2-Amino-5-bromo­pyridine–benzoic acid (1/1)

In the title adduct, C₅H₅BrN₂·C₇H₆O₂, the carboxyl group of the benzoic acid mol­ecule is twisted away from the attached ring by 12.97 (11)°. The 2-amino-5-bromo­pyridine mol­ecules inter­act with the carboxylic group of neighbouring benzoic acid mol­ecules through N—H...O and O—H...N hydrogen bonds, forming cyclic R₂²(8) hydrogen-bonded motifs and linking the mol­ecules into a two-dimensional network lying parallel to (100). The crystal structure is further stabilized by weak C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.045
• wR factor = 0.123
• Data-to-parameter ratio = 35.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.50
PLAT431_ALERT_2_C Short Inter HL..A Contact  Br1    ..  Br1     ..       3.53 Ang.
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          6
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         34
PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF ....          1
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ          ?
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         32

Alert level G
PLAT063_ALERT_4_G Crystal Size Likely too Large for Beam Size ....       0.61 mm

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

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 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 A
PUBL022_ALERT_1_A There is a mismatched ~ on line 130
              In the title compound, C~5~H~5~BrN~2.C~7~H~6~O~2~, the carboxyl group of the
              If you require a ~ then it should be escaped
              with a \, i.e. \~
              Otherwise there must be a matching closing ~, e.g. C~2~H~4~

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

---

S1. Comment

Pyridine and its derivatives play an important role in heterocyclic chemistry (Pozharski et al., 1997; Katritzky et al., 1996). They are often involved in hydrogen-bond interactions (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997). The crystal structures of 2-amino-5-bromopyridine (Goubitz et al., 2001) and 2-amino-5-bromopyridinium propynoate (Vaday & Foxman, 1999) have been reported in the literature. In the present study, the hydrogen-bonding patterns in the 2-amino-5-bromopyridine benzoic acid (1/1) cocrystal are investigated.

The asymmetric unit (Fig 1), contains one 2-amino-5-bromopyridine molecule and one benzoic acid molecule. The 2-amino-5-bromopyridine molecule is planar, with a maximum deviation of 0.024 (2)Å for atom N2. The carboxyl group of the benzoic acid molecule is twisted away from the attached ring by 12.97 (11)° . The bond lengths (Allen et al., 1987) and angles are normal.

In the crystal packing (Fig. 2), the 2-amino-5-bromopyridine molecules interact with the carboxylic group of the respective benzoic acid molecules through N2—H2A···O2 and O1—H1···N1 hydrogen bonds, forming a cyclic hydrogen-bonded motif R₂²(8) (Bernstein et al., 1995), and linking the molecules into 2-dimensional networks parallel to the (100) plane. The crystal structure is further stabilized by strong N2—H2B···O1 and weak C7—H7···O2 (Table 1) hydrogen bonds.

Related literature

For background to the chemistry of substituted pyridines, see: Pozharski et al. (1997); Katritzky et al. (1996). For related structures, see: Goubitz et al. (2001); Vaday & Foxman (1999). For details of hydrogen bonding, see: Jeffrey & Saenger (1991); Jeffrey (1997); Scheiner (1997). For hydrogen-bond motifs, see: Bernstein et al. (1995); For bond-length data, see: Allen et al. (1987). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

S2. Experimental

A hot methanol solution (20 ml) of 2-amino-5-bromopyridine (87 mg, Aldrich) and benzoic acid (61 mg, Merck) were mixed and warmed over a heating magnetic stirrer for a few minutes. The resulting solution was allowed to cool slowly at room temperature and crystals of the title compound appeared after a few days.

S3. Refinement

All hydrogen atoms were positioned geometrically [C–H = 0.93 Å, N–H = 0.86 Å and O–H = 0.82 Å] and were refined using a riding model, with U_iso(H) = 1.2 U_eq(C, N) or 1.5 U_eq(O).

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. The asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The crystal packing of the title compound, showing hydrogen-bonded (dashed lines) networks.

2-Amino-5-bromopyridine–benzoic acid (1/1)

Crystal data

C5H5BrN2·C7H6O2	F(000) = 592
Mr = 295.14	Dx = 1.663 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3648 reflections
a = 18.5614 (16) Å	θ = 3.8–32.0°
b = 5.1769 (5) Å	µ = 3.48 mm^−1
c = 12.3613 (11) Å	T = 100 K
β = 97.016 (2)°	Plate, colourless
V = 1178.91 (19) Å^3	0.61 × 0.21 × 0.07 mm
Z = 4

Data collection

Bruker APEX DUO CCD area-detector diffractometer	5495 independent reflections
Radiation source: fine-focus sealed tube	3709 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.057
ϕ and ω scans	θmax = 35.9°, θmin = 3.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −30→30
Tmin = 0.228, Tmax = 0.788	k = −8→8
19825 measured reflections	l = −20→20

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.123	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.064P)^2] where P = (Fo^2 + 2Fc^2)/3
5495 reflections	(Δ/σ)max = 0.001
155 parameters	Δρmax = 1.25 e Å^−3
0 restraints	Δρmin = −0.50 e Å^−3

Special details

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) k.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
Br1	0.470134 (11)	0.30630 (5)	0.886018 (18)	0.02683 (8)
N1	0.31375 (10)	−0.1799 (3)	0.73265 (14)	0.0191 (3)
N2	0.25884 (11)	−0.2217 (4)	0.55605 (15)	0.0252 (4)
H2A	0.2364	−0.3558	0.5758	0.030*
H2B	0.2519	−0.1704	0.4894	0.030*
C1	0.30452 (10)	−0.0928 (4)	0.62906 (16)	0.0188 (3)
C2	0.34283 (11)	0.1260 (4)	0.59759 (17)	0.0214 (4)
H2	0.3351	0.1861	0.5262	0.026*
C3	0.39160 (12)	0.2490 (4)	0.67336 (19)	0.0231 (4)
H3	0.4172	0.3930	0.6543	0.028*
C4	0.40175 (11)	0.1516 (4)	0.78013 (17)	0.0210 (4)
C5	0.36211 (11)	−0.0591 (4)	0.80675 (16)	0.0206 (4)
H5	0.3688	−0.1204	0.8780	0.025*
O1	0.23842 (7)	0.4732 (3)	0.82571 (10)	0.0188 (3)
H1	0.2668	0.5550	0.7929	0.028*
O2	0.19345 (9)	0.3546 (3)	0.65709 (11)	0.0217 (3)
C7	0.13808 (11)	0.1436 (4)	0.91317 (15)	0.0186 (4)
H7	0.1616	0.2660	0.9600	0.022*
C8	0.09178 (11)	−0.0370 (4)	0.95201 (16)	0.0215 (4)
H8	0.0842	−0.0341	1.0250	0.026*
C9	0.05710 (11)	−0.2199 (4)	0.88304 (18)	0.0215 (4)
H9	0.0265	−0.3401	0.9097	0.026*
C10	0.06795 (12)	−0.2244 (4)	0.77347 (18)	0.0217 (4)
H10	0.0446	−0.3477	0.7269	0.026*
C11	0.11352 (10)	−0.0450 (4)	0.73404 (15)	0.0191 (3)
H11	0.1205	−0.0473	0.6608	0.023*
C12	0.14884 (10)	0.1389 (4)	0.80347 (15)	0.0163 (3)
C13	0.19580 (10)	0.3321 (4)	0.75609 (15)	0.0163 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.02372 (11)	0.02522 (13)	0.03212 (12)	−0.00568 (8)	0.00565 (8)	−0.00818 (9)
N1	0.0222 (7)	0.0160 (8)	0.0196 (7)	−0.0029 (6)	0.0045 (6)	−0.0009 (6)
N2	0.0331 (9)	0.0235 (9)	0.0182 (7)	−0.0074 (8)	0.0000 (7)	0.0037 (7)
C1	0.0201 (8)	0.0154 (8)	0.0212 (8)	0.0012 (7)	0.0041 (7)	0.0016 (7)
C2	0.0221 (8)	0.0194 (9)	0.0239 (8)	0.0008 (7)	0.0076 (7)	0.0056 (8)
C3	0.0208 (8)	0.0181 (9)	0.0320 (10)	−0.0006 (7)	0.0097 (8)	0.0032 (8)
C4	0.0191 (8)	0.0176 (9)	0.0268 (9)	−0.0005 (7)	0.0053 (7)	−0.0045 (7)
C5	0.0220 (8)	0.0194 (9)	0.0208 (8)	−0.0005 (8)	0.0043 (7)	0.0011 (7)
O1	0.0209 (6)	0.0193 (7)	0.0159 (6)	−0.0052 (6)	0.0013 (5)	0.0003 (5)
O2	0.0310 (7)	0.0199 (7)	0.0145 (5)	−0.0032 (6)	0.0043 (5)	0.0000 (5)
C7	0.0219 (8)	0.0183 (9)	0.0153 (7)	−0.0007 (7)	0.0010 (6)	0.0010 (7)
C8	0.0225 (8)	0.0226 (10)	0.0199 (8)	−0.0018 (8)	0.0041 (7)	0.0052 (8)
C9	0.0207 (8)	0.0165 (9)	0.0277 (9)	−0.0007 (7)	0.0043 (7)	0.0054 (8)
C10	0.0218 (8)	0.0168 (9)	0.0266 (9)	−0.0009 (7)	0.0027 (7)	−0.0033 (8)
C11	0.0214 (8)	0.0171 (9)	0.0190 (8)	0.0013 (7)	0.0033 (6)	−0.0029 (7)
C12	0.0176 (7)	0.0141 (8)	0.0173 (7)	0.0018 (6)	0.0031 (6)	0.0008 (6)
C13	0.0191 (8)	0.0143 (8)	0.0158 (7)	0.0022 (7)	0.0028 (6)	0.0002 (6)

Geometric parameters (Å, º)

Br1—C4	1.887 (2)	O1—H1	0.8200
N1—C1	1.349 (3)	O2—C13	1.225 (2)
N1—C5	1.355 (3)	C7—C8	1.394 (3)
N2—C1	1.339 (3)	C7—C12	1.395 (2)
N2—H2A	0.8600	C7—H7	0.9300
N2—H2B	0.8600	C8—C9	1.380 (3)
C1—C2	1.417 (3)	C8—H8	0.9300
C2—C3	1.377 (3)	C9—C10	1.394 (3)
C2—H2	0.9300	C9—H9	0.9300
C3—C4	1.404 (3)	C10—C11	1.384 (3)
C3—H3	0.9300	C10—H10	0.9300
C4—C5	1.378 (3)	C11—C12	1.391 (3)
C5—H5	0.9300	C11—H11	0.9300
O1—C13	1.317 (2)	C12—C13	1.493 (3)
C1—N1—C5	118.98 (18)	C8—C7—H7	120.3
C1—N2—H2A	120.0	C12—C7—H7	120.3
C1—N2—H2B	120.0	C9—C8—C7	120.53 (18)
H2A—N2—H2B	120.0	C9—C8—H8	119.7
N2—C1—N1	118.04 (19)	C7—C8—H8	119.7
N2—C1—C2	120.74 (19)	C8—C9—C10	120.01 (19)
N1—C1—C2	121.21 (19)	C8—C9—H9	120.0
C3—C2—C1	119.56 (19)	C10—C9—H9	120.0
C3—C2—H2	120.2	C11—C10—C9	119.9 (2)
C1—C2—H2	120.2	C11—C10—H10	120.1
C2—C3—C4	118.38 (19)	C9—C10—H10	120.1
C2—C3—H3	120.8	C10—C11—C12	120.26 (18)
C4—C3—H3	120.8	C10—C11—H11	119.9
C5—C4—C3	119.6 (2)	C12—C11—H11	119.9
C5—C4—Br1	120.26 (16)	C11—C12—C7	119.95 (18)
C3—C4—Br1	120.10 (16)	C11—C12—C13	118.04 (16)
N1—C5—C4	122.22 (19)	C7—C12—C13	121.98 (18)
N1—C5—H5	118.9	O2—C13—O1	123.04 (18)
C4—C5—H5	118.9	O2—C13—C12	120.31 (18)
C13—O1—H1	109.5	O1—C13—C12	116.65 (16)
C8—C7—C12	119.37 (19)
C5—N1—C1—N2	177.14 (19)	C7—C8—C9—C10	−0.3 (3)
C5—N1—C1—C2	−1.8 (3)	C8—C9—C10—C11	−0.1 (3)
N2—C1—C2—C3	−177.5 (2)	C9—C10—C11—C12	0.4 (3)
N1—C1—C2—C3	1.4 (3)	C10—C11—C12—C7	−0.3 (3)
C1—C2—C3—C4	0.1 (3)	C10—C11—C12—C13	−178.42 (19)
C2—C3—C4—C5	−1.2 (3)	C8—C7—C12—C11	0.0 (3)
C2—C3—C4—Br1	178.02 (16)	C8—C7—C12—C13	177.99 (19)
C1—N1—C5—C4	0.6 (3)	C11—C12—C13—O2	12.0 (3)
C3—C4—C5—N1	0.9 (3)	C7—C12—C13—O2	−166.00 (19)
Br1—C4—C5—N1	−178.36 (15)	C11—C12—C13—O1	−168.26 (18)
C12—C7—C8—C9	0.3 (3)	C7—C12—C13—O1	13.7 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1^i	0.82	1.83	2.626 (2)	162
N2—H2A···O2^ii	0.86	2.02	2.866 (3)	167
N2—H2B···O1^iii	0.86	2.25	3.105 (2)	171
C7—H7···O2^iv	0.93	2.51	3.064 (2)	118

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