Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S2053229615020288/fm3029sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S2053229615020288/fm3029Isup2.hkl |
CCDC reference: 1433351
The design and synthesis of metal coordination and supramolecular frameworks containing N-donor ligands and dicyanidoargentate ligands is currently an active area of research due to their potential applications in the fields of molecular magnetism (Xie et al., 2010), catalysis (Ma et al., 2009), nonlinear optics (Zang et al., 2006) and luminescence (Mao et al., 2014). The design and synthesis of extended frameworks via supramolecular interactions represent an area of considerable interest (Hogan et al., 2011; Cook et al., 2013). In particular, hydrogen bonding, π–π stacking and van der Waals interactions have been exploited for molecular recognition associated with biological activity and for the engineering of molecular solids (Hogan et al., 2011; Cook et al., 2013). In the present work, a new two-dimensional supramolecular framework of the one-dimensional chain compound [Ag(CN)(5,5'-dmbpy)]n (5,5'-dmbpy is 5,5'-dimethyl-2,2'-bipyridine), (I), was synthesized successfully, structurally characterized and compared with the structures of other relevant compounds.
Compound (I) was synthesized by the reaction of two aqueous solutions at room temperature, one containing a mixture of (NH4)2Fe(SO4)2.H2O (0.10 mmol, 98 mg) and 5,5'-dmbpy (0.2 mmol, 92 mg) in water (10 ml), and the other containing K[Ag(CN)2] (0.5 mmol, 10.6 mg) in water (5 ml). After 3 d, brown crystals of (I) were obtained; the yield based on Ag was about 71%.
Crystal data, data collection and structure refinement details are summarized in Table 1. C-bound H atoms were positioned geometrically, with C—H = 0.93 (aromatic) or 0.96 Å (methyl), and included as riding atoms, with Uiso(H) = 1.5Ueq(C) for methyl groups and 1.2Ueq(C) otherwise. The C and N atoms of the cyanide group are substitutionally disordered (N1 and C1), with site occupancies of 0.5. Thus, these atoms were modelled as C/N composites. DFIX, ISOR, and EADP commands were used in the refinement of the substitutionally disordered cyanide ligand [Please describe what the commands actually do rather than giving program-specific instructions], with a fixed C—N distance of 1.12 (1) Å (Bowmaker et al., 2004).
In the IR spectrum of (I), a sharp ν(CN) band of medium intensity is observed at 2134 cm-1, and a band of K[Ag(CN)2] appears at 2140 cm-1. The appearance of this band confirms the presence of the cyanide group in the structure. The ν(C═C) vibration of 5,5'-dmbpy is observed at 1481 cm-1. Weak signals in the region of 3123–2921 cm-1 due to C—H stretching of 5,5'-dmbpy are also observed. Two sharp bands of medium intensity are observed at 2038 and 833 cm-1 due to the pyridine ring of 5,5'-dmbpy.
The results of the single-crystal X-ray analysis are consistent with the formulation of (I) as [(AgCN)(5,5'-dmbpy)]n with an Ag–CN–5,5'-dmbpy stoichiometric ratio of 1:1:1. It crystallizes in the monoclinic space group C2/c with the AgI cation on an inversion centre, a disordered cyanide ligand and half a molecule of 5,5'-dmbpy in the asymmetric unit (Table 2).
Each AgI cation exhibits a distorted tetrahedral geometry; the coordination environment comprises one C(N) atom and one N(C) atom from disordered cyanide groups, and two N atoms from a bidentate-chelating 5,5'-dmbpy ligand (Fig. 1), with the twist angle between the two bpy rings being 26.62 (9)° and the N1—Ag1—N1ii bite angle being 68.13 (10)° [symmetry code: (ii) -x, y, -z + 1/2]. The cyanide group exhibits substitutional disorder with site occupancies of 0.5 for the C and N atoms, and links adjacent AgI cations, generating a one-dimensional zigzag chain (Fig. 2) with an Ag1i···Ag1···Ag1iv angle of 132.427 (2)° and an Ag···Agi separation of 5.4161 (9) Å [symmetry codes: (i) [Please complete]; (iv) [Please complete]].
These chains are linked together via a weak nonclassical intermolecular C—H···π interaction between the methyl group (C7—H7C) and the aromatic ring of an adjacent 5,5'-dmbpy ligand (Cg4v), with a C7—H7C···Cg4v distance of 2.89 Å (Table 3) and a strong interchain face-to-face π–π interaction between adjacent aromatic rings of 5,5'-dmbpy ligands (Cg4), with a Cg4···Cg4iv distance of 3.722 (17) Å (Table 4), generating a two-dimensional supramolecular network, as shown in Fig. 3.
Cyanidometallates, such as [Fe(CN)6]3- (Nayak et al., 2006), [Ni(CN)4]2- (Akitsu et al., 2008), [Pd(CN)4]2- (Manna et al., 2007), [Au(CN)2]- (Katz et al., 2008) and [Ag(CN)2]- (Ahmad et al., 2007; Zhang et al., 2006), have been used extensively as the design elements in supramolecular coordination systems, where they can act as multidentate ligands linking numerous metal centres together to form stable and high-dimensional coordination polymers with transition metal cations.
Following this approach, the combination of metal(II) ions, [Ag(CN)2]- groups and N-donor ligands has produced metal–organic frameworks (MOFs) with different topologies and interesting properties (Agustí et al., 2008). Listed here are important studies related to the present compound system: the spin-crossover three-dimensional coordination framework of [Fe(pmd)2{Ag(CN)2}2]n (pmd is pyrimidine; Rodríguez-Velamazán et al., 2014), a novel silver complex, [Ag5(CN)5(bipy)2]n, with a one-dimensional architecture constructed through a ligand-unsupported argentophilic interaction (Liu et al., 2006), the one-dimensional chain structure of [Cu(en)2Ag2(CN)4] (Černák et al., 1998) exhibiting magnetic properties, the quasi-linear chain of {[Zn(en)2NCAgCN][Ag(CN)2]}n (en is 1,2-diaminoethane; Kappenstein et al., 1988), and some adducts of silver(I) cyanide and (oligo-)pyridine bases with a one-dimensional polymeric zigzag chain, {[LAg2(CN)2][Ag2(CN)2]2[L(py)Ag2(CN)2]}n and [(bpy)Ag(CN)]n (L is 2,2':6',2''-terpyridine, bpy is 2,2'-bipyridine and py is pyridine; Bowmaker et al., 2004). In addition, two multiple-layer heterometallic MnII–AgI coordination polymers, namely [Mn(ampyz)(H2O){Ag2(CN)3}{Ag(CN)2}(ampyz)]n (ampyz is 2-aminopyrazine) and {[Mn(benzim)2{Ag(CN)2}2][(benzim)Ag(CN)].H2O}n (benzim is benzimidazole) were observed (Wannarit et al., 2012), with an additional tricyanidodiargentate group in the former and an additional monocyanidoargentate group in the latter. However, mononuclear compounds have also been observed, viz. [Cd{Ag(CN)2}2(5,5'-dmbpy)2] (Piromchom et al., 2013) and [Cu(imidazole)4{Ag(CN)2}2] (Ahmad et al., 2012), and these molecular units are self-assembled via supramolecular interactions (hydrogen bonding, π–π and Ag···Ag), generating three-dimensional supramolecular networks. With the iron(II) salt in the synthesis of (I), a novel one-dimensional chain structure containing only a monocyanidoargentate group and an N-donor bidentate-chelating ligand was observed.
To investigate the thermal stability of (I), thermogravimetric analysis (TGA) was carried out under a nitrogen atmosphere (Fig. 4). The TGA curve shows a weight loss of 57.03% in the temperature range 553–803 K, corresponding to the loss of one 5,5'-dmbpy (calculated 57.87%). The framework collapses on further heating. The phase purity of the bulk as-synthesized sample of (I) was examined by powder X-ray diffraction (PXRD). All peaks from the experimental PXRD trace match well with those from the simulated PXRD pattern, indicating reasonable crystalline phase purity (Fig. 5).
Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
[Ag(CN)(C12H12N2)] | F(000) = 632 |
Mr = 318.13 | Dx = 1.727 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
a = 15.464 (2) Å | Cell parameters from 8541 reflections |
b = 8.663 (1) Å | θ = 2.8–28.3° |
c = 9.912 (2) Å | µ = 1.63 mm−1 |
β = 112.832 (2)° | T = 293 K |
V = 1223.8 (3) Å3 | Block, colourless |
Z = 4 | 0.25 × 0.15 × 0.09 mm |
Bruker APEX CCD area-detector diffractometer | 1525 independent reflections |
Radiation source: fine-focus sealed tube | 1395 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.017 |
φ and ω scans | θmax = 28.3°, θmin = 2.8° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2000) | h = −20→20 |
Tmin = 0.748, Tmax = 0.865 | k = −11→11 |
8245 measured reflections | l = −13→13 |
Refinement on F2 | 7 restraints |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.029 | H-atom parameters constrained |
wR(F2) = 0.071 | w = 1/[σ2(Fo2) + (0.0262P)2 + 2.5229P] where P = (Fo2 + 2Fc2)/3 |
S = 1.14 | (Δ/σ)max < 0.001 |
1525 reflections | Δρmax = 0.89 e Å−3 |
82 parameters | Δρmin = −0.70 e Å−3 |
[Ag(CN)(C12H12N2)] | V = 1223.8 (3) Å3 |
Mr = 318.13 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 15.464 (2) Å | µ = 1.63 mm−1 |
b = 8.663 (1) Å | T = 293 K |
c = 9.912 (2) Å | 0.25 × 0.15 × 0.09 mm |
β = 112.832 (2)° |
Bruker APEX CCD area-detector diffractometer | 1525 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2000) | 1395 reflections with I > 2σ(I) |
Tmin = 0.748, Tmax = 0.865 | Rint = 0.017 |
8245 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | 7 restraints |
wR(F2) = 0.071 | H-atom parameters constrained |
S = 1.14 | Δρmax = 0.89 e Å−3 |
1525 reflections | Δρmin = −0.70 e Å−3 |
82 parameters |
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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Ag1 | 0.0000 | 0.37392 (4) | 0.2500 | 0.04983 (12) | |
N2 | 0.0135 (9) | 0.523 (3) | −0.041 (2) | 0.041 (2) | 0.5 |
C1 | 0.0105 (12) | 0.473 (3) | 0.061 (3) | 0.041 (2) | 0.5 |
N1 | −0.08214 (15) | 0.1388 (2) | 0.2735 (2) | 0.0385 (4) | |
C2 | −0.15096 (19) | 0.1412 (3) | 0.3238 (3) | 0.0434 (6) | |
H2A | −0.1811 | 0.2347 | 0.3212 | 0.052* | |
C3 | −0.18042 (18) | 0.0141 (3) | 0.3794 (3) | 0.0442 (6) | |
C4 | −0.1333 (2) | −0.1224 (3) | 0.3851 (3) | 0.0485 (6) | |
H4A | −0.1497 | −0.2107 | 0.4230 | 0.058* | |
C5 | −0.0618 (2) | −0.1278 (3) | 0.3343 (3) | 0.0449 (6) | |
H5A | −0.0298 | −0.2196 | 0.3380 | 0.054* | |
C6 | −0.03821 (16) | 0.0043 (3) | 0.2780 (3) | 0.0350 (5) | |
C7 | −0.2595 (2) | 0.0266 (5) | 0.4316 (4) | 0.0627 (8) | |
H7A | −0.2893 | −0.0722 | 0.4233 | 0.094* | |
H7B | −0.3045 | 0.1007 | 0.3728 | 0.094* | |
H7C | −0.2351 | 0.0592 | 0.5321 | 0.094* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ag1 | 0.05559 (19) | 0.04347 (17) | 0.0614 (2) | 0.000 | 0.03473 (15) | 0.000 |
N2 | 0.043 (6) | 0.0368 (16) | 0.044 (5) | 0.003 (5) | 0.017 (5) | −0.001 (3) |
C1 | 0.043 (6) | 0.0368 (16) | 0.044 (5) | 0.003 (5) | 0.017 (5) | −0.001 (3) |
N1 | 0.0439 (11) | 0.0333 (10) | 0.0424 (10) | 0.0019 (8) | 0.0211 (9) | 0.0025 (8) |
C2 | 0.0437 (13) | 0.0420 (14) | 0.0487 (14) | 0.0023 (11) | 0.0226 (11) | 0.0027 (11) |
C3 | 0.0384 (12) | 0.0547 (16) | 0.0388 (12) | −0.0075 (11) | 0.0143 (10) | 0.0026 (11) |
C4 | 0.0486 (14) | 0.0456 (14) | 0.0495 (14) | −0.0099 (12) | 0.0172 (12) | 0.0099 (12) |
C5 | 0.0468 (14) | 0.0341 (12) | 0.0513 (14) | −0.0024 (11) | 0.0163 (11) | 0.0048 (11) |
C6 | 0.0363 (11) | 0.0312 (11) | 0.0350 (11) | −0.0009 (9) | 0.0111 (9) | 0.0007 (9) |
C7 | 0.0503 (16) | 0.080 (2) | 0.0669 (19) | −0.0075 (16) | 0.0333 (15) | 0.0062 (17) |
Ag1—C1i | 2.12 (3) | C2—H2A | 0.9300 |
Ag1—C1 | 2.12 (3) | C3—C4 | 1.378 (4) |
Ag1—N2ii | 2.19 (2) | C3—C7 | 1.505 (4) |
Ag1—N2iii | 2.19 (2) | C4—C5 | 1.382 (4) |
Ag1—N1i | 2.459 (2) | C4—H4A | 0.9300 |
Ag1—N1 | 2.459 (2) | C5—C6 | 1.383 (3) |
N2—C1 | 1.123 (6) | C5—H5A | 0.9300 |
N2—N2iii | 1.13 (4) | C6—C6i | 1.488 (5) |
N2—Ag1iii | 2.19 (2) | C7—H7A | 0.9600 |
C1—C1iii | 1.22 (5) | C7—H7B | 0.9600 |
N1—C2 | 1.339 (3) | C7—H7C | 0.9600 |
N1—C6 | 1.341 (3) | Ag1—Ag1iii | 5.4161 (11) |
C2—C3 | 1.385 (4) | ||
C1i—Ag1—C1 | 132.1 (16) | C4—C3—C2 | 116.6 (2) |
N2ii—Ag1—N2iii | 131.6 (13) | C4—C3—C7 | 122.3 (3) |
C1i—Ag1—N1i | 129.7 (7) | C2—C3—C7 | 121.1 (3) |
C1—Ag1—N1i | 92.0 (7) | C3—C4—C5 | 120.0 (2) |
N2ii—Ag1—N1 | 96.4 (6) | C3—C4—H4A | 120.0 |
N2iii—Ag1—N1i | 96.5 (6) | C5—C4—H4A | 120.0 |
C1i—Ag1—N1 | 92.0 (7) | C4—C5—C6 | 119.5 (3) |
C1—Ag1—N1 | 129.7 (7) | C4—C5—H5A | 120.3 |
N2ii—Ag1—N1 | 96.5 (6) | C6—C5—H5A | 120.3 |
N2iii—Ag1—N1 | 124.4 (5) | N1—C6—C5 | 121.5 (2) |
N1i—Ag1—N1 | 68.13 (10) | N1—C6—C6i | 116.94 (14) |
C1—N2—Ag1iii | 172.5 (4) | C5—C6—C6i | 121.52 (16) |
N2iii—N2—Ag1iii | 154.9 (15) | C3—C7—H7A | 109.5 |
N2—C1—Ag1 | 177.5 (10) | C3—C7—H7B | 109.5 |
C1iii—C1—Ag1 | 162 (2) | H7A—C7—H7B | 109.5 |
C2—N1—C6 | 117.8 (2) | C3—C7—H7C | 109.5 |
C2—N1—Ag1 | 122.45 (17) | H7A—C7—H7C | 109.5 |
C6—N1—Ag1 | 116.70 (16) | H7B—C7—H7C | 109.5 |
N1—C2—C3 | 124.6 (3) | C1i—Ag1—N2iii | 131.1 |
N1—C2—H2A | 117.7 | Ag1iii—Ag1—Ag1iv | 132.43 (2) |
C3—C2—H2A | 117.7 |
Symmetry codes: (i) −x, y, −z+1/2; (ii) x, −y+1, z+1/2; (iii) −x, −y+1, −z; (iv) −x, −y+1, −z+1. |
Cg4 is the centroid of the N1/C2–C6 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C7—H7C···Cg4v | 0.96 | 2.89 | 3.734 (2) | 146 |
Symmetry code: (v) x, −y, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | [Ag(CN)(C12H12N2)] |
Mr | 318.13 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 15.464 (2), 8.663 (1), 9.912 (2) |
β (°) | 112.832 (2) |
V (Å3) | 1223.8 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.63 |
Crystal size (mm) | 0.25 × 0.15 × 0.09 |
Data collection | |
Diffractometer | Bruker APEX CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2000) |
Tmin, Tmax | 0.748, 0.865 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8245, 1525, 1395 |
Rint | 0.017 |
(sin θ/λ)max (Å−1) | 0.667 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.071, 1.14 |
No. of reflections | 1525 |
No. of parameters | 82 |
No. of restraints | 7 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.89, −0.70 |
Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2003), SHELXS97 (Sheldrick, 2008), SHELXL2014 (Sheldrick, 2015), SHELXTL (Sheldrick, 2008).
Ag1—C1 | 2.12 (3) | Ag1—N1ii | 2.459 (2) |
Ag1—N2i | 2.19 (2) | Ag1—Ag1i | 5.4161 (11) |
N2iii—Ag1—N1 | 96.4 (6) | N1ii—Ag1—N1 | 68.13 (10) |
N2i—Ag1—N1ii | 96.5 (6) | C1ii—Ag1—N2i | 131.1 |
C1ii—Ag1—N1 | 92.0 (7) | Ag1i—Ag1—Ag1iv | 132.43 (2) |
Symmetry codes: (i) −x, −y+1, −z; (ii) −x, y, −z+1/2; (iii) x, −y+1, z+1/2; (iv) −x, −y+1, −z+1. |
Cg4 is the centroid of the N1/C2–C6 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C7—H7C···Cg4v | 0.96 | 2.89 | 3.734 (2) | 146 |
Symmetry code: (v) x, −y, z+1/2. |
CCD is the centre-to-centre distance (distance between ring centroids), IPD is the mean interplanar distance (perpendicular distance from one plane to the neighbouring centroid) and SA is the mean slippage angle (angle subtended by the intercentroid vector to the plane normal); for details, see Janiak (2000). Cg4 is the centroid of the N1/C2–C6 ring. |
Group1/group2 | CCD (Å) | SA (°) | IPD (Å) |
Cg4···Cg4iv | 3.722 (17) | 20.0 | 3.4984 (10) |
Symmetry codes: (iv) -x, -y, -z + 1. |