2
.