4,4′-Bipyridinium μ-oxo-bis(fluoro­dioxochromate)

In the cation of the title compound, (C₁₀H₁₀N₂)[Cr₂O₅F₂], a mirror plane passes through the N atoms of the two pyridine rings and the —C—C— bridge connecting them, while the two halves of the anion are symmetry-related across a mirror plane passing through the O atom at the centre of the anion. Chiral chains of the title compound are built up via N—H...O and N—H...F hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.036
• wR factor = 0.079
• Data-to-parameter ratio = 13.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT232_ALERT_2_B Hirshfeld Test Diff (M-X)  Cr1    -   F1      ..      11.35 su

Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        Cr1
PLAT432_ALERT_2_C Short Inter X...Y Contact  O1     ..  C6      ..       3.01 Ang.
PLAT731_ALERT_1_C Bond    Calc     0.83(5), Rep     0.83(2) ......       2.50 su-Ra
              N1   -H11     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.83(5), Rep     0.83(2) ......       2.50 su-Ra
              N1   -H11     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.83(5), Rep     0.83(2) ......       2.50 su-Ra
              N1   -H11     1.555   1.555
PLAT736_ALERT_1_C H...A   Calc     2.38(3), Rep   2.380(14) ......       2.14 su-Ra
              H11  -F1      1.555   6.558
PLAT736_ALERT_1_C H...A   Calc     2.38(3), Rep   2.380(14) ......       2.14 su-Ra
              H11  -F1      1.555   3.457
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.14 Ratio

Alert level G
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
   9 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   8 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
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and PARST (Nardelli, 1995).

4,4'bipyridinium di(fluorotrioxochromate)

Crystal data

C10H10N2^2+·Cr2O5F2^2^−	F(000) = 760
Mr = 380.20	Dx = 1.937 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 5320 reflections
a = 20.883 (3) Å	θ = 2–27°
b = 12.3458 (13) Å	µ = 1.71 mm^−1
c = 5.0566 (5) Å	T = 293 K
V = 1303.7 (3) Å^3	Prism, orange
Z = 4	0.58 × 0.32 × 0.15 mm

Data collection

STOE IPDS 2 diffractometer	1495 independent reflections
Radiation source: fine-focus sealed tube	819 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.066
Detector resolution: 6.67 pixels mm^-1	θmax = 27.1°, θmin = 2.0°
ω scans	h = −23→26
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −15→15
Tmin = 0.524, Tmax = 0.772	l = −5→6
5320 measured reflections

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)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.079	H atoms treated by a mixture of independent and constrained refinement
S = 0.85	w = 1/[σ^2(Fo^2) + (0.031P)^2] where P = (Fo^2 + 2Fc^2)/3
1495 reflections	(Δ/σ)max = 0.001
109 parameters	Δρmax = 0.29 e Å^−3
3 restraints	Δρmin = −0.29 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.

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.

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

	x	y	z	Uiso*/Ueq
C1	0.27541 (19)	0.1561 (4)	1.0844 (8)	0.0533 (11)
H1	0.2569	0.0918	1.1422	0.064*
C2	0.32605 (17)	0.1541 (3)	0.9084 (7)	0.0459 (10)
H2	0.3423	0.0882	0.8498	0.055*
C3	0.3526 (2)	0.2500	0.8192 (11)	0.0325 (11)
C4	0.4071 (2)	0.2500	0.6296 (9)	0.0295 (11)
C5	0.43347 (18)	0.1548 (3)	0.5363 (8)	0.0472 (10)
H5	0.4174	0.0887	0.5942	0.057*
C6	0.48282 (18)	0.1568 (4)	0.3604 (8)	0.0521 (11)
H6	0.5004	0.0921	0.3002	0.063*
N1	0.2537 (2)	0.2500	1.1693 (11)	0.0515 (13)
N2	0.5059 (2)	0.2500	0.2749 (9)	0.0412 (12)
O1	0.57717 (13)	0.0318 (2)	0.9225 (6)	0.0496 (7)
O2	0.62822 (15)	0.1100 (3)	0.4869 (5)	0.0614 (7)
F1	0.69678 (11)	0.1048 (2)	0.9196 (5)	0.0731 (8)
O3	0.59440 (19)	0.2500	0.8917 (8)	0.0504 (11)
Cr1	0.62576 (3)	0.11955 (4)	0.80103 (10)	0.03642 (17)
H11	0.233 (3)	0.2500	1.309 (8)	0.062 (19)*
H22	0.5389 (17)	0.2500	0.182 (9)	0.045 (15)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.045 (2)	0.061 (3)	0.054 (3)	−0.008 (2)	0.0064 (19)	0.014 (2)
C2	0.039 (2)	0.052 (2)	0.046 (2)	0.0063 (19)	0.0148 (17)	0.0076 (18)
C3	0.028 (2)	0.039 (3)	0.031 (3)	0.000	−0.001 (2)	0.000
C4	0.022 (2)	0.041 (3)	0.026 (3)	0.000	0.0004 (19)	0.000
C5	0.044 (2)	0.039 (2)	0.059 (3)	−0.0085 (19)	0.0188 (19)	−0.0109 (19)
C6	0.046 (2)	0.050 (2)	0.060 (3)	−0.008 (2)	0.017 (2)	−0.018 (2)
N1	0.034 (3)	0.085 (4)	0.036 (3)	0.000	0.010 (2)	0.000
N2	0.029 (2)	0.062 (3)	0.033 (3)	0.000	0.006 (2)	0.000
O1	0.0432 (14)	0.0470 (15)	0.0586 (19)	−0.0099 (14)	0.0061 (13)	−0.0105 (13)
O2	0.0561 (15)	0.096 (2)	0.0317 (12)	0.002 (2)	−0.0015 (13)	−0.0148 (15)
F1	0.0546 (14)	0.097 (2)	0.0675 (17)	−0.0007 (16)	−0.0065 (11)	−0.0054 (16)
O3	0.061 (2)	0.038 (2)	0.052 (3)	0.000	0.0273 (19)	0.000
Cr1	0.0319 (2)	0.0459 (3)	0.0315 (3)	−0.0008 (4)	0.0012 (3)	−0.0090 (3)

Geometric parameters (Å, º)

C1—N1	1.317 (5)	C6—N2	1.320 (5)
C1—C2	1.382 (5)	C6—H6	0.9300
C1—H1	0.9300	N1—C1^i	1.317 (5)
C2—C3	1.382 (4)	N1—H11	0.83 (2)
C2—H2	0.9300	N2—C6^i	1.320 (5)
C3—C2^i	1.382 (4)	N2—H22	0.83 (2)
C3—C4	1.489 (6)	O1—Cr1	1.606 (3)
C4—C5^i	1.381 (4)	O2—Cr1	1.594 (2)
C4—C5	1.381 (4)	F1—Cr1	1.610 (2)
C5—C6	1.362 (5)	O3—Cr1^i	1.7979 (16)
C5—H5	0.9300	O3—Cr1	1.7979 (16)
N1—C1—C2	119.3 (4)	N2—C6—H6	119.8
N1—C1—H1	120.4	C5—C6—H6	119.8
C2—C1—H1	120.4	C1^i—N1—C1	123.3 (5)
C3—C2—C1	120.1 (4)	C1^i—N1—H11	117.2 (8)
C3—C2—H2	120.0	C1—N1—H11	117.2 (8)
C1—C2—H2	120.0	C6^i—N2—C6	121.3 (5)
C2—C3—C2^i	117.8 (5)	C6^i—N2—H22	119.0 (4)
C2—C3—C4	121.1 (2)	C6—N2—H22	119.0 (4)
C2^i—C3—C4	121.1 (2)	Cr1^i—O3—Cr1	127.2 (2)
C5^i—C4—C5	116.7 (5)	O2—Cr1—O1	110.59 (16)
C5^i—C4—C3	121.7 (2)	O2—Cr1—F1	109.46 (16)
C5—C4—C3	121.7 (2)	O1—Cr1—F1	111.32 (15)
C6—C5—C4	120.6 (4)	O2—Cr1—O3	109.38 (17)
C6—C5—H5	119.7	O1—Cr1—O3	106.05 (15)
C4—C5—H5	119.7	F1—Cr1—O3	109.98 (17)
N2—C6—C5	120.4 (4)
N1—C1—C2—C3	−1.2 (7)	C3—C4—C5—C6	179.2 (4)
C1—C2—C3—C2^i	−1.1 (8)	C4—C5—C6—N2	−0.5 (7)
C1—C2—C3—C4	−180.0 (4)	C2—C1—N1—C1^i	3.8 (9)
C2—C3—C4—C5^i	179.1 (5)	C5—C6—N2—C6^i	1.4 (8)
C2^i—C3—C4—C5^i	0.3 (6)	Cr1^i—O3—Cr1—O2	−57.8 (3)
C2—C3—C4—C5	−0.3 (6)	Cr1^i—O3—Cr1—O1	−177.1 (3)
C2^i—C3—C4—C5	−179.1 (5)	Cr1^i—O3—Cr1—F1	62.5 (3)
C5^i—C4—C5—C6	−0.3 (8)

Symmetry code: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H11···F1^ii	0.83 (2)	2.38 (1)	2.991 (5)	131 (1)
N2—H22···O3^iii	0.83 (2)	1.87 (3)	2.678 (6)	162 (5)
N1—H11···F1^iv	0.83 (2)	2.38 (1)	2.991 (5)	131 (1)

Symmetry codes: (ii) x−1/2, y, −z+5/2; (iii) x, y, z−1; (iv) x−1/2, −y+1/2, −z+5/2.