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The Cd atom in the title compound, (C12H14N2)[CdBr2Cl2], is coordinated by four halogen atoms in a tetra­hedral geometry. The cation lies on a centre of inversion and the anion about a mirror plane. The halogen atoms on the mirror plane are both disordered between Br and Cl in a ratio of 0.75:0.25. The halogen atom in the general position is disordered between Br and Cl in a ratio of 0.25:0.75.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807025585/wn2141sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807025585/wn2141Isup2.hkl
Contains datablock I

CCDC reference: 624131

Key indicators

  • Single-crystal X-ray study
  • T = 295 K
  • Mean [sigma](C-C) = 0.014 Å
  • Disorder in main residue
  • R factor = 0.057
  • wR factor = 0.179
  • Data-to-parameter ratio = 19.8

checkCIF/PLATON results

No syntax errors found



Alert level A PLAT061_ALERT_3_A Tmax/Tmin Range Test RR' too Large ............. 0.46
Author Response: Although the crystal was quite small (0.20 x 0.20 x 0.10 mm), because there are heavy atoms, the range of values should be much greater than the predicted ratio of approximately 0.5. In the CIF, the ratio is 0.25. In the SADABS absorption correction step, a model with heavy scatterers was assumed. If a model without heavy scatterers, then the ratio would probably be closer to the expected values. The low ratio is in agreement with the presence of heavy atoms. The ratio as given in the cif was taken from the SADABS run instead of using the value predicted by SHELXL.

Alert level B ABSTM02_ALERT_3_B The ratio of expected to reported Tmax/Tmin(RR') is < 0.75 Tmin and Tmax reported: 0.147 0.574 Tmin(prime) and Tmax expected: 0.271 0.535 RR(prime) = 0.506 Please check that your absorption correction is appropriate. PLAT242_ALERT_2_B Check Low Ueq as Compared to Neighbors for Cd1
Alert level C PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ? PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.93 PLAT301_ALERT_3_C Main Residue Disorder ......................... 15.00 Perc. PLAT342_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ... 14 PLAT432_ALERT_2_C Short Inter X...Y Contact Br1 .. C5 .. 3.31 Ang.
Alert level G ABSTM02_ALERT_3_G When printed, the submitted absorption T values will be replaced by the scaled T values. Since the ratio of scaled T's is identical to the ratio of reported T values, the scaling does not imply a change to the absorption corrections used in the study. Ratio of Tmax expected/reported 0.933 Tmax scaled 0.535 Tmin scaled 0.137 PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints ....... 44
1 ALERT level A = In general: serious problem 2 ALERT level B = Potentially serious problem 5 ALERT level C = Check and explain 2 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 6 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Comment top

The discrete tetrahedral tetrahalidocadmate(II) dianion has been characterized in a number of salts (Cambridge Structural Database, Version 5.28; Allen, 2002); examples of the ammonium salts include, for example, bis(tetramethylammonium) tetrachloridocadmate, bis(tetramethylammonium) tetrabromidomercurate (Sato et al., 1986) and bis(tetramethylammonium) tetraiodidocadmate (Kallel et al., 1981). In the 1,2-ethanedipyridinium salt of the mixed-halogen cadmate, the metal atom is coordinated by four halogen atoms in a tetrahedral geometry; the halogen atoms are disordered (Fig. 1). The cations and anions do not have signification interactions with each other.

Related literature top

For related literature, see: Allen (2002); Kallel et al. (1981); Sato et al. (1986).

Experimental top

The salt was synthesized from the reaction of ethane-1,2-dipyridinium dibromide (0.035 g, 0.1 mmol) in methanol (5 ml) and cadmium dichloride (0.037 g, 0.2 mmol) in DMF (10 ml). The mixture was set aside for the formation of colourless block-shaped crystals in 40% yield after several days. CH&N elemental analysis: Calc. C 27.22, H 2.67, N 5.29%. Found C 27.89, H 2.49, N 5.36%.

Refinement top

Of the three halogens in the asymmetric unit, one lies in a general position and the other two on a mirror plane. Initial attempts to refine the structure with either three chlorines or three bromines gave unacceptably high R-indices (and large peaks/holes). The three halogen atoms were then refined as three (Br+Cl) mixtures; in one attempt the components had only the same displacement parameters. A second attempt allowed the mixtures to have the same displacement parameters as well as sharing the same site. The second led to a formulation consisting of approximately two Br and two Cl atoms. The use of a special restraint command that fixed the number of Br and Cl atoms as both being exactly two led to the occupancy of Br1 as nearly 0.25 and that of Br2 and Br3 as both nearly 0.75. In the best disorder model, the halogen in the general position was set to (0.25Br + 0.75Cl); those in the special position were both set to (0.75Br + 0.25Cl)·The anion is [CdBr2Cl2]2-, a formulation that is supported by CH&N elemental analysis. Other formulations led to much larger peaks/holes.

Disorder also affected the cation; the pyridyl ring was refined as a rigid hexagon of 1.39 Å sides. The C—C distance was restrained to 1.50±0.01 Å, and the N···C distance to 2.45±0.01 Å. The displacement parameters of atoms of the cation were restrained to be nearly isotropic. Carbon-bound H atoms were positioned geometrically (C–H 0.93 and 0.97 Å), and were included in the refinement in the riding model approximation, with Uiso(H) = 1.2Ueq(C).

In the final difference Fourier map the largest peak was 0.9 Å from C6 and the deepest hole at 0.6 Å from Cl3.

Structure description top

The discrete tetrahedral tetrahalidocadmate(II) dianion has been characterized in a number of salts (Cambridge Structural Database, Version 5.28; Allen, 2002); examples of the ammonium salts include, for example, bis(tetramethylammonium) tetrachloridocadmate, bis(tetramethylammonium) tetrabromidomercurate (Sato et al., 1986) and bis(tetramethylammonium) tetraiodidocadmate (Kallel et al., 1981). In the 1,2-ethanedipyridinium salt of the mixed-halogen cadmate, the metal atom is coordinated by four halogen atoms in a tetrahedral geometry; the halogen atoms are disordered (Fig. 1). The cations and anions do not have signification interactions with each other.

For related literature, see: Allen (2002); Kallel et al. (1981); Sato et al. (1986).

Computing details top

Data collection: SMART (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2007).

Figures top
[Figure 1] Fig. 1. The structure of [C12H14N2][CdBr2Cl2], with displacement ellipsoids drawn at the 50% probability level. The bromine and chlorine atoms are disordered; the halogen atom on the general position is labelled X1 (and the symmetry-related X1i); those on the special position are labelled X2 and X3. Hydrogen atoms are drawn as spheres of arbitrary radius. [Symmetry code: i = x, 3/2 – y, z.] Unlabelled atoms in the cation are related to labelled atoms by (1 – x, 1 – y, 1 – z).
Ethylenedipyridinium dibromidodichloridocadmate(II) top
Crystal data top
(C12H14N2)[CdBr2Cl2]F(000) = 1008
Mr = 529.37Dx = 2.056 Mg m3
Orthorhombic, PnmaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2nCell parameters from 4134 reflections
a = 17.955 (2) Åθ = 2.3–27.4°
b = 14.338 (1) ŵ = 6.25 mm1
c = 6.6437 (6) ÅT = 295 K
V = 1710.4 (3) Å3Block, colourless
Z = 40.20 × 0.20 × 0.10 mm
Data collection top
Bruker APEX area-detector
diffractometer
1564 independent reflections
Radiation source: fine-focus sealed tube1415 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.025
φ and ω scansθmax = 25.0°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1721
Tmin = 0.147, Tmax = 0.574k = 1517
8939 measured reflectionsl = 77
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.057Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.179H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.1162P)2 + 9.0378P]
where P = (Fo2 + 2Fc2)/3
1564 reflections(Δ/σ)max = 0.001
79 parametersΔρmax = 1.77 e Å3
44 restraintsΔρmin = 1.30 e Å3
Crystal data top
(C12H14N2)[CdBr2Cl2]V = 1710.4 (3) Å3
Mr = 529.37Z = 4
Orthorhombic, PnmaMo Kα radiation
a = 17.955 (2) ŵ = 6.25 mm1
b = 14.338 (1) ÅT = 295 K
c = 6.6437 (6) Å0.20 × 0.20 × 0.10 mm
Data collection top
Bruker APEX area-detector
diffractometer
1564 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1415 reflections with I > 2σ(I)
Tmin = 0.147, Tmax = 0.574Rint = 0.025
8939 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.05744 restraints
wR(F2) = 0.179H-atom parameters constrained
S = 1.06Δρmax = 1.77 e Å3
1564 reflectionsΔρmin = 1.30 e Å3
79 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cd10.92879 (4)0.75000.64150 (12)0.0371 (3)
Br10.91363 (10)0.60359 (14)0.4500 (3)0.0702 (6)0.25
Br20.82923 (11)0.75000.9121 (3)0.0760 (6)0.75
Br31.06428 (9)0.75000.7605 (3)0.0720 (6)0.75
Cl10.91363 (10)0.60359 (14)0.4500 (3)0.0702 (6)0.75
Cl20.82923 (11)0.75000.9121 (3)0.0760 (6)0.25
Cl31.06428 (9)0.75000.7605 (3)0.0720 (6)0.25
N10.5912 (2)0.5361 (5)0.4128 (9)0.069 (2)
C10.6503 (3)0.5331 (5)0.5477 (8)0.075 (3)
C20.7163 (2)0.5795 (5)0.5034 (8)0.056 (2)
C30.7231 (2)0.6288 (4)0.3243 (8)0.055 (2)
C40.6640 (3)0.6318 (4)0.1894 (7)0.053 (2)
C50.5980 (2)0.5854 (4)0.2336 (7)0.055 (2)
C60.5283 (5)0.4733 (7)0.4383 (15)0.080 (3)
H10.64570.50010.66750.090*
H20.75580.57750.59370.067*
H30.76730.65990.29470.067*
H40.66860.66480.06950.064*
H50.55850.58740.14340.066*
H6a0.54360.41700.50810.096*
H6b0.50760.45610.30870.096*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cd10.0328 (5)0.0379 (5)0.0406 (5)0.0000.0018 (3)0.000
Br10.0544 (10)0.0715 (12)0.0846 (13)0.0025 (8)0.0020 (9)0.0256 (10)
Br20.0685 (11)0.1012 (14)0.0584 (10)0.0000.0344 (8)0.000
Br30.0437 (9)0.0825 (12)0.0897 (14)0.0000.0088 (8)0.000
Cl10.0544 (10)0.0715 (12)0.0846 (13)0.0025 (8)0.0020 (9)0.0256 (10)
Cl20.0685 (11)0.1012 (14)0.0584 (10)0.0000.0344 (8)0.000
Cl30.0437 (9)0.0825 (12)0.0897 (14)0.0000.0088 (8)0.000
N10.033 (3)0.105 (6)0.069 (4)0.018 (4)0.009 (3)0.033 (4)
C10.057 (5)0.100 (7)0.069 (5)0.008 (5)0.006 (4)0.034 (5)
C20.025 (3)0.070 (5)0.072 (5)0.002 (3)0.008 (3)0.018 (4)
C30.032 (4)0.061 (5)0.073 (5)0.010 (4)0.005 (4)0.011 (4)
C40.050 (4)0.054 (4)0.055 (4)0.010 (4)0.006 (4)0.009 (4)
C50.036 (4)0.069 (5)0.059 (5)0.011 (4)0.002 (4)0.013 (4)
C60.100 (7)0.066 (5)0.074 (6)0.021 (5)0.016 (5)0.011 (5)
Geometric parameters (Å, º) top
Cd1—Br12.470 (2)C2—H20.9300
Cd1—Br1i2.470 (2)C3—C41.3900
Cd1—Br22.535 (2)C3—H30.9300
Cd1—Br32.558 (2)C4—C51.3900
N1—C11.3900C4—H40.9300
N1—C51.3900C5—H50.9300
N1—C61.453 (12)C6—C6ii1.514 (9)
C1—C21.3900C6—H6A0.9700
C1—H10.9300C6—H6B0.9700
C2—C31.3900
Br1—Cd1—Br1i116.4 (1)C4—C3—C2120.0
Br1—Cd1—Br2106.7 (1)C4—C3—H3120.0
Br1—Cd1—Br3105.3 (1)C2—C3—H3120.0
Br1i—Cd1—Br2106.7 (1)C3—C4—C5120.0
Br1i—Cd1—Br3105.3 (1)C3—C4—H4120.0
Br2—Cd1—Br3116.8 (1)C5—C4—H4120.0
C1—N1—C5120.0C4—C5—N1120.0
C1—N1—C6119.9 (6)C4—C5—H5120.0
C5—N1—C6118.9 (6)N1—C5—H5120.0
N1—C1—C2120.0N1—C6—C6ii105.8 (10)
N1—C1—H1120.0N1—C6—H6A110.6
C2—C1—H1120.0C6ii—C6—H6A110.6
C1—C2—C3120.0N1—C6—H6B110.6
C1—C2—H2120.0C6ii—C6—H6B110.6
C3—C2—H2120.0H6A—C6—H6B108.7
C5—N1—C1—C20.0C3—C4—C5—N10.0
C6—N1—C1—C2167.7 (7)C1—N1—C5—C40.0
N1—C1—C2—C30.0C6—N1—C5—C4167.8 (6)
C1—C2—C3—C40.0C1—N1—C6—C6ii93.0 (11)
C2—C3—C4—C50.0C5—N1—C6—C6ii99.2 (11)
Symmetry codes: (i) x, y+3/2, z; (ii) x+1, y+1, z+1.

Experimental details

Crystal data
Chemical formula(C12H14N2)[CdBr2Cl2]
Mr529.37
Crystal system, space groupOrthorhombic, Pnma
Temperature (K)295
a, b, c (Å)17.955 (2), 14.338 (1), 6.6437 (6)
V3)1710.4 (3)
Z4
Radiation typeMo Kα
µ (mm1)6.25
Crystal size (mm)0.20 × 0.20 × 0.10
Data collection
DiffractometerBruker APEX area-detector
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.147, 0.574
No. of measured, independent and
observed [I > 2σ(I)] reflections
8939, 1564, 1415
Rint0.025
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.057, 0.179, 1.06
No. of reflections1564
No. of parameters79
No. of restraints44
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)1.77, 1.30

Computer programs: SMART (Bruker, 2004), SAINT (Bruker, 2004), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), X-SEED (Barbour, 2001), publCIF (Westrip, 2007).

Selected geometric parameters (Å, º) top
Cd1—Br12.470 (2)Cd1—Br32.558 (2)
Cd1—Br22.535 (2)
Br1—Cd1—Br1i116.4 (1)Br1—Cd1—Br3105.3 (1)
Br1—Cd1—Br2106.7 (1)Br2—Cd1—Br3116.8 (1)
Symmetry code: (i) x, y+3/2, z.
 

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