2-Amino-4-(4-pyridyl)­pyrimidine and the 1:1 adduct with 4-amino­benzoic acid

The structure of the title compound, C₉H₈N₄, comprises non-planar mol­ecules that associate via pyrimidine N—H...N dimer R(8) hydrogen-bonding associations [N...N 3.1870 (17) Å] and form linear hydrogen-bonded chains via a pyrimidine N—H...N(pyridyl) interaction [N...N 3.0295 (19) Å]. The dihedral angle between the two rings is 24.57 (5)°. The structure of the 1:1 adduct with 4-amino­benzoic acid, C₉H₈N₄·C₇H₇NO₂, exhibits a hydrogen-bond­ing network involving COOH...N(pyridyl) [O...N 2.6406 (17) Å], pyrimidine N—H...N [N...N 3.0737 (19) and 3.1755 (18) Å] and acid N—H...O interactions [N...O 3.0609 (17) and 2.981 (2) Å]. The dihedral angle between the two linked rings of the base is 38.49 (6)° and the carboxyl­ic acid group binds to the stronger base group in contrast to the (less basic) complementary hydrogen-bonding site.

S1. Comment

The design of multi-dimensional organic crystal lattices requires the use of molecules with several interactive substituents. Ideally, the association of these substituents can be predicted and their specific position used to construct the desired array (Desiraju, 1995). For a number of years the principal author has studied the association between carboxylic acids and either pyridines or 2-aminopyridine type molecules with the additional amine group used to lock the COOH and the heterocyclic ring in essentially the same plane (Fig. 1). If the secondary substituents on the carboxylic acid molecule do not have the hydrogen-bonding donor strength of the acid itself then association between the acid and the Lewis base can be expected (Lynch et al., 2000). However, competition between these two types of bases (in one molecule) has never been investigated by X-ray crystallography and the authors postulated as to which of the two groups a carboxylic acid would preferentially bind. Etter (1991) inversely showed that the same pyridine base, when placed in a mixed carboxylic acid solution, selectively co-crystallized the acid with the lower pK_a value. Our purpose for this study was to investigate whether the same pK_a difference would be important when two different bases were in competition for the same acid?

The principal author has always assumed that the 2-aminopyridine site is more stable for binding with COOH groups than pyridine itself, because the resultant synthon mimics acid dimer formation. Therefore, a simple molecule containing both a pyridine N and a 2-aminopyridine site has been produced to test whether a COOH group is preferentially attracted to either the stronger base or the more stable binding site. One of a series of simple molecules which contain both types of bases is 2-amino-4-(pyrid-4-yl)pyrimidine. This molecule subsequently exhibited a large difference in the pK_a values of the two bases (pK_a = 5.58 and 1.83 for the pyridine and the pyrimidine, respectively). The chosen acid was 4-aminobenzoic acid, which has proven to be a very useful crystallization aid for a number of functional multi-substituted molecules (Smith et al., 1997). The amine group, with the lesser inherent acid strength (pK_a = 5.05), was not expected to directly compete with the COOH (pK_a = 2.38) for binding to the stronger base yet additional hydrogen-bonding donors were required to satisfy the remaining hydrogen-bonding acceptors (after the COOH has bound). Here we report the single-crystal structures of 2-amino-4-(pyrid-4-yl)pyrimidine, (I), and its 1:1 adduct with 4-aminobenzoic acid, (II). \sch

The structure of (I) comprises nonplanar molecules (Fig. 2) that, similar to other analogous compounds, form R₂²(8) hydrogen-bonded dimers across one of the pyrimidine N/NH₂ sites. The second amine H atom, instead of forming another dimer, interacts with the pyridyl N atom thus creating a linear hydrogen-bonded polymer chain (Fig. 3), the hydrogen-bonding geometry is listed in Table 1. In (I), the dihedral angle between the two rings is 24.57 (5)°. The structure of (II) (Fig. 4) comprises twisted 2-aminopyrimidine derivatives associating via continuous R₂²(8) hydrogen-bonded dimers with the inclusion of the acid molecules bound to the 4-pyridyl group (Fig. 5). The two 4-amino H atoms are also involved in the hydrogen-bonding network with three-centre associations to the carbonyl O atom and the hydrogen-bonding geometry is listed in Table 2. The dihedral angle between the two linked rings of the base in the structure of (II) is 38.49 (6)°.

4-Aminobenzoic acid is a relatively strong organic acid with a pK_a value of 2.38, thus when adducted with 2-amino-4-(pyrid-4-yl)pyrimidine the carboxylic acid group could have bound to a complementary acidic pyrimidine N/NH₂ site (pK_a = 1.83), but instead was found to prefer the more basic pyridyl N atom (pK_a = 5.58). The pK_a difference between the COOH and the pyridyl group is < 3.75 (Johnson & Rumon, 1965) so no proton-transfer (and hence an organic salt) results. The pyrimidine N/NH₂ sites then form dimers with themselves and leave the 4-amino H atoms to associate with the only other available hydrogen-bonding acceptor atom, the carbonyl O atom (although a few cases exist where the 4-amino N atoms have also been hydrogen-bond acceptors). The results of this study may have been affected by the fact that the carboxylic acid group has a higher pK_a value than the pyrimidine N/NH₂ site. However, to use an organic acid with a pK_a < 1.83 would have led to a pK_a difference between the COOH group and the pyridyl N atom being > 3.75, above which proton-transfer to the pyridyl group could have occurred (Johnson & Rumon, 1965), assuring binding to the pyridyl N atom. The acidity of the pyrimidine group was also affected by the direct substitution of an electron accepting group, thus attempts are underway to synthesize a molecule which contains these two heterocyclic bases but between which is an alkyl spacer (preferably hexa-cyclic such that the conformation can be controlled). In such a molecule the pK_a value of the pyrimidine ring should be closer to the pK_a value of 2-aminopyrimidine itself (pK_a = 2.40). A lowering of the inherent acid strength of this group thus increases the potential for COOH binding to the pyrimidine as opposed to the pyridine.

S2. Experimental

The title compound, (I), was prepared by Spa Contract Synthesis. Crystals of (I) were grown from an ethanol solution. Crystals of (II) were grown from an ethanol solution of equimolar amounts of (I) and 4-aminobenzoic acid (Aldrich). Theoretical pK_a values were calculated using pKalc 3.2 from PALLAS 2.1 available from Compudrug; www.compudrug.com.

S3. Refinement

All aromatic H atoms were included in the refinement at calculated positions, as riding models with C—H set to 0.95 Å. All H atoms involved in the hydrogen-bonding associations were located in difference syntheses and both position and thermal parameters subsequently refined.

Computing details

Data collection: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998) for (I); DENZO (Otwinowski & Minor, 1997 and COLLECT (Hooft, 1998) for (II). For both compounds, cell refinement: DENZO and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON97 (Spek, 1997); software used to prepare material for publication: SHELXL97.

Figures

Fig. 1. Hydrogen-bonding pattern for a 2-aminopyrimidine-carboxylic acid interaction. Fig. 2. Molecular configuration and atom numbering scheme for (I), showing 30% probability ellipsoids. Fig. 3. Molecular packing for (I). Hydrogen-bonding associations are shown as dotted lines. Symmetry codes: (i) -x, 2 - y, -1 - z; (ii) x - 1, y, z - 1. Fig. 4. Molecular configuration and atom numbering scheme for (II), showing 30% probability ellipsoids. Fig. 5. Molecular packing for (II). Hydrogen-bonding associations are shown as dotted lines. Symmetry codes: (i) -2 - x, 1 - y, -1 - z; (ii) -1 - x, 1 - y, -1 - z; (iii) 1 + x, 1/2 - y, 1/2 + z; (iv) 1 + x, y, z.

(I) 2-Amino-4-(pyrid-4-yl)pyrimidine

Crystal data

C9H8N4	Dx = 1.411 Mg m^−3
Mr = 172.19	Melting point: 353-356 K K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 9.450 (2) Å	Cell parameters from 3577 reflections
b = 13.689 (3) Å	θ = 2.9–47.8°
c = 6.439 (1) Å	µ = 0.09 mm^−1
β = 103.35 (3)°	T = 150 K
V = 810.4 (3) Å^3	Prism, yellow
Z = 4	0.27 × 0.12 × 0.12 mm
F(000) = 360

Data collection

Kappa-CCD diffractometer	1841 independent reflections
Radiation source: Enraf Nonius FR591 rotating anode	1417 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.04
Detector resolution: 9.091 pixels mm^-1	θmax = 27.5°, θmin = 3.0°
ϕ and ω scans	h = −11→12
Absorption correction: multi-scan (SORTAV; Blessing, 1995)	k = −17→17
Tmin = 0.976, Tmax = 0.989	l = −8→8
6415 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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.132	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0846P)^2 + 0.0128P] where P = (Fo^2 + 2Fc^2)/3
1841 reflections	(Δ/σ)max < 0.001
126 parameters	Δρmax = 0.25 e Å^−3
0 restraints	Δρmin = −0.25 e Å^−3

Special details

Experimental. PLEASE NOTE cell_measurement_ fields are not relevant to area detector data, the entire data set is used to refine the cell, which is indexed from all observed reflections in a 10 degree phi range.

Geometry. Mean plane data ex SHELXL97 ###########################

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

- 2.4652 (0.0045) x + 12.1614 (0.0072) y + 2.7539 (0.0034) z = 10.3692 (0.0063)

* -0.0001 (0.0008) N1 * -0.0082 (0.0008) C2 * 0.0105 (0.0008) N3 * -0.0050 (0.0008) C4 * -0.0029 (0.0008) C5 * 0.0057 (0.0009) C6 - 0.0523 (0.0018) N21

Rms deviation of fitted atoms = 0.0064

- 0.4015 (0.0048) x + 13.6705 (0.0072) y + 0.2478 (0.0039) z = 11.9322 (0.0065)

Angle to previous plane (with approximate e.s.d.) = 24.57 (0.05)

* 0.0070 (0.0009) C7 * -0.0051 (0.0009) C8 * -0.0005 (0.0009) C9 * 0.0044 (0.0009) N10 * -0.0024 (0.0009) C11 * -0.0033 (0.0009) C12

Rms deviation of fitted atoms = 0.0043

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

	x	y	z	Uiso*/Ueq
N1	−0.24503 (12)	0.86156 (8)	−0.25879 (16)	0.0263 (3)
C2	−0.14313 (14)	0.90228 (9)	−0.35034 (18)	0.0229 (3)
N21	−0.18924 (13)	0.93476 (9)	−0.55106 (16)	0.0287 (3)
H21	−0.283 (2)	0.9241 (11)	−0.627 (2)	0.040 (4)*
H22	−0.1250 (18)	0.9663 (11)	−0.615 (2)	0.045 (4)*
N3	−0.00036 (11)	0.91179 (7)	−0.25774 (15)	0.0227 (3)
C4	0.04501 (14)	0.87496 (8)	−0.06011 (19)	0.0218 (3)
C5	−0.05131 (14)	0.83165 (9)	0.04571 (19)	0.0265 (3)
H5	−0.0194	0.8060	0.1859	0.033*
C6	−0.19526 (14)	0.82755 (9)	−0.0619 (2)	0.0272 (3)
H6	−0.2628	0.7988	0.0085	0.034*
C7	0.20356 (15)	0.87872 (9)	0.03404 (19)	0.0232 (3)
C8	0.26123 (16)	0.87555 (10)	0.2533 (2)	0.0302 (3)
H8	0.1988	0.8711	0.3492	0.038*
C9	0.41009 (17)	0.87887 (10)	0.3299 (2)	0.0353 (4)
H9	0.4472	0.8772	0.4801	0.044*
N10	0.50522 (13)	0.88427 (9)	0.20589 (19)	0.0350 (3)
C11	0.44911 (16)	0.88593 (10)	−0.0045 (2)	0.0332 (4)
H10	0.5144	0.8892	−0.0965	0.042*
C12	0.30230 (15)	0.88321 (10)	−0.0957 (2)	0.0286 (3)
H12	0.2686	0.8844	−0.2466	0.036*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0204 (6)	0.0303 (6)	0.0285 (6)	0.0002 (4)	0.0061 (4)	0.0022 (4)
C2	0.0215 (7)	0.0232 (6)	0.0236 (6)	0.0005 (5)	0.0040 (5)	−0.0017 (5)
N21	0.0210 (7)	0.0398 (7)	0.0230 (5)	−0.0022 (5)	0.0002 (5)	0.0041 (5)
N3	0.0215 (6)	0.0249 (6)	0.0209 (5)	−0.0005 (4)	0.0031 (4)	0.0001 (4)
C4	0.0229 (7)	0.0210 (6)	0.0212 (6)	0.0010 (5)	0.0041 (5)	−0.0018 (4)
C5	0.0265 (8)	0.0292 (7)	0.0232 (6)	0.0019 (5)	0.0049 (5)	0.0039 (5)
C6	0.0250 (8)	0.0288 (7)	0.0294 (7)	0.0005 (5)	0.0093 (5)	0.0042 (5)
C7	0.0236 (7)	0.0213 (6)	0.0229 (6)	0.0001 (5)	0.0018 (5)	0.0011 (5)
C8	0.0281 (8)	0.0376 (8)	0.0236 (6)	−0.0019 (6)	0.0034 (5)	0.0002 (5)
C9	0.0330 (9)	0.0451 (9)	0.0237 (7)	−0.0033 (6)	−0.0018 (6)	0.0014 (6)
N10	0.0238 (7)	0.0460 (7)	0.0312 (6)	−0.0010 (5)	−0.0019 (5)	0.0056 (5)
C11	0.0228 (8)	0.0445 (8)	0.0309 (7)	0.0034 (6)	0.0034 (6)	0.0057 (6)
C12	0.0255 (8)	0.0364 (8)	0.0226 (6)	0.0021 (6)	0.0029 (5)	0.0042 (5)

Geometric parameters (Å, º)

N1—C6	1.3303 (16)	C6—H6	0.95
N1—C2	1.3592 (16)	C7—C12	1.3899 (19)
C2—N21	1.3408 (15)	C7—C8	1.3914 (17)
C2—N3	1.3496 (17)	C8—C9	1.380 (2)
N21—H21	0.919 (18)	C8—H8	0.95
N21—H22	0.917 (16)	C9—N10	1.3349 (18)
N3—C4	1.3436 (16)	C9—H9	0.95
C4—C5	1.3895 (17)	N10—C11	1.3358 (18)
C4—C7	1.482 (2)	C11—C12	1.377 (2)
C5—C6	1.3779 (19)	C11—H10	0.95
C5—H5	0.95	C12—H12	0.95
C6—N1—C2	115.26 (11)	C12—C7—C8	116.80 (13)
N21—C2—N3	117.59 (11)	C12—C7—C4	120.76 (11)
N21—C2—N1	116.67 (12)	C8—C7—C4	122.43 (12)
N3—C2—N1	125.74 (11)	C9—C8—C7	119.33 (13)
C2—N21—H21	121.4 (9)	C9—C8—H8	120.3
C2—N21—H22	119.3 (10)	C7—C8—H8	120.3
H21—N21—H22	119.3 (13)	N10—C9—C8	124.04 (12)
C4—N3—C2	116.75 (11)	N10—C9—H9	118.0
N3—C4—C5	121.50 (12)	C8—C9—H9	118.0
N3—C4—C7	116.48 (11)	C9—N10—C11	116.27 (13)
C5—C4—C7	121.96 (11)	N10—C11—C12	123.86 (13)
C6—C5—C4	116.95 (11)	N10—C11—H10	118.1
C6—C5—H5	121.5	C12—C11—H10	118.1
C4—C5—H5	121.5	C11—C12—C7	119.68 (12)
N1—C6—C5	123.77 (11)	C11—C12—H12	120.2
N1—C6—H6	118.1	C7—C12—H12	120.2
C5—C6—H6	118.1
C6—N1—C2—N21	178.18 (11)	C5—C4—C7—C12	152.98 (12)
C6—N1—C2—N3	−1.11 (19)	N3—C4—C7—C8	157.49 (12)
N21—C2—N3—C4	−177.15 (11)	C5—C4—C7—C8	−25.40 (17)
N1—C2—N3—C4	2.13 (18)	C12—C7—C8—C9	1.23 (18)
C2—N3—C4—C5	−1.73 (17)	C4—C7—C8—C9	179.68 (11)
C2—N3—C4—C7	175.40 (9)	C7—C8—C9—N10	−0.6 (2)
N3—C4—C5—C6	0.47 (17)	C8—C9—N10—C11	−0.3 (2)
C7—C4—C5—C6	−176.50 (11)	C9—N10—C11—C12	0.5 (2)
C2—N1—C6—C5	−0.34 (19)	N10—C11—C12—C7	0.2 (2)
C4—C5—C6—N1	0.63 (19)	C8—C7—C12—C11	−1.06 (19)
N3—C4—C7—C12	−24.13 (16)	C4—C7—C12—C11	−179.53 (11)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N21—H22···N3^i	0.917 (16)	2.303 (17)	3.1870 (17)	161.7 (13)
N21—H21···N10^ii	0.919 (18)	2.114 (19)	3.0295 (19)	174.1 (14)

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

(II) 2-Amino-4-(pyrid-4-yl)pyrimidine 4-aminobenzoic acid

Crystal data

C9H8N4·C7H7NO2	Dx = 1.386 Mg m^−3
Mr = 309.33	Melting point: 356-358 K K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.881 (2) Å	Cell parameters from 10808 reflections
b = 26.354 (5) Å	θ = 1.0–27.5°
c = 7.297 (2) Å	µ = 0.10 mm^−1
β = 102.04 (3)°	T = 150 K
V = 1482.2 (5) Å^3	Prism, yellow
Z = 4	0.55 × 0.20 × 0.20 mm
F(000) = 648

Data collection

Kappa-CCD diffractometer	3303 independent reflections
Radiation source: Enraf Nonius FR591 rotating anode	2349 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.047
Detector resolution: 9.091 pixels mm^-1	θmax = 27.5°, θmin = 2.6°
ϕ and ω scans	h = −9→10
Absorption correction: multi-scan (SORTAV; Blessing, 1995)	k = −34→27
Tmin = 0.949, Tmax = 0.981	l = −9→9
10418 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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.123	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0708P)^2] where P = (Fo^2 + 2Fc^2)/3
3303 reflections	(Δ/σ)max < 0.001
228 parameters	Δρmax = 0.28 e Å^−3
0 restraints	Δρmin = −0.32 e Å^−3

Special details

Experimental. PLEASE NOTE cell_measurement_ fields are not relevant to area detector data, the entire data set is used to refine the cell, which is indexed from all observed reflections in a 10 degree phi range.

Geometry. Mean plane data ex SHELXL97 ###########################

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

- 1.5580 (0.0042) x + 17.9884 (0.0152) y + 5.3219 (0.0042) z = 7.6095 (0.0075)

* 0.0123 (0.0010) N1A * -0.0092 (0.0010) C2A * -0.0042 (0.0009) N3A * 0.0141 (0.0010) C4A * -0.0101 (0.0010) C5A * -0.0028 (0.0010) C6A

Rms deviation of fitted atoms = 0.0097

- 4.2315 (0.0043) x + 3.4876 (0.0165) y + 6.7635 (0.0038) z = 2.6173 (0.0067)

Angle to previous plane (with approximate e.s.d.) = 38.49 (0.06)

* 0.0017 (0.0010) C7A * 0.0102 (0.0010) C8A * -0.0126 (0.0010) C9A * 0.0022 (0.0010) N10A * 0.0102 (0.0010) C11A * -0.0117 (0.0010) C12A

Rms deviation of fitted atoms = 0.0092

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

	x	y	z	Uiso*/Ueq
N1A	−0.87542 (14)	0.45140 (5)	−0.34988 (16)	0.0244 (3)
C2A	−0.72994 (17)	0.47322 (6)	−0.3851 (2)	0.0228 (3)
N21A	−0.75169 (17)	0.50959 (5)	−0.51658 (19)	0.0330 (4)
H21A	−0.863 (2)	0.5206 (7)	−0.568 (2)	0.045 (5)*
H22A	−0.655 (2)	0.5214 (7)	−0.555 (2)	0.043 (5)*
N3A	−0.56584 (14)	0.46184 (5)	−0.29763 (16)	0.0231 (3)
C4A	−0.54805 (18)	0.42559 (5)	−0.16648 (19)	0.0214 (3)
C5A	−0.68880 (18)	0.39977 (6)	−0.1250 (2)	0.0260 (3)
H5A	−0.6748	0.3732	−0.0350	0.032*
C6A	−0.85032 (18)	0.41491 (6)	−0.2220 (2)	0.0249 (3)
H6A	−0.9493	0.3982	−0.1957	0.031*
C7A	−0.36937 (17)	0.41571 (6)	−0.05824 (19)	0.0212 (3)
C8A	−0.31596 (18)	0.36718 (6)	0.0015 (2)	0.0250 (3)
H8A	−0.3926	0.3392	−0.0289	0.031*
C9A	−0.15072 (19)	0.36007 (6)	0.1051 (2)	0.0270 (4)
H9A	−0.1143	0.3265	0.1411	0.034*
N10A	−0.03918 (15)	0.39798 (5)	0.15756 (17)	0.0259 (3)
C11A	−0.09118 (19)	0.44479 (6)	0.1021 (2)	0.0275 (4)
H11A	−0.0135	0.4722	0.1398	0.034*
C12A	−0.25215 (18)	0.45521 (6)	−0.0073 (2)	0.0251 (3)
H12A	−0.2826	0.4889	−0.0472	0.031*
C1B	0.48115 (18)	0.32246 (5)	0.51343 (19)	0.0221 (3)
C11B	0.30006 (18)	0.33616 (6)	0.4293 (2)	0.0234 (3)
O10B	0.17457 (12)	0.31097 (4)	0.45158 (15)	0.0319 (3)
O11B	0.28353 (13)	0.37776 (4)	0.32739 (15)	0.0320 (3)
H11B	0.157 (3)	0.3855 (8)	0.272 (3)	0.072 (7)*
C2B	0.51641 (18)	0.27978 (6)	0.6282 (2)	0.0247 (3)
H2B	0.4231	0.2597	0.6514	0.031*
C3B	0.68411 (18)	0.26637 (6)	0.7082 (2)	0.0258 (3)
H3B	0.7050	0.2375	0.7878	0.032*
C4B	0.82499 (18)	0.29487 (6)	0.67384 (19)	0.0234 (3)
N41B	0.99257 (18)	0.28304 (6)	0.7566 (2)	0.0324 (3)
H41B	1.016 (2)	0.2544 (9)	0.811 (3)	0.056 (6)*
H42B	1.076 (2)	0.2932 (7)	0.697 (3)	0.046 (5)*
C5B	0.78847 (17)	0.33739 (6)	0.55653 (19)	0.0234 (3)
H5B	0.8814	0.3571	0.5301	0.029*
C6B	0.62055 (18)	0.35102 (6)	0.47934 (19)	0.0223 (3)
H6B	0.5990	0.3803	0.4018	0.028*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1A	0.0184 (6)	0.0286 (8)	0.0258 (7)	−0.0015 (5)	0.0036 (5)	0.0004 (5)
C2A	0.0188 (7)	0.0242 (8)	0.0241 (7)	0.0015 (6)	0.0019 (6)	0.0003 (6)
N21A	0.0187 (7)	0.0397 (9)	0.0393 (8)	0.0029 (6)	0.0031 (6)	0.0176 (7)
N3A	0.0187 (6)	0.0238 (7)	0.0255 (7)	0.0011 (5)	0.0018 (5)	0.0018 (5)
C4A	0.0217 (7)	0.0207 (8)	0.0213 (7)	0.0013 (6)	0.0030 (6)	−0.0015 (6)
C5A	0.0260 (8)	0.0242 (8)	0.0269 (8)	−0.0004 (6)	0.0036 (6)	0.0032 (6)
C6A	0.0220 (7)	0.0279 (9)	0.0251 (7)	−0.0027 (6)	0.0059 (6)	−0.0009 (6)
C7A	0.0203 (7)	0.0245 (8)	0.0191 (7)	0.0028 (6)	0.0047 (6)	0.0003 (6)
C8A	0.0245 (8)	0.0222 (8)	0.0270 (8)	0.0004 (6)	0.0023 (6)	0.0010 (6)
C9A	0.0275 (8)	0.0248 (9)	0.0279 (8)	0.0054 (6)	0.0041 (6)	0.0050 (6)
N10A	0.0221 (6)	0.0295 (8)	0.0248 (6)	0.0037 (5)	0.0018 (5)	0.0028 (5)
C11A	0.0234 (8)	0.0263 (9)	0.0309 (8)	−0.0013 (6)	0.0017 (6)	−0.0013 (7)
C12A	0.0224 (8)	0.0221 (8)	0.0298 (8)	0.0024 (6)	0.0031 (6)	0.0014 (6)
C1B	0.0225 (7)	0.0217 (8)	0.0216 (7)	0.0001 (6)	0.0036 (6)	−0.0033 (6)
C11B	0.0229 (8)	0.0244 (8)	0.0230 (7)	0.0008 (6)	0.0047 (6)	−0.0028 (6)
O10B	0.0219 (6)	0.0333 (7)	0.0397 (6)	−0.0034 (5)	0.0042 (5)	0.0012 (5)
O11B	0.0216 (6)	0.0334 (7)	0.0382 (6)	0.0034 (5)	−0.0001 (5)	0.0119 (5)
C2B	0.0241 (8)	0.0243 (9)	0.0263 (8)	−0.0017 (6)	0.0065 (6)	0.0001 (6)
C3B	0.0295 (8)	0.0225 (8)	0.0247 (8)	0.0042 (6)	0.0043 (6)	0.0037 (6)
C4B	0.0234 (8)	0.0251 (8)	0.0208 (7)	0.0038 (6)	0.0021 (6)	−0.0025 (6)
N41B	0.0238 (7)	0.0352 (9)	0.0362 (8)	0.0068 (6)	0.0014 (6)	0.0073 (7)
C5B	0.0210 (8)	0.0242 (8)	0.0244 (7)	−0.0020 (6)	0.0036 (6)	−0.0020 (6)
C6B	0.0241 (7)	0.0208 (8)	0.0213 (7)	0.0012 (6)	0.0030 (6)	0.0002 (6)

Geometric parameters (Å, º)

N1A—C6A	1.3256 (19)	C11A—H11A	0.95
N1A—C2A	1.3543 (18)	C12A—H12A	0.95
C2A—N21A	1.3418 (19)	C1B—C2B	1.395 (2)
C2A—N3A	1.3511 (18)	C1B—C6B	1.396 (2)
N21A—H21A	0.928 (18)	C1B—C11B	1.476 (2)
N21A—H22A	0.917 (17)	C11B—O10B	1.2297 (17)
N3A—C4A	1.3386 (18)	C11B—O11B	1.3160 (18)
C4A—C5A	1.388 (2)	O11B—H11B	1.01 (2)
C4A—C7A	1.487 (2)	C2B—C3B	1.375 (2)
C5A—C6A	1.380 (2)	C2B—H2B	0.95
C5A—H5A	0.95	C3B—C4B	1.406 (2)
C6A—H6A	0.95	C3B—H3B	0.95
C7A—C8A	1.388 (2)	C4B—N41B	1.3687 (19)
C7A—C12A	1.390 (2)	C4B—C5B	1.403 (2)
C8A—C9A	1.376 (2)	N41B—H41B	0.85 (2)
C8A—H8A	0.95	N41B—H42B	0.90 (2)
C9A—N10A	1.333 (2)	C5B—C6B	1.3735 (19)
C9A—H9A	0.95	C5B—H5B	0.95
N10A—C11A	1.336 (2)	C6B—H6B	0.95
C11A—C12A	1.378 (2)
C6A—N1A—C2A	115.69 (12)	C12A—C11A—H11A	118.4
N21A—C2A—N3A	117.59 (13)	C11A—C12A—C7A	119.07 (14)
N21A—C2A—N1A	116.88 (13)	C11A—C12A—H12A	120.5
N3A—C2A—N1A	125.52 (13)	C7A—C12A—H12A	120.5
C2A—N21A—H21A	118.6 (11)	C2B—C1B—C6B	118.42 (13)
C2A—N21A—H22A	118.2 (11)	C2B—C1B—C11B	120.06 (13)
H21A—N21A—H22A	123.2 (16)	C6B—C1B—C11B	121.51 (13)
C4A—N3A—C2A	116.31 (12)	O10B—C11B—O11B	122.47 (13)
N3A—C4A—C5A	122.46 (13)	O10B—C11B—C1B	123.21 (14)
N3A—C4A—C7A	116.82 (12)	O11B—C11B—C1B	114.32 (12)
C5A—C4A—C7A	120.65 (13)	C11B—O11B—H11B	111.4 (12)
C6A—C5A—C4A	116.10 (14)	C3B—C2B—C1B	121.04 (14)
C6A—C5A—H5A	122.0	C3B—C2B—H2B	119.5
C4A—C5A—H5A	122.0	C1B—C2B—H2B	119.5
N1A—C6A—C5A	123.85 (14)	C2B—C3B—C4B	120.79 (14)
N1A—C6A—H6A	118.1	C2B—C3B—H3B	119.6
C5A—C6A—H6A	118.1	C4B—C3B—H3B	119.6
C8A—C7A—C12A	117.71 (13)	N41B—C4B—C5B	120.48 (14)
C8A—C7A—C4A	121.32 (13)	N41B—C4B—C3B	121.67 (14)
C12A—C7A—C4A	120.92 (13)	C5B—C4B—C3B	117.80 (13)
C9A—C8A—C7A	119.25 (14)	C4B—N41B—H41B	119.9 (13)
C9A—C8A—H8A	120.4	C4B—N41B—H42B	116.8 (12)
C7A—C8A—H8A	120.4	H41B—N41B—H42B	112.4 (17)
N10A—C9A—C8A	123.20 (14)	C6B—C5B—C4B	121.10 (13)
N10A—C9A—H9A	118.4	C6B—C5B—H5B	119.5
C8A—C9A—H9A	118.4	C4B—C5B—H5B	119.5
C9A—N10A—C11A	117.58 (13)	C5B—C6B—C1B	120.84 (14)
N10A—C11A—C12A	123.13 (14)	C5B—C6B—H6B	119.6
N10A—C11A—H11A	118.4	C1B—C6B—H6B	119.6
C6A—N1A—C2A—N21A	178.75 (14)	C9A—N10A—C11A—C12A	−0.8 (2)
C6A—N1A—C2A—N3A	−2.1 (2)	N10A—C11A—C12A—C7A	2.1 (2)
N21A—C2A—N3A—C4A	179.68 (14)	C8A—C7A—C12A—C11A	−1.2 (2)
N1A—C2A—N3A—C4A	0.5 (2)	C4A—C7A—C12A—C11A	176.36 (13)
C2A—N3A—C4A—C5A	1.8 (2)	C2B—C1B—C11B—O10B	−1.6 (2)
C2A—N3A—C4A—C7A	−175.06 (12)	C6B—C1B—C11B—O10B	177.64 (13)
N3A—C4A—C5A—C6A	−2.4 (2)	C2B—C1B—C11B—O11B	178.57 (13)
C7A—C4A—C5A—C6A	174.39 (13)	C6B—C1B—C11B—O11B	−2.2 (2)
C2A—N1A—C6A—C5A	1.4 (2)	C6B—C1B—C2B—C3B	0.9 (2)
C4A—C5A—C6A—N1A	0.7 (2)	C11B—C1B—C2B—C3B	−179.89 (13)
N3A—C4A—C7A—C8A	−145.34 (14)	C1B—C2B—C3B—C4B	−1.1 (2)
C5A—C4A—C7A—C8A	37.7 (2)	C2B—C3B—C4B—N41B	178.02 (14)
N3A—C4A—C7A—C12A	37.15 (19)	C2B—C3B—C4B—C5B	0.4 (2)
C5A—C4A—C7A—C12A	−139.81 (15)	N41B—C4B—C5B—C6B	−177.03 (13)
C12A—C7A—C8A—C9A	−0.8 (2)	C3B—C4B—C5B—C6B	0.6 (2)
C4A—C7A—C8A—C9A	−178.43 (13)	C4B—C5B—C6B—C1B	−0.9 (2)
C7A—C8A—C9A—N10A	2.3 (2)	C2B—C1B—C6B—C5B	0.1 (2)
C8A—C9A—N10A—C11A	−1.5 (2)	C11B—C1B—C6B—C5B	−179.08 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N21A—H21A···N1A^i	0.928 (18)	2.151 (18)	3.0737 (19)	172.8 (16)
N21A—H22A···N3A^ii	0.917 (17)	2.274 (17)	3.1755 (18)	167.5 (15)
O11B—H11B···N10A	1.01 (2)	1.63 (2)	2.6406 (17)	173 (2)
N41B—H41B···O10B^iii	0.85 (2)	2.25 (2)	3.0609 (19)	159.0 (17)
N41B—H42B···O10B^iv	0.90 (2)	2.15 (2)	2.981 (2)	153.6 (16)

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