Bis[4-(dimethyl­amino)pyridinium] 3.75-bromido-0.25-chloridodiphenyl­plumbate(IV)

The Pb^IV atom of the plumbate dianion in the title compound, (C₇H₁₁N)₂[Pb(Br_3.75Cl_0.25)(C₆H₅)₂], lies on a centre of inversion in a tetra­gonally compressed octa­hedral geometry. One of the attached Br atoms is disordered with respect to a Cl atom in a 7:1 ratio. The disordered halogen atom is an N—H...(Br/Cl) hydrogen-bond acceptor for the cation.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.005 Å
• Disorder in main residue
• R factor = 0.022
• wR factor = 0.048
• Data-to-parameter ratio = 20.0

checkCIF/PLATON results

No syntax errors found



Alert level C
            Value of measurement temperature given =   100.000
            Value of melting point given =     0.000
PLAT301_ALERT_3_C Main Residue  Disorder .........................      10.00 Perc.
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 ............       0.50 Ratio
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.82
PLAT077_ALERT_4_C Unitcell contains non-integer number of atoms ..          ?
PLAT731_ALERT_1_C Bond    Calc     0.87(3), Rep   0.870(10) ......       3.00 su-Ra
              N1   -H1      1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.87(3), Rep   0.870(10) ......       3.00 su-Ra
              N1   -H1      1.555   1.555

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      0.818
            Tmax scaled      0.331 Tmin scaled      0.287
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

   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

   5 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
   3 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check


checkCIF publication errors

Alert level G
PUBL013_ALERT_1_G The _publ_section_comment (discussion of study) is
            missing. This is required for a full paper submission (but is
            optional for an electronic paper).

   0 ALERT level A = Data missing that is essential or data in wrong format
   1 ALERT level G = General alerts. Data that may be required is missing

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Related literature

For the structure of the isostructural compound bis(4-dimethylaminopyridinium) tetrabromidodiphenylplumbate, see: Lo & Ng (2008).

S1. Experimental

Diphenyllead dichloride (1.3 g, 3 mmol) and 4-dimethylaminopyridine hydrobromide perbromide (1.1 g, 3 mmol) were heated in chloroform (100 ml) for an hour. The filtered solution when allowed to evaporate yielded large colorless crystals of (I).

S2. Refinement

The carbon-bound H-atoms were placed in calculated positions (C—H = 0.95–0.98 Å) and refined as riding with U_iso(H) = 1.2 to 1.5U_eq(C). The ammonium H atom was located in a difference Fourier map, and was refined with a distance constraint of N—H = 0.88 (1) Å; its U_iso value was refined.

The two independent halogen atoms were initially refined as full-occupancy Br atoms; however, the difference Fourier map had a deep hole near one of the two. When this atom was allowed to refine as a mixture of bromine and chlorine, the refinement converged, and it gave the Br:Cl ratio as 0.88:0.12. The ratio was subsequently fixed as 0.875:0.125. Attempts to model the Br and Cl atoms on separate sites were not successful.

The published (C₇H₁₁N)₂[PbBr₄(C₆H₅)₂] structure (Lo & Ng, 2008) does not contain any chlorine as the compound was synthesized by the cleavage of tetraphenyllead by 4-aminomethylpyridine hydrobromide perbromide.

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. View of the molecular structure of (I) at the 70% probability level. H atoms are drawn as spheres of arbitrary radius. Unlabelled atoms in the anion are generated by the symmetry operation (1 - x, 1 - y, 1 - z).

Bis[4-(dimethylamino)pyridinium] 3.75-bromido-0.25-chloridodiphenylplumbate(IV)

Crystal data

(C7H11N)2[PbBr3.75(C6H5)2Cl0.25]	F(000) = 867
Mr = 916.27	Dx = 2.102 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 4255 reflections
a = 9.5010 (2) Å	θ = 2.4–28.4°
b = 13.8916 (3) Å	µ = 11.05 mm^−1
c = 10.9851 (2) Å	T = 100 K
β = 92.996 (1)°	Faceted block, colourless
V = 1447.88 (5) Å^3	0.12 × 0.11 × 0.10 mm
Z = 2

Data collection

Bruker SMART APEX CCD diffractometer	3327 independent reflections
Radiation source: fine-focus sealed tube	2909 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
ω scans	θmax = 27.5°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −12→12
Tmin = 0.351, Tmax = 0.405	k = −15→18
10028 measured reflections	l = −14→14

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)] = 0.022	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.048	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0227P)^2 + 0.2619P] where P = (Fo^2 + 2Fc^2)/3
3327 reflections	(Δ/σ)max = 0.001
166 parameters	Δρmax = 0.77 e Å^−3
1 restraint	Δρmin = −0.52 e Å^−3

Special details

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.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Pb1	0.5000	0.5000	0.5000	0.01182 (5)
Br1	0.55819 (4)	0.61268 (2)	0.29147 (3)	0.01476 (8)	0.875
Br2	0.76221 (3)	0.40251 (2)	0.46037 (3)	0.01660 (8)
Cl1	0.55819 (4)	0.61268 (2)	0.29147 (3)	0.01476 (8)	0.125
N1	0.8894 (3)	0.5871 (2)	0.2345 (3)	0.0224 (7)
H1	0.815 (3)	0.582 (3)	0.277 (3)	0.042 (13)*
N2	1.1998 (3)	0.59111 (19)	−0.0113 (2)	0.0173 (6)
C1	0.6143 (3)	0.6021 (2)	0.6197 (3)	0.0138 (6)
C2	0.7445 (3)	0.6367 (2)	0.5890 (3)	0.0152 (7)
H2	0.7856	0.6156	0.5167	0.018*
C3	0.8144 (4)	0.7030 (2)	0.6660 (3)	0.0198 (7)
H3	0.9040	0.7271	0.6465	0.024*
C4	0.7533 (4)	0.7336 (2)	0.7709 (3)	0.0191 (7)
H4	0.8009	0.7790	0.8229	0.023*
C5	0.6228 (4)	0.6982 (2)	0.8003 (3)	0.0204 (7)
H5	0.5814	0.7194	0.8724	0.024*
C6	0.5527 (4)	0.6321 (2)	0.7248 (3)	0.0163 (7)
H6	0.4635	0.6076	0.7448	0.020*
C7	1.0060 (4)	0.5338 (3)	0.2555 (3)	0.0208 (7)
H7	1.0141	0.4941	0.3260	0.025*
C8	1.1124 (4)	0.5356 (2)	0.1781 (3)	0.0189 (7)
H8	1.1945	0.4980	0.1953	0.023*
C9	1.1019 (3)	0.5933 (2)	0.0715 (3)	0.0146 (7)
C10	0.9798 (4)	0.6523 (2)	0.0576 (3)	0.0189 (7)
H10	0.9701	0.6959	−0.0089	0.023*
C11	0.8778 (4)	0.6469 (2)	0.1382 (3)	0.0220 (8)
H11	0.7962	0.6860	0.1267	0.026*
C12	1.3282 (4)	0.5343 (3)	0.0091 (3)	0.0225 (7)
H12A	1.3034	0.4683	0.0313	0.034*
H12B	1.3872	0.5632	0.0752	0.034*
H12C	1.3803	0.5332	−0.0656	0.034*
C13	1.1938 (4)	0.6535 (3)	−0.1175 (3)	0.0267 (8)
H13A	1.0952	0.6658	−0.1434	0.040*
H13B	1.2414	0.6222	−0.1840	0.040*
H13C	1.2409	0.7146	−0.0970	0.040*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Pb1	0.01154 (9)	0.01443 (9)	0.00939 (8)	−0.00187 (6)	−0.00034 (6)	−0.00126 (6)
Br1	0.01359 (18)	0.01750 (17)	0.01320 (16)	0.00047 (13)	0.00073 (13)	0.00243 (12)
Br2	0.01506 (17)	0.02009 (17)	0.01462 (16)	0.00203 (12)	0.00038 (12)	−0.00043 (12)
Cl1	0.01359 (18)	0.01750 (17)	0.01320 (16)	0.00047 (13)	0.00073 (13)	0.00243 (12)
N1	0.0161 (17)	0.0309 (17)	0.0206 (16)	−0.0016 (13)	0.0056 (12)	−0.0050 (13)
N2	0.0201 (16)	0.0158 (14)	0.0162 (14)	0.0043 (11)	0.0029 (11)	0.0024 (11)
C1	0.0133 (17)	0.0130 (16)	0.0146 (16)	−0.0008 (12)	−0.0031 (12)	0.0003 (12)
C2	0.0157 (17)	0.0171 (16)	0.0127 (16)	0.0016 (13)	−0.0020 (12)	0.0004 (12)
C3	0.0186 (19)	0.0201 (18)	0.0204 (18)	−0.0036 (14)	−0.0008 (14)	0.0032 (13)
C4	0.024 (2)	0.0171 (18)	0.0156 (17)	−0.0024 (14)	−0.0081 (14)	−0.0015 (13)
C5	0.029 (2)	0.0191 (18)	0.0133 (16)	−0.0003 (14)	−0.0015 (14)	−0.0027 (13)
C6	0.0147 (18)	0.0197 (17)	0.0143 (16)	0.0007 (13)	−0.0017 (13)	0.0031 (13)
C7	0.022 (2)	0.0252 (18)	0.0149 (17)	−0.0029 (15)	0.0004 (14)	−0.0010 (14)
C8	0.0188 (18)	0.0211 (17)	0.0170 (17)	0.0021 (14)	0.0014 (13)	−0.0004 (13)
C9	0.0158 (17)	0.0164 (16)	0.0113 (15)	−0.0013 (12)	−0.0011 (12)	−0.0051 (12)
C10	0.0213 (19)	0.0171 (17)	0.0183 (18)	0.0024 (14)	−0.0009 (14)	−0.0008 (13)
C11	0.0188 (19)	0.0229 (19)	0.0242 (19)	0.0047 (14)	−0.0015 (14)	−0.0052 (14)
C12	0.0190 (19)	0.0306 (19)	0.0180 (18)	0.0059 (15)	0.0027 (14)	0.0008 (15)
C13	0.032 (2)	0.028 (2)	0.0203 (19)	0.0065 (16)	0.0057 (16)	0.0057 (15)

Geometric parameters (Å, º)

Pb1—C1^i	2.184 (3)	C4—C5	1.388 (5)
Pb1—C1	2.184 (3)	C4—H4	0.9500
Pb1—Br1	2.8523 (3)	C5—C6	1.385 (4)
Pb1—Cl1^i	2.8523 (3)	C5—H5	0.9500
Pb1—Br1^i	2.8523 (3)	C6—H6	0.9500
Pb1—Br2	2.8885 (3)	C7—C8	1.355 (4)
Pb1—Br2^i	2.8885 (3)	C7—H7	0.9500
N1—C7	1.342 (5)	C8—C9	1.419 (4)
N1—C11	1.345 (5)	C8—H8	0.9500
N1—H1	0.87 (1)	C9—C10	1.421 (4)
N2—C9	1.335 (4)	C10—C11	1.348 (5)
N2—C13	1.452 (4)	C10—H10	0.9500
N2—C12	1.461 (4)	C11—H11	0.9500
C1—C6	1.385 (4)	C12—H12A	0.9800
C1—C2	1.385 (4)	C12—H12B	0.9800
C2—C3	1.395 (4)	C12—H12C	0.9800
C2—H2	0.9500	C13—H13A	0.9800
C3—C4	1.383 (4)	C13—H13B	0.9800
C3—H3	0.9500	C13—H13C	0.9800
C1^i—Pb1—C1	180.00 (12)	C3—C4—C5	120.2 (3)
C1^i—Pb1—Br1	89.09 (8)	C3—C4—H4	119.9
C1—Pb1—Br1	90.91 (8)	C5—C4—H4	119.9
C1^i—Pb1—Cl1^i	90.91 (8)	C6—C5—C4	120.2 (3)
C1—Pb1—Cl1^i	89.09 (8)	C6—C5—H5	119.9
Br1—Pb1—Cl1^i	180.0	C4—C5—H5	119.9
C1^i—Pb1—Br1^i	90.91 (8)	C5—C6—C1	119.2 (3)
C1—Pb1—Br1^i	89.09 (8)	C5—C6—H6	120.4
Br1—Pb1—Br1^i	180.0	C1—C6—H6	120.4
Cl1^i—Pb1—Br1^i	0.000 (17)	N1—C7—C8	121.2 (3)
C1^i—Pb1—Br2	90.60 (8)	N1—C7—H7	119.4
C1—Pb1—Br2	89.40 (8)	C8—C7—H7	119.4
Br1—Pb1—Br2	86.065 (9)	C7—C8—C9	120.4 (3)
Cl1^i—Pb1—Br2	93.935 (9)	C7—C8—H8	119.8
Br1^i—Pb1—Br2	93.935 (9)	C9—C8—H8	119.8
C1^i—Pb1—Br2^i	89.40 (8)	N2—C9—C8	121.9 (3)
C1—Pb1—Br2^i	90.60 (8)	N2—C9—C10	122.3 (3)
Br1—Pb1—Br2^i	93.935 (9)	C8—C9—C10	115.9 (3)
Cl1^i—Pb1—Br2^i	86.065 (9)	C11—C10—C9	120.5 (3)
Br1^i—Pb1—Br2^i	86.065 (9)	C11—C10—H10	119.7
Br2—Pb1—Br2^i	180.0	C9—C10—H10	119.7
C7—N1—C11	120.6 (3)	N1—C11—C10	121.2 (3)
C7—N1—H1	124 (3)	N1—C11—H11	119.4
C11—N1—H1	116 (3)	C10—C11—H11	119.4
C9—N2—C13	122.3 (3)	N2—C12—H12A	109.5
C9—N2—C12	120.9 (3)	N2—C12—H12B	109.5
C13—N2—C12	116.3 (3)	H12A—C12—H12B	109.5
C6—C1—C2	121.3 (3)	N2—C12—H12C	109.5
C6—C1—Pb1	118.6 (2)	H12A—C12—H12C	109.5
C2—C1—Pb1	120.1 (2)	H12B—C12—H12C	109.5
C1—C2—C3	119.0 (3)	N2—C13—H13A	109.5
C1—C2—H2	120.5	N2—C13—H13B	109.5
C3—C2—H2	120.5	H13A—C13—H13B	109.5
C4—C3—C2	120.1 (3)	N2—C13—H13C	109.5
C4—C3—H3	120.0	H13A—C13—H13C	109.5
C2—C3—H3	120.0	H13B—C13—H13C	109.5
Br1—Pb1—C1—C6	133.5 (2)	C4—C5—C6—C1	−0.2 (5)
Cl1^i—Pb1—C1—C6	−46.5 (2)	C2—C1—C6—C5	0.2 (5)
Br1^i—Pb1—C1—C6	−46.5 (2)	Pb1—C1—C6—C5	−178.8 (2)
Br2—Pb1—C1—C6	−140.4 (2)	C11—N1—C7—C8	−2.8 (5)
Br2^i—Pb1—C1—C6	39.6 (2)	N1—C7—C8—C9	−0.8 (5)
Br1—Pb1—C1—C2	−45.5 (2)	C13—N2—C9—C8	−176.7 (3)
Cl1^i—Pb1—C1—C2	134.5 (2)	C12—N2—C9—C8	−4.9 (5)
Br1^i—Pb1—C1—C2	134.5 (2)	C13—N2—C9—C10	4.3 (5)
Br2—Pb1—C1—C2	40.6 (2)	C12—N2—C9—C10	176.2 (3)
Br2^i—Pb1—C1—C2	−139.4 (2)	C7—C8—C9—N2	−174.7 (3)
C6—C1—C2—C3	0.0 (5)	C7—C8—C9—C10	4.3 (5)
Pb1—C1—C2—C3	179.0 (2)	N2—C9—C10—C11	174.6 (3)
C1—C2—C3—C4	−0.3 (5)	C8—C9—C10—C11	−4.4 (5)
C2—C3—C4—C5	0.3 (5)	C7—N1—C11—C10	2.6 (5)
C3—C4—C5—C6	−0.1 (5)	C9—C10—C11—N1	1.1 (5)

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	0.87 (1)	2.49 (2)	3.260 (3)	148 (4)