Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807046880/bg3057sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807046880/bg3057Isup2.hkl |
CCDC reference: 663660
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (g-Br) = 0.001 Å Some non-H atoms missing
- R factor = 0.030
- wR factor = 0.068
- Data-to-parameter ratio = 16.5
checkCIF/PLATON results
No syntax errors found
Alert level B PLAT242_ALERT_2_B Check Low Ueq as Compared to Neighbors for N1
Alert level C CHEMW03_ALERT_2_C The ratio of given/expected molecular weight as calculated from the _atom_site* data lies outside the range 0.99 <> 1.01 From the CIF: _cell_formula_units_Z 4 From the CIF: _chemical_formula_weight 341.84 TEST: Calculate formula weight from _atom_site_* atom mass num sum C 12.01 4.00 48.04 H 1.01 16.00 16.13 N 14.01 1.00 14.01 Ag 107.87 1.00 107.87 Br 79.90 2.00 159.81 Calculated formula weight 345.85
Alert level G FORMU01_ALERT_2_G There is a discrepancy between the atom counts in the _chemical_formula_sum and the formula from the _atom_site* data. Atom count from _chemical_formula_sum:C4 H12 Ag1 Br2 N1 Atom count from the _atom_site data: C4 H16 Ag1 Br2 N1 CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected. CELLZ01_ALERT_1_G ALERT: Large difference may be due to a symmetry error - see SYMMG tests From the CIF: _cell_formula_units_Z 4 From the CIF: _chemical_formula_sum C4 H12 Ag Br2 N TEST: Compare cell contents of formula and atom_site data atom Z*formula cif sites diff C 16.00 16.00 0.00 H 48.00 64.00 -16.00 Ag 4.00 4.00 0.00 Br 8.00 8.00 0.00 N 4.00 4.00 0.00 PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K
0 ALERT level A = In general: serious problem 1 ALERT level B = Potentially serious problem 1 ALERT level C = Check and explain 5 ALERT level G = General alerts; check 4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 3 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 0 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
For related literature, see: Bringley et al. (2005), and references therein; Helgesson & Jagner (1991); Liu et al. (2005, 2006); Steiner (1996); Stomberg (1969).
For related literature, see: Johnson (1976).
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.
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.
For related literature, see: Bringley et al. (2005), and references therein; Helgesson & Jagner (1991); Liu et al. (2005, 2006); Steiner (1996); Stomberg (1969).
For related literature, see: Johnson (1976).
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).
(C4H12N)[AgBr2] | F(000) = 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 = 3.3–27.5° |
b = 9.1535 (14) Å | µ = 10.63 mm−1 |
c = 15.057 (2) Å | T = 293 K |
V = 934.7 (2) Å3 | Prism, colourless |
Z = 4 | 0.20 × 0.20 × 0.16 mm |
Rigaku Mercury CCD diffractometer | 494 independent reflections |
Radiation source: rotating-anode generator | 459 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.031 |
ω scans | θmax = 25.0°, θmin = 3.3° |
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 on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.030 | H-atom parameters constrained |
wR(F2) = 0.068 | w = 1/[σ2(Fo2) + (0.0315P)2 + 4.8P] where P = (Fo2 + 2Fc2)/3 |
S = 1.00 | (Δ/σ)max < 0.001 |
494 reflections | Δρmax = 0.65 e Å−3 |
30 parameters | Δρmin = −0.77 e Å−3 |
0 restraints | 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) |
(C4H12N)[AgBr2] | V = 934.7 (2) Å3 |
Mr = 341.84 | Z = 4 |
Orthorhombic, Immm | Mo Kα radiation |
a = 6.7817 (9) Å | µ = 10.63 mm−1 |
b = 9.1535 (14) Å | T = 293 K |
c = 15.057 (2) Å | 0.20 × 0.20 × 0.16 mm |
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 |
R[F2 > 2σ(F2)] = 0.030 | 0 restraints |
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 |
30 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. |
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. |
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* |
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) |
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. |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2C···Br1iv | 0.96 | 2.85 | 3.802 (4) | 172 |
Symmetry code: (iv) x+1/2, −y+3/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | (C4H12N)[AgBr2] |
Mr | 341.84 |
Crystal system, space group | Orthorhombic, Immm |
Temperature (K) | 293 |
a, b, c (Å) | 6.7817 (9), 9.1535 (14), 15.057 (2) |
V (Å3) | 934.7 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 10.63 |
Crystal size (mm) | 0.20 × 0.20 × 0.16 |
Data collection | |
Diffractometer | Rigaku Mercury CCD |
Absorption correction | Multi-scan (SPHERE in CrystalClear; Rigaku, 2002) |
Tmin, Tmax | 0.13, 0.18 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2952, 494, 459 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.068, 1.00 |
No. of reflections | 494 |
No. of parameters | 30 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.65, −0.77 |
Computer programs: CrystalClear (Rigaku, 2002), SHELXTL (Siemens, 1994) and ORTEP (Johnson, 1976).
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. |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2C···Br1iii | 0.96 | 2.85 | 3.802 (4) | 171.6 |
Symmetry code: (iii) x+1/2, −y+3/2, −z+1/2. |
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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.