The title salt, C
6H
9N
2+·C
2F
3O
2−, is a monoclinic polymorph of a previously reported structure [Hemamalini & Fun (2010).
Acta Cryst. E
66, o781–o782]. In the crystal structure, the cations and anions are linked by two different types of N—H

O hydrogen bonds, forming cation–anion pairs. These pairs are hydrogen bonded to neighbouring pairs
via another N—H

O hydrogen bonds involving an H atom of the NH
2 group and one of the O atoms of the COO
− group into a chain extended along the
b axis.
Supporting information
CCDC reference: 774282
Key indicators
- Single-crystal X-ray study
- T = 100 K
- Mean
(C-C) = 0.002 Å
- R factor = 0.035
- wR factor = 0.098
- Data-to-parameter ratio = 14.6
checkCIF/PLATON results
No syntax errors found
Alert level A
DIFF019_ALERT_1_A _diffrn_standards_number is missing
Number of standards used in measurement.
DIFF020_ALERT_1_A _diffrn_standards_interval_count and
_diffrn_standards_interval_time are missing. Number of measurements
between standards or time (min) between standards.
DIFF022_ALERT_1_A _diffrn_standards_decay_% is missing
Percentage decrease in standards intensity.
Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low ....... 0.97
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L= 0.600 43
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L= 0.600 77
3 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
3 ALERT level C = Check and explain
0 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
2 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
The title compound was obtained accidently from the reaction between
2,2,2-trifluoroacetamide, phosphorus pentachloride and formic acid and then
the treatment of 2-amino-4-methylpyridine and triethylamine. The crystal was
obtained from chloroform and n-heptane at room temperature.
The H atoms of the NH2 group were located from the difference Fourier synthesis
and refined isotropically, no restraints were used. Finally, the geometrical
and thermal parameters obtained for these H-atoms, as well as parameters of
the hydrogen bonds for these H-atoms included, were rather realistic. The H(C)
atom positions were calculated and refined in isotropic approximation in
riding model with the Uiso(H) parameters equal to 1.2 Ueq(Ci) for the aromatic
C atoms, for methyl groups equal to 1.5 Ueq(Cii), where U(Ci) and U(Cii) are
respectively the equivalent thermal parameters of the carbon atoms to which
corresponding H atoms are bonded.
Data collection: SMART (Bruker, 2005); cell refinement: SAINT (Bruker 2005); data reduction: SAINT (Bruker 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
2-Amino-4-methylpyridinium trifluoroacetate
top
Crystal data top
C6H9N2+·C2F3O2− | F(000) = 456 |
Mr = 222.17 | Dx = 1.549 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 5265 reflections |
a = 8.5315 (7) Å | θ = 2.7–28.0° |
b = 11.4901 (9) Å | µ = 0.15 mm−1 |
c = 9.7206 (8) Å | T = 100 K |
β = 90.820 (1)° | Block, colorless |
V = 952.79 (13) Å3 | 0.30 × 0.20 × 0.10 mm |
Z = 4 | |
Data collection top
Bruker SMART APEX diffractometer | 1784 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.036 |
Graphite monochromator | θmax = 28.2°, θmin = 2.4° |
ϕ and ω scans | h = −5→11 |
10752 measured reflections | k = −14→14 |
2197 independent reflections | l = −12→12 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.035 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.098 | w = 1/[σ2(Fo2) + (0.0474P)2 + 0.2454P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.001 |
2197 reflections | Δρmax = 0.29 e Å−3 |
150 parameters | Δρmin = −0.23 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0084 (16) |
Crystal data top
C6H9N2+·C2F3O2− | V = 952.79 (13) Å3 |
Mr = 222.17 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.5315 (7) Å | µ = 0.15 mm−1 |
b = 11.4901 (9) Å | T = 100 K |
c = 9.7206 (8) Å | 0.30 × 0.20 × 0.10 mm |
β = 90.820 (1)° | |
Data collection top
Bruker SMART APEX diffractometer | 1784 reflections with I > 2σ(I) |
10752 measured reflections | Rint = 0.036 |
2197 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.098 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.29 e Å−3 |
2197 reflections | Δρmin = −0.23 e Å−3 |
150 parameters | |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are
estimated using the full covariance matrix. The cell esds are taken into
account individually in the estimation of esds in distances, angles and
torsion angles; correlations between esds in cell parameters are only used
when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds 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 (Å2) top | x | y | z | Uiso*/Ueq | |
F1 | 0.16929 (11) | 0.27679 (7) | 1.06142 (10) | 0.0350 (2) | |
F2 | 0.08357 (10) | 0.40806 (8) | 0.92121 (10) | 0.0358 (2) | |
F3 | 0.25375 (10) | 0.45302 (7) | 1.07851 (9) | 0.0316 (2) | |
O1 | 0.36035 (11) | 0.23798 (8) | 0.85540 (11) | 0.0259 (2) | |
O2 | 0.41240 (11) | 0.42938 (8) | 0.83832 (10) | 0.0257 (2) | |
N1 | 0.61429 (13) | 0.37742 (9) | 0.62595 (12) | 0.0212 (2) | |
H1B | 0.544 (2) | 0.3930 (17) | 0.699 (2) | 0.048 (5)* | |
N2 | 0.56684 (13) | 0.18015 (10) | 0.63958 (12) | 0.0223 (3) | |
H2C | 0.504 (2) | 0.1964 (16) | 0.711 (2) | 0.040 (5)* | |
H2B | 0.588 (2) | 0.1040 (16) | 0.6158 (18) | 0.034 (5)* | |
C1 | 0.68436 (16) | 0.47274 (12) | 0.56989 (15) | 0.0251 (3) | |
H1A | 0.6618 | 0.5480 | 0.6049 | 0.030* | |
C2 | 0.78596 (16) | 0.46100 (12) | 0.46475 (15) | 0.0250 (3) | |
H2A | 0.8341 | 0.5277 | 0.4261 | 0.030* | |
C3 | 0.81986 (15) | 0.34848 (12) | 0.41287 (14) | 0.0214 (3) | |
C4 | 0.74763 (14) | 0.25417 (11) | 0.47012 (13) | 0.0206 (3) | |
H4A | 0.7689 | 0.1784 | 0.4359 | 0.025* | |
C5 | 0.64122 (14) | 0.26797 (11) | 0.58005 (14) | 0.0196 (3) | |
C6 | 0.93335 (16) | 0.33574 (13) | 0.29694 (15) | 0.0260 (3) | |
H6A | 0.9287 | 0.2560 | 0.2612 | 0.039* | |
H6B | 1.0398 | 0.3523 | 0.3307 | 0.039* | |
H6C | 0.9055 | 0.3905 | 0.2233 | 0.039* | |
C7 | 0.34308 (14) | 0.34184 (11) | 0.88424 (14) | 0.0200 (3) | |
C8 | 0.21258 (15) | 0.36940 (11) | 0.98849 (15) | 0.0236 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
F1 | 0.0412 (5) | 0.0257 (5) | 0.0385 (5) | −0.0036 (4) | 0.0209 (4) | 0.0027 (4) |
F2 | 0.0220 (4) | 0.0367 (5) | 0.0488 (6) | 0.0070 (3) | 0.0017 (4) | −0.0026 (4) |
F3 | 0.0328 (5) | 0.0271 (5) | 0.0350 (5) | −0.0012 (3) | 0.0096 (4) | −0.0114 (4) |
O1 | 0.0294 (5) | 0.0168 (5) | 0.0319 (6) | −0.0008 (4) | 0.0099 (4) | −0.0027 (4) |
O2 | 0.0292 (5) | 0.0179 (5) | 0.0303 (6) | −0.0033 (4) | 0.0105 (4) | 0.0005 (4) |
N1 | 0.0223 (5) | 0.0177 (5) | 0.0237 (6) | 0.0006 (4) | 0.0044 (4) | −0.0015 (5) |
N2 | 0.0250 (6) | 0.0168 (6) | 0.0253 (6) | −0.0007 (4) | 0.0073 (5) | −0.0007 (5) |
C1 | 0.0272 (7) | 0.0168 (6) | 0.0314 (8) | −0.0007 (5) | 0.0026 (6) | −0.0014 (5) |
C2 | 0.0250 (7) | 0.0200 (7) | 0.0302 (8) | −0.0033 (5) | 0.0032 (5) | 0.0040 (5) |
C3 | 0.0181 (6) | 0.0239 (7) | 0.0223 (7) | −0.0005 (5) | 0.0013 (5) | 0.0008 (5) |
C4 | 0.0206 (6) | 0.0187 (6) | 0.0224 (7) | 0.0006 (5) | 0.0019 (5) | −0.0010 (5) |
C5 | 0.0185 (6) | 0.0181 (6) | 0.0221 (6) | 0.0003 (4) | −0.0005 (5) | −0.0005 (5) |
C6 | 0.0236 (7) | 0.0298 (7) | 0.0247 (7) | −0.0021 (5) | 0.0052 (5) | 0.0023 (6) |
C7 | 0.0200 (6) | 0.0185 (6) | 0.0217 (7) | −0.0005 (5) | 0.0022 (5) | −0.0010 (5) |
C8 | 0.0227 (6) | 0.0182 (6) | 0.0299 (7) | −0.0008 (5) | 0.0060 (5) | −0.0015 (5) |
Geometric parameters (Å, º) top
F1—C8 | 1.3337 (15) | C1—H1A | 0.9500 |
F2—C8 | 1.3475 (16) | C2—C3 | 1.4190 (19) |
F3—C8 | 1.3429 (16) | C2—H2A | 0.9500 |
O1—C7 | 1.2352 (15) | C3—C4 | 1.3688 (18) |
O2—C7 | 1.2523 (15) | C3—C6 | 1.5033 (18) |
N1—C5 | 1.3552 (16) | C4—C5 | 1.4209 (17) |
N1—C1 | 1.3650 (17) | C4—H4A | 0.9500 |
N1—H1B | 0.952 (19) | C6—H6A | 0.9800 |
N2—C5 | 1.3290 (16) | C6—H6B | 0.9800 |
N2—H2C | 0.901 (18) | C6—H6C | 0.9800 |
N2—H2B | 0.923 (18) | C7—C8 | 1.5490 (18) |
C1—C2 | 1.356 (2) | | |
| | | |
C5—N1—C1 | 122.40 (12) | N2—C5—N1 | 118.49 (12) |
C5—N1—H1B | 122.1 (12) | N2—C5—C4 | 123.85 (12) |
C1—N1—H1B | 115.5 (12) | N1—C5—C4 | 117.67 (12) |
C5—N2—H2C | 118.0 (12) | C3—C6—H6A | 109.5 |
C5—N2—H2B | 121.1 (11) | C3—C6—H6B | 109.5 |
H2C—N2—H2B | 120.5 (16) | H6A—C6—H6B | 109.5 |
C2—C1—N1 | 120.62 (12) | C3—C6—H6C | 109.5 |
C2—C1—H1A | 119.7 | H6A—C6—H6C | 109.5 |
N1—C1—H1A | 119.7 | H6B—C6—H6C | 109.5 |
C1—C2—C3 | 119.61 (12) | O1—C7—O2 | 129.54 (12) |
C1—C2—H2A | 120.2 | O1—C7—C8 | 115.80 (11) |
C3—C2—H2A | 120.2 | O2—C7—C8 | 114.62 (11) |
C4—C3—C2 | 118.79 (12) | F1—C8—F3 | 107.24 (12) |
C4—C3—C6 | 121.75 (12) | F1—C8—F2 | 106.89 (11) |
C2—C3—C6 | 119.46 (12) | F3—C8—F2 | 106.54 (10) |
C3—C4—C5 | 120.90 (12) | F1—C8—C7 | 113.06 (11) |
C3—C4—H4A | 119.5 | F3—C8—C7 | 112.88 (11) |
C5—C4—H4A | 119.5 | F2—C8—C7 | 109.85 (11) |
| | | |
C5—N1—C1—C2 | −0.3 (2) | C3—C4—C5—N2 | 179.68 (13) |
N1—C1—C2—C3 | −0.1 (2) | C3—C4—C5—N1 | −0.10 (19) |
C1—C2—C3—C4 | 0.5 (2) | O1—C7—C8—F1 | 18.42 (18) |
C1—C2—C3—C6 | −179.60 (13) | O2—C7—C8—F1 | −163.72 (12) |
C2—C3—C4—C5 | −0.37 (19) | O1—C7—C8—F3 | 140.38 (12) |
C6—C3—C4—C5 | 179.73 (12) | O2—C7—C8—F3 | −41.76 (17) |
C1—N1—C5—N2 | −179.33 (12) | O1—C7—C8—F2 | −100.87 (14) |
C1—N1—C5—C4 | 0.46 (19) | O2—C7—C8—F2 | 76.99 (14) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1B···O2 | 0.952 (19) | 1.82 (2) | 2.7724 (14) | 177.4 (18) |
N2—H2C···O1 | 0.901 (18) | 1.938 (19) | 2.8376 (15) | 176.3 (17) |
N2—H2B···O2i | 0.923 (18) | 2.055 (18) | 2.8946 (15) | 150.5 (15) |
Symmetry code: (i) −x+1, y−1/2, −z+3/2. |
Experimental details
Crystal data |
Chemical formula | C6H9N2+·C2F3O2− |
Mr | 222.17 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 100 |
a, b, c (Å) | 8.5315 (7), 11.4901 (9), 9.7206 (8) |
β (°) | 90.820 (1) |
V (Å3) | 952.79 (13) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.15 |
Crystal size (mm) | 0.30 × 0.20 × 0.10 |
|
Data collection |
Diffractometer | Bruker SMART APEX diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10752, 2197, 1784 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.664 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.098, 1.06 |
No. of reflections | 2197 |
No. of parameters | 150 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.29, −0.23 |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1B···O2 | 0.952 (19) | 1.82 (2) | 2.7724 (14) | 177.4 (18) |
N2—H2C···O1 | 0.901 (18) | 1.938 (19) | 2.8376 (15) | 176.3 (17) |
N2—H2B···O2i | 0.923 (18) | 2.055 (18) | 2.8946 (15) | 150.5 (15) |
Symmetry code: (i) −x+1, y−1/2, −z+3/2. |
In the previous works, the structure determinations of 2-aminopyridinium trifluoroacetate and the triclinic polymorph of 2-amino-4-methylpyridinium trifluoroacetate (Hemamalini & Fun, 2010a,b) have been investigated; we report here on the crystal structure of title compound, 4-methyl-2-aminopyridinium trifluoroacetate (Fig. 1). The cation and anion are linked by two different types of N—H···O hydrogen bonds, forming the cation-anion pair. The pairs are hydrogen bonded to neighbouring pairs via another N—H···O hydrogen bonds between the hydrogen of NH2 moiety and one of the oxygen atom of COO- group into chain extended along the b axis (Fig. 2).