l-Histidinium trifluoro­acetate

Gokul Raj, S.; Kumar, G.R.; Mohan, R.; Jayavel, R.

doi:10.1107/S1600536805038791

Buy article online - an online subscription or single-article purchase is required to access this article.

L-Histidinium trifluoroacetate

S. Gokul Raj, G. R. Kumar, R. Mohan and R. Jayavel

The title compound, C₆H₁₀N₃O₂⁺·C₂F₃O₂⁻, crystallizes with two histidine cations and two trifluoroacetate anions in the asymmetric unit. The protonated cations and deprotonated anions are linked by a number of intermolecular N—H

O hydrogen bonds to form a three-dimensional network.

Read article Similar articles

Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536805038791/su6250sup1.cif Contains datablocks global, I
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536805038791/su6250Isup2.hkl Contains datablock I

CCDC reference: 281106

checkCIF report

Key indicators

Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.005 Å
R factor = 0.038
wR factor = 0.108
Data-to-parameter ratio = 5.4

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT089_ALERT_3_B Poor Data / Parameter Ratio (Zmax .LT. 18) .....       5.40

Alert level C
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.33 Ratio
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C7
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C15
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C16
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          5
PLAT352_ALERT_3_C Short   N-H Bond (0.87A)   N4     -   H4     ...       0.76 Ang.
PLAT432_ALERT_2_C Short Inter X...Y Contact  O6     ..  C6      ..       2.94 Ang.
PLAT731_ALERT_1_C Bond    Calc     0.85(4), Rep   0.847(11) ......       3.64 su-Rat
              C2   -H2'     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.94(4), Rep   0.935(11) ......       3.64 su-Rat
              N3   -H3A     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.93(4), Rep   0.932(11) ......       3.64 su-Rat
              N3   -H3C     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.93(3), Rep   0.926(11) ......       2.73 su-Rat
              N6   -H6A     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.93(3), Rep   0.932(11) ......       2.73 su-Rat
              N6   -H6B     1.555   1.555
PLAT736_ALERT_1_C H...A   Calc     1.85(4), Rep   1.855(13) ......       3.08 su-Rat
              H3A  -O4      1.555   1.555
PLAT736_ALERT_1_C H...A   Calc     1.98(5), Rep     1.98(2) ......       2.50 su-Rat
              H3B  -O1      1.555   1.455
PLAT736_ALERT_1_C H...A   Calc     1.81(3), Rep   1.806(14) ......       2.14 su-Rat
              H6B  -O3      1.555   1.565
PLAT736_ALERT_1_C H...A   Calc     1.92(5), Rep     1.92(2) ......       2.50 su-Rat
              H6C  -O8      1.555   1.555
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C6 H10 N3 O2
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          4
              C2 F3 O2

Alert level G
FORMU01_ALERT_1_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and _chemical_formula_moiety. This is
            usually due to the moiety formula being in the wrong format.
            Atom count from _chemical_formula_sum:   C8 H10 F3 N3 O4
            Atom count from _chemical_formula_moiety:C8 H10 F3 N3 O3
REFLT03_ALERT_4_G  WARNING: CuKa measured Friedel data can be used to
                     determine absolute structure in a light-atom
                     study only if the Friedel fraction is large.
           From the CIF: _diffrn_reflns_theta_max           67.95
           From the CIF: _reflns_number_total               2063
           Count of symmetry unique reflns         1971
           Completeness (_total/calc)            104.67%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured        92
           Fraction of Friedel pairs measured     0.047
           Are heavy atom types Z>Si present         no

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

  12 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion

Comment top

Histidine is an interesting molecule from a crystal engineering point of view. It can act as a proton donor, a proton acceptor, a nucleophilic agent and a ligand for complexation with various metal ions. It exists as both orthorhombic and monclinic polymorphic forms. The crystal structures of L-histidine (Madden, McGandy & Seeman, 1972; Madden, McGandy, Seeman, Harding & Hoy, 1972) and its complexes, such as L-histidinium hydrochloride (Fuess & Bartunik 1976; Donohue & Caron 1964), L-histidinium dinitrate (Benali-Cherif et al., 2002), L-histidinium sulfate (Kumar et al., 2005) and L-histidinium tetrafluorosuccinate (Akkurt et al., 2004), have been reported, and recently the crystal structure of L-histidinium trichloroacetate (Gokulraj et al., 2005) has also been published. In the present study, we report the crystal structure of L-histidinium trifluoroacetate, (I).

The molecular structure of (I) is illustrated in Fig. 1, and selected bond distances and angles are given in Table 1. Compound (I) crystallizes with two histidine cations (A and B) and two trifluoroacetate anions in the unit cell of the non-centrosymmetric triclinic space group P1. The α-amino and imidazole groups of the L-histidine cations are protonated and positively charged, while the carboxyl groups are in the ionized state and are negatively charged. Moreover, the zwitterionic cation carries a net positive charge. The conformation angles of the histidine side chain (IUPAC–IUB Commission on Biochemical Nomenclature, 1970) are χ¹ [−68.5 (4) and −69.9 (4)°], χ²¹ [−54.5 (5) and 54.1 (5)°] and χ²² [126.2 (4) and 132.0 (4)° for cations A and B, respectively]. The conformation ψ¹ is such that it is in a gauche II form for both molecules, having a closed conformation (Pratap et al., 2000) (see Table 1). The difference in the absolute values of χ²¹ and χ²² is about 180°, indicating the planarity of the imidazole group. The deviations in the preferred torsion angles of χ²¹ at −90 and 90° are due to the interactions of the imidazole ring with other groups in the structure. The imidazole group of L-histidine is in a trans conformation, for both A [C3—C4—C5—C6 = 170.3 (3)°] and B [C11—C12—C13—C14 = 168.9 (3)°], with respect to the carboxyl group, and gauche with respect to the amino N atom. The corresponding gauche II conformation angles observed in other complexes are −60 and −60.9° in L-histidine formate formic acid, −60 and −67.5° in DL-histidine formate monohydrate, −60.2 (3)° in L-histidine dinitrate, 58.2 and −96.8° in L-histidine glycolate, −61.2 (5) and 99.2 (5)° in monoclinic L-histidine acetate and 37.1 (6) and −78.8 (6)° in L-histidinium trichloroacetate.

The trifluoroacetate anions play a vital role in the hydrogen bonding with the histidinium cation via the amine N atom and the N atom of the imidazole ring. The three-dimensional network of N—H···O bonds links the cations and trifluoroacetate anions stabilizing the crystal packing as shown in Fig. 2.

Experimental top

Crystals of the title compound, (I), were grown from a mixture of L-histidine and trifluoroacetic acid, in the stoichiometric ratio of 1:1, by slow evaporation at room temperature.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1997); cell refinement: CAD-4 Software; data reduction: XCAD4 in WinGX (Farrugia, 1999); program(s) used to solve structure: SIR92 (Burla et al., 1989); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-32 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures top

	Fig. 1. The molecular structure of (I), with the atomic numbering scheme and 50% probability displacement ellipsoids. H atoms have been omitted.
	Fig. 2. The crystal packing of (I), viewed down the b axis. The intramolecular N—H···O bonds are shown as broken lines.

L-Histidinium trifluoroacetate top

Crystal data top

C₆H₁₀N₃O₂⁺·C₂F₃O²⁻	Z = 2
M_r = 269.19	F(000) = 276
Triclinic, P1	D_x = 1.649 Mg m⁻³
Hall symbol: P 1	Cu Kα radiation, λ = 1.54180 Å
a = 5.1724 (6) Å	Cell parameters from 25 reflections
b = 8.8183 (12) Å	θ = 20–30°
c = 12.481 (3) Å	µ = 1.46 mm⁻¹
α = 96.193 (17)°	T = 293 K
β = 99.853 (13)°	Block, brown
γ = 102.106 (13)°	0.2 × 0.2 × 0.1 mm
V = 542.26 (16) Å³

Data collection top

Enraf–Nonius CAD-4 diffractometer	2053 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.001
Graphite monochromator	θ_max = 68.0°, θ_min = 3.6°
ω/2θ scans	h = −6→6
Absorption correction: ψ scan (North et al., 1968)	k = −10→10
T_min = 0.790, T_max = 0.864	l = −14→15
2064 measured reflections	2 standard reflections every 60 min
2063 independent reflections	intensity decay: none

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F² > 2σ(F²)] = 0.038	w = 1/[σ²(F_o²) + (0.0775P)² + 0.22P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.108	(Δ/σ)_max < 0.001
S = 1.01	Δρ_max = 0.42 e Å⁻³
2063 reflections	Δρ_min = −0.32 e Å⁻³
382 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
13 restraints	Extinction coefficient: 0.055 (4)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 92 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.04 (2)

Crystal data top

C₆H₁₀N₃O₂⁺·C₂F₃O²⁻	γ = 102.106 (13)°
M_r = 269.19	V = 542.26 (16) Å³
Triclinic, P1	Z = 2
a = 5.1724 (6) Å	Cu Kα radiation
b = 8.8183 (12) Å	µ = 1.46 mm⁻¹
c = 12.481 (3) Å	T = 293 K
α = 96.193 (17)°	0.2 × 0.2 × 0.1 mm
β = 99.853 (13)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	2053 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.001
T_min = 0.790, T_max = 0.864	2 standard reflections every 60 min
2064 measured reflections	intensity decay: none
2063 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.038	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.108	Δρ_max = 0.42 e Å⁻³
S = 1.01	Δρ_min = −0.32 e Å⁻³
2063 reflections	Absolute structure: Flack (1983), 92 Friedel pairs
382 parameters	Absolute structure parameter: 0.04 (2)
13 restraints

Special details top

Experimental. psi-scan absorption correction: North et al. (1968) Number of psi-scan sets used was 4 Theta correction was applied. Averaged transmission function was used. No Fourier smoothing was applied.

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 (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.8441 (8)	0.2285 (5)	−0.2787 (4)	0.0460 (9)
C2	1.1001 (11)	0.1445 (4)	−0.1522 (4)	0.0524 (11)
C3	1.0878 (7)	0.3327 (4)	−0.2536 (3)	0.0331 (7)
C4	1.1832 (8)	0.4790 (4)	−0.2996 (3)	0.0379 (8)
H4A	1.0329	0.4972	−0.3507	0.045*
H4B	1.3199	0.4626	−0.3411	0.045*
C5	1.3010 (6)	0.6273 (3)	−0.2138 (3)	0.0272 (6)
H5A	1.4381	0.6052	−0.1568	0.033*
C6	1.4345 (6)	0.7612 (4)	−0.2695 (3)	0.0289 (6)
C7	1.0914 (8)	0.4240 (4)	0.0842 (3)	0.0412 (8)
C8	0.8156 (7)	0.3716 (4)	0.0061 (3)	0.0369 (7)
C9	0.9856 (9)	0.9431 (6)	0.5115 (4)	0.0523 (10)
C10	0.6365 (9)	0.7805 (5)	0.4043 (4)	0.0467 (9)
C11	0.8024 (8)	0.8432 (4)	0.3391 (3)	0.0402 (8)
C12	0.7871 (10)	0.8073 (4)	0.2184 (3)	0.0462 (9)
H12A	0.6122	0.7387	0.1858	0.055*
H12B	0.9228	0.7497	0.2067	0.055*
C13	0.8268 (6)	0.9487 (4)	0.1569 (3)	0.0303 (6)
H13	0.9902	1.0259	0.1958	0.036*
C14	0.8615 (7)	0.8969 (4)	0.0390 (3)	0.0345 (7)
C15	0.7585 (11)	1.3651 (5)	0.3768 (5)	0.0661 (14)
C16	0.5426 (10)	1.2437 (6)	0.4187 (4)	0.0568 (12)
N1	0.8581 (8)	0.1136 (4)	−0.2154 (4)	0.0566 (10)
N2	1.2439 (7)	0.2766 (3)	−0.1733 (3)	0.0378 (6)
N3	1.0882 (6)	0.6752 (3)	−0.1614 (2)	0.0313 (6)
N4	1.0179 (8)	0.9436 (5)	0.4079 (3)	0.0476 (8)
N5	0.7568 (8)	0.8435 (5)	0.5115 (3)	0.0503 (9)
N6	0.5937 (6)	1.0230 (3)	0.1517 (2)	0.0339 (6)
O1	1.6392 (5)	0.7386 (3)	−0.3067 (2)	0.0394 (6)
O2	1.3431 (5)	0.8785 (3)	−0.2730 (2)	0.0411 (6)
O3	0.6610 (6)	0.2548 (4)	0.0239 (3)	0.0614 (9)
O4	0.7704 (5)	0.4498 (3)	−0.0692 (2)	0.0475 (7)
O5	1.0912 (5)	0.8762 (4)	0.0320 (2)	0.0484 (7)
O6	0.6702 (6)	0.8824 (4)	−0.0369 (2)	0.0556 (8)
O7	0.4911 (11)	1.2820 (8)	0.5071 (3)	0.1013 (17)
O8	0.4445 (7)	1.1223 (4)	0.3506 (3)	0.0530 (7)
F1	1.0849 (7)	0.5183 (4)	0.1742 (2)	0.0693 (8)
F2	1.2823 (5)	0.5032 (3)	0.0376 (2)	0.0600 (7)
F3	1.1793 (6)	0.3021 (3)	0.1180 (3)	0.0637 (7)
F4	0.9327 (8)	1.2950 (5)	0.3359 (5)	0.1025 (14)
F5	0.6422 (8)	1.4234 (5)	0.2938 (3)	0.0916 (11)
F6	0.8936 (13)	1.4847 (5)	0.4500 (4)	0.130 (2)
H1	0.710 (12)	0.017 (7)	−0.223 (5)	0.058 (14)*
H1'	0.694 (9)	0.218 (10)	−0.323 (6)	0.11 (3)*
H2	1.407 (11)	0.327 (6)	−0.141 (4)	0.044 (12)*
H2'	1.183 (9)	0.101 (6)	−0.104 (3)	0.050 (13)*
H3A	0.996 (8)	0.596 (4)	−0.128 (3)	0.036 (10)*
H3B	0.970 (9)	0.714 (6)	−0.210 (4)	0.063 (15)*
H3C	1.163 (10)	0.758 (4)	−0.104 (3)	0.059 (14)*
H4	1.141 (12)	0.986 (7)	0.389 (5)	0.057 (16)*
H5	0.727 (11)	0.816 (6)	0.567 (5)	0.055 (14)*
H6A	0.440 (5)	0.965 (4)	0.103 (3)	0.033 (10)*
H6B	0.614 (9)	1.110 (3)	0.115 (3)	0.037 (10)*
H6C	0.578 (15)	1.067 (8)	0.221 (3)	0.09 (2)*
H9'	1.104 (10)	0.982 (7)	0.569 (3)	0.075 (18)*
H10'	0.489 (6)	0.713 (5)	0.377 (4)	0.054 (14)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.040 (2)	0.0367 (18)	0.052 (2)	−0.0070 (15)	0.0130 (18)	−0.0066 (16)
C2	0.084 (3)	0.0276 (17)	0.055 (3)	0.0163 (19)	0.029 (2)	0.0160 (17)
C3	0.0343 (16)	0.0264 (14)	0.0362 (17)	0.0007 (12)	0.0120 (13)	−0.0009 (13)
C4	0.050 (2)	0.0297 (16)	0.0325 (17)	0.0021 (14)	0.0119 (15)	0.0039 (13)
C5	0.0297 (14)	0.0246 (14)	0.0265 (14)	0.0023 (11)	0.0062 (11)	0.0082 (11)
C6	0.0275 (14)	0.0292 (14)	0.0252 (14)	−0.0027 (11)	0.0011 (11)	0.0088 (11)
C7	0.0461 (19)	0.0408 (18)	0.042 (2)	0.0143 (15)	0.0142 (16)	0.0109 (16)
C8	0.0408 (18)	0.0362 (17)	0.0415 (19)	0.0124 (14)	0.0183 (15)	0.0174 (15)
C9	0.057 (2)	0.074 (3)	0.0308 (19)	0.018 (2)	0.0151 (18)	0.0149 (19)
C10	0.059 (2)	0.044 (2)	0.045 (2)	0.0155 (18)	0.0230 (19)	0.0195 (17)
C11	0.059 (2)	0.0395 (17)	0.0339 (18)	0.0221 (16)	0.0195 (16)	0.0208 (15)
C12	0.076 (3)	0.0374 (18)	0.0330 (18)	0.0198 (18)	0.0196 (18)	0.0114 (15)
C13	0.0346 (15)	0.0320 (15)	0.0250 (15)	0.0060 (12)	0.0091 (12)	0.0054 (12)
C14	0.0380 (17)	0.0360 (16)	0.0265 (16)	0.0012 (13)	0.0086 (13)	0.0025 (12)
C15	0.072 (3)	0.045 (2)	0.067 (3)	0.012 (2)	−0.017 (3)	−0.001 (2)
C16	0.067 (3)	0.075 (3)	0.036 (2)	0.039 (2)	0.0035 (19)	0.002 (2)
N1	0.064 (2)	0.0285 (15)	0.072 (3)	−0.0132 (15)	0.032 (2)	0.0000 (16)
N2	0.0411 (16)	0.0304 (13)	0.0410 (16)	0.0032 (12)	0.0113 (13)	0.0069 (12)
N3	0.0371 (14)	0.0268 (12)	0.0321 (14)	0.0051 (10)	0.0120 (11)	0.0101 (11)
N4	0.054 (2)	0.064 (2)	0.0331 (17)	0.0189 (17)	0.0187 (15)	0.0212 (15)
N5	0.068 (2)	0.064 (2)	0.0354 (17)	0.0283 (18)	0.0267 (16)	0.0268 (16)
N6	0.0382 (14)	0.0367 (14)	0.0284 (14)	0.0082 (12)	0.0094 (11)	0.0079 (11)
O1	0.0350 (12)	0.0497 (14)	0.0389 (13)	0.0068 (10)	0.0166 (10)	0.0215 (11)
O2	0.0462 (13)	0.0314 (11)	0.0503 (14)	0.0079 (10)	0.0146 (11)	0.0208 (11)
O3	0.0518 (16)	0.0565 (18)	0.080 (2)	0.0037 (13)	0.0146 (16)	0.0421 (17)
O4	0.0412 (13)	0.0536 (15)	0.0528 (16)	0.0075 (11)	0.0136 (12)	0.0299 (13)
O5	0.0405 (13)	0.0647 (17)	0.0360 (14)	0.0072 (12)	0.0134 (11)	−0.0089 (12)
O6	0.0502 (16)	0.083 (2)	0.0282 (13)	0.0158 (15)	0.0020 (12)	−0.0051 (13)
O7	0.115 (3)	0.161 (5)	0.0402 (19)	0.070 (3)	0.017 (2)	−0.010 (2)
O8	0.0631 (17)	0.0536 (16)	0.0461 (15)	0.0097 (14)	0.0271 (14)	0.0060 (13)
F1	0.0872 (19)	0.0697 (17)	0.0504 (15)	0.0236 (15)	0.0151 (14)	−0.0059 (13)
F2	0.0432 (13)	0.0721 (17)	0.0599 (15)	−0.0005 (11)	0.0103 (11)	0.0160 (13)
F3	0.0614 (15)	0.0599 (15)	0.0738 (18)	0.0265 (12)	0.0020 (13)	0.0210 (13)
F4	0.078 (2)	0.079 (2)	0.160 (4)	0.0144 (18)	0.047 (3)	0.031 (3)
F5	0.107 (3)	0.082 (2)	0.070 (2)	0.0078 (19)	−0.0181 (19)	0.0230 (17)
F6	0.189 (5)	0.072 (2)	0.079 (3)	−0.006 (3)	−0.047 (3)	−0.0087 (19)

Geometric parameters (Å, º) top

C1—N1	1.357 (6)	C10—H10'	0.85 (5)
C1—C3	1.360 (5)	C11—N4	1.363 (6)
C1—H1'	0.85 (6)	C11—C12	1.491 (5)
C2—N1	1.317 (7)	C12—C13	1.530 (5)
C2—N2	1.323 (5)	C12—H12A	0.9700
C2—H2'	0.847 (11)	C12—H12B	0.9700
C3—N2	1.378 (5)	C13—N6	1.483 (4)
C3—C4	1.492 (5)	C13—C14	1.544 (4)
C4—C5	1.539 (4)	C13—H13	0.9800
C4—H4A	0.9700	C14—O6	1.222 (5)
C4—H4B	0.9700	C14—O5	1.255 (5)
C5—N3	1.483 (4)	C15—F6	1.303 (6)
C5—C6	1.535 (4)	C15—F5	1.316 (6)
C5—H5A	0.9800	C15—F4	1.333 (7)
C6—O2	1.226 (4)	C15—C16	1.577 (8)
C6—O1	1.270 (4)	C16—O7	1.208 (6)
C7—F3	1.333 (5)	C16—O8	1.247 (6)
C7—F1	1.333 (5)	N1—H1	1.00 (6)
C7—F2	1.340 (5)	N2—H2	0.87 (5)
C7—C8	1.533 (5)	N3—H3A	0.93 (5)
C8—O3	1.231 (5)	N3—H3B	0.93 (5)
C8—O4	1.243 (5)	N3—H3C	0.93 (5)
C9—N5	1.318 (7)	N4—H4	0.75 (7)
C9—N4	1.332 (6)	N5—H5	0.79 (6)
C9—H9'	0.85 (5)	N6—H6A	0.93 (5)
C10—C11	1.357 (6)	N6—H6B	0.93 (5)
C10—N5	1.377 (6)	N6—H6C	0.93 (5)

N1—C1—C3	107.6 (4)	C11—C12—H12B	108.3
N1—C1—H1'	115 (6)	C13—C12—H12B	108.3
C3—C1—H1'	137 (6)	H12A—C12—H12B	107.4
N1—C2—N2	108.7 (4)	N6—C13—C12	111.0 (3)
N1—C2—H2'	136 (4)	N6—C13—C14	109.4 (3)
N2—C2—H2'	115 (4)	C12—C13—C14	109.9 (3)
C1—C3—N2	105.8 (3)	N6—C13—H13	108.8
C1—C3—C4	129.9 (4)	C12—C13—H13	108.8
N2—C3—C4	124.3 (3)	C14—C13—H13	108.8
C3—C4—C5	115.1 (3)	O6—C14—O5	126.7 (3)
C3—C4—H4A	108.5	O6—C14—C13	118.4 (3)
C5—C4—H4A	108.5	O5—C14—C13	114.9 (3)
C3—C4—H4B	108.5	F6—C15—F5	106.3 (4)
C5—C4—H4B	108.5	F6—C15—F4	108.7 (6)
H4A—C4—H4B	107.5	F5—C15—F4	104.6 (5)
N3—C5—C6	109.6 (2)	F6—C15—C16	115.0 (5)
N3—C5—C4	111.1 (3)	F5—C15—C16	110.5 (4)
C6—C5—C4	109.4 (3)	F4—C15—C16	111.1 (4)
N3—C5—H5A	108.9	O7—C16—O8	130.2 (6)
C6—C5—H5A	108.9	O7—C16—C15	117.4 (5)
C4—C5—H5A	108.9	O8—C16—C15	112.4 (4)
O2—C6—O1	125.9 (3)	C2—N1—C1	109.0 (3)
O2—C6—C5	119.4 (3)	C2—N1—H1	127 (3)
O1—C6—C5	114.6 (3)	C1—N1—H1	124 (3)
F3—C7—F1	106.8 (3)	C2—N2—C3	108.9 (3)
F3—C7—F2	106.8 (3)	C2—N2—H2	128 (3)
F1—C7—F2	106.2 (3)	C3—N2—H2	123 (3)
F3—C7—C8	111.7 (3)	C5—N3—H3A	113 (3)
F1—C7—C8	112.3 (3)	C5—N3—H3B	112 (4)
F2—C7—C8	112.7 (3)	H3A—N3—H3B	112 (4)
O3—C8—O4	126.4 (4)	C5—N3—H3C	111 (3)
O3—C8—C7	116.4 (3)	H3A—N3—H3C	104 (4)
O4—C8—C7	117.2 (3)	H3B—N3—H3C	105 (5)
N5—C9—N4	108.4 (4)	C9—N4—C11	109.5 (4)
N5—C9—H9'	123 (5)	C9—N4—H4	126 (5)
N4—C9—H9'	127 (5)	C11—N4—H4	124 (4)
C11—C10—N5	107.4 (4)	C9—N5—C10	108.4 (3)
C11—C10—H10'	121 (4)	C9—N5—H5	120 (4)
N5—C10—H10'	132 (4)	C10—N5—H5	130 (4)
C10—C11—N4	106.2 (4)	C13—N6—H6A	113 (3)
C10—C11—C12	130.8 (4)	C13—N6—H6B	113 (3)
N4—C11—C12	122.8 (4)	H6A—N6—H6B	96 (4)
C11—C12—C13	116.0 (3)	C13—N6—H6C	112 (5)
C11—C12—H12A	108.3	H6A—N6—H6C	119 (5)
C13—C12—H12A	108.3	H6B—N6—H6C	102 (5)

N1—C1—C3—N2	−0.5 (4)	C11—C12—C13—C14	168.9 (3)
N1—C1—C3—C4	179.2 (3)	N6—C13—C14—O6	−19.2 (4)
C1—C3—C4—C5	126.2 (4)	C12—C13—C14—O6	102.9 (4)
N2—C3—C4—C5	−54.1 (5)	N6—C13—C14—O5	159.8 (3)
C3—C4—C5—N3	−68.5 (4)	C12—C13—C14—O5	−78.1 (4)
C3—C4—C5—C6	170.3 (3)	F6—C15—C16—O7	11.0 (7)
N3—C5—C6—O2	−5.9 (4)	F5—C15—C16—O7	−109.4 (5)
C4—C5—C6—O2	116.2 (3)	F4—C15—C16—O7	135.0 (5)
N3—C5—C6—O1	172.8 (3)	F6—C15—C16—O8	−171.2 (5)
C4—C5—C6—O1	−65.1 (3)	F5—C15—C16—O8	68.4 (5)
F3—C7—C8—O3	33.6 (5)	F4—C15—C16—O8	−47.2 (5)
F1—C7—C8—O3	−86.3 (4)	N2—C2—N1—C1	−0.2 (5)
F2—C7—C8—O3	153.9 (4)	C3—C1—N1—C2	0.5 (5)
F3—C7—C8—O4	−145.9 (4)	N1—C2—N2—C3	−0.1 (4)
F1—C7—C8—O4	94.2 (4)	C1—C3—N2—C2	0.4 (4)
F2—C7—C8—O4	−25.6 (5)	C4—C3—N2—C2	−179.3 (3)
N5—C10—C11—N4	−0.5 (4)	N5—C9—N4—C11	0.9 (5)
N5—C10—C11—C12	173.7 (4)	C10—C11—N4—C9	−0.2 (5)
C10—C11—C12—C13	132.0 (4)	C12—C11—N4—C9	−175.0 (4)
N4—C11—C12—C13	−54.6 (5)	N4—C9—N5—C10	−1.2 (5)
C11—C12—C13—N6	−69.9 (4)	C11—C10—N5—C9	1.0 (5)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O2ⁱ	1.00 (6)	1.99 (6)	2.935 (4)	157 (5)
N2—H2···O4ⁱⁱ	0.87 (5)	1.97 (6)	2.838 (4)	178 (4)
N3—H3A···O4	0.94 (1)	1.86 (1)	2.784 (4)	172 (4)
N3—H3B···O1ⁱⁱⁱ	0.93 (5)	1.98 (2)	2.884 (4)	162 (5)
N3—H3C···O5	0.93 (1)	2.03 (3)	2.832 (4)	144 (5)
N4—H4···O8ⁱⁱ	0.75 (7)	1.93 (7)	2.681 (5)	172 (6)
N5—H5···O1^iv	0.79 (6)	1.87 (6)	2.657 (4)	176 (6)
N6—H6A···O5ⁱⁱⁱ	0.93 (1)	1.84 (2)	2.740 (4)	165 (4)
N6—H6B···O3^v	0.93 (1)	1.81 (1)	2.728 (4)	170 (4)
N6—H6C···O8	0.93 (5)	1.92 (2)	2.827 (4)	164 (7)

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

Experimental details

Crystal data
Chemical formula	C₆H₁₀N₃O₂⁺·C₂F₃O²⁻
M_r	269.19
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	5.1724 (6), 8.8183 (12), 12.481 (3)
α, β, γ (°)	96.193 (17), 99.853 (13), 102.106 (13)
V (Å³)	542.26 (16)
Z	2
Radiation type	Cu Kα
µ (mm⁻¹)	1.46
Crystal size (mm)	0.2 × 0.2 × 0.1

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.790, 0.864
No. of measured, independent and observed [I > 2σ(I)] reflections	2064, 2063, 2053
R_int	0.001
(sin θ/λ)_max (Å⁻¹)	0.601

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.038, 0.108, 1.01
No. of reflections	2063
No. of parameters	382
No. of restraints	13
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.42, −0.32
Absolute structure	Flack (1983), 92 Friedel pairs
Absolute structure parameter	0.04 (2)

Computer programs: CAD-4 Software (Enraf–Nonius, 1997), CAD-4 Software, XCAD4 in WinGX (Farrugia, 1999), SIR92 (Burla et al., 1989), SHELXL97 (Sheldrick, 1997), ORTEP-32 (Farrugia, 1997), SHELXL97.

Selected geometric parameters (Å, º) top

C1—N1	1.357 (6)	C6—O1	1.270 (4)
C2—N1	1.317 (7)	C7—F3	1.333 (5)
C2—N2	1.323 (5)	C7—F1	1.333 (5)
C3—N2	1.378 (5)	C7—F2	1.340 (5)
C5—N3	1.483 (4)	C8—O3	1.231 (5)
C6—O2	1.226 (4)	C8—O4	1.243 (5)

N1—C1—C3	107.6 (4)	F3—C7—F2	106.8 (3)
N1—C2—N2	108.7 (4)	F1—C7—F2	106.2 (3)
C1—C3—N2	105.8 (3)	F3—C7—C8	111.7 (3)
N2—C3—C4	124.3 (3)	F1—C7—C8	112.3 (3)
N3—C5—C6	109.6 (2)	F2—C7—C8	112.7 (3)
N3—C5—C4	111.1 (3)	O3—C8—O4	126.4 (4)
O2—C6—O1	125.9 (3)	O3—C8—C7	116.4 (3)
O2—C6—C5	119.4 (3)	O4—C8—C7	117.2 (3)
O1—C6—C5	114.6 (3)	C2—N1—C1	109.0 (3)
F3—C7—F1	106.8 (3)	C2—N2—C3	108.9 (3)

C1—C3—C4—C5	126.2 (4)	C3—C4—C5—C6	170.3 (3)
N2—C3—C4—C5	−54.1 (5)	C11—C12—C13—C14	168.9 (3)
C3—C4—C5—N3	−68.5 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O2ⁱ	1.00 (6)	1.99 (6)	2.935 (4)	157 (5)
N2—H2···O4ⁱⁱ	0.87 (5)	1.97 (6)	2.838 (4)	178 (4)
N3—H3A···O4	0.935 (11)	1.855 (13)	2.784 (4)	172 (4)
N3—H3B···O1ⁱⁱⁱ	0.93 (5)	1.98 (2)	2.884 (4)	162 (5)
N3—H3C···O5	0.932 (11)	2.03 (3)	2.832 (4)	144 (5)
N4—H4···O8ⁱⁱ	0.75 (7)	1.93 (7)	2.681 (5)	172 (6)
N5—H5···O1^iv	0.79 (6)	1.87 (6)	2.657 (4)	176 (6)
N6—H6A···O5ⁱⁱⁱ	0.926 (11)	1.835 (16)	2.740 (4)	165 (4)
N6—H6B···O3^v	0.932 (11)	1.806 (14)	2.728 (4)	170 (4)
N6—H6C···O8	0.93 (5)	1.92 (2)	2.827 (4)	164 (7)

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

Subscribe to Acta Crystallographica Section E: Crystallographic Communications

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.

E-mail address*
Repeat e-mail address* (for error checking)

Format*	PDF (US $40)
	HTML (US $40)
	PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number (non-UK EC countries only)
Country*

Terms and conditions of use
Contact us

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Text
		Plain Text

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Text
		Plain Text

Search IUCr Journals		doi		Advanced search
Author		volume	page

L-Histidinium trifluoro­acetate