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Yellow needle-shaped crystals of the title compound, {[Ag(C
30H
22N
4)][Ag(NO
3)
2]}
n, were obtained by the reaction of AgNO
3 and 9,10-bis(benzimidazol-1-ylmethyl)anthracene (
L) in a 2:1 ratio. The asymmetric unit consists of two Ag
I cations, one half
L ligand and one nitrate anion. One Ag
I cation occupies a crystallographic inversion centre and links two N-atom donors of two distinct
L ligands to form an infinite one-dimensional coordination polymer. The second Ag
I cation lies on a crystallographic twofold axis and is coordinated by two O-atom donors of two nitrate anions to form an [Ag(NO
3)
2]
- counter-ion. The polymeric chains are linked into a supramolecular framework
via weak Ag
O [3.124 (5) Å] and Ag
(2.982 Å) interactions (
is the centroid of an outer anthracene benzene ring). The
interactions contain two short Ag
C contacts [2.727 (6) and 2.765 (6) Å], which can be considered to define Ag-
2-anthracene bonding interactions. In comparison with a previously reported binuclear Ag
I complex [Du, Hu, Zhang, Zeng & Bu (2008).
CrystEngComm,
10, 1866-1874], this new one-dimensional coordination polymer was obtained by changing the metal-ligand ratio during the synthesis.
Supporting information
CCDC reference: 906563
9,10-Bis(benzimidazol-1-ylmethyl)anthracence (L) was prepared according
to the literature method of Du et al. (2008). A buffer layer of
a
solution (5 ml) of methanol and chloroform (1:1 v/v) was
carefully layered over a chloroform solution (5 ml) of L (0.05 mmol)
and then a solution of AgNO3 (0.10 mmol) in methanol (5 ml) was layered
over the buffer layer. The container was left in the dark for about three
weeks at room temperature, after which yellow needle-shaped crystals of (I)
were obtained (yield ~30%, based on L). Analysis, calculated for
C30H22Ag2N6O6: C 46.30, H 2.85, N 10.80%; found: C 46.48, H 2.68, N
10.88%.
All H atoms were placed in geometrically idealized positions and constrained to
ride on their parent atoms, with C—H = 0.93 (CH) or 0.97 Å (CH2), and
with Uiso(H) = 1.2Ueq(C).
Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
catena-Poly[[silver(I)-µ-[9,10-bis(1
H-benzimidazol-1-
ylmethyl)anthracene]-
κ2N3:
N3']
bis(nitrato-
κO)silver(I)]
top
Crystal data top
[Ag(C30H22N4)][Ag(NO3)2] | F(000) = 1544 |
Mr = 778.28 | Dx = 1.885 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 10039 reflections |
a = 24.980 (5) Å | θ = 3.2–27.5° |
b = 6.5472 (13) Å | µ = 1.49 mm−1 |
c = 17.278 (4) Å | T = 293 K |
β = 103.96 (3)° | Needle, yellow |
V = 2742.3 (10) Å3 | 0.23 × 0.21 × 0.16 mm |
Z = 4 | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 2415 independent reflections |
Radiation source: fine-focus sealed tube | 1697 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.088 |
ϕ and ω scans | θmax = 25.0°, θmin = 3.2° |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −29→29 |
Tmin = 0.726, Tmax = 0.797 | k = −7→7 |
10890 measured reflections | l = −20→20 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.061 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.103 | H-atom parameters constrained |
S = 1.11 | w = 1/[σ2(Fo2) + (0.0306P)2 + 4.9608P] where P = (Fo2 + 2Fc2)/3 |
2415 reflections | (Δ/σ)max < 0.001 |
201 parameters | Δρmax = 0.70 e Å−3 |
0 restraints | Δρmin = −0.43 e Å−3 |
Crystal data top
[Ag(C30H22N4)][Ag(NO3)2] | V = 2742.3 (10) Å3 |
Mr = 778.28 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 24.980 (5) Å | µ = 1.49 mm−1 |
b = 6.5472 (13) Å | T = 293 K |
c = 17.278 (4) Å | 0.23 × 0.21 × 0.16 mm |
β = 103.96 (3)° | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 2415 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | 1697 reflections with I > 2σ(I) |
Tmin = 0.726, Tmax = 0.797 | Rint = 0.088 |
10890 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.061 | 0 restraints |
wR(F2) = 0.103 | H-atom parameters constrained |
S = 1.11 | Δρmax = 0.70 e Å−3 |
2415 reflections | Δρmin = −0.43 e Å−3 |
201 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.
planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor
wR and goodness of fit S are based on F2, conventional
R-factors R are based on F, with F set to zero for
negative F2. The threshold expression of F2 >
σ(F2) is used only for calculating R-factors(gt) etc.
and is not relevant to the choice of reflections for refinement.
R-factors based on F2 are statistically about twice as large
as those based on F, and R-factors based on ALL data will be
even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Ag1 | 0.7500 | 0.7500 | 0.0000 | 0.0507 (3) | |
Ag2 | 0.5000 | 0.48981 (13) | 0.2500 | 0.0608 (3) | |
N2 | 0.71269 (19) | 0.5045 (7) | 0.0491 (3) | 0.0391 (12) | |
N1 | 0.64601 (17) | 0.3056 (7) | 0.0731 (3) | 0.0317 (12) | |
N3 | 0.4046 (2) | 0.2521 (9) | 0.1480 (4) | 0.0459 (13) | |
C6 | 0.5346 (2) | 0.5513 (8) | 0.0761 (3) | 0.0266 (13) | |
C9 | 0.6586 (2) | 0.4756 (9) | 0.0373 (3) | 0.0372 (15) | |
H9 | 0.6322 | 0.5635 | 0.0076 | 0.045* | |
C5 | 0.4887 (2) | 0.6818 (8) | 0.0380 (3) | 0.0263 (13) | |
C15 | 0.6954 (2) | 0.2111 (8) | 0.1094 (3) | 0.0316 (14) | |
C10 | 0.7369 (2) | 0.3386 (9) | 0.0942 (3) | 0.0365 (15) | |
C7 | 0.5443 (2) | 0.3710 (8) | 0.0366 (3) | 0.0285 (13) | |
C1 | 0.5677 (2) | 0.6069 (9) | 0.1527 (3) | 0.0363 (15) | |
H1 | 0.5969 | 0.5233 | 0.1774 | 0.044* | |
C8 | 0.5912 (2) | 0.2303 (9) | 0.0784 (3) | 0.0331 (14) | |
H8A | 0.5906 | 0.2177 | 0.1341 | 0.040* | |
H8B | 0.5853 | 0.0955 | 0.0546 | 0.040* | |
C3 | 0.5122 (3) | 0.9063 (10) | 0.1540 (4) | 0.0421 (16) | |
H3 | 0.5049 | 1.0230 | 0.1803 | 0.050* | |
C4 | 0.4797 (2) | 0.8590 (9) | 0.0816 (4) | 0.0368 (15) | |
H4 | 0.4504 | 0.9450 | 0.0593 | 0.044* | |
C14 | 0.7071 (3) | 0.0326 (9) | 0.1535 (4) | 0.0464 (17) | |
H14 | 0.6792 | −0.0495 | 0.1638 | 0.056* | |
O2 | 0.37198 (19) | 0.1697 (7) | 0.0922 (3) | 0.0681 (14) | |
C13 | 0.7620 (3) | −0.0175 (10) | 0.1815 (4) | 0.0579 (19) | |
H13 | 0.7715 | −0.1367 | 0.2109 | 0.070* | |
C12 | 0.8036 (3) | 0.1082 (11) | 0.1664 (4) | 0.0523 (19) | |
H12 | 0.8402 | 0.0702 | 0.1864 | 0.063* | |
C2 | 0.5573 (2) | 0.7799 (9) | 0.1902 (4) | 0.0404 (16) | |
H2A | 0.5798 | 0.8151 | 0.2396 | 0.048* | |
C11 | 0.7924 (2) | 0.2854 (10) | 0.1232 (4) | 0.0501 (18) | |
H11 | 0.8206 | 0.3669 | 0.1135 | 0.060* | |
O3 | 0.4363 (2) | 0.3849 (8) | 0.1328 (3) | 0.0758 (16) | |
O1 | 0.4065 (3) | 0.2081 (8) | 0.2170 (3) | 0.0878 (19) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Ag1 | 0.0411 (4) | 0.0478 (5) | 0.0674 (6) | −0.0077 (4) | 0.0213 (4) | 0.0133 (4) |
Ag2 | 0.0596 (5) | 0.0719 (6) | 0.0471 (5) | 0.000 | 0.0055 (4) | 0.000 |
N2 | 0.035 (3) | 0.037 (3) | 0.046 (3) | −0.002 (3) | 0.011 (2) | 0.011 (3) |
N1 | 0.023 (3) | 0.032 (3) | 0.039 (3) | 0.002 (2) | 0.005 (2) | 0.010 (2) |
N3 | 0.040 (3) | 0.047 (3) | 0.047 (4) | 0.009 (3) | 0.003 (3) | 0.006 (3) |
C6 | 0.023 (3) | 0.027 (3) | 0.031 (3) | −0.003 (2) | 0.009 (3) | −0.001 (3) |
C9 | 0.027 (3) | 0.043 (4) | 0.040 (4) | 0.002 (3) | 0.004 (3) | 0.010 (3) |
C5 | 0.022 (3) | 0.030 (3) | 0.030 (3) | −0.004 (2) | 0.012 (3) | 0.000 (3) |
C15 | 0.027 (3) | 0.033 (4) | 0.033 (3) | 0.002 (3) | 0.003 (3) | −0.002 (3) |
C10 | 0.033 (4) | 0.039 (4) | 0.038 (4) | 0.002 (3) | 0.009 (3) | −0.004 (3) |
C7 | 0.021 (3) | 0.033 (3) | 0.033 (3) | 0.000 (3) | 0.009 (3) | 0.012 (3) |
C1 | 0.028 (3) | 0.042 (4) | 0.034 (4) | −0.004 (3) | −0.002 (3) | 0.003 (3) |
C8 | 0.025 (3) | 0.036 (3) | 0.038 (3) | −0.003 (3) | 0.006 (3) | −0.002 (3) |
C3 | 0.051 (4) | 0.042 (4) | 0.038 (4) | −0.002 (3) | 0.020 (3) | −0.011 (3) |
C4 | 0.035 (4) | 0.040 (4) | 0.037 (4) | 0.003 (3) | 0.013 (3) | 0.004 (3) |
C14 | 0.041 (4) | 0.039 (4) | 0.057 (4) | 0.005 (3) | 0.007 (3) | 0.014 (3) |
O2 | 0.054 (3) | 0.060 (3) | 0.078 (4) | −0.005 (3) | −0.008 (3) | 0.001 (3) |
C13 | 0.063 (5) | 0.045 (4) | 0.057 (5) | 0.016 (4) | −0.003 (4) | 0.011 (4) |
C12 | 0.030 (4) | 0.058 (5) | 0.061 (5) | 0.014 (4) | −0.005 (3) | −0.001 (4) |
C2 | 0.041 (4) | 0.043 (4) | 0.035 (4) | −0.013 (3) | 0.004 (3) | −0.008 (3) |
C11 | 0.027 (3) | 0.060 (5) | 0.061 (5) | −0.003 (3) | 0.006 (3) | 0.000 (4) |
O3 | 0.065 (3) | 0.091 (4) | 0.068 (4) | −0.036 (3) | 0.009 (3) | 0.005 (3) |
O1 | 0.135 (5) | 0.080 (4) | 0.050 (4) | 0.020 (4) | 0.027 (4) | 0.020 (3) |
Geometric parameters (Å, º) top
Ag1—N2 | 2.134 (5) | C10—C11 | 1.401 (8) |
Ag1—N2i | 2.134 (5) | C7—C5iii | 1.396 (7) |
Ag2—O3 | 2.356 (5) | C7—C8 | 1.528 (7) |
Ag2—O3ii | 2.356 (5) | C1—C2 | 1.361 (8) |
N2—C9 | 1.331 (7) | C1—H1 | 0.9300 |
N2—C10 | 1.387 (7) | C8—H8A | 0.9700 |
N1—C9 | 1.347 (6) | C8—H8B | 0.9700 |
N1—C15 | 1.387 (7) | C3—C4 | 1.354 (8) |
N1—C8 | 1.478 (6) | C3—C2 | 1.415 (8) |
N3—O1 | 1.216 (6) | C3—H3 | 0.9300 |
N3—O2 | 1.227 (6) | C4—H4 | 0.9300 |
N3—O3 | 1.245 (6) | C14—C13 | 1.380 (8) |
C6—C7 | 1.413 (7) | C14—H14 | 0.9300 |
C6—C1 | 1.428 (7) | C13—C12 | 1.398 (9) |
C6—C5 | 1.454 (7) | C13—H13 | 0.9300 |
C9—H9 | 0.9300 | C12—C11 | 1.372 (8) |
C5—C7iii | 1.396 (7) | C12—H12 | 0.9300 |
C5—C4 | 1.430 (7) | C2—H2A | 0.9300 |
C15—C14 | 1.387 (7) | C11—H11 | 0.9300 |
C15—C10 | 1.405 (8) | | |
| | | |
N2—Ag1—N2i | 180.0 (2) | C2—C1—H1 | 119.3 |
O3—Ag2—O3ii | 146.1 (3) | C6—C1—H1 | 119.3 |
C9—N2—C10 | 105.2 (5) | N1—C8—C7 | 112.7 (4) |
C9—N2—Ag1 | 124.8 (4) | N1—C8—H8A | 109.1 |
C10—N2—Ag1 | 129.8 (4) | C7—C8—H8A | 109.1 |
C9—N1—C15 | 107.2 (5) | N1—C8—H8B | 109.1 |
C9—N1—C8 | 128.7 (5) | C7—C8—H8B | 109.1 |
C15—N1—C8 | 124.0 (4) | H8A—C8—H8B | 107.8 |
O1—N3—O2 | 121.8 (6) | C4—C3—C2 | 120.8 (6) |
O1—N3—O3 | 119.7 (6) | C4—C3—H3 | 119.6 |
O2—N3—O3 | 118.5 (6) | C2—C3—H3 | 119.6 |
C7—C6—C1 | 122.2 (5) | C3—C4—C5 | 122.4 (6) |
C7—C6—C5 | 118.7 (5) | C3—C4—H4 | 118.8 |
C1—C6—C5 | 119.1 (5) | C5—C4—H4 | 118.8 |
N2—C9—N1 | 112.8 (5) | C13—C14—C15 | 116.9 (6) |
N2—C9—H9 | 123.6 | C13—C14—H14 | 121.5 |
N1—C9—H9 | 123.6 | C15—C14—H14 | 121.5 |
C7iii—C5—C4 | 123.6 (5) | C14—C13—C12 | 121.0 (6) |
C7iii—C5—C6 | 119.9 (5) | C14—C13—H13 | 119.5 |
C4—C5—C6 | 116.5 (5) | C12—C13—H13 | 119.5 |
N1—C15—C14 | 132.1 (5) | C11—C12—C13 | 122.4 (6) |
N1—C15—C10 | 105.4 (5) | C11—C12—H12 | 118.8 |
C14—C15—C10 | 122.4 (5) | C13—C12—H12 | 118.8 |
N2—C10—C11 | 131.0 (6) | C1—C2—C3 | 119.9 (6) |
N2—C10—C15 | 109.3 (5) | C1—C2—H2A | 120.0 |
C11—C10—C15 | 119.8 (6) | C3—C2—H2A | 120.0 |
C5iii—C7—C6 | 121.4 (5) | C12—C11—C10 | 117.4 (6) |
C5iii—C7—C8 | 120.1 (5) | C12—C11—H11 | 121.3 |
C6—C7—C8 | 118.4 (5) | C10—C11—H11 | 121.3 |
C2—C1—C6 | 121.3 (5) | N3—O3—Ag2 | 110.7 (4) |
| | | |
C10—N2—C9—N1 | 1.5 (7) | C5—C6—C7—C8 | −177.6 (4) |
Ag1—N2—C9—N1 | 178.1 (4) | C7—C6—C1—C2 | −179.2 (5) |
C15—N1—C9—N2 | −1.9 (7) | C5—C6—C1—C2 | −0.5 (8) |
C8—N1—C9—N2 | 175.4 (5) | C9—N1—C8—C7 | −0.1 (8) |
C7—C6—C5—C7iii | −0.8 (8) | C15—N1—C8—C7 | 176.8 (5) |
C1—C6—C5—C7iii | −179.6 (5) | C5iii—C7—C8—N1 | 103.1 (6) |
C7—C6—C5—C4 | 178.2 (4) | C6—C7—C8—N1 | −78.4 (6) |
C1—C6—C5—C4 | −0.6 (7) | C2—C3—C4—C5 | 0.0 (9) |
C9—N1—C15—C14 | −179.5 (6) | C7iii—C5—C4—C3 | 179.8 (5) |
C8—N1—C15—C14 | 3.1 (9) | C6—C5—C4—C3 | 0.8 (8) |
C9—N1—C15—C10 | 1.4 (6) | N1—C15—C14—C13 | −179.9 (6) |
C8—N1—C15—C10 | −176.0 (5) | C10—C15—C14—C13 | −0.9 (9) |
C9—N2—C10—C11 | 178.8 (6) | C15—C14—C13—C12 | 0.6 (10) |
Ag1—N2—C10—C11 | 2.4 (10) | C14—C13—C12—C11 | −0.3 (11) |
C9—N2—C10—C15 | −0.5 (6) | C6—C1—C2—C3 | 1.4 (8) |
Ag1—N2—C10—C15 | −176.9 (4) | C4—C3—C2—C1 | −1.1 (9) |
N1—C15—C10—N2 | −0.6 (6) | C13—C12—C11—C10 | 0.2 (10) |
C14—C15—C10—N2 | −179.8 (5) | N2—C10—C11—C12 | −179.7 (6) |
N1—C15—C10—C11 | −180.0 (5) | C15—C10—C11—C12 | −0.4 (9) |
C14—C15—C10—C11 | 0.8 (9) | O1—N3—O3—Ag2 | 6.4 (7) |
C1—C6—C7—C5iii | 179.5 (5) | O2—N3—O3—Ag2 | −174.1 (4) |
C5—C6—C7—C5iii | 0.8 (8) | O3ii—Ag2—O3—N3 | 48.3 (4) |
C1—C6—C7—C8 | 1.1 (7) | | |
Symmetry codes: (i) −x+3/2, −y+3/2, −z; (ii) −x+1, y, −z+1/2; (iii) −x+1, −y+1, −z. |
Experimental details
Crystal data |
Chemical formula | [Ag(C30H22N4)][Ag(NO3)2] |
Mr | 778.28 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 24.980 (5), 6.5472 (13), 17.278 (4) |
β (°) | 103.96 (3) |
V (Å3) | 2742.3 (10) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.49 |
Crystal size (mm) | 0.23 × 0.21 × 0.16 |
|
Data collection |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2000) |
Tmin, Tmax | 0.726, 0.797 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10890, 2415, 1697 |
Rint | 0.088 |
(sin θ/λ)max (Å−1) | 0.595 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.061, 0.103, 1.11 |
No. of reflections | 2415 |
No. of parameters | 201 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.70, −0.43 |
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The design and construction of novel metal–organic frameworks (MOFs) based on transition metals and organic spacers are currently attracting considerable attention, because MOFs have intriguing aesthetic structures with wide potential applications, such as molecular magnetism (Marino et al., 2011), heterogeneous catalysis (Malla et al., 2010), gas storage (Lin et al., 2010) and photoluminescence (Pandey et al., 2010). Generally, MOFs are constructed through coordination of metal ions and organic linkers. For the construction of metal complexes, many factors can affect the final crystal structure, such as the structure of the organic ligand, the coordination geometry of the metal ion, the metal–ligand ratio and so on. Secondary interactions such as hydrogen bonding, π–π stacking and host–guest interactions must also be considered.
Flexible ligands have drawn much attention in this area because the flexible spacers allow them to bend or rotate when coordinating to metal centres in order to conform to the coordination geometries of the metal ions. Several N-donor ligands, such as triazole (Klaus & Yassin, 2006), imidazole (Carlucci et al., 2004) and benzimidazole-containing ligands (Zhang et al., 2007), have been synthesized and their coordination polymers show interesting properties. In our previous work, flexible ligands were used to construct various complex structures, including discrete molecules and one-, two- and three-dimensional networks, and their coordination polymers showed interesting fluorescence properties (Du et al., 2008, 2012). In the present work, the title one-dimensional AgI coordination polymer, (I), has been synthesized and its structure is now reported.
The asymmetric unit of (I) contains two crystallographically independent AgI cations, one half of a 9,10-bis(1H-benzimidazol-1-ylmethyl)anthracene ligand (L) and one nitrate anion (Fig. 1). Atom Ag1 occupies a crystallographic inversion centre and is linked by two N-atom donors from two distinct ligands [Ag1—N2 = 2.134 (5) Å] in a bicoordinated linear fashion, creating a polymeric cationic one-dimensional chain (Fig. 2). Each L ligand coordinates to two AgI ions and all ligands are equivalent, adopting trans–gauche conformations. The dihedral angle between the planes of the benzimidazole and anthracene rings is 75.95 (11)°. The Ag—N bond length and the conformation of the ligand are similar to those in AgI complexes of related flexible ligands (Wang et al., 2007). The nearest nonbonding Ag···Ag distance along the polymer is 12.912 (2) Å. Atom Ag2 lies on a crystallographic twofold axis and is linked by two O-atom donors from two nitrate anions to form an [Ag(NO3)2]- counter-ion [Ag2—O3 = 2.356 (5) Å; Fig. 1]. The coordination geometry of Ag2 is distorted from linear [O3—Ag2—O3ii = 146.1 (3)°; symmetry code: (ii) -x + 1, y, -z + 1/2].
Interactions between a cation and the π system of a ligand represent a possible driving force for the building of novel molecular architectures. Several similar complexes have been reported in which Ag–η2-anthracene bonding interactions have been discussed. In anthracene tetrakis(silver perchlorate) monohydrate, for example, a silver–anthracene interaction was reported with Ag—C distances of 2.454 (8) and 2.560 (8) Å (Griffith & Amma, 1974). Discrete mononuclear complexes, [Ag(L1)(ClO4)(C6H6)2] and [Ag2(L2)0.5(C6H6)0.5(CF3SO3)2] (L1 = ???? [Please define] and L2 = 9,10-diphenylanthracene), were synthesized by Munakata and co-workers with Ag—C distances ranging from 2.41 (1) to 2.68 (8) Å (Munakata et al., 1998, 2003). Only one previous example in a coordination polymer was found in the literature, namely {[Ag8(L3)3(l4-hmt)2(H2O)6](ClO4)2}∞ (L3 = anthracene-9,10-dicarboxylate and hmt = hexamethylenetetramine; l4-hmt is what?), with reported Ag—C distances of 2.631 (4) and 2.740 (4) Å (Liu et al., 2008). In (I), the Ag2—C1 and Ag2—C2 distances are 2.727 (6) and 2.765 (6) Å, respectively, similar to the previously reported results. The corresponding distance to the centroid of the C1–C6 aromatic ring is 2.982 Å. Considering these Ag···π interactions, the coordination geometry of Ag2 can be described as a flattened tetrahedron.
Weak Ag···O interactions also exist between the different units (Fig. 2), with the Ag1···O2i distance being 3.124 (5) Å [symmetry code: (i) -x + 1, -y + 1, -z]. Considering these interactions, the coordination geometry of Ag1 resembles a distorted square plane.
The reaction between this bi-benzimidazole ligand [9,10-bis(benzimidazol-1-ylmethyl)anthracene, L] and AgNO3 has been studied previously (Du et al., 2008). It is interesting that the metal–ligand ratio affects the final structure of the complex. When the metal–ligand ratio is 1:1, a discrete binuclear AgI complex is obtained and the ligand adopts a cis conformation. A similar binuclear AgI complex based on a related flexible bi-benzimidizole ligand has also been reported by other researchers (Su et al., 2003). The one-dimensional chain coordination polymer in this present work was synthesized under similar reaction conditions, except that the metal–ligand ratio was changed to 2:1. In the polymer thus formed, the ligand adopts a trans conformation. An additional AgI cation is incorporated in the structure as [Ag(NO3)2]- counter-ions.
In summary, a new polymer with a one-dimensional chain motif has been obtained based on a flexible bi-benzimidazole organic ligand, 9,10-bis(benzimidazol-1-ylmethyl)anthracene, and AgNO3. The metal–ligand ratio during synthesis can affect the self-assembly process and the final structure. Weak Ag···O and Ag···π interactions link the different units into a three-dimensional supramolecular structure.