metal-organic compounds
Table 1
Hydrogen-bond geometry (A, ).
ꢂ
˚
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
O6—H1Wꢀ ꢀ ꢀO3i
O6—H1Wꢀ ꢀ ꢀO4i
O1—H1ꢀ ꢀ ꢀO6ii
O6—H2Wꢀ ꢀ ꢀO2
O6—H2Wꢀ ꢀ ꢀO5
0.84 (1)
0.84 (1)
0.82
0.84 (1)
0.84 (1)
2.57 (6)
2.48 (2)
1.91
2.23 (5)
2.57 (4)
3.217 (7)
3.316 (9)
2.721 (5)
2.973 (8)
3.363 (9)
135 (7)
169 (9)
170
146 (9)
157 (7)
1
2
3
2
1
2
Symmetry codes: (i) x ꢁ ; ꢁy þ ; z ꢁ ; (ii) x; y; z þ 1.
Experimental
2-[2-(Pyridin-4-yl)-1H-benzimidazol-1-ylmethyl]phenol (L) was syn-
thesized according to a modification of a previously reported
procedure (Fellah et al., 2010). To a solution of o-phenylenediamine
(2.16 g, 20 mmol) in ethanol (20 ml), 2-hydroxybenzaldehyde (1.22 g,
10 mmol) dissolved in ethanol (10 ml) was added dropwise. The
mixture was stirred at room temperature for 8 h. A yellow precipitate
formed and was isolated by filtration. The crude product, L0 (see
Scheme 1), was then crystallized from ethanol. A solution of L0
(2.12 g, 10 mmol) and pyridine-4-carbaldehyde (1.07 g, 10 mmol) in
ethanol (50 ml) was heated for 10 h under reflux. The reaction
mixture was cooled, and a white precipitate of L formed and was
filtered off (yield 71 wt%).
Figure 5
The thermogravimetric analysis (TGA) curve for (I).
To a solution of L (0.1 mmol, 30.1 mg) in a mixture (10 ml) of
methanol and tetrahydrofuran (1:1 v/v), AgClO4 (21 mg, 0.1 mmol)
was added. After stirring at room temperature for 30 min, NH3ꢀH2O
(2 ml) was added dropwise. The mixture was stirred for another
30 min and then filtered. Colourless block-shaped crystals of (I) were
obtained by evaporation after one week (yield 40 wt%, based on L).
Analysis calculated for C19H17AgClN3O6: C 43.33, H 3.25, N 7.98%;
found: C 43.81, H 3.11, N 7.64%. FT–IR (KBr, ꢃ, cmꢁ1): 3454 (s), 3058
(s), 2951 (s), 2860 (s), 2727 (s), 2609 (s), 1604 (m), 1506 (w), 1444 (s),
1412 (s), 1273 (m), 1241 (m), 1156 (w), 1070 (m), 984 (w), 909 (w),
835 (m), 749 (m), 674 (w), 589 (w), 535 (w).
Crystal data
3
˚
[Ag(C19H15N3O)]ClO4ꢀH2O
V = 2000.8 (11) A
Z = 4
Figure 6
The photoluminescent spectrum of (I).
Mr = 526.68
Monoclinic, P21=n
Mo Kꢅ radiation
ꢀ = 1.18 mmꢁ1
T = 296 K
˚
a = 9.739 (3) A
˚
b = 21.260 (7) A
Thermogravimetric analysis (TGA) of the title polymer
under an N2 atmosphere with a heating rate of 10 K minꢁ1 was
investigated in the temperature range 303–873 K (Fig. 5). The
TGA curve displays a weight loss of 3.2% at 353–423 K, which
corresponds to the loss of the solvent water molecule. On
heating above 506 K, a second weight loss of 19.5% is
observed in the temperature range 506–650 K, which corre-
sponds to the loss of the perchlorate anion. The framework
starts to decompose at 650 K.
˚
c = 9.952 (3) A
0.23 ꢄ 0.21 ꢄ 0.16 mm
ꢄ = 103.851 (3)ꢂ
Data collection
Bruker APEXII CCD area-detector
diffractometer
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
Tmin = 0.772, Tmax = 0.833
10711 measured reflections
3712 independent reflections
3023 reflections with I > 2ꢆ(I)
Rint = 0.026
The free L ligand shows very weak luminescence (almost
undetectable) in acetonitrile solution at ambient temperature.
However, (I) does exhibit photoluminescence in acetonitrile
solution at room temperature. Excitation of (I) at 320 nm
produces a luminescence peak with a maximum at 390 nm
(Fig. 6). This increase in the intensity of the luminescence may
be attributed to the coordination of the L ligand to the AgI
cation, which increases the rigidity of the L ligand and reduces
the nonradiative relaxation process (Fang & Zhang, 2006).
Refinement
R[F2 > 2ꢆ(F2)] = 0.038
wR(F2) = 0.098
S = 1.12
3712 reflections
280 parameters
3 restraints
H atoms treated by a mixture of
independent and constrained
refinement
ꢁ3
˚
Áꢇmax = 0.62 e A
ꢁ3
˚
Áꢇmin = ꢁ0.68 e A
The hydroxy H atom was positioned and refined by a freely
˚
rotating O—H bond and with a fixed distance of O—H = 0.82 A and
ꢃ
358 Hu et al. [Ag(C19H15N3O)]ClO4ꢀH2O
Acta Cryst. (2013). C69, 356–359