Bis[4-(dimethyl­amino)­pyridinium] dibromidodichloridodimethyl­stannate(IV)

The tin(IV) atom in the salt, (C₇H₁₁N₂)₂[SnBr₂(CH₃)₂Cl₂], lies on a center of inversion in a tetra­gonally compressed octa­hedron; the bromine atoms are disordered with the chlorine atoms, so that they appear to share the same site. The crystal structure is stabilized by N—H...Br hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.009 Å
• Disorder in main residue
• R factor = 0.046
• wR factor = 0.124
• Data-to-parameter ratio = 22.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT301_ALERT_3_C Main Residue  Disorder .........................      17.00 Perc.
PLAT342_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          9
PLAT021_ALERT_1_C Ratio Unique / Expected Reflections too High ...       1.02
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.92

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:   C16 H28 Br2 Cl2 N4 Sn1
            Atom count from _chemical_formula_moiety:C14 H22 N4
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      0.916
            Tmax scaled      0.493 Tmin scaled      0.353
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          4

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

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 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

Bis(4-methylaminopyridinium) tetrabromidodiphenylstannate is produced from the cleavage of the mixed alkyl/triarylstannate, cyclopentyltriphenyltin, by 4-dimethylaminopyridine hydrobromide perbromide (Yap et al., 2008). In principle, the salt can be synthesized from the reaction of 4-dimethylaminopyridine hydrobromide perbromide and diphenyltin dibromide. The possibility is borne out by reacting the organic reagent with dimethyltin dichloride to yield the title salt (Scheme I, Fig. 1). The Sn^IV atom of the stannate lies on a center-of-inversion in tetragonally compressed octahedron; the two indepedent bromine atom share the sames site as the two independent chlorine atoms.

Related literature

For the structure of bis(4-dimethylaminopyridinium) tetrabromidodiphenylstannate, see: Yap et al. (2008).

S2. Experimental

Dimethyltin dichoride (2.20 g, 1 mmol) and 4-dimethylaminopyridine hydrobromide perbromide (3.62 g, 1 mmol) were heated in ethanol in an attempt to synthesize the bromodichloridodimethylstannate salt. Colorless crystals separated from it after a few days.

S3. Refinement

Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 to 0.98 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2 to 1.5U_eq(C). The ammonium H atom was similarly treated (N–H 0.88 Å; U(H) = 1.2 U_eq(N)).

The chlorine atoms are disordered with respect to the bromine atoms, so that the halogen site is occupied by both a chlorine and a bromine. Constraints were applied so that at each site, the atoms had the same coordinates and the same anisotropic displacement parameters. The occupancies refined to 0.4551 (15) for the Br1/Cl2 pair, and to 0.5449 (15) for the Br2/Cl1 pair. The final difference Fourier map had a large peak at 1 Å from Sn1.

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2008).

Figures

Fig. 1. Thermal ellipsoid plot (Barbour, 2001) plot of [C7H11N]2 [SnBr2Cl2(CH3)2] at the 70% probability level. Hydrogen atoms are drawn as spheres of arbitrary radius. The disorder is not shown.

Bis[4-(dimethylamino)pyridinium] dibromidodichloridodimethylstannate(IV)

Crystal data

(C7H11N2)2[SnBr2(CH3)2Cl2]	Z = 1
Mr = 625.83	F(000) = 306
Triclinic, P1	Dx = 1.767 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.3573 (3) Å	Cell parameters from 1302 reflections
b = 8.7717 (3) Å	θ = 2.3–23.1°
c = 9.6644 (4) Å	µ = 4.72 mm^−1
α = 97.183 (3)°	T = 100 K
β = 107.990 (3)°	Prism, colorless
γ = 90.052 (2)°	0.25 × 0.20 × 0.15 mm
V = 588.04 (4) Å^3

Data collection

Bruker SMART APEX diffractometer	2756 independent reflections
Radiation source: fine-focus sealed tube	1656 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
ω scans	θmax = 27.5°, θmin = 2.3°
Absorption correction: multi-scan (SADABS;Sheldrick, 1996)	h = −9→9
Tmin = 0.385, Tmax = 0.538	k = −11→11
4965 measured reflections	l = −10→12

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.123	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.051P)^2] where P = (Fo^2 + 2Fc^2)/3
2756 reflections	(Δ/σ)max = 0.001
122 parameters	Δρmax = 0.82 e Å^−3
4 restraints	Δρmin = −1.14 e Å^−3

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Sn1	0.5000	0.5000	0.5000	0.0414 (2)
Br1	0.50474 (16)	0.50403 (11)	0.77987 (11)	0.0610 (3)	0.4551 (15)
Br2	0.36593 (14)	0.78543 (10)	0.49452 (10)	0.0588 (3)	0.5449 (15)
Cl1	0.50474 (16)	0.50403 (11)	0.77987 (11)	0.0610 (3)	0.5449 (15)
Cl2	0.36593 (14)	0.78543 (10)	0.49452 (10)	0.0588 (3)	0.4551 (15)
N1	0.6576 (7)	0.1602 (6)	0.8588 (6)	0.0552 (14)
H1	0.6205	0.2248	0.7938	0.066*
N2	0.8414 (7)	−0.1391 (6)	1.1635 (6)	0.0557 (14)
C1	0.2014 (7)	0.4016 (6)	0.4157 (6)	0.0344 (12)
H1A	0.2023	0.2904	0.4192	0.052*
H1B	0.1432	0.4214	0.3142	0.052*
H1C	0.1271	0.4495	0.4767	0.052*
C2	0.6816 (9)	0.2092 (8)	1.0006 (8)	0.0581 (18)
H2	0.6571	0.3128	1.0290	0.070*
C3	0.7413 (9)	0.1116 (7)	1.1061 (7)	0.0545 (16)
H3	0.7570	0.1480	1.2060	0.065*
C4	0.7793 (8)	−0.0433 (7)	1.0650 (7)	0.0443 (15)
C5	0.7486 (8)	−0.0875 (7)	0.9140 (7)	0.0488 (15)
H5	0.7698	−0.1904	0.8805	0.059*
C6	0.6890 (9)	0.0144 (8)	0.8144 (7)	0.0536 (16)
H6	0.6698	−0.0183	0.7132	0.064*
C7	0.8687 (11)	−0.0920 (10)	1.3200 (8)	0.084 (3)
H7A	0.9886	−0.0305	1.3639	0.127*
H7B	0.8740	−0.1836	1.3695	0.127*
H7C	0.7616	−0.0305	1.3310	0.127*
C8	0.8809 (10)	−0.2972 (8)	1.1236 (9)	0.071 (2)
H8A	0.7602	−0.3560	1.0736	0.106*
H8B	0.9498	−0.3417	1.2124	0.106*
H8C	0.9594	−0.3008	1.0579	0.106*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.0437 (4)	0.0408 (3)	0.0388 (4)	0.0028 (3)	0.0122 (3)	0.0040 (3)
Br1	0.0938 (9)	0.0501 (6)	0.0460 (6)	0.0082 (5)	0.0319 (6)	0.0062 (5)
Br2	0.0809 (7)	0.0458 (5)	0.0461 (6)	0.0187 (5)	0.0144 (5)	0.0062 (4)
Cl1	0.0938 (9)	0.0501 (6)	0.0460 (6)	0.0082 (5)	0.0319 (6)	0.0062 (5)
Cl2	0.0809 (7)	0.0458 (5)	0.0461 (6)	0.0187 (5)	0.0144 (5)	0.0062 (4)
N1	0.050 (3)	0.064 (4)	0.052 (4)	0.001 (3)	0.012 (3)	0.020 (3)
N2	0.048 (3)	0.070 (4)	0.050 (3)	0.004 (3)	0.012 (3)	0.017 (3)
C1	0.032 (3)	0.039 (3)	0.040 (3)	0.009 (2)	0.019 (3)	0.012 (3)
C2	0.050 (4)	0.058 (4)	0.064 (5)	0.007 (3)	0.016 (4)	0.004 (4)
C3	0.048 (4)	0.065 (4)	0.048 (4)	0.001 (3)	0.016 (3)	−0.006 (3)
C4	0.031 (3)	0.063 (4)	0.037 (3)	−0.005 (3)	0.008 (3)	0.009 (3)
C5	0.047 (4)	0.050 (3)	0.047 (4)	−0.003 (3)	0.013 (3)	0.002 (3)
C6	0.054 (4)	0.064 (4)	0.042 (4)	−0.013 (3)	0.016 (3)	0.001 (3)
C7	0.075 (5)	0.136 (7)	0.043 (4)	0.025 (5)	0.013 (4)	0.028 (5)
C8	0.071 (5)	0.063 (5)	0.079 (6)	0.002 (4)	0.016 (4)	0.026 (4)

Geometric parameters (Å, º)

Sn1—C1^i	2.225 (5)	C1—H1C	0.9800
Sn1—C1	2.225 (5)	C2—C3	1.381 (8)
Sn1—Br1	2.690 (1)	C2—H2	0.9500
Sn1—Cl1^i	2.690 (1)	C3—C4	1.420 (9)
Sn1—Br1^i	2.690 (1)	C3—H3	0.9500
Sn1—Br2^i	2.6926 (8)	C4—C5	1.409 (9)
Sn1—Br2	2.6926 (8)	C5—C6	1.369 (8)
Sn1—Cl2^i	2.6926 (8)	C5—H5	0.9500
N1—C2	1.341 (9)	C6—H6	0.9500
N1—C6	1.341 (9)	C7—H7A	0.9800
N1—H1	0.8800	C7—H7B	0.9800
N2—C4	1.324 (7)	C7—H7C	0.9800
N2—C8	1.446 (9)	C8—H8A	0.9800
N2—C7	1.467 (9)	C8—H8B	0.9800
C1—H1A	0.9800	C8—H8C	0.9800
C1—H1B	0.9800
C1^i—Sn1—C1	180.0	Sn1—C1—H1A	109.5
C1^i—Sn1—Br1	88.38 (14)	Sn1—C1—H1B	109.5
C1—Sn1—Br1	91.62 (14)	H1A—C1—H1B	109.5
C1^i—Sn1—Cl1^i	91.62 (14)	Sn1—C1—H1C	109.5
C1—Sn1—Cl1^i	88.38 (14)	H1A—C1—H1C	109.5
Br1—Sn1—Cl1^i	180.0	H1B—C1—H1C	109.5
C1^i—Sn1—Br1^i	91.62 (14)	N1—C2—C3	121.1 (6)
C1—Sn1—Br1^i	88.38 (14)	N1—C2—H2	119.5
Br1—Sn1—Br1^i	180.0	C3—C2—H2	119.5
Cl1^i—Sn1—Br1^i	0.0	C2—C3—C4	120.0 (6)
C1^i—Sn1—Br2^i	89.83 (13)	C2—C3—H3	120.0
C1—Sn1—Br2^i	90.17 (13)	C4—C3—H3	120.0
Br1—Sn1—Br2^i	89.12 (3)	N2—C4—C5	122.5 (6)
Cl1^i—Sn1—Br2^i	90.88 (3)	N2—C4—C3	121.6 (6)
Br1^i—Sn1—Br2^i	90.88 (3)	C5—C4—C3	115.9 (6)
C1^i—Sn1—Br2	90.17 (13)	C6—C5—C4	121.5 (6)
C1—Sn1—Br2	89.83 (13)	C6—C5—H5	119.2
Br1—Sn1—Br2	90.88 (3)	C4—C5—H5	119.2
Cl1^i—Sn1—Br2	89.12 (3)	N1—C6—C5	120.4 (6)
Br1^i—Sn1—Br2	89.12 (3)	N1—C6—H6	119.8
Br2^i—Sn1—Br2	180.0	C5—C6—H6	119.8
C1^i—Sn1—Cl2^i	89.83 (13)	N2—C7—H7A	109.5
C1—Sn1—Cl2^i	90.17 (13)	N2—C7—H7B	109.5
Br1—Sn1—Cl2^i	89.12 (3)	H7A—C7—H7B	109.5
Cl1^i—Sn1—Cl2^i	90.88 (3)	N2—C7—H7C	109.5
Br1^i—Sn1—Cl2^i	90.88 (3)	H7A—C7—H7C	109.5
Br2^i—Sn1—Cl2^i	0.000 (13)	H7B—C7—H7C	109.5
Br2—Sn1—Cl2^i	180.0	N2—C8—H8A	109.5
C2—N1—C6	121.1 (6)	N2—C8—H8B	109.5
C2—N1—H1	119.4	H8A—C8—H8B	109.5
C6—N1—H1	119.4	N2—C8—H8C	109.5
C4—N2—C8	122.3 (6)	H8A—C8—H8C	109.5
C4—N2—C7	121.8 (6)	H8B—C8—H8C	109.5
C8—N2—C7	115.9 (6)
C6—N1—C2—C3	0.6 (9)	C2—C3—C4—N2	178.3 (5)
N1—C2—C3—C4	0.3 (10)	C2—C3—C4—C5	−1.1 (8)
C8—N2—C4—C5	−0.6 (9)	N2—C4—C5—C6	−178.3 (6)
C7—N2—C4—C5	−178.7 (6)	C3—C4—C5—C6	1.1 (9)
C8—N2—C4—C3	−180.0 (5)	C2—N1—C6—C5	−0.7 (9)
C7—N2—C4—C3	1.9 (9)	C4—C5—C6—N1	−0.2 (9)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Br1	0.88	2.60	3.316 (5)	139
N1—H1···Br2^i	0.88	2.81	3.458 (6)	132

Symmetry code: (i) −x+1, −y+1, −z+1.