catena-Poly[[silver(I)-μ-1,1′-methyl­enediimidazole] hexa­fluoridophosphate]

The title compound, {[Ag(C₇H₈N₄)]PF₆}_n, has a one-dimensional zigzag chain structure. The Ag⁺ cation and the PF₆⁻ anion reside on crystallographic inversion centres. The Ag⁺ cation is coordinated by the unsubstituted N atoms of two separate 1,1′-methyl­enediimidazole ligands. The closest Ag...Ag separation in the same cationic chain is 7.704 (2) Å and the dihedral angle between the two imidazole rings in the same ligand is 85.5 (1)°. A two-dimensional layer framework is formed by weak Ag...N inter­actions between adjacent chains, with an Ag...N distance of 3.472 (2) Å.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.036
• wR factor = 0.104
• Data-to-parameter ratio = 14.3

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT242_ALERT_2_B Check Low       Ueq as Compared to Neighbors for         P1

Alert level C
PLAT128_ALERT_4_C Non-standard setting of Space group P2/c    ....    P2/n
PLAT480_ALERT_4_C Long H...A H-Bond Reported H3     ..  F2      ..       2.78 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H3     ..  F3      ..       2.87 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H4A    ..  F2      ..       2.62 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H2     ..  F1      ..       2.81 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H1     ..  F3      ..       2.58 Ang.
PLAT481_ALERT_4_C Long D...A H-Bond Reported C3     ..  F2      ..       3.69 Ang.

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K
PLAT794_ALERT_5_G Check Predicted Bond Valency for Ag1         (9)       1.03

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   7 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   7 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

The construction of solid-state architectures and crystal engineering has become rapidly developing areas of supramolecular chemistry in the past decade (Desiraju, 1995; Batten & Robson, 1998; Leininger et al., 2000; Moulton & Zaworotko, 2001). Such molecular architectures have been successfully designed and synthesized by judicious combination of a metal 'node' and an organic ligand 'spacer'. The roles of counter anions and different solvent molecules are also of significant effect on supramolecular self-assembly. More recently, the molecular geometry and flexibility of multidentate N-donor spacer ligands play key roles in the development of the tailor-made molecular materials and supramolecular self-assemble crystal engineering. For example, 4, 4'-bipyridine, 1, 2-bis(4-pyridyl)ethane and trans-bis(4-pyridyl)ethene as ligands can form a lot of coordination polymers with different structure features (Barnett & Champness, 2003; Pschirer et al., 2002). The coordination polymer frameworks which were built by methylene C-bridged bipyridine, bitriazole and bipyrazole ligands have also been described widely (Lobbia et al., 2002; Hamilton & Ziegler, 2004). Bis(imidazol-1-yl)-methane (BIM) is flexibility V-shaped N-donor ligand which was built by methylene C-bridged two imidazole rings. The title compound, [Ag(BIM)PF₆]_n, (I), with a one-dimensional zigzag cationic chain structural motifs, was formed by the addition of a solution of BIM to AgPF₆.

Single crystal X-ray diffraction analysis reveals that complex (I) consist of one dimensional cationic polymeric chains and uncoordinated PF₆^-. The Ag^I ion occupies a crystallographic inversion centre and is coordinated by two imidazolyl nitrogen atoms of independent BIM ligands, which act as bridges between silver(I) centers, generated one dimensional zigzag cationic chain polymeric structure (Fig.1). Ag^I ion is a linear coordination mode with the bond angles of N—Ag—N being 180.0 (1)°, and the bond lengths of Ag—N is 2.097 (3) Å. The adjacent Ag······Ag distance in the same cationic chain is 7.704 (2)Å and the dihedral angle of the two imidazole rings in the same ligand is 85.5 (1)°. The two-dimensional layer network was built by weak interactions between Ag^I ion and two nitrogen atoms from imidazole rings in the adjacent one-dimensional zigzag chain with the distance of Ag—N being 3.472 (2)Å (Fig. 2). The non-coordinated PF₆^- anions were filled in the void of each zigzag cationic chain through the weak C—H······F hydrogen-bond interactions (Table 1).

Related literature

For related literature, see: Barnett & Champness (2003); Batten & Robson (1998); Desiraju (1995); Hamilton & Ziegler (2004); Moulton & Zaworotko (2001); Leininger et al. (2000); Lobbia et al. (2002); Pschirer et al. (2002).

S2. Experimental

An acetone solution (5 ml) of BIM (74 mg, 0.5 mmol) was slowly diffused into an aqueous solution (5 ml) of AgPF₆(126 mg, 0.5 mmol) in test tube. Colorless crystals of [Ag(BIM) PF₆]_n were formed at the interface of solvent in two weeks and were obtained in 82% yield. Anal. Calcd for C₇H₈AgF₆N₄P: C, 20.97; H, 2.01; N, 13.97; Found (%): C, 21.04; H, 2.49; N, 13.92; IR (KBr, cm^-1): ν = 3150 s, 3114w, 3038w, 1712w, 1614w, 1530 s, 1411m, 1377w, 1355w, 1339w, 1291m, 1243 s, 1116 s, 1031w, 835 s, 747 s, 713w, 652m, 613w, 560 s.

S3. Refinement

H atoms were positioned geometrically at distances of 0.93 (CH), 0.97 (CH₂) and 0.96Å (CH₃) from the parent C atoms, a riding model was used during the refinement process. The U_iso values were constrained to be 1.2U_eq of the carrier atom, except for methyl H atoms that were constrained to 1.5Ueq of the C atom.

Computing details

Data collection: SMART, (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL (Bruker, 2001.

Figures

	Fig. 1. The structure of (I) showing the atom-numbering of unsymmetry unit. Displacement ellipsoids are drawn at the 50% probability level. H atoms have been omitted for clarity. [Symmetry codes: (A) -x + 2, -y, -z + 1.]
	Fig. 2. Two-dimensional layer structure assembled by one-dimensional zigzag chains with weak Ag······N interactions.

catena-Poly[[silver(I)-µ-1,1'-methylenediimidazole] hexafluoridophosphate]

Crystal data

[Ag(C7H8N4)]PF6	F(000) = 388
Mr = 401.01	Dx = 2.264 Mg m^−3
Monoclinic, P2/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yac	Cell parameters from 1730 reflections
a = 8.3966 (10) Å	θ = 5.5–56.3°
b = 5.1604 (6) Å	µ = 1.92 mm^−1
c = 13.6211 (16) Å	T = 293 K
β = 94.666 (2)°	Prismatic, colorless
V = 588.24 (12) Å^3	0.23 × 0.15 × 0.12 mm
Z = 2

Data collection

SMART APEX-CCD diffractometer	1285 independent reflections
Radiation source: fine-focus sealed tube	1073 reflections with > 2s˘I)
Graphite monochromator	Rint = 0.080
phi and ω scans	θmax = 27.0°, θmin = 2.8°
Absorption correction: multi-scan SADABS (Sheldrick, 1996)	h = −10→10
Tmin = 0.596, Tmax = 0.793	k = −6→6
3264 measured reflections	l = −17→8

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.104	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0602P)^2 + 0.0221P] where P = (Fo^2 + 2Fc^2)/3
1285 reflections	(Δ/σ)max = 0.003
90 parameters	Δρmax = 0.81 e Å^−3
0 restraints	Δρmin = −0.62 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Ag1	1.0000	0.0000	0.5000	0.0467 (2)
P1	0.5000	0.0000	0.5000	0.0395 (3)
F1	0.6294 (4)	0.1949 (7)	0.5436 (2)	0.0925 (11)
F2	0.4980 (3)	0.1377 (6)	0.39578 (17)	0.0719 (7)
F3	0.3615 (4)	0.1824 (7)	0.5298 (2)	0.0900 (10)
N1	0.9785 (3)	0.3049 (5)	0.39798 (19)	0.0421 (6)
N2	0.8717 (3)	0.6069 (5)	0.30233 (19)	0.0356 (6)
C1	0.8469 (4)	0.4306 (7)	0.3711 (3)	0.0397 (7)
H1	0.7490	0.4010	0.3965	0.048*
C2	1.0280 (4)	0.5957 (9)	0.2850 (3)	0.0547 (9)
H2	1.0798	0.6969	0.2410	0.066*
C3	1.0936 (4)	0.4092 (10)	0.3443 (3)	0.0592 (10)
H3	1.2003	0.3590	0.3482	0.071*
C4	0.7500	0.7683 (8)	0.2500	0.0403 (10)
H4A	0.7007	0.8786	0.2966	0.048*	0.50
H4B	0.7993	0.8786	0.2034	0.048*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ag1	0.0582 (3)	0.0379 (3)	0.0419 (3)	0.00042 (13)	−0.00903 (18)	0.00663 (14)
P1	0.0398 (7)	0.0396 (7)	0.0398 (7)	0.0011 (4)	0.0072 (5)	−0.0004 (5)
F1	0.104 (2)	0.103 (2)	0.088 (2)	−0.0565 (19)	−0.0051 (18)	−0.0118 (19)
F2	0.0843 (17)	0.0799 (19)	0.0524 (13)	0.0033 (13)	0.0112 (12)	0.0182 (13)
F3	0.103 (2)	0.101 (2)	0.086 (2)	0.0592 (18)	0.0278 (17)	0.0008 (19)
N1	0.0489 (14)	0.0392 (14)	0.0367 (14)	0.0002 (11)	−0.0051 (11)	0.0052 (12)
N2	0.0402 (13)	0.0338 (13)	0.0321 (13)	−0.0031 (10)	−0.0006 (10)	0.0002 (11)
C1	0.0439 (17)	0.0339 (14)	0.0411 (18)	−0.0017 (13)	0.0025 (14)	0.0024 (14)
C2	0.0441 (18)	0.072 (2)	0.049 (2)	−0.0050 (18)	0.0074 (16)	0.023 (2)
C3	0.0408 (18)	0.076 (2)	0.061 (2)	0.0030 (19)	0.0024 (17)	0.015 (2)
C4	0.050 (2)	0.029 (2)	0.041 (2)	0.000	−0.0025 (19)	0.000

Geometric parameters (Å, º)

Ag1—N1^i	2.097 (3)	N2—C1	1.334 (5)
Ag1—N1	2.097 (3)	N2—C2	1.354 (4)
P1—F1	1.562 (2)	N2—C4	1.459 (3)
P1—F1^ii	1.562 (2)	C1—H1	0.9300
P1—F3	1.575 (2)	C2—C3	1.345 (6)
P1—F3^ii	1.575 (2)	C2—H2	0.9300
P1—F2	1.586 (2)	C3—H3	0.9300
P1—F2^ii	1.586 (2)	C4—N2^iii	1.459 (3)
N1—C1	1.308 (4)	C4—H4A	0.9700
N1—C3	1.369 (5)	C4—H4B	0.9700
N1^i—Ag1—N1	180.000 (1)	C1—N2—C2	107.6 (3)
F1—P1—F1^ii	180.00 (18)	C1—N2—C4	126.1 (2)
F1—P1—F3	91.3 (2)	C2—N2—C4	126.2 (3)
F1^ii—P1—F3	88.7 (2)	N1—C1—N2	111.0 (3)
F1—P1—F3^ii	88.7 (2)	N1—C1—H1	124.5
F1^ii—P1—F3^ii	91.3 (2)	N2—C1—H1	124.5
F3—P1—F3^ii	180.0 (2)	C3—C2—N2	106.4 (3)
F1—P1—F2	90.48 (15)	C3—C2—H2	126.8
F1^ii—P1—F2	89.52 (15)	N2—C2—H2	126.8
F3—P1—F2	90.52 (15)	C2—C3—N1	109.2 (3)
F3^ii—P1—F2	89.48 (15)	C2—C3—H3	125.4
F1—P1—F2^ii	89.52 (15)	N1—C3—H3	125.4
F1^ii—P1—F2^ii	90.48 (15)	N2^iii—C4—N2	110.4 (3)
F3—P1—F2^ii	89.48 (15)	N2^iii—C4—H4A	109.6
F3^ii—P1—F2^ii	90.52 (15)	N2—C4—H4A	109.6
F2—P1—F2^ii	180.000 (1)	N2^iii—C4—H4B	109.6
C1—N1—C3	105.8 (3)	N2—C4—H4B	109.6
C1—N1—Ag1	125.7 (2)	H4A—C4—H4B	108.1
C3—N1—Ag1	128.5 (2)
C3—N1—C1—N2	0.8 (4)	N2—C2—C3—N1	0.1 (6)
Ag1—N1—C1—N2	−177.7 (2)	C1—N1—C3—C2	−0.5 (5)
C2—N2—C1—N1	−0.7 (4)	Ag1—N1—C3—C2	177.8 (3)
C4—N2—C1—N1	175.0 (3)	C1—N2—C4—N2^iii	−58.6 (3)
C1—N2—C2—C3	0.4 (5)	C2—N2—C4—N2^iii	116.4 (4)
C4—N2—C2—C3	−175.4 (4)

Symmetry codes: (i) −x+2, −y, −z+1; (ii) −x+1, −y, −z+1; (iii) −x+3/2, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···F2^iv	0.93	2.78	3.687 (5)	167
C3—H3···F3^iv	0.93	2.87	3.448 (5)	122
C4—H4A···F2^v	0.97	2.62	3.569 (4)	165
C4—H4A···F3^vi	0.97	2.48	3.224 (3)	133
C2—H2···F1^vii	0.93	2.81	3.628 (5)	148
C1—H1···F3^vi	0.93	2.58	3.043 (4)	111

Symmetry codes: (iv) x+1, y, z; (v) x, y+1, z; (vi) −x+1, −y+1, −z+1; (vii) x+1/2, −y+1, z−1/2.