L-2-Aminobutyric acid: two fully ordered polymorphs with Z′ = 4

The crystal structure of L-2-aminobutyric acid, an L-alanine analogue with an ethyl rather than a methyl side chain, has proved elusive owing to problems growing diffraction quality crystals. Good diffraction data have now been obtained for two polymorphs, in space groups P2₁ and I2, revealing surprisingly complex, yet fully ordered crystalline arrangements with Z′ = 4. The closely related structures are divided into hydrophilic and hydrophobic layers, the latter being the thinnest ever found for an amino acid (other than α-glycine). The hydrophobic layers furthermore contain conspicuous pseudo-centers-of-symmetry, leading to overall centrosymmetric intensity statistics. Uniquely, the four molecules in the asymmetric unit can be divided into two pairs that each forms an independent hydrogen-bond network.

Computing details

For both structures, data collection: APEX2 (Bruker, 2007); cell refinement: SAINT-Plus (Bruker, 2007); data reduction: SAINT-Plus (Bruker, 2007); 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).

(S)-2-aminobutyric acid (I)

Crystal data

C4H9NO2	F(000) = 448
Mr = 103.12	Dx = 1.296 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 2696 reflections
a = 9.614 (6) Å	θ = 2.5–27.8°
b = 5.227 (3) Å	µ = 0.10 mm^−1
c = 21.385 (13) Å	T = 110 K
β = 100.326 (7)°	Elongated plate, colourless
V = 1057.1 (11) Å^3	1.10 × 0.34 × 0.10 mm
Z = 8

Data collection

Bruker Apex II CCD diffractometer	2700 independent reflections
Radiation source: fine-focus sealed tube	2468 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
Detector resolution: 8.3 pixels mm^-1	θmax = 28.6°, θmin = 2.2°
Sets of exposures each taken over 0.5° ω rotation scans	h = −12→12
Absorption correction: multi-scan SADABS (Bruker, 2007)	k = −7→6
Tmin = 0.749, Tmax = 0.990	l = −28→26
6460 measured reflections

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)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.165	H-atom parameters constrained
S = 1.12	w = 1/[σ^2(Fo^2) + (0.085P)^2 + 0.488P] where P = (Fo^2 + 2Fc^2)/3
2700 reflections	(Δ/σ)max < 0.001
261 parameters	Δρmax = 0.37 e Å^−3
1 restraint	Δρmin = −0.26 e Å^−3
0 constraints

Special details

Experimental. Soft crystal, easily bent.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1A	0.1618 (2)	0.7249 (5)	0.05862 (11)	0.0189 (5)
O2A	0.2490 (3)	0.3333 (5)	0.08128 (13)	0.0269 (6)
N1A	0.4156 (3)	0.9310 (5)	0.05725 (12)	0.0165 (6)
H1A	0.3903	0.9014	0.0148	0.025*
H2A	0.5047	0.9968	0.0655	0.025*
H3A	0.3543	1.0444	0.0698	0.025*
C1A	0.2622 (3)	0.5696 (7)	0.07523 (15)	0.0162 (6)
C2A	0.4119 (3)	0.6861 (7)	0.09261 (16)	0.0185 (7)
H21A	0.4815	0.5645	0.0794	0.022*
C3A	0.4532 (4)	0.7370 (9)	0.16363 (16)	0.0291 (8)
H31A	0.3766	0.8344	0.1781	0.035*
H32A	0.5395	0.8443	0.1713	0.035*
C4A	0.4810 (4)	0.4918 (11)	0.20304 (18)	0.0413 (11)
H41A	0.5037	0.5357	0.2483	0.062*
H42A	0.5607	0.3993	0.1908	0.062*
H43A	0.3965	0.3833	0.1953	0.062*
O1B	0.6611 (2)	0.2229 (5)	0.06230 (11)	0.0197 (5)
O2B	0.7617 (3)	−0.1383 (5)	0.10293 (13)	0.0266 (6)
N1B	0.9102 (3)	0.4579 (6)	0.06143 (12)	0.0150 (5)
H1B	0.8819	0.4100	0.0202	0.023*
H2B	0.9993	0.5231	0.0667	0.023*
H3B	0.8502	0.5791	0.0717	0.023*
C1B	0.7664 (3)	0.0909 (7)	0.08684 (14)	0.0164 (6)
C2B	0.9089 (3)	0.2305 (7)	0.10364 (16)	0.0206 (7)
H21B	0.9874	0.1115	0.0983	0.025*
C3B	0.9265 (4)	0.3171 (8)	0.17455 (16)	0.0277 (8)
H31B	0.8420	0.4167	0.1801	0.033*
H32B	0.9304	0.1630	0.2017	0.033*
C4B	1.0564 (4)	0.4770 (10)	0.19724 (17)	0.0330 (9)
H41B	1.0695	0.4971	0.2435	0.050*
H42B	1.0447	0.6458	0.1770	0.050*
H43B	1.1394	0.3921	0.1860	0.050*
O1C	0.1142 (2)	0.1140 (5)	0.43818 (10)	0.0187 (5)
O2C	0.1771 (2)	0.4896 (5)	0.40269 (13)	0.0262 (6)
N1C	0.3644 (3)	−0.1063 (6)	0.44032 (12)	0.0165 (5)
H1C	0.4488	−0.1724	0.4347	0.025*
H2C	0.2934	−0.2140	0.4231	0.025*
H3C	0.3643	−0.0877	0.4826	0.025*
C1C	0.2007 (3)	0.2611 (7)	0.41789 (15)	0.0176 (6)
C2C	0.3426 (3)	0.1488 (6)	0.40840 (15)	0.0174 (6)
H21C	0.4195	0.2660	0.4290	0.021*
C3C	0.3509 (4)	0.1284 (8)	0.33786 (16)	0.0264 (8)
H31C	0.3459	0.3027	0.3195	0.032*
H32C	0.4439	0.0551	0.3338	0.032*
C4C	0.2358 (4)	−0.0335 (10)	0.29949 (16)	0.0349 (9)
H41C	0.2479	−0.0364	0.2550	0.052*
H42C	0.1432	0.0393	0.3023	0.052*
H43C	0.2418	−0.2083	0.3163	0.052*
O1D	0.6104 (2)	0.6060 (5)	0.43697 (10)	0.0189 (5)
O2D	0.6838 (2)	1.0001 (5)	0.41945 (13)	0.0272 (6)
N1D	0.8699 (3)	0.4063 (5)	0.44150 (12)	0.0161 (6)
H1D	0.9521	0.3410	0.4327	0.024*
H2D	0.7987	0.2920	0.4296	0.024*
H3D	0.8797	0.4370	0.4840	0.024*
C1D	0.6999 (3)	0.7623 (7)	0.42291 (15)	0.0168 (6)
C2D	0.8361 (3)	0.6502 (6)	0.40584 (15)	0.0161 (6)
H21D	0.9153	0.7740	0.4187	0.019*
C3D	0.8199 (3)	0.5966 (7)	0.33422 (15)	0.0223 (7)
H31D	0.9062	0.5093	0.3259	0.027*
H32D	0.7391	0.4791	0.3213	0.027*
C4D	0.7962 (4)	0.8363 (9)	0.29379 (17)	0.0303 (8)
H41D	0.7890	0.7903	0.2489	0.045*
H42D	0.8759	0.9538	0.3062	0.045*
H43D	0.7086	0.9197	0.3002	0.045*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1A	0.0137 (9)	0.0180 (12)	0.0248 (12)	−0.0022 (9)	0.0029 (8)	0.0034 (10)
O2A	0.0188 (11)	0.0160 (13)	0.0468 (15)	−0.0007 (10)	0.0087 (10)	0.0047 (12)
N1A	0.0134 (11)	0.0143 (15)	0.0220 (13)	−0.0010 (10)	0.0040 (9)	0.0002 (10)
C1A	0.0145 (13)	0.0158 (16)	0.0185 (14)	−0.0019 (12)	0.0035 (10)	0.0007 (12)
C2A	0.0124 (13)	0.0163 (17)	0.0274 (16)	0.0005 (12)	0.0051 (11)	0.0024 (12)
C3A	0.0209 (15)	0.040 (2)	0.0262 (18)	−0.0064 (16)	0.0030 (12)	0.0036 (17)
C4A	0.0315 (19)	0.060 (3)	0.0280 (19)	−0.010 (2)	−0.0059 (14)	0.016 (2)
O1B	0.0133 (9)	0.0218 (13)	0.0242 (11)	−0.0031 (10)	0.0039 (8)	0.0027 (10)
O2B	0.0217 (12)	0.0130 (12)	0.0470 (15)	−0.0015 (10)	0.0114 (10)	0.0025 (12)
N1B	0.0122 (10)	0.0121 (13)	0.0209 (13)	−0.0026 (10)	0.0034 (8)	0.0001 (10)
C1B	0.0179 (14)	0.0147 (16)	0.0177 (14)	−0.0016 (13)	0.0062 (10)	−0.0024 (13)
C2B	0.0125 (13)	0.0176 (17)	0.0305 (17)	−0.0013 (12)	0.0009 (11)	0.0073 (14)
C3B	0.0239 (16)	0.031 (2)	0.0277 (18)	−0.0062 (15)	0.0028 (12)	0.0050 (15)
C4B	0.0252 (17)	0.044 (2)	0.0295 (18)	−0.0087 (18)	0.0028 (13)	−0.0009 (18)
O1C	0.0149 (10)	0.0183 (12)	0.0238 (11)	0.0038 (9)	0.0060 (8)	0.0029 (10)
O2C	0.0178 (11)	0.0156 (13)	0.0451 (15)	0.0027 (10)	0.0050 (9)	0.0034 (12)
N1C	0.0129 (11)	0.0148 (14)	0.0224 (13)	0.0019 (10)	0.0048 (9)	0.0006 (11)
C1C	0.0161 (13)	0.0157 (17)	0.0203 (15)	0.0005 (13)	0.0014 (10)	−0.0018 (13)
C2C	0.0149 (13)	0.0115 (15)	0.0258 (16)	0.0021 (12)	0.0037 (11)	0.0018 (12)
C3C	0.0230 (15)	0.029 (2)	0.0286 (18)	0.0039 (15)	0.0091 (12)	0.0038 (16)
C4C	0.045 (2)	0.038 (2)	0.0219 (18)	0.000 (2)	0.0056 (14)	0.0015 (17)
O1D	0.0143 (10)	0.0153 (12)	0.0277 (12)	0.0011 (9)	0.0057 (8)	0.0013 (10)
O2D	0.0156 (11)	0.0154 (13)	0.0516 (16)	0.0040 (10)	0.0083 (10)	0.0028 (12)
N1D	0.0113 (11)	0.0150 (14)	0.0223 (13)	0.0025 (10)	0.0039 (9)	−0.0006 (10)
C1D	0.0137 (13)	0.0152 (16)	0.0214 (15)	0.0015 (12)	0.0029 (10)	−0.0011 (13)
C2D	0.0127 (13)	0.0133 (15)	0.0229 (16)	0.0009 (11)	0.0045 (10)	0.0019 (12)
C3D	0.0203 (15)	0.0232 (18)	0.0237 (16)	0.0008 (14)	0.0045 (11)	−0.0013 (14)
C4D	0.0333 (19)	0.031 (2)	0.0276 (18)	−0.0018 (16)	0.0071 (14)	0.0037 (16)

Geometric parameters (Å, º)

O1A—C1A	1.262 (4)	O1C—C1C	1.265 (4)
O2A—C1A	1.251 (4)	O2C—C1C	1.248 (5)
N1A—C2A	1.490 (4)	N1C—C2C	1.495 (4)
N1A—H1A	0.9100	N1C—H1C	0.9100
N1A—H2A	0.9100	N1C—H2C	0.9100
N1A—H3A	0.9100	N1C—H3C	0.9100
C1A—C2A	1.545 (4)	C1C—C2C	1.532 (4)
C2A—C3A	1.523 (5)	C2C—C3C	1.529 (5)
C2A—H21A	1.0000	C2C—H21C	1.0000
C3A—C4A	1.531 (5)	C3C—C4C	1.513 (5)
C3A—H31A	0.9900	C3C—H31C	0.9900
C3A—H32A	0.9900	C3C—H32C	0.9900
C4A—H41A	0.9800	C4C—H41C	0.9800
C4A—H42A	0.9800	C4C—H42C	0.9800
C4A—H43A	0.9800	C4C—H43C	0.9800
O1B—C1B	1.259 (4)	O1D—C1D	1.261 (4)
O2B—C1B	1.249 (4)	O2D—C1D	1.253 (4)
N1B—C2B	1.494 (4)	N1D—C2D	1.491 (4)
N1B—H1B	0.9100	N1D—H1D	0.9100
N1B—H2B	0.9100	N1D—H2D	0.9100
N1B—H3B	0.9100	N1D—H3D	0.9100
C1B—C2B	1.537 (4)	C1D—C2D	1.536 (4)
C2B—C3B	1.562 (5)	C2D—C3D	1.537 (4)
C2B—H21B	1.0000	C2D—H21D	1.0000
C3B—C4B	1.509 (5)	C3D—C4D	1.516 (5)
C3B—H31B	0.9900	C3D—H31D	0.9900
C3B—H32B	0.9900	C3D—H32D	0.9900
C4B—H41B	0.9800	C4D—H41D	0.9800
C4B—H42B	0.9800	C4D—H42D	0.9800
C4B—H43B	0.9800	C4D—H43D	0.9800
C2A—N1A—H1A	109.5	C2C—N1C—H1C	109.5
C2A—N1A—H2A	109.5	C2C—N1C—H2C	109.5
H1A—N1A—H2A	109.5	H1C—N1C—H2C	109.5
C2A—N1A—H3A	109.5	C2C—N1C—H3C	109.5
H1A—N1A—H3A	109.5	H1C—N1C—H3C	109.5
H2A—N1A—H3A	109.5	H2C—N1C—H3C	109.5
O2A—C1A—O1A	125.2 (3)	O2C—C1C—O1C	124.8 (3)
O2A—C1A—C2A	118.2 (3)	O2C—C1C—C2C	117.2 (3)
O1A—C1A—C2A	116.5 (3)	O1C—C1C—C2C	117.9 (3)
N1A—C2A—C3A	109.3 (3)	N1C—C2C—C3C	111.1 (3)
N1A—C2A—C1A	108.8 (2)	N1C—C2C—C1C	109.7 (2)
C3A—C2A—C1A	112.0 (3)	C3C—C2C—C1C	111.3 (3)
N1A—C2A—H21A	108.9	N1C—C2C—H21C	108.2
C3A—C2A—H21A	108.9	C3C—C2C—H21C	108.2
C1A—C2A—H21A	108.9	C1C—C2C—H21C	108.2
C2A—C3A—C4A	113.1 (3)	C4C—C3C—C2C	114.3 (3)
C2A—C3A—H31A	109.0	C4C—C3C—H31C	108.7
C4A—C3A—H31A	109.0	C2C—C3C—H31C	108.7
C2A—C3A—H32A	109.0	C4C—C3C—H32C	108.7
C4A—C3A—H32A	109.0	C2C—C3C—H32C	108.7
H31A—C3A—H32A	107.8	H31C—C3C—H32C	107.6
C3A—C4A—H41A	109.5	C3C—C4C—H41C	109.5
C3A—C4A—H42A	109.5	C3C—C4C—H42C	109.5
H41A—C4A—H42A	109.5	H41C—C4C—H42C	109.5
C3A—C4A—H43A	109.5	C3C—C4C—H43C	109.5
H41A—C4A—H43A	109.5	H41C—C4C—H43C	109.5
H42A—C4A—H43A	109.5	H42C—C4C—H43C	109.5
C2B—N1B—H1B	109.5	C2D—N1D—H1D	109.5
C2B—N1B—H2B	109.5	C2D—N1D—H2D	109.5
H1B—N1B—H2B	109.5	H1D—N1D—H2D	109.5
C2B—N1B—H3B	109.5	C2D—N1D—H3D	109.5
H1B—N1B—H3B	109.5	H1D—N1D—H3D	109.5
H2B—N1B—H3B	109.5	H2D—N1D—H3D	109.5
O2B—C1B—O1B	125.1 (3)	O2D—C1D—O1D	125.0 (3)
O2B—C1B—C2B	117.7 (3)	O2D—C1D—C2D	117.8 (3)
O1B—C1B—C2B	117.0 (3)	O1D—C1D—C2D	117.1 (3)
N1B—C2B—C1B	109.9 (2)	N1D—C2D—C1D	108.8 (2)
N1B—C2B—C3B	110.2 (3)	N1D—C2D—C3D	109.1 (3)
C1B—C2B—C3B	107.6 (3)	C1D—C2D—C3D	111.6 (2)
N1B—C2B—H21B	109.7	N1D—C2D—H21D	109.1
C1B—C2B—H21B	109.7	C1D—C2D—H21D	109.1
C3B—C2B—H21B	109.7	C3D—C2D—H21D	109.1
C4B—C3B—C2B	114.4 (3)	C4D—C3D—C2D	113.3 (3)
C4B—C3B—H31B	108.7	C4D—C3D—H31D	108.9
C2B—C3B—H31B	108.7	C2D—C3D—H31D	108.9
C4B—C3B—H32B	108.7	C4D—C3D—H32D	108.9
C2B—C3B—H32B	108.7	C2D—C3D—H32D	108.9
H31B—C3B—H32B	107.6	H31D—C3D—H32D	107.7
C3B—C4B—H41B	109.5	C3D—C4D—H41D	109.5
C3B—C4B—H42B	109.5	C3D—C4D—H42D	109.5
H41B—C4B—H42B	109.5	H41D—C4D—H42D	109.5
C3B—C4B—H43B	109.5	C3D—C4D—H43D	109.5
H41B—C4B—H43B	109.5	H41D—C4D—H43D	109.5
H42B—C4B—H43B	109.5	H42D—C4D—H43D	109.5
N1A—C2A—C1A—O1A	−27.4 (4)	O2B—C1B—C2B—N1B	158.7 (3)
N1A—C2A—C3A—C4A	−168.6 (3)	O2B—C1B—C2B—C3B	−81.4 (4)
N1B—C2B—C1B—O1B	−26.7 (4)	O1B—C1B—C2B—C3B	93.2 (3)
N1B—C2B—C3B—C4B	−55.5 (4)	C1B—C2B—C3B—C4B	−175.2 (3)
N1C—C2C—C1C—O1C	−13.5 (4)	O2C—C1C—C2C—N1C	169.1 (3)
N1C—C2C—C3C—C4C	64.2 (4)	O2C—C1C—C2C—C3C	−67.5 (4)
N1D—C2D—C1D—O1D	−30.4 (4)	O1C—C1C—C2C—C3C	109.9 (3)
N1D—C2D—C3D—C4D	−175.6 (3)	C1C—C2C—C3C—C4C	−58.4 (4)
O2A—C1A—C2A—N1A	155.7 (3)	O2D—C1D—C2D—N1D	152.3 (3)
O2A—C1A—C2A—C3A	−83.4 (4)	O2D—C1D—C2D—C3D	−87.3 (4)
O1A—C1A—C2A—C3A	93.5 (4)	O1D—C1D—C2D—C3D	90.0 (4)
C1A—C2A—C3A—C4A	70.8 (4)	C1D—C2D—C3D—C4D	64.1 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1A—H1A···O1B^i	0.91	1.88	2.754 (4)	160
N1A—H2A···O1B^ii	0.91	1.92	2.796 (4)	160
N1A—H3A···O2A^ii	0.91	1.86	2.747 (4)	165
N1B—H1B···O1A^iii	0.91	1.92	2.814 (4)	165
N1B—H2B···O1A^iv	0.91	1.92	2.803 (3)	164
N1B—H3B···O2B^ii	0.91	1.89	2.781 (4)	168
N1C—H1C···O1D^v	0.91	1.93	2.815 (4)	163
N1C—H2C···O2C^v	0.91	1.91	2.799 (4)	163
N1C—H3C···O1D^vi	0.91	1.97	2.819 (4)	154
N1D—H1D···O1C^iv	0.91	1.95	2.813 (3)	159
N1D—H2D···O2D^v	0.91	1.87	2.762 (4)	165
N1D—H3D···O1C^vii	0.91	1.90	2.771 (4)	161

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

(S)-2-aminobutyric acid (II)

Crystal data

C4H9NO2	F(000) = 896
Mr = 103.12	Dx = 1.291 Mg m^−3
Monoclinic, I2	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: I 2y	Cell parameters from 3867 reflections
a = 9.646 (2) Å	θ = 1.9–25.0°
b = 5.2145 (12) Å	µ = 0.10 mm^−1
c = 42.885 (10) Å	T = 110 K
β = 100.295 (3)°	Block, colourless
V = 2122.5 (8) Å^3	0.40 × 0.32 × 0.18 mm
Z = 16

Data collection

Bruker Apex II CCD diffractometer	2083 independent reflections
Radiation source: fine-focus sealed tube	1852 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
Detector resolution: 8.3 pixels mm^-1	θmax = 25.0°, θmin = 1.9°
Sets of exposures each taken over 0.5° ω rotation scans	h = −11→11
Absorption correction: multi-scan SADABS (Bruker, 2007)	k = −6→6
Tmin = 0.791, Tmax = 0.982	l = −50→50
7238 measured reflections

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.120	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0531P)^2 + 3.6316P] where P = (Fo^2 + 2Fc^2)/3
2083 reflections	(Δ/σ)max < 0.001
261 parameters	Δρmax = 0.26 e Å^−3
1 restraint	Δρmin = −0.25 e Å^−3
0 constraints

Special details

Experimental. Broad reflections

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1A	−0.0869 (2)	0.7794 (5)	0.03248 (6)	0.0173 (6)
O2A	0.0039 (3)	0.3905 (5)	0.04313 (7)	0.0235 (7)
N1A	0.1646 (3)	0.9851 (6)	0.02779 (6)	0.0147 (7)
H1A	0.1327	0.9516	0.0069	0.022*
H2A	0.2539	1.0481	0.0303	0.022*
H3A	0.1075	1.1029	0.0347	0.022*
C1A	0.0151 (4)	0.6258 (8)	0.03974 (8)	0.0157 (8)
C2A	0.1642 (3)	0.7444 (7)	0.04644 (8)	0.0160 (8)
H21A	0.2329	0.6204	0.0400	0.019*
C3A	0.2086 (4)	0.8080 (9)	0.08173 (8)	0.0256 (9)
H32A	0.2977	0.9066	0.0847	0.031*
H31A	0.1359	0.9192	0.0883	0.031*
C4A	0.2295 (4)	0.5748 (11)	0.10308 (10)	0.0372 (12)
H41A	0.2625	0.6292	0.1250	0.056*
H42A	0.2996	0.4610	0.0964	0.056*
H43A	0.1399	0.4831	0.1016	0.056*
O1B	0.4092 (2)	0.2807 (5)	0.02806 (5)	0.0171 (6)
O2B	0.5037 (3)	−0.0834 (5)	0.04897 (7)	0.0253 (7)
N1B	0.6605 (3)	0.5128 (7)	0.03150 (6)	0.0141 (6)
H1B	0.6329	0.4693	0.0108	0.021*
H2B	0.7505	0.5731	0.0346	0.021*
H3B	0.6024	0.6367	0.0368	0.021*
C1B	0.5113 (3)	0.1463 (8)	0.04154 (8)	0.0146 (8)
C2B	0.6537 (3)	0.2824 (8)	0.05180 (8)	0.0155 (8)
H21B	0.7318	0.1621	0.0493	0.019*
C3B	0.6679 (4)	0.3597 (8)	0.08685 (8)	0.0211 (9)
H31B	0.5844	0.4625	0.0895	0.025*
H32B	0.6677	0.2024	0.0998	0.025*
C4B	0.7997 (4)	0.5129 (10)	0.09953 (8)	0.0275 (9)
H41B	0.8093	0.5310	0.1226	0.041*
H42B	0.7927	0.6831	0.0897	0.041*
H43B	0.8824	0.4234	0.0945	0.041*
O1C	−0.1360 (2)	0.1523 (5)	0.21886 (5)	0.0157 (5)
O2C	−0.0733 (3)	0.5268 (5)	0.20093 (6)	0.0232 (6)
N1C	0.1143 (3)	−0.0685 (6)	0.21989 (6)	0.0151 (7)
H1C	0.1128	−0.0502	0.2409	0.023*
H3C	0.1990	−0.1337	0.2173	0.023*
H2C	0.0443	−0.1773	0.2111	0.023*
C1C	−0.0498 (4)	0.2987 (8)	0.20865 (8)	0.0155 (8)
C2C	0.0925 (4)	0.1868 (7)	0.20399 (8)	0.0159 (8)
H21C	0.1690	0.3048	0.2142	0.019*
C3C	0.1008 (4)	0.1653 (9)	0.16876 (8)	0.0218 (9)
H31C	0.0963	0.3398	0.1596	0.026*
H32C	0.1934	0.0911	0.1668	0.026*
C4C	−0.0146 (4)	0.0026 (10)	0.14943 (8)	0.0279 (9)
H41C	−0.0048	0.0061	0.1271	0.042*
H42C	−0.1069	0.0715	0.1516	0.042*
H43C	−0.0064	−0.1745	0.1572	0.042*
O1D	0.3607 (2)	0.6429 (5)	0.21874 (5)	0.0160 (6)
O2D	0.4339 (3)	1.0372 (5)	0.21033 (6)	0.0238 (6)
N1D	0.6197 (3)	0.4426 (6)	0.22100 (6)	0.0138 (7)
H1D	0.6245	0.4710	0.2421	0.021*
H2D	0.5512	0.3250	0.2142	0.021*
H3D	0.7040	0.3824	0.2175	0.021*
C1D	0.4505 (3)	0.8002 (8)	0.21183 (8)	0.0139 (8)
C2D	0.5857 (3)	0.6874 (7)	0.20336 (8)	0.0141 (8)
H21D	0.6647	0.8114	0.2098	0.017*
C3D	0.5697 (4)	0.6341 (8)	0.16771 (8)	0.0201 (8)
H31D	0.6544	0.5416	0.1637	0.024*
H32D	0.4873	0.5210	0.1611	0.024*
C4D	0.5508 (4)	0.8772 (9)	0.14760 (9)	0.0263 (10)
H41D	0.5433	0.8316	0.1252	0.039*
H42D	0.6321	0.9902	0.1539	0.039*
H43D	0.4648	0.9659	0.1507	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1A	0.0135 (11)	0.0169 (14)	0.0220 (12)	−0.0016 (12)	0.0046 (9)	0.0043 (12)
O2A	0.0205 (14)	0.0143 (17)	0.0377 (16)	−0.0023 (12)	0.0105 (12)	0.0035 (13)
N1A	0.0123 (13)	0.0145 (17)	0.0183 (14)	−0.0026 (13)	0.0055 (11)	−0.0029 (14)
C1A	0.0146 (17)	0.019 (2)	0.0158 (18)	−0.0013 (17)	0.0080 (14)	0.0012 (17)
C2A	0.0141 (16)	0.013 (2)	0.0222 (18)	−0.0016 (16)	0.0062 (14)	0.0021 (16)
C3A	0.0186 (18)	0.035 (3)	0.0237 (19)	−0.005 (2)	0.0044 (15)	0.000 (2)
C4A	0.028 (2)	0.052 (3)	0.029 (2)	−0.008 (2)	−0.0027 (17)	0.014 (2)
O1B	0.0136 (11)	0.0170 (14)	0.0209 (13)	−0.0019 (12)	0.0037 (10)	0.0020 (12)
O2B	0.0198 (13)	0.0113 (15)	0.0475 (17)	−0.0005 (12)	0.0130 (12)	0.0023 (14)
N1B	0.0106 (13)	0.0127 (16)	0.0197 (14)	−0.0022 (13)	0.0046 (11)	0.0002 (14)
C1B	0.0136 (17)	0.013 (2)	0.0192 (18)	0.0010 (17)	0.0093 (14)	−0.0016 (17)
C2B	0.0144 (16)	0.0090 (19)	0.0234 (18)	0.0011 (16)	0.0041 (14)	0.0043 (17)
C3B	0.0224 (19)	0.023 (2)	0.0190 (18)	−0.0029 (17)	0.0070 (15)	0.0048 (16)
C4B	0.028 (2)	0.036 (2)	0.0186 (18)	−0.009 (2)	0.0039 (15)	−0.003 (2)
O1C	0.0131 (11)	0.0126 (13)	0.0227 (12)	0.0020 (11)	0.0063 (9)	0.0027 (12)
O2C	0.0179 (12)	0.0123 (14)	0.0392 (15)	0.0044 (12)	0.0048 (11)	0.0066 (15)
N1C	0.0144 (14)	0.0132 (16)	0.0188 (15)	0.0017 (14)	0.0055 (11)	−0.0003 (13)
C1C	0.0156 (16)	0.015 (2)	0.0160 (17)	−0.0003 (17)	0.0019 (13)	−0.0028 (17)
C2C	0.0144 (16)	0.0120 (19)	0.0218 (18)	−0.0002 (16)	0.0041 (14)	−0.0012 (16)
C3C	0.0191 (17)	0.023 (2)	0.026 (2)	0.0007 (18)	0.0097 (15)	0.0028 (19)
C4C	0.039 (2)	0.028 (2)	0.0178 (18)	0.000 (2)	0.0076 (16)	0.0014 (19)
O1D	0.0112 (11)	0.0133 (14)	0.0247 (13)	0.0021 (11)	0.0065 (9)	0.0025 (12)
O2D	0.0205 (13)	0.0103 (15)	0.0419 (16)	0.0024 (13)	0.0092 (12)	0.0020 (14)
N1D	0.0122 (14)	0.0110 (16)	0.0189 (14)	0.0014 (13)	0.0042 (11)	−0.0022 (13)
C1D	0.0148 (16)	0.014 (2)	0.0120 (16)	0.0012 (17)	0.0008 (13)	−0.0008 (16)
C2D	0.0146 (16)	0.0070 (18)	0.0208 (18)	0.0021 (15)	0.0038 (13)	0.0011 (15)
C3D	0.0201 (18)	0.021 (2)	0.0208 (18)	0.0019 (18)	0.0079 (14)	−0.0001 (18)
C4D	0.031 (2)	0.027 (2)	0.0226 (19)	−0.0012 (19)	0.0087 (16)	0.0057 (18)

Geometric parameters (Å, º)

O1A—C1A	1.264 (5)	O1C—C1C	1.263 (4)
O2A—C1A	1.243 (5)	O2C—C1C	1.245 (5)
N1A—C2A	1.489 (5)	N1C—C2C	1.494 (5)
N1A—H1A	0.9100	N1C—H1C	0.9100
N1A—H2A	0.9100	N1C—H3C	0.9100
N1A—H3A	0.9100	N1C—H2C	0.9100
C1A—C2A	1.544 (5)	C1C—C2C	1.538 (5)
C2A—C3A	1.534 (5)	C2C—C3C	1.531 (5)
C2A—H21A	1.0000	C2C—H21C	1.0000
C3A—C4A	1.514 (6)	C3C—C4C	1.522 (6)
C3A—H32A	0.9900	C3C—H31C	0.9900
C3A—H31A	0.9900	C3C—H32C	0.9900
C4A—H41A	0.9800	C4C—H41C	0.9800
C4A—H42A	0.9800	C4C—H42C	0.9800
C4A—H43A	0.9800	C4C—H43C	0.9800
O1B—C1B	1.261 (4)	O1D—C1D	1.266 (4)
O2B—C1B	1.245 (5)	O2D—C1D	1.247 (5)
N1B—C2B	1.492 (5)	N1D—C2D	1.490 (5)
N1B—H1B	0.9100	N1D—H3D	0.9100
N1B—H2B	0.9100	N1D—H2D	0.9100
N1B—H3B	0.9100	N1D—H1D	0.9100
C1B—C2B	1.539 (5)	C1D—C2D	1.532 (5)
C2B—C3B	1.538 (5)	C2D—C3D	1.534 (5)
C2B—H21B	1.0000	C2D—H21D	1.0000
C3B—C4B	1.518 (5)	C3D—C4D	1.526 (6)
C3B—H31B	0.9900	C3D—H31D	0.9900
C3B—H32B	0.9900	C3D—H32D	0.9900
C4B—H41B	0.9800	C4D—H41D	0.9800
C4B—H42B	0.9800	C4D—H42D	0.9800
C4B—H43B	0.9800	C4D—H43D	0.9800
C2A—N1A—H1A	109.5	C2C—N1C—H1C	109.5
C2A—N1A—H2A	109.5	C2C—N1C—H3C	109.5
H1A—N1A—H2A	109.5	H1C—N1C—H3C	109.5
C2A—N1A—H3A	109.5	C2C—N1C—H2C	109.5
H1A—N1A—H3A	109.5	H1C—N1C—H2C	109.5
H2A—N1A—H3A	109.5	H3C—N1C—H2C	109.5
O2A—C1A—O1A	125.0 (4)	O2C—C1C—O1C	124.7 (3)
O2A—C1A—C2A	118.1 (4)	O2C—C1C—C2C	116.9 (3)
O1A—C1A—C2A	116.8 (4)	O1C—C1C—C2C	118.3 (3)
N1A—C2A—C3A	108.7 (3)	N1C—C2C—C3C	110.9 (3)
N1A—C2A—C1A	109.2 (3)	N1C—C2C—C1C	109.6 (3)
C3A—C2A—C1A	110.9 (3)	C3C—C2C—C1C	111.2 (3)
N1A—C2A—H21A	109.3	N1C—C2C—H21C	108.4
C3A—C2A—H21A	109.3	C3C—C2C—H21C	108.4
C1A—C2A—H21A	109.3	C1C—C2C—H21C	108.4
C4A—C3A—C2A	114.0 (4)	C4C—C3C—C2C	114.6 (3)
C4A—C3A—H32A	108.8	C4C—C3C—H31C	108.6
C2A—C3A—H32A	108.8	C2C—C3C—H31C	108.6
C4A—C3A—H31A	108.8	C4C—C3C—H32C	108.6
C2A—C3A—H31A	108.8	C2C—C3C—H32C	108.6
H32A—C3A—H31A	107.7	H31C—C3C—H32C	107.6
C3A—C4A—H41A	109.5	C3C—C4C—H41C	109.5
C3A—C4A—H42A	109.5	C3C—C4C—H42C	109.5
H41A—C4A—H42A	109.5	H41C—C4C—H42C	109.5
C3A—C4A—H43A	109.5	C3C—C4C—H43C	109.5
H41A—C4A—H43A	109.5	H41C—C4C—H43C	109.5
H42A—C4A—H43A	109.5	H42C—C4C—H43C	109.5
C2B—N1B—H1B	109.5	C2D—N1D—H3D	109.5
C2B—N1B—H2B	109.5	C2D—N1D—H2D	109.5
H1B—N1B—H2B	109.5	H3D—N1D—H2D	109.5
C2B—N1B—H3B	109.5	C2D—N1D—H1D	109.5
H1B—N1B—H3B	109.5	H3D—N1D—H1D	109.5
H2B—N1B—H3B	109.5	H2D—N1D—H1D	109.5
O2B—C1B—O1B	125.1 (4)	O2D—C1D—O1D	124.5 (3)
O2B—C1B—C2B	117.4 (3)	O2D—C1D—C2D	118.4 (3)
O1B—C1B—C2B	117.3 (3)	O1D—C1D—C2D	117.0 (3)
N1B—C2B—C3B	110.7 (3)	N1D—C2D—C1D	109.1 (3)
N1B—C2B—C1B	109.5 (3)	N1D—C2D—C3D	108.9 (3)
C3B—C2B—C1B	108.6 (3)	C1D—C2D—C3D	111.6 (3)
N1B—C2B—H21B	109.3	N1D—C2D—H21D	109.0
C3B—C2B—H21B	109.3	C1D—C2D—H21D	109.0
C1B—C2B—H21B	109.3	C3D—C2D—H21D	109.0
C4B—C3B—C2B	114.2 (3)	C4D—C3D—C2D	113.2 (3)
C4B—C3B—H31B	108.7	C4D—C3D—H31D	108.9
C2B—C3B—H31B	108.7	C2D—C3D—H31D	108.9
C4B—C3B—H32B	108.7	C4D—C3D—H32D	108.9
C2B—C3B—H32B	108.7	C2D—C3D—H32D	108.9
H31B—C3B—H32B	107.6	H31D—C3D—H32D	107.8
C3B—C4B—H41B	109.5	C3D—C4D—H41D	109.5
C3B—C4B—H42B	109.5	C3D—C4D—H42D	109.5
H41B—C4B—H42B	109.5	H41D—C4D—H42D	109.5
C3B—C4B—H43B	109.5	C3D—C4D—H43D	109.5
H41B—C4B—H43B	109.5	H41D—C4D—H43D	109.5
H42B—C4B—H43B	109.5	H42D—C4D—H43D	109.5
N1A—C2A—C1A—O1A	−28.9 (4)	O2B—C1B—C2B—N1B	159.0 (3)
N1A—C2A—C3A—C4A	−173.1 (3)	O2B—C1B—C2B—C3B	−80.0 (4)
N1B—C2B—C1B—O1B	−25.5 (4)	O1B—C1B—C2B—C3B	95.5 (4)
N1B—C2B—C3B—C4B	−55.7 (4)	C1B—C2B—C3B—C4B	−176.0 (4)
N1C—C2C—C1C—O1C	−13.0 (4)	O2C—C1C—C2C—N1C	169.4 (3)
N1C—C2C—C3C—C4C	64.4 (4)	O2C—C1C—C2C—C3C	−67.6 (4)
N1D—C2D—C1D—O1D	−30.6 (4)	O1C—C1C—C2C—C3C	109.9 (4)
N1D—C2D—C3D—C4D	−173.7 (3)	C1C—C2C—C3C—C4C	−57.8 (5)
O2A—C1A—C2A—N1A	154.1 (3)	O2D—C1D—C2D—N1D	152.1 (3)
O2A—C1A—C2A—C3A	−86.2 (4)	O2D—C1D—C2D—C3D	−87.5 (4)
O1A—C1A—C2A—C3A	90.9 (4)	O1D—C1D—C2D—C3D	89.9 (4)
C1A—C2A—C3A—C4A	66.8 (4)	C1D—C2D—C3D—C4D	65.8 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1A—H1A···O1A^i	0.91	1.89	2.775 (4)	162
N1A—H2A···O1B^ii	0.91	1.94	2.816 (4)	160
N1A—H3A···O2A^ii	0.91	1.87	2.769 (4)	168
N1B—H1B···O1B^iii	0.91	1.91	2.798 (4)	163
N1B—H2B···O1A^iv	0.91	1.92	2.799 (4)	163
N1B—H3B···O2B^ii	0.91	1.87	2.773 (4)	173
N1C—H1C···O1D^v	0.91	1.98	2.824 (4)	154
N1C—H2C···O2C^vi	0.91	1.92	2.804 (4)	164
N1C—H3C···O1D^vi	0.91	1.94	2.821 (4)	163
N1D—H1D···O1C^vii	0.91	1.91	2.780 (4)	160
N1D—H2D···O2D^vi	0.91	1.87	2.756 (4)	164
N1D—H3D···O1C^iv	0.91	1.95	2.817 (4)	159

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