supplementary materials
catena-Poly[tetramethylammonium [argentate(I)-di-![[mu]](/logos/entities/mu_rmgif.gif)
-bromido]]
The title compound, {(C4H12N)[AgBr2]}n, is isomorphous with its chloride analogue [Helgesson, Josefsson & Jagner (1988). Acta Cryst. C44, 1729-1731]. It displays a one-dimensional ![[infinity]](/logos/entities/infin_rmgif.gif)
1[Ag2Br4]n2n- anionic chain structure accompanied by isolated tetramethylammonium cations. All the crystallographically independent non-H atoms lie on special positions, namely Ag on 2mm, Br on mm2 or m2m, N on mm2, and C on sites of symmetry ma or mb. The tetramethylammonium cations reside between these anionic chains, with weak C-H
Br hydrogen-bonding interactions forming a layer perpendicular to the c axis; these layers stack together along the c direction merely by van der Waals forces.
A mixture of AgCN (238 mg, 1.8 mmol) and Me4NBr (139 mg, 0.9 mmol) in 10 ml of dry and distilled acetonitrile was sealed into a 25 ml polytetrafluoroethylene-lined stainless steel containers under autogenous pressure and heated at 120 °C for 3 days, followed by cooling to room temperature. The resulted solution was filtered in a small tube, which was loaded into a large vial containing 5 ml diethyl ether. The large vial was sealed and left undisturbed at room temperature, and colourless crystals of the title complex were obtained in 7 days. Yield: 40%. Calc. for C8H24Ag2Br4N2: C, 14.05; H, 3.54; N, 4.10; Found: C, 14.12; H, 3.60; N, 4.02.
Methyl H atoms were added geometrically and allowed to ride on their respective parent carbon atoms (C—H = 0.96 Å and Uiso(H) = 1.5Ueq(C)). The groups were also allowed to rotate around the N—C vector.
Data collection: CrystalClear (Rigaku, 2002); cell refinement: CrystalClear (Rigaku, 2002); data reduction: CrystalClear (Rigaku, 2002); program(s) used to solve structure: SHELXTL (Siemens, 1994); program(s) used to refine structure: SHELXTL (Siemens, 1994); molecular graphics: SHELXTL (Siemens, 1994) and ORTEP (Johnson, 1976); software used to prepare material for publication: SHELXTL (Siemens, 1994).
catena-Poly[tetramethylammonium [argentate(I)-di-µ-bromido]]
top
Crystal data top
| (C4H12N)[AgBr2] | F000 = 640 |
| Mr = 341.84 | Dx = 2.429 Mg m−3 |
| Orthorhombic, Immm | Mo Kα radiation
λ = 0.71073 Å |
| Hall symbol: -I 2 2 | Cell parameters from 972 reflections |
| a = 6.7817 (9) Å | θ = 3.3–27.5º |
| b = 9.1535 (14) Å | µ = 10.63 mm−1 |
| c = 15.057 (2) Å | T = 293 (2) K |
| V = 934.7 (2) Å3 | Prism, colourless |
| Z = 4 | 0.20 × 0.20 × 0.16 mm |
Data collection top
Rigaku Mercury CCD
diffractometer | 494 independent reflections |
| Radiation source: rotating-anode generator | 459 reflections with I > 2σ(I) |
| Monochromator: graphite | Rint = 0.031 |
| T = 293(2) K | θmax = 25.0º |
| ω scans | θmin = 3.3º |
Absorption correction: multi-scan
(SPHERE in CrystalClear; Rigaku, 2002) | h = −8→8 |
| Tmin = 0.13, Tmax = 0.18 | k = −10→10 |
| 2952 measured reflections | l = −9→17 |
Refinement top
| Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
| Least-squares matrix: full | H-atom parameters constrained |
| R[F2 > 2σ(F2)] = 0.030 | w = 1/[σ2(Fo2) + (0.0315P)2 + 4.8P]
where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 0.068 | (Δ/σ)max < 0.001 |
| S = 1.00 | Δρmax = 0.65 e Å−3 |
| 494 reflections | Δρmin = −0.77 e Å−3 |
| 30 parameters | Extinction correction: SHELXTL (Siemens, 1994), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.00064 (14) |
| Secondary atom site location: difference Fourier map | |
Crystal data top
| (C4H12N)[AgBr2] | V = 934.7 (2) Å3 |
| Mr = 341.84 | Z = 4 |
| Orthorhombic, Immm | Mo Kα |
| a = 6.7817 (9) Å | µ = 10.63 mm−1 |
| b = 9.1535 (14) Å | T = 293 (2) K |
| c = 15.057 (2) Å | 0.20 × 0.20 × 0.16 mm |
Data collection top
Rigaku Mercury CCD
diffractometer | 494 independent reflections |
Absorption correction: multi-scan
(SPHERE in CrystalClear; Rigaku, 2002) | 459 reflections with I > 2σ(I) |
| Tmin = 0.13, Tmax = 0.18 | Rint = 0.031 |
| 2952 measured reflections | |
Refinement top
| R[F2 > 2σ(F2)] = 0.030 | 30 parameters |
| wR(F2) = 0.068 | H-atom parameters constrained |
| S = 1.00 | Δρmax = 0.65 e Å−3 |
| 494 reflections | Δρmin = −0.77 e Å−3 |
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 | Occ. (<1) |
| Ag1 | 0.26353 (6) | 0.5000 | 0.5000 | 0.05861 (12) | |
| Br1 | 0.0000 | 0.5000 | 0.36364 (3) | 0.05356 (14) | |
| Br2 | 0.5000 | 0.26262 (5) | 0.5000 | 0.05680 (15) | |
| N1 | 0.5000 | 0.5000 | 0.1917 (3) | 0.0490 (11) | |
| C1 | 0.3206 (6) | 0.5000 | 0.1370 (3) | 0.121 (2) | |
| H1A | 0.3205 | 0.4156 | 0.0992 | 0.181* | 0.50 |
| H1B | 0.3174 | 0.5868 | 0.1013 | 0.181* | 0.50 |
| H1C | 0.2067 | 0.4976 | 0.1748 | 0.181* | |
| C2 | 0.5000 | 0.6304 (4) | 0.2516 (3) | 0.0781 (14) | |
| H2A | 0.6152 | 0.6282 | 0.2887 | 0.117* | 0.50 |
| H2B | 0.3840 | 0.6288 | 0.2882 | 0.117* | 0.50 |
| H2C | 0.5008 | 0.7179 | 0.2165 | 0.117* | |
Atomic displacement parameters (Å2) top| | U11 | U22 | U33 | U12 | U13 | U23 |
| Ag1 | 0.0521 (2) | 0.0711 (2) | 0.0526 (2) | 0.000 | 0.000 | 0.000 |
| Br1 | 0.0402 (2) | 0.0777 (3) | 0.0428 (2) | 0.000 | 0.000 | 0.000 |
| Br2 | 0.0566 (3) | 0.0474 (3) | 0.0664 (3) | 0.000 | 0.000 | 0.000 |
| N1 | 0.0416 (19) | 0.061 (2) | 0.044 (2) | 0.000 | 0.000 | 0.000 |
| C1 | 0.064 (3) | 0.224 (7) | 0.073 (3) | 0.000 | −0.035 (2) | 0.000 |
| C2 | 0.072 (2) | 0.051 (2) | 0.111 (3) | 0.000 | 0.000 | −0.005 (2) |
Geometric parameters (Å, °) top
| Ag1—Br2i | 2.7006 (5) | N1—C2iii | 1.496 (5) |
| Ag1—Br2 | 2.7006 (5) | C1—H1A | 0.9600 |
| Ag1—Br1 | 2.7221 (5) | C1—H1B | 0.9600 |
| Ag1—Br1ii | 2.7221 (5) | C1—H1C | 0.9600 |
| N1—C1 | 1.470 (5) | C2—H2A | 0.9600 |
| N1—C1iii | 1.470 (5) | C2—H2B | 0.9600 |
| N1—C2 | 1.496 (5) | C2—H2C | 0.9600 |
| | | |
| Br2i—Ag1—Br2 | 107.14 (2) | C2—N1—C2iii | 105.9 (4) |
| Br2i—Ag1—Br1 | 112.947 (7) | N1—C1—H1A | 109.5 |
| Br2—Ag1—Br1 | 112.947 (7) | N1—C1—H1B | 109.5 |
| Br2i—Ag1—Br1ii | 112.947 (7) | H1A—C1—H1B | 109.5 |
| Br2—Ag1—Br1ii | 112.947 (7) | N1—C1—H1C | 109.5 |
| Br1—Ag1—Br1ii | 97.93 (2) | H1A—C1—H1C | 110.5 |
| Br2i—Ag1—Ag1i | 53.571 (11) | H1B—C1—H1C | 108.5 |
| Ag1—Br1—Ag1ii | 82.07 (2) | N1—C2—H2A | 109.5 |
| Ag1i—Br2—Ag1 | 72.86 (2) | N1—C2—H2B | 109.5 |
| C1—N1—C1iii | 111.8 (4) | H2A—C2—H2B | 109.5 |
| C1—N1—C2 | 109.76 (13) | N1—C2—H2C | 109.5 |
| C1iii—N1—C2 | 109.76 (13) | H2A—C2—H2C | 109.5 |
| C1—N1—C2iii | 109.76 (13) | H2B—C2—H2C | 109.5 |
| C1iii—N1—C2iii | 109.76 (13) | | |
| | | |
| Br2i—Ag1—Br1—Ag1ii | −119.104 (11) | Br2i—Ag1—Br2—Ag1i | 0.0 |
| Br2—Ag1—Br1—Ag1ii | 119.104 (11) | Br1—Ag1—Br2—Ag1i | 125.005 (12) |
| Br1ii—Ag1—Br1—Ag1ii | 0.0 | Br1ii—Ag1—Br2—Ag1i | −125.005 (12) |
| Ag1i—Ag1—Br1—Ag1ii | 180.0 | | |
| Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x, −y+1, −z+1; (iii) −x+1, −y+1, z. |
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| C2—H2C···Br1iv | 0.96 | 2.85 | 3.802 (4) | 172 |
| Symmetry codes: (iv) x+1/2, −y+3/2, −z+1/2. |
Table 1
Selected geometric parameters (Å, °) top| Ag1—Br2 | 2.7006 (5) | Ag1—Br1 | 2.7221 (5) |
| | | |
| Br2i—Ag1—Br2 | 107.14 (2) | Br1—Ag1—Br1ii | 97.93 (2) |
| Br2—Ag1—Br1 | 112.947 (7) | | |
| Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x, −y+1, −z+1. |
Table 2
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| C2—H2C···Br1iii | 0.96 | 2.85 | 3.802 (4) | 172 |
| Symmetry codes: (iii) x+1/2, −y+3/2, −z+1/2. |
We gratefully acknowledge financial support by the Scientific Research Foundation for Doctors of Chongqing Normal University (06XLB016), the Scientific Project of Chongqing Municipal Education Commission (KJ070812) and the Natural Science Foundation Project of CQ (CSTC2007BB4234).
Bringley, J. F., Rajeswaran, M., Olson, L. P. M. & Liebert, N. (2005). J. Solid State Chem. 178, 3074–3089.
Helgesson, G., Josefsson, M. & Jagner, S. (1988). Acta Cryst. C44, 1729–1731.
Helgesson, G. & Jagner, S. (1991). Inorg. Chem. 30, 2574–2577.
Johnson, C. K. (1976). ORTEPII. Report ORNL-5138. Oak Ridge National Laboratory, Tennessee, USA.
Liu, X., Guo, G.-C., Fu, M.-L., Chen, W.-T., Zhang, J.-Z. & Huang, J.-S. (2006). Dalton Trans. pp. 884–886.
Liu, X., Guo, G.-C., Liu, B., Chen, W.-T. & Huang, J.-S. (2005). Cryst. Growth Des. 5, 841–843.
Rigaku (2002). CrystalClear. Version 1.35. Rigaku Corporation, Tokyo, Japan.
Siemens (1994). SHELXTL. Version 5. Siemens Energy and Automation Inc., Madison, Wisconsin, USA.
Steiner, Th. (1996). Crystallogr. Rev. 6, 1–57.
Stomberg, R. (1969). Acta Chem. Scand. 23, 3498–3512.
![[Figure 1]](./bg3057fig1thm.gif)
![[Figure 2]](./bg3057fig2thm.gif)
Great interest is presently being focused on the controllable preparation of silver-halide-organoamonium compounds due to their potential application in photographic, photothermal, and other imaging or printing modalities (Bringley et al., 2005, and references therein). In these photographic functional compounds, the [AgaXb]n– parts may serve as commercial photographic color developer molecules. The reactions of silver(I) cyanide with Me4NBr (tetramethylammonioum) in acetonitrile solution and then diffused with aether lead to a AgBr-based complex, [Me4N]2[Ag2Br4] (I), isomorphous to its Cl analogue, reported by Helgesson et al., 1988.
Compound (I) displays a one-dimensional ∞1[Ag2Br4]n2n– anionic chain structure accompanied with isolated [Me4N]+ cations. As shown in Figure 1, one crystallographically independent silver cation in the center of a slightly distorted tetrahedral geometry is coordinated by four µ-Br atoms. The Ag—Br bond distances range from 2.7006 (5) to 2.7221 (5) Å, and the Br—Ag—Br bond angels vary between 97.93 (2) to 112.947 (7) °, in agreement with those in the [AgaBrb]n– clusters (Stomberg, 1969; Helgesson & Jagner, 1991; Liu et al., 2006). The silver cations are double bridged by µ-Br atoms to form an one-dimensional ∞1[Ag2Br4]n2n– anionic chain along the a direction, which also can be regarded as the common chain formed by edge-sharing [AgBr4]3– tetrahedrons (Stomberg, 1969; Helgesson & Jagner, 1991). While the [Me4N]+ cations reside between these anionic chains with weak C—H···Br hydrogen bonding interactions (Steiner, 1996; Liu et al., 2005) to form a special layer along the a and b directions (Figure 2). These special layers further stack together along the c direction merely by Van der Waals forces.
Solid-state luminescence spectra show that comound I exhibits a broad strong blue emission band centered around 485 nm upon photo-excitation at 300 nm (Figure 3) and its lifetime was measured to be 3.3 µs, suggesting to be a potential candidate for luminescent material. Density of states (DOS) calculation sindicate that the top of valence bands (VBs) are mostly formed by Ag-4 d state mixing with Br-4p state, while the bottom of conduction bands (CBs) are almost contribution from the Br-4 s state, indicating the luminescent emission probably originated from metal-to-ligand charge transfer (MLCT) accompanied with hybridizations between Ag-4 d and Br-4p.