DL-Leucinium nitrate

The crystal structure of DL-2-ammonium-4-meth­ylvaleric acid nitrate (C₆H₁₄NO₂⁺·NO₃^-, DL-leucinium nitrate) can be described by considering two types of layers parallel to the bc plane: hydro­philic layers including the head of the leucinium residue (ammonium and carboxylic groups) with the nitrate anion, and hydro­phobic layers including the tail of the leucinium residue.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.041
• wR factor = 0.093
• Data-to-parameter ratio = 23.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT026_ALERT_3_C Ratio Observed / Unique Reflections too Low ....         47 Perc.
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       3.31 Ratio
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C4
PLAT480_ALERT_4_C Long H...A H-Bond Reported H5A    ..  O5      ..       2.81 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H6A    ..  O2      ..       2.83 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H3     ..  O5      ..       2.78 Ang.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   7 ALERT level C = Check and explain
   0 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
   1 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: KappaCCD Server Software (Nonius, 1998); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997) and CAMERON (Watkin et al., 1993); software used to prepare material for publication: WinGX (Farrugia, 1999).

(I)

Crystal data

C6H14NO2^+·NO3^−	F(000) = 416
Mr = 194.19	Dx = 1.316 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 10828 reflections
a = 11.0324 (2) Å	θ = 5.9–30.0°
b = 5.6200 (2) Å	µ = 0.11 mm^−1
c = 16.4317 (3) Å	T = 293 K
β = 105.789 (2)°	Needle, colorless
V = 980.36 (4) Å^3	0.30 × 0.15 × 0.10 mm
Z = 4

Data collection

Nonius KappaCCD area-detector diffractometer	1319 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.094
Graphite monochromator	θmax = 30.0°, θmin = 5.9°
φ scans	h = −15→15
10828 measured reflections	k = −7→7
2829 independent reflections	l = −23→21

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.093	H-atom parameters constrained
S = 0.84	w = 1/[σ^2(Fo^2) + (0.0367P)^2] where P = (Fo^2 + 2Fc^2)/3
2829 reflections	(Δ/σ)max = 0.001
120 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.21 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
O1	0.09496 (10)	0.40736 (17)	0.24550 (6)	0.0440 (3)
O2	0.17335 (12)	0.71614 (18)	0.19082 (6)	0.0560 (4)
O3	0.14638 (11)	0.55468 (16)	0.03754 (6)	0.0467 (3)
O4	0.14021 (12)	0.31326 (15)	−0.06470 (7)	0.0523 (3)
O5	0.13372 (11)	0.17466 (16)	0.05629 (7)	0.0504 (3)
N1	0.14016 (12)	0.3422 (2)	0.01044 (8)	0.0364 (3)
N2	0.09190 (11)	0.66803 (17)	0.38411 (7)	0.0321 (3)
C1	0.14300 (14)	0.6012 (2)	0.25169 (9)	0.0328 (3)
C2	0.17719 (13)	0.7413 (2)	0.33314 (8)	0.0293 (3)
C3	0.31288 (15)	0.6977 (2)	0.38471 (9)	0.0393 (4)
C4	0.41433 (17)	0.7766 (3)	0.34429 (11)	0.0565 (5)
C5	0.5430 (2)	0.7065 (5)	0.40116 (16)	0.0951 (8)
H5A	0.6069	0.7468	0.3739	0.143*
H5B	0.5447	0.5383	0.4115	0.143*
H5C	0.5583	0.7903	0.4539	0.143*
C6	0.4070 (2)	1.0423 (4)	0.32614 (17)	0.0969 (8)
H6A	0.3308	1.0770	0.2831	0.145*
H6B	0.4782	1.0899	0.3071	0.145*
H6C	0.4073	1.1276	0.3768	0.145*
H1	0.0128	0.6947	0.3569	0.050*
H2	0.1073	0.7559	0.4294	0.050*
H3	0.0987	0.5190	0.3958	0.050*
H4	0.3267	0.5286	0.3994	0.050*
H5	0.3229	0.7959	0.4395	0.050*
H6	0.1597	0.6333	0.1429	0.050*
H7	0.1593	0.9173	0.3176	0.050*
H8	0.3971	0.6815	0.2892	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0565 (8)	0.0432 (6)	0.0319 (6)	−0.0124 (5)	0.0114 (5)	−0.0082 (4)
O2	0.0873 (10)	0.0599 (6)	0.0250 (6)	−0.0287 (6)	0.0225 (6)	−0.0091 (5)
O3	0.0760 (9)	0.0358 (5)	0.0292 (6)	0.0022 (5)	0.0159 (6)	−0.0051 (4)
O4	0.0911 (10)	0.0399 (6)	0.0332 (6)	−0.0031 (6)	0.0292 (6)	−0.0045 (5)
O5	0.0617 (8)	0.0445 (6)	0.0510 (7)	0.0053 (5)	0.0258 (6)	0.0187 (5)
N1	0.0413 (9)	0.0381 (6)	0.0310 (7)	0.0038 (6)	0.0120 (6)	0.0041 (6)
N2	0.0381 (8)	0.0333 (6)	0.0264 (6)	0.0015 (5)	0.0112 (6)	−0.0005 (5)
C1	0.0330 (9)	0.0394 (8)	0.0259 (8)	0.0012 (7)	0.0076 (7)	−0.0018 (6)
C2	0.0347 (9)	0.0325 (7)	0.0219 (7)	−0.0011 (6)	0.0097 (6)	−0.0009 (5)
C3	0.0363 (10)	0.0471 (8)	0.0325 (8)	−0.0020 (7)	0.0061 (7)	−0.0055 (6)
C4	0.0389 (11)	0.0871 (12)	0.0460 (11)	−0.0112 (10)	0.0155 (9)	−0.0187 (9)
C5	0.0409 (13)	0.154 (2)	0.0860 (18)	−0.0087 (14)	0.0105 (13)	−0.0174 (15)
C6	0.0861 (19)	0.1035 (17)	0.116 (2)	−0.0366 (14)	0.0529 (16)	0.0157 (15)

Geometric parameters (Å, º)

O1—C1	1.2037 (15)	N2—H2	0.87
O2—C1	1.3083 (17)	N2—H3	0.86
O3—N1	1.2698 (13)	C2—H7	1.03
O4—N1	1.2455 (14)	C3—H4	0.98
O5—N1	1.2200 (14)	C3—H5	1.04
N2—C2	1.4783 (17)	C4—H8	1.02
C1—C2	1.5097 (19)	C5—H5A	0.96
C2—C3	1.526 (2)	C5—H5B	0.96
C3—C4	1.515 (2)	C5—H5C	0.96
C4—C6	1.520 (2)	C6—H6A	0.96
C4—C5	1.523 (3)	C6—H6B	0.96
O2—H6	0.89	C6—H6C	0.96
N2—H1	0.88
O5—N1—O4	121.81 (11)	C3—C2—H7	113.00
O5—N1—O3	121.06 (12)	C4—C3—H4	108.00
O4—N1—O3	117.13 (11)	C2—C3—H4	111.00
O1—C1—O2	125.49 (13)	C4—C3—H5	108.00
O1—C1—C2	123.02 (13)	C2—C3—H5	105.00
O2—C1—C2	111.48 (12)	H4—C3—H5	109.00
N2—C2—C1	108.24 (11)	C3—C4—H8	105.00
N2—C2—C3	108.67 (11)	C6—C4—H8	111.00
C1—C2—C3	112.28 (12)	C5—C4—H8	109.00
C4—C3—C2	116.08 (14)	C4—C5—H5A	109.5
C3—C4—C6	111.54 (15)	C4—C5—H5B	109.5
C3—C4—C5	109.35 (17)	H5A—C5—H5B	109.5
C6—C4—C5	111.42 (18)	C4—C5—H5C	109.5
C1—O2—H6	114.00	H5A—C5—H5C	109.5
C2—N2—H1	111.00	H5B—C5—H5C	109.5
C2—N2—H2	109.00	C4—C6—H6A	109.5
H1—N2—H2	106.00	C4—C6—H6B	109.5
C2—N2—H3	112.00	H6A—C6—H6B	109.5
H1—N2—H3	107.00	C4—C6—H6C	109.5
H2—N2—H3	112.00	H6A—C6—H6C	109.5
N2—C2—H7	107.00	H6B—C6—H6C	109.5
C1—C2—H7	107.00
O1—C1—C2—N2	−27.18 (19)	N2—C2—C3—C4	−176.47 (11)
O2—C1—C2—N2	153.48 (12)	C1—C2—C3—C4	63.83 (16)
O1—C1—C2—C3	92.77 (17)	C2—C3—C4—C6	59.81 (19)
O2—C1—C2—C3	−86.57 (15)	C2—C3—C4—C5	−176.49 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H6···O3	0.89	1.75	2.617 (1)	162
C2—H7···O4^i	1.03	2.51	3.102 (2)	116
C4—H8···O2	1.02	2.56	3.146 (2)	116
C5—H5A···O5^ii	0.96	2.81	3.448 (2)	125
C6—H6A···O2	0.96	2.83	3.439 (2)	122
N2—H1···O5^iii	0.88	2.43	2.913 (2)	115
N2—H1···O1^iii	0.88	2.14	2.865 (1)	139
N2—H2···O4^i	0.87	2.45	3.041 (1)	126
N2—H2···O3^i	0.87	2.01	2.885 (1)	177
N2—H3···O5^iv	0.86	2.78	3.349 (2)	125
N2—H3···O4^iv	0.86	1.99	2.840 (1)	171

Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) −x+1, y+1/2, −z+1/2; (iii) −x, y+1/2, −z+1/2; (iv) x, −y+1/2, z+1/2.