1,1'-(Propane-1,3-diyl)dipyridinium dibromidodichloridocadmate(II)

The Cd atom in the title compound, (C₁₃H₁₆N₂)[CdBr₂Cl₂], is coordinated by four halogen atoms in a tetra­hedral geometry. The four halogen atoms are each disordered between Br and Cl, with the Br:Cl ratios being approximately 0.5:0.5, 0.6:0.4, 0.4:0.6 and 0.8:0.2.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.012 Å
• Disorder in main residue
• R factor = 0.037
• wR factor = 0.121
• Data-to-parameter ratio = 16.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.25 Ratio
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.95
PLAT180_ALERT_3_C Check Cell Rounding: # of Values Ending with 0 =          3
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N1
PLAT301_ALERT_3_C Main Residue  Disorder .........................      17.00 Perc.
PLAT342_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...         12

Alert level G
FORMU01_ALERT_1_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and _chemical_formula_moiety. This is
            usually due to the moiety formula being in the wrong format.
            Atom count from _chemical_formula_sum:   C13 H16 Br2.25 Cd1 Cl1.75 N
            Atom count from _chemical_formula_moiety:
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          6

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

   4 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
   4 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

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S1. Comment

The preceding paper reports the structure of the tetrahedral dibromidodichloridocadmate(II), which has been isolated as the 1,2-ethanedipyridinium salt (Liu et al., 2007). The structure of propyl-1,3-di(4-pyridinium) tetrabromidocadmate(II) has been reported in the non-centrosymmetric space group Cc (Kao & Chen, 2004). The title compound, [C₁₃H₁₆N₂][CdBr₂Cl₂] is not, however, isostructural. The cadmium atom in the centrosymmetric structure 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

For related literature, see: Kao & Chen (2004); Liu et al. (2007).

S2. Experimental

The salt was synthesized from the reaction of 1,3-propanedipyridinium dibromide (0.036 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 crystals in 30% yield after several days.

S3. Refinement

The halogens lie in general positions; initial attempts to refine the structure with either four chlorines or four bromines gave unacceptably high R-indices (and large peaks/holes). The four halogen atoms were then refined as four (Br+Cl) mixtures; one attempt allowed the mixtures to have the same displacement parameters as well as to share the same site. A second attempt had the components having only the same displacement parameters. The second led to a formulation consisting of approximately 2.25 Br and 1.75 Cl atoms for the anion. A special restraint was used that fixed the total number of Br and Cl atoms as exactly 2.25 Br and 1.75 Cl. In the best disorder model, the site occupancy factors for the (Br+Cl) mixtures refined to 0.486 (2):0.514 (2), 0.561 (2):0.439 (2), 0.431 (2):0.569 (2) and 0.771 (2):0.229 (2).

The compound is [C₁₃H₁₆N₂] [CdBr_2.25Cl_1.75] but because it has nearly equal numbers of bromine and chlorine atoms, it is regarded as [C₁₃H₁₆N₂] [CdBr₂Cl₂] for the purpose of naming the compound. The CH&N elemental percentages are in fair agreement with the [C₁₃H₁₆N₂] [CdBr_2.25Cl_1.75] formulation.

The disorder in the anion did not affect the cation. 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 U_iso(H) = 1.2U_eq(C).

Computing details

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

Fig. 1. The structure of [C13H16N2][CdBr2Cl2], with displacement ellipsoids drawn at the 50% probability level. The bromine and chlorine atoms are disordered; the figure depicts the anion as a [CdX4]^2- species. Hydrogen atoms are drawn as spheres of arbitrary radius.

Propane-1,3-diyldipyridinium dibromidodichloridocadmate(II)

Crystal data

(C13H16N2)[CdBr2Cl2]	F(000) = 1058
Mr = 554.51	Dx = 2.003 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2441 reflections
a = 8.1159 (6) Å	θ = 2.7–21.3°
b = 15.058 (1) Å	µ = 6.32 mm^−1
c = 15.103 (1) Å	T = 295 K
β = 95.023 (1)°	Block, colourless
V = 1838.6 (2) Å^3	0.15 × 0.10 × 0.08 mm
Z = 4

Data collection

Bruker APEX area-detector diffractometer	3220 independent reflections
Radiation source: fine-focus sealed tube	2287 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
φ and ω scans	θmax = 25.0°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.409, Tmax = 0.632	k = −17→17
10838 measured reflections	l = −17→17

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.121	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0638P)^2] where P = (Fo^2 + 2Fc^2)/3
3220 reflections	(Δ/σ)max = 0.001
201 parameters	Δρmax = 0.82 e Å^−3
6 restraints	Δρmin = −0.63 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Cd1	0.25358 (6)	0.20461 (3)	0.28984 (3)	0.0586 (2)
Br1	0.4650 (9)	0.3290 (3)	0.2721 (6)	0.0757 (10)	0.4863 (18)
Cl1	0.485 (2)	0.3078 (9)	0.2754 (14)	0.0757 (10)	0.5137 (18)
Br2	0.3988 (7)	0.0714 (3)	0.3716 (4)	0.0712 (8)	0.561 (2)
Cl2	0.416 (2)	0.0906 (10)	0.3671 (15)	0.0712 (8)	0.439 (2)
Br3	0.1618 (15)	0.1511 (12)	0.1337 (11)	0.0651 (15)	0.431 (2)
Cl3	0.135 (3)	0.145 (2)	0.139 (2)	0.0651 (15)	0.569 (2)
Br4	0.0147 (3)	0.27032 (12)	0.36647 (16)	0.0712 (5)	0.771 (2)
Cl4	−0.011 (3)	0.2488 (14)	0.3558 (16)	0.0712 (5)	0.229 (2)
N1	0.6152 (5)	0.1612 (3)	0.0464 (3)	0.0528 (12)
C1	0.6960 (9)	0.1278 (5)	−0.0181 (5)	0.0695 (18)
H1	0.7119	0.1625	−0.0676	0.083*
C2	0.7553 (10)	0.0450 (6)	−0.0135 (6)	0.095 (3)
H2	0.8148	0.0240	−0.0590	0.114*
C3	0.7317 (11)	−0.0074 (6)	0.0538 (8)	0.098 (3)
H3	0.7691	−0.0658	0.0551	0.118*
C4	0.6496 (10)	0.0269 (6)	0.1227 (7)	0.096 (3)
H4	0.6339	−0.0077	0.1723	0.115*
C5	0.5921 (8)	0.1118 (5)	0.1169 (5)	0.073 (2)
H5	0.5362	0.1354	0.1628	0.088*
N2	0.9403 (6)	0.3797 (3)	0.1317 (3)	0.0568 (13)
C6	1.0594 (8)	0.3774 (5)	0.0759 (4)	0.0649 (17)
H6	1.0619	0.3315	0.0347	0.078*
C7	1.1779 (9)	0.4426 (6)	0.0793 (6)	0.084 (2)
H7	1.2612	0.4416	0.0409	0.101*
C8	1.1712 (9)	0.5093 (6)	0.1404 (6)	0.087 (2)
H8	1.2503	0.5541	0.1435	0.104*
C9	1.0487 (11)	0.5103 (6)	0.1970 (5)	0.087 (2)
H9	1.0438	0.5555	0.2386	0.105*
C10	0.9341 (9)	0.4443 (5)	0.1915 (5)	0.0731 (19)
H10	0.8505	0.4443	0.2299	0.088*
C11	0.5538 (8)	0.2530 (4)	0.0405 (5)	0.0660 (18)
H11A	0.4859	0.2640	0.0891	0.079*
H11B	0.4847	0.2604	−0.0147	0.079*
C12	0.6934 (8)	0.3208 (4)	0.0443 (5)	0.0657 (18)
H12A	0.7527	0.3149	−0.0084	0.079*
H12B	0.6470	0.3801	0.0446	0.079*
C13	0.8126 (8)	0.3086 (5)	0.1259 (5)	0.073 (2)
H13A	0.7524	0.3100	0.1786	0.087*
H13B	0.8660	0.2511	0.1235	0.087*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.0570 (3)	0.0650 (3)	0.0539 (3)	0.0085 (2)	0.0050 (2)	−0.0107 (2)
Br1	0.077 (2)	0.062 (3)	0.0900 (11)	−0.0072 (19)	0.0218 (13)	−0.022 (2)
Cl1	0.077 (2)	0.062 (3)	0.0900 (11)	−0.0072 (19)	0.0218 (13)	−0.022 (2)
Br2	0.0635 (15)	0.056 (2)	0.0904 (11)	0.0047 (14)	−0.0153 (10)	0.0029 (17)
Cl2	0.0635 (15)	0.056 (2)	0.0904 (11)	0.0047 (14)	−0.0153 (10)	0.0029 (17)
Br3	0.067 (4)	0.072 (3)	0.056 (2)	0.003 (3)	0.004 (2)	−0.0156 (17)
Cl3	0.067 (4)	0.072 (3)	0.056 (2)	0.003 (3)	0.004 (2)	−0.0156 (17)
Br4	0.0762 (11)	0.0748 (13)	0.0660 (9)	0.0202 (8)	0.0252 (7)	0.0008 (8)
Cl4	0.0762 (11)	0.0748 (13)	0.0660 (9)	0.0202 (8)	0.0252 (7)	0.0008 (8)
N1	0.051 (3)	0.056 (3)	0.051 (3)	−0.005 (2)	0.001 (2)	0.006 (2)
C1	0.085 (5)	0.064 (5)	0.062 (4)	−0.008 (4)	0.018 (4)	−0.010 (4)
C2	0.099 (7)	0.077 (6)	0.111 (7)	−0.005 (5)	0.025 (5)	−0.025 (5)
C3	0.083 (6)	0.056 (5)	0.150 (9)	−0.001 (4)	−0.025 (6)	−0.015 (6)
C4	0.092 (6)	0.076 (6)	0.112 (7)	−0.019 (5)	−0.028 (5)	0.043 (6)
C5	0.060 (4)	0.092 (6)	0.069 (5)	−0.013 (4)	0.012 (3)	0.009 (4)
N2	0.052 (3)	0.060 (3)	0.057 (3)	0.010 (3)	−0.001 (2)	0.005 (3)
C6	0.060 (4)	0.071 (5)	0.065 (4)	0.007 (4)	0.012 (3)	−0.006 (3)
C7	0.076 (5)	0.094 (6)	0.085 (6)	−0.001 (5)	0.020 (4)	0.009 (5)
C8	0.068 (5)	0.075 (5)	0.114 (7)	−0.008 (4)	−0.014 (5)	0.011 (5)
C9	0.090 (6)	0.075 (6)	0.091 (6)	0.017 (5)	−0.018 (5)	−0.018 (5)
C10	0.065 (4)	0.088 (5)	0.065 (4)	0.020 (4)	0.001 (3)	−0.006 (4)
C11	0.057 (4)	0.063 (4)	0.076 (5)	0.002 (3)	−0.004 (3)	0.009 (4)
C12	0.072 (4)	0.052 (4)	0.070 (4)	0.004 (3)	−0.011 (3)	0.005 (3)
C13	0.062 (4)	0.073 (5)	0.081 (5)	−0.006 (4)	−0.002 (4)	0.015 (4)

Geometric parameters (Å, º)

Cd1—Cl2	2.404 (19)	N2—C10	1.331 (8)
Cd1—Cl1	2.46 (2)	N2—C6	1.338 (8)
Cd1—Br3	2.540 (17)	N2—C13	1.488 (8)
Cd1—Br4	2.544 (2)	C6—C7	1.373 (10)
Cd1—Cl4	2.53 (2)	C6—H6	0.9300
Cd1—Cl3	2.55 (3)	C7—C8	1.368 (11)
Cd1—Br1	2.570 (8)	C7—H7	0.9300
Cd1—Br2	2.585 (5)	C8—C9	1.366 (11)
N1—C1	1.320 (8)	C8—H8	0.9300
N1—C5	1.327 (8)	C9—C10	1.358 (10)
N1—C11	1.469 (8)	C9—H9	0.9300
C1—C2	1.336 (11)	C10—H10	0.9300
C1—H1	0.9300	C11—C12	1.522 (9)
C2—C3	1.314 (12)	C11—H11A	0.9700
C2—H2	0.9300	C11—H11B	0.9700
C3—C4	1.383 (12)	C12—C13	1.511 (9)
C3—H3	0.9300	C12—H12A	0.9700
C4—C5	1.362 (11)	C12—H12B	0.9700
C4—H4	0.9300	C13—H13A	0.9700
C5—H5	0.9300	C13—H13B	0.9700
Cl2—Cd1—Cl1	95.9 (5)	C5—C4—H4	120.4
Cl2—Cd1—Br3	109.1 (7)	C3—C4—H4	120.4
Cl1—Cd1—Br3	106.4 (6)	N1—C5—C4	120.4 (7)
Cl2—Cd1—Br4	117.7 (6)	N1—C5—H5	119.8
Cl1—Cd1—Br4	114.4 (3)	C4—C5—H5	119.8
Br3—Cd1—Br4	111.9 (3)	C10—N2—C6	121.3 (6)
Cl2—Cd1—Cl4	116.4 (8)	C10—N2—C13	119.9 (6)
Cl1—Cd1—Cl4	123.3 (6)	C6—N2—C13	118.8 (6)
Br3—Cd1—Cl4	105.0 (6)	N2—C6—C7	119.9 (7)
Br4—Cd1—Cl4	9.3 (5)	N2—C6—H6	120.0
Cl2—Cd1—Cl3	109.2 (9)	C7—C6—H6	120.0
Cl1—Cd1—Cl3	112.1 (8)	C8—C7—C6	118.8 (7)
Br3—Cd1—Cl3	5.9 (7)	C8—C7—H7	120.6
Br4—Cd1—Cl3	107.3 (6)	C6—C7—H7	120.6
Cl4—Cd1—Cl3	100.1 (7)	C7—C8—C9	120.3 (8)
Cl2—Cd1—Br1	103.2 (4)	C7—C8—H8	119.9
Cl1—Cd1—Br1	7.9 (4)	C9—C8—H8	119.9
Br3—Cd1—Br1	106.2 (4)	C10—C9—C8	119.0 (8)
Br4—Cd1—Br1	107.84 (13)	C10—C9—H9	120.5
Cl4—Cd1—Br1	116.5 (5)	C8—C9—H9	120.5
Cl3—Cd1—Br1	111.6 (6)	N2—C10—C9	120.6 (7)
Cl2—Cd1—Br2	6.4 (5)	N2—C10—H10	119.7
Cl1—Cd1—Br2	102.2 (4)	C9—C10—H10	119.7
Br3—Cd1—Br2	106.4 (4)	N1—C11—C12	112.4 (5)
Br4—Cd1—Br2	114.72 (16)	N1—C11—H11A	109.1
Cl4—Cd1—Br2	112.5 (6)	C12—C11—H11A	109.1
Cl3—Cd1—Br2	105.8 (8)	N1—C11—H11B	109.1
Br1—Cd1—Br2	109.55 (17)	C12—C11—H11B	109.1
C1—N1—C5	119.6 (6)	H11A—C11—H11B	107.9
C1—N1—C11	120.1 (5)	C13—C12—C11	111.8 (6)
C5—N1—C11	120.3 (6)	C13—C12—H12A	109.3
N1—C1—C2	121.1 (7)	C11—C12—H12A	109.3
N1—C1—H1	119.4	C13—C12—H12B	109.3
C2—C1—H1	119.4	C11—C12—H12B	109.3
C3—C2—C1	121.7 (8)	H12A—C12—H12B	107.9
C3—C2—H2	119.2	N2—C13—C12	110.7 (6)
C1—C2—H2	119.2	N2—C13—H13A	109.5
C2—C3—C4	118.0 (8)	C12—C13—H13A	109.5
C2—C3—H3	121.0	N2—C13—H13B	109.5
C4—C3—H3	121.0	C12—C13—H13B	109.5
C5—C4—C3	119.2 (8)	H13A—C13—H13B	108.1
C5—N1—C1—C2	−0.2 (10)	C6—C7—C8—C9	0.2 (12)
C11—N1—C1—C2	178.9 (7)	C7—C8—C9—C10	0.0 (12)
N1—C1—C2—C3	2.1 (13)	C6—N2—C10—C9	0.4 (10)
C1—C2—C3—C4	−3.0 (13)	C13—N2—C10—C9	−179.2 (6)
C2—C3—C4—C5	2.1 (12)	C8—C9—C10—N2	−0.3 (11)
C1—N1—C5—C4	−0.7 (9)	C1—N1—C11—C12	−66.1 (7)
C11—N1—C5—C4	−179.7 (6)	C5—N1—C11—C12	112.9 (7)
C3—C4—C5—N1	−0.3 (11)	N1—C11—C12—C13	−54.8 (8)
C10—N2—C6—C7	−0.2 (10)	C10—N2—C13—C12	106.4 (7)
C13—N2—C6—C7	179.4 (6)	C6—N2—C13—C12	−73.3 (8)
N2—C6—C7—C8	−0.1 (11)	C11—C12—C13—N2	−175.6 (5)