3,5-Dicarboxypyridinium fluoride.

The cation of the title salt, C(7)H(6)NO(4) (+.)F(-), lies on a twofold rotation axis that passes through the N and 4-C atoms of the pyridine ring; the carb-oxy-lic acid substituent features unambiguous carbon-oxygen single and double bonds. The fluoride ion is a hydrogen-bond acceptor to two hy-droxy and one amino groups, these O-H⋯F and N-H⋯F hydrogen bonds leading to the formation of a layer structure parallel to the ab plane. The F atom lies on a position of 2 site symmetry.

Related literature

For the crystal structure of pyridine-3,5-dicarb­oxy­lic acid, see: Cowan et al. (2005 ▶); Takusagawa et al. (1973 ▶).

Experimental

Crystal data

C7H6NO4 +·F−

M = 187.13

Monoclinic,

a = 11.3959 (14) Å

b = 11.4503 (14) Å

c = 6.1601 (7) Å

β = 104.197 (2)°

V = 779.26 (16) Å3

Z = 4

Mo Kα radiation

μ = 0.15 mm−1

T = 293 K

0.40 × 0.35 × 0.25 mm

Data collection

Bruker SMART APEX diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.686, T max = 0.746

2354 measured reflections

883 independent reflections

750 reflections with I > 2σ(I)

R int = 0.012

Refinement

R[F 2 > 2σ(F 2)] = 0.034

wR(F 2) = 0.105

S = 1.11

883 reflections

67 parameters

2 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.29 e Å−3

Δρmin = −0.16 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; 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, 2010 ▶).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811021593/si2360sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811021593/si2360Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811021593/si2360Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C7H6NO4+·F−	F(000) = 384
Mr = 187.13	Dx = 1.595 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1129 reflections
a = 11.3959 (14) Å	θ = 2.6–28.4°
b = 11.4503 (14) Å	µ = 0.15 mm−1
c = 6.1601 (7) Å	T = 293 K
β = 104.197 (2)°	Block, yellow
V = 779.26 (16) Å3	0.40 × 0.35 × 0.25 mm
Z = 4

Bruker SMART APEX diffractometer	883 independent reflections
Radiation source: fine-focus sealed tube	750 reflections with I > 2σ(I)
graphite	Rint = 0.012
ω scans	θmax = 27.5°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→14
Tmin = 0.686, Tmax = 0.746	k = −13→14
2354 measured reflections	l = −8→5

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.105	H atoms treated by a mixture of independent and constrained refinement
S = 1.11	w = 1/[σ2(Fo2) + (0.0615P)2 + 0.1524P] where P = (Fo2 + 2Fc2)/3
883 reflections	(Δ/σ)max = 0.001
67 parameters	Δρmax = 0.29 e Å−3
2 restraints	Δρmin = −0.16 e Å−3

	x	y	z	Uiso*/Ueq
F1	0.5000	0.54662 (9)	0.7500	0.0536 (4)
O1	0.30965 (8)	0.64863 (8)	0.74566 (19)	0.0454 (3)
H1	0.3745 (12)	0.6097 (17)	0.747 (3)	0.069 (6)*
O2	0.21589 (9)	0.47552 (8)	0.71733 (17)	0.0428 (3)
H2	0.0000	0.8997 (9)	0.7500	0.050 (6)*
N1	0.0000	0.82283 (12)	0.7500	0.0346 (4)
C1	0.21620 (10)	0.58059 (11)	0.7326 (2)	0.0321 (3)
C2	0.10381 (10)	0.64621 (10)	0.73953 (19)	0.0294 (3)
C3	0.10135 (10)	0.76662 (11)	0.7394 (2)	0.0328 (3)
H3	0.1701	0.8087	0.7320	0.039*
C4	0.0000	0.58621 (14)	0.7500	0.0294 (4)
H4	0.0000	0.5050	0.7500	0.035*

	U11	U22	U33	U12	U13	U23
F1	0.0272 (6)	0.0273 (6)	0.1130 (11)	0.000	0.0301 (6)	0.000
O1	0.0245 (5)	0.0335 (5)	0.0811 (7)	0.0017 (4)	0.0183 (5)	−0.0042 (5)
O2	0.0370 (6)	0.0281 (5)	0.0663 (7)	0.0059 (4)	0.0184 (5)	−0.0033 (4)
N1	0.0268 (7)	0.0209 (7)	0.0570 (9)	0.000	0.0121 (6)	0.000
C1	0.0265 (6)	0.0299 (6)	0.0409 (7)	0.0029 (5)	0.0102 (5)	−0.0008 (5)
C2	0.0249 (6)	0.0254 (6)	0.0385 (6)	0.0012 (4)	0.0087 (5)	−0.0012 (4)
C3	0.0239 (6)	0.0260 (6)	0.0495 (7)	−0.0025 (4)	0.0108 (5)	−0.0004 (5)
C4	0.0272 (8)	0.0218 (7)	0.0394 (9)	0.000	0.0085 (6)	0.000

O1—C1	1.306 (1)	C1—C2	1.495 (2)
O1—H1	0.86 (1)	C2—C3	1.379 (2)
O2—C1	1.207 (2)	C2—C4	1.383 (1)
N1—C3i	1.338 (1)	C3—H3	0.9300
N1—C3	1.338 (1)	C4—C2i	1.383 (1)
N1—H2	0.88 (1)	C4—H4	0.9300
C1—O1—H1	112.1 (14)	C3—C2—C1	121.33 (11)
C3i—N1—C3	122.48 (15)	C4—C2—C1	120.03 (11)
C3i—N1—H2	118.76 (7)	N1—C3—C2	119.92 (11)
C3—N1—H2	118.76 (7)	N1—C3—H3	120.0
O2—C1—O1	125.90 (11)	C2—C3—H3	120.0
O2—C1—C2	121.15 (11)	C2—C4—C2i	120.44 (15)
O1—C1—C2	112.95 (11)	C2—C4—H4	119.8
C3—C2—C4	118.62 (11)	C2i—C4—H4	119.8
O2—C1—C2—C3	−174.90 (12)	C4—C2—C3—N1	0.20 (16)
O1—C1—C2—C3	5.39 (16)	C1—C2—C3—N1	−178.73 (9)
O2—C1—C2—C4	6.18 (17)	C3—C2—C4—C2i	−0.10 (8)
O1—C1—C2—C4	−173.53 (9)	C1—C2—C4—C2i	178.85 (11)
C3i—N1—C3—C2	−0.10 (8)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···F1	0.86 (1)	1.60 (1)	2.458 (1)	176 (2)
N1—H2···F1ii	0.88 (1)	1.68 (1)	2.563 (2)	180

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯F1	0.86 (1)	1.60 (1)	2.458 (1)	176 (2)
N1—H2⋯F1i	0.88 (1)	1.68 (1)	2.563 (2)	180

Symmetry code: (i) .