Tris[2-(pyrrol-2-ylmethyl­eneamino)eth­yl]amine

Wang, Y.; Liang, T.; Yao, J.; Zhai, T.; Fu, H.

doi:10.1107/S1600536807065907

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 64| Part 3| March 2008| Page o629

doi:10.1107/S1600536807065907

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Tris[2-(pyrrol-2-ylmethyleneamino)ethyl]amine

Yaobing Wang,^a Tongling Liang,^a Jiannian Yao,^a ^* Tianyou Zhai ^a and Hongbing Fu ^a

^aBeijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
^*Correspondence e-mail: jnyao@iccas.ac.cn

(Received 5 November 2007; accepted 6 December 2007; online 27 February 2008)

The title compound, C₂₁H₂₇N₇, was synthesized by reaction of tris(2-aminoethyl)amine and pyrrole-2-carbaldehyde in ethanol at room temperature. The structure is stabilized by intra- and intermolecular C—H⋯N and N—H⋯N hydrogen-bonding interactions.

Related literature

For the self-assembly of pyrrole Schiff base–metal complexes, see: Wu et al. (2003 , 2006 ); Yang, Chen et al. (2004 ); Yang, Shan et al. (2004 ).

Experimental

Crystal data

C₂₁H₂₇N₇
M_r = 377.50
Monoclinic, P 2₁ /n
a = 11.494 (2) Å
b = 9.4875 (19) Å
c = 20.232 (4) Å
β = 105.97 (3)°
V = 2121.1 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 (2) K
0.80 × 0.08 × 0.05 mm

Data collection

Rigaku R-AXIS RAPID IP diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ) T_min = 0.943, T_max = 0.995
19300 measured reflections
4832 independent reflections
1905 reflections with I > 2σ(I)
R_int = 0.0685

Refinement

R[F² > 2σ(F²)] = 0.049
wR(F²) = 0.142
S = 1.01
4832 reflections
253 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15B⋯N2	0.97	2.59	3.246 (4)	125
N3—H3A⋯N6ⁱ	0.86	2.14	2.956 (3)	159
N5—H5A⋯N4ⁱⁱ	0.86	2.20	3.029 (3)	163
N7—H7A⋯N2ⁱ	0.86	2.13	2.940 (3)	158
Symmetry codes: (i) -x+1, -y+1, -z; (ii) -x, -y, -z.

Data collection: RAPID-AUTO (Rigaku, 2001 ); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL/PC (Sheldrick, 1994 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807065907/rz2179sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536807065907/rz2179Isup2.hkl

checkCIF report

Comment top

The chemistry and crystal structure of Schiff base derivatives of pyrrole have been extensively studied for many years as these compounds represent the basic units of porphyrins. More recently, it has been pointed out that pyrrole Schiff bases are ideal building blocks for the self-assembly of metallosupramolecules (Wu et al., 2006; Wu et al., 2003; Yang, Chen et al., 2004; Yang, Shan et al., 2004) due to the presence of many hydrogen bond donors and acceptors. In view of its potential interest in this field, the title compound was synthesized and its crystal structure is reported here.

In the title compound, bond lengths and angles are as expected, with the N2—C3, N4—C10 and N6—C17 bond lengths (mean value 1.270 (3) Å) indicating a remarkable double-bond character. The molecular conformation is stabilized by an intramolecular C—H···N hydrogen bond (Table 1). In the crystal structure, the molecules are linked by intermolecular N—H···N hydrogen bonding interactions (Table 1).

Related literature top

For the self-assembly of pyrrole Schiff base–metal complexes, see: Wu et al. (2003, 2006); Yang, Chen et al. (2004); Yang, Shan et al. (2004).

Experimental top

The title compound was prepared by reaction of tris(2-aminoethyl)amine, (0.05 mol) and pyrrole-2-carbaldehyde (0.15 mol) in ethanol (40 ml) at room temperature. Single crystals suitable for X-ray measurements were obtained by slow evaporation of an ethanol/acetonitrile solution (1:1 v/v) at room temperature.

Computing details top

Data collection: RAPID-AUTO (Rigaku, 2001); cell refinement: RAPID-AUTO (Rigaku, 2001); data reduction: RAPID-AUTO (Rigaku, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL/PC (Sheldrick, 1994); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures top

Fig. 1. The molecular structure of the title compound showing 50% probability displacement ellipsoids and the atom-numbering scheme.

Tris[2-(pyrrol-2-ylmethyleneamino)ethyl]amine top

Crystal data top

C₂₁H₂₇N₇	F(000) = 808
M_r = 377.50	D_x = 1.182 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 19300 reflections
a = 11.494 (2) Å	θ = 1.9–27.5°
b = 9.4875 (19) Å	µ = 0.08 mm⁻¹
c = 20.232 (4) Å	T = 293 K
β = 105.97 (3)°	Needle, brown
V = 2121.1 (8) Å³	0.80 × 0.08 × 0.05 mm
Z = 4

Data collection top

Rigaku R-AXIS RAPID IP diffractometer	4832 independent reflections
Radiation source: Rotating Anode	1905 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.069
oscillation scans	θ_max = 27.5°, θ_min = 1.9°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −14→14
T_min = 0.943, T_max = 0.995	k = 0→12
19300 measured reflections	l = −13→26

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.049	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.142	H-atom parameters constrained
S = 1.01	w = 1/[σ²(F_o²) + (0.0318P)²] where P = (F_o² + 2F_c²)/3
4832 reflections	(Δ/σ)_max < 0.001
253 parameters	Δρ_max = 0.20 e Å⁻³
0 restraints	Δρ_min = −0.19 e Å⁻³

Crystal data top

C₂₁H₂₇N₇	V = 2121.1 (8) Å³
M_r = 377.50	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 11.494 (2) Å	µ = 0.08 mm⁻¹
b = 9.4875 (19) Å	T = 293 K
c = 20.232 (4) Å	0.80 × 0.08 × 0.05 mm
β = 105.97 (3)°

Data collection top

Rigaku R-AXIS RAPID IP diffractometer	4832 independent reflections
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	1905 reflections with I > 2σ(I)
T_min = 0.943, T_max = 0.995	R_int = 0.069
19300 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.049	0 restraints
wR(F²) = 0.142	H-atom parameters constrained
S = 1.01	Δρ_max = 0.20 e Å⁻³
4832 reflections	Δρ_min = −0.19 e Å⁻³
253 parameters

Special details top

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
N1	0.32208 (19)	0.2117 (2)	−0.04712 (11)	0.0456 (6)
N2	0.3346 (2)	0.3634 (2)	−0.17842 (11)	0.0439 (6)
N3	0.47309 (19)	0.6138 (3)	−0.18248 (11)	0.0493 (7)
H3A	0.4361	0.6213	−0.1510	0.059*
N4	0.1461 (2)	0.1199 (3)	0.03356 (12)	0.0477 (6)
N5	0.1051 (2)	−0.1779 (3)	0.05915 (12)	0.0523 (7)
H5A	0.0388	−0.1426	0.0339	0.063*
N6	0.6284 (2)	0.2840 (2)	0.07191 (11)	0.0443 (6)
N7	0.8400 (2)	0.4282 (2)	0.15596 (12)	0.0453 (6)
H7A	0.7761	0.4688	0.1611	0.054*
C1	0.3214 (3)	0.1456 (3)	−0.11191 (15)	0.0520 (8)
H1A	0.2744	0.0595	−0.1159	0.062*
H1B	0.4039	0.1183	−0.1093	0.062*
C2	0.2728 (3)	0.2291 (3)	−0.17799 (14)	0.0503 (8)
H2B	0.2810	0.1726	−0.2164	0.060*
H2C	0.1873	0.2469	−0.1845	0.060*
C3	0.4025 (3)	0.3753 (3)	−0.21867 (14)	0.0470 (8)
H3B	0.4080	0.2990	−0.2465	0.056*
C4	0.4703 (3)	0.4995 (3)	−0.22330 (15)	0.0454 (7)
C5	0.5409 (3)	0.5307 (4)	−0.26616 (17)	0.0646 (10)
H5B	0.5556	0.4714	−0.2996	0.078*
C6	0.5863 (3)	0.6656 (4)	−0.25109 (18)	0.0690 (10)
H6B	0.6366	0.7136	−0.2725	0.083*
C7	0.5439 (3)	0.7142 (4)	−0.19947 (16)	0.0620 (9)
H7B	0.5604	0.8023	−0.1789	0.074*
C8	0.2084 (2)	0.2788 (3)	−0.04489 (15)	0.0553 (8)
H8A	0.1423	0.2371	−0.0799	0.066*
H8B	0.2117	0.3782	−0.0555	0.066*
C9	0.1833 (3)	0.2634 (3)	0.02435 (15)	0.0536 (8)
H9A	0.2556	0.2865	0.0606	0.064*
H9B	0.1199	0.3285	0.0274	0.064*
C10	0.2245 (3)	0.0402 (4)	0.07166 (15)	0.0513 (8)
H10A	0.2993	0.0804	0.0929	0.062*
C11	0.2099 (3)	−0.1055 (3)	0.08539 (15)	0.0483 (8)
C12	0.2924 (3)	−0.2002 (4)	0.12203 (16)	0.0643 (10)
H12A	0.3723	−0.1802	0.1455	0.077*
C13	0.2371 (3)	−0.3313 (4)	0.11832 (18)	0.0688 (10)
H13A	0.2724	−0.4144	0.1388	0.083*
C14	0.1217 (3)	−0.3143 (4)	0.07898 (17)	0.0640 (9)
H14A	0.0634	−0.3849	0.0675	0.077*
C15	0.4299 (2)	0.2945 (3)	−0.01526 (14)	0.0475 (8)
H15A	0.4098	0.3670	0.0135	0.057*
H15B	0.4583	0.3405	−0.0507	0.057*
C16	0.5290 (2)	0.2023 (3)	0.02762 (15)	0.0508 (8)
H16A	0.4952	0.1410	0.0560	0.061*
H16B	0.5606	0.1433	−0.0026	0.061*
C17	0.7349 (3)	0.2535 (3)	0.07048 (14)	0.0448 (7)
H17A	0.7445	0.1841	0.0399	0.054*
C18	0.8415 (2)	0.3190 (3)	0.11291 (13)	0.0422 (7)
C19	0.9607 (3)	0.2851 (4)	0.12042 (15)	0.0558 (9)
H19A	0.9887	0.2142	0.0970	0.067*
C20	1.0321 (3)	0.3751 (4)	0.16917 (17)	0.0640 (10)
H20A	1.1161	0.3751	0.1848	0.077*
C21	0.9557 (3)	0.4631 (4)	0.18960 (16)	0.0587 (9)
H21A	0.9787	0.5355	0.2215	0.070*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0367 (14)	0.0511 (15)	0.0462 (14)	−0.0059 (12)	0.0069 (11)	0.0022 (14)
N2	0.0470 (15)	0.0457 (15)	0.0387 (14)	−0.0016 (13)	0.0110 (11)	−0.0027 (13)
N3	0.0465 (15)	0.0601 (17)	0.0389 (14)	−0.0048 (14)	0.0076 (12)	0.0047 (15)
N4	0.0402 (14)	0.0572 (17)	0.0477 (15)	−0.0037 (13)	0.0154 (12)	0.0050 (14)
N5	0.0446 (16)	0.0555 (17)	0.0549 (16)	0.0010 (13)	0.0104 (12)	0.0092 (15)
N6	0.0392 (15)	0.0470 (14)	0.0438 (14)	−0.0015 (12)	0.0066 (11)	−0.0065 (13)
N7	0.0389 (14)	0.0478 (15)	0.0489 (15)	−0.0009 (12)	0.0118 (11)	0.0055 (14)
C1	0.0474 (18)	0.0435 (18)	0.061 (2)	−0.0076 (16)	0.0084 (15)	0.0023 (18)
C2	0.0528 (19)	0.0506 (19)	0.0442 (18)	−0.0093 (16)	0.0080 (15)	−0.0090 (17)
C3	0.0523 (19)	0.0499 (19)	0.0377 (16)	0.0076 (17)	0.0103 (15)	−0.0031 (16)
C4	0.0474 (18)	0.0479 (19)	0.0404 (17)	0.0032 (16)	0.0110 (14)	0.0010 (17)
C5	0.066 (2)	0.076 (3)	0.060 (2)	0.006 (2)	0.0314 (18)	0.007 (2)
C6	0.063 (2)	0.086 (3)	0.061 (2)	−0.011 (2)	0.0206 (18)	0.018 (2)
C7	0.062 (2)	0.060 (2)	0.055 (2)	−0.0187 (19)	0.0002 (17)	0.010 (2)
C8	0.0402 (18)	0.067 (2)	0.0571 (19)	−0.0017 (17)	0.0110 (15)	0.0140 (19)
C9	0.0436 (18)	0.064 (2)	0.0541 (19)	−0.0028 (17)	0.0150 (15)	0.0061 (18)
C10	0.0402 (18)	0.072 (2)	0.0429 (18)	−0.0119 (18)	0.0141 (14)	−0.0050 (19)
C11	0.0395 (18)	0.062 (2)	0.0438 (18)	−0.0033 (17)	0.0114 (14)	0.0017 (18)
C12	0.0400 (19)	0.088 (3)	0.059 (2)	0.004 (2)	0.0024 (16)	0.012 (2)
C13	0.063 (2)	0.067 (2)	0.074 (2)	0.014 (2)	0.0140 (19)	0.018 (2)
C14	0.058 (2)	0.062 (2)	0.070 (2)	−0.0003 (19)	0.0128 (19)	0.009 (2)
C15	0.0443 (18)	0.0481 (18)	0.0476 (17)	−0.0060 (15)	0.0087 (14)	0.0018 (16)
C16	0.0450 (18)	0.0510 (19)	0.0530 (18)	−0.0034 (16)	0.0077 (14)	−0.0060 (17)
C17	0.0464 (19)	0.0486 (18)	0.0404 (16)	0.0026 (16)	0.0134 (14)	−0.0026 (16)
C18	0.0435 (19)	0.0478 (19)	0.0370 (16)	−0.0018 (15)	0.0141 (14)	0.0012 (16)
C19	0.0418 (19)	0.075 (2)	0.056 (2)	0.0056 (18)	0.0231 (15)	0.007 (2)
C20	0.0361 (18)	0.080 (3)	0.073 (2)	−0.004 (2)	0.0112 (17)	0.013 (2)
C21	0.047 (2)	0.058 (2)	0.061 (2)	−0.0204 (18)	−0.0026 (16)	0.0047 (19)

Geometric parameters (Å, º) top

N1—C1	1.451 (3)	C6—H6B	0.9300
N1—C15	1.460 (3)	C7—H7B	0.9300
N1—C8	1.465 (3)	C8—C9	1.513 (4)
N2—C3	1.279 (3)	C8—H8A	0.9700
N2—C2	1.459 (3)	C8—H8B	0.9700
N3—C7	1.357 (4)	C9—H9A	0.9700
N3—C4	1.358 (3)	C9—H9B	0.9700
N3—H3A	0.8600	C10—C11	1.429 (4)
N4—C10	1.264 (3)	C10—H10A	0.9300
N4—C9	1.454 (4)	C11—C12	1.368 (4)
N5—C14	1.352 (4)	C12—C13	1.388 (4)
N5—C11	1.362 (3)	C12—H12A	0.9300
N5—H5A	0.8600	C13—C14	1.356 (4)
N6—C17	1.267 (3)	C13—H13A	0.9300
N6—C16	1.464 (3)	C14—H14A	0.9300
N7—C21	1.357 (3)	C15—C16	1.506 (3)
N7—C18	1.357 (3)	C15—H15A	0.9700
N7—H7A	0.8600	C15—H15B	0.9700
C1—C2	1.522 (4)	C16—H16A	0.9700
C1—H1A	0.9700	C16—H16B	0.9700
C1—H1B	0.9700	C17—C18	1.430 (4)
C2—H2B	0.9700	C17—H17A	0.9300
C2—H2C	0.9700	C18—C19	1.374 (4)
C3—C4	1.430 (4)	C19—C20	1.389 (4)
C3—H3B	0.9300	C19—H19A	0.9300
C4—C5	1.373 (4)	C20—C21	1.356 (4)
C5—C6	1.385 (4)	C20—H20A	0.9300
C5—H5B	0.9300	C21—H21A	0.9300
C6—C7	1.350 (4)

C1—N1—C15	115.1 (2)	N4—C9—C8	110.3 (3)
C1—N1—C8	115.6 (2)	N4—C9—H9A	109.6
C15—N1—C8	114.1 (2)	C8—C9—H9A	109.6
C3—N2—C2	117.7 (2)	N4—C9—H9B	109.6
C7—N3—C4	108.8 (3)	C8—C9—H9B	109.6
C7—N3—H3A	125.6	H9A—C9—H9B	108.1
C4—N3—H3A	125.6	N4—C10—C11	126.5 (3)
C10—N4—C9	117.0 (3)	N4—C10—H10A	116.7
C14—N5—C11	109.3 (3)	C11—C10—H10A	116.7
C14—N5—H5A	125.4	N5—C11—C12	106.6 (3)
C11—N5—H5A	125.4	N5—C11—C10	123.5 (3)
C17—N6—C16	117.5 (2)	C12—C11—C10	129.8 (3)
C21—N7—C18	108.9 (3)	C11—C12—C13	108.7 (3)
C21—N7—H7A	125.5	C11—C12—H12A	125.6
C18—N7—H7A	125.5	C13—C12—H12A	125.6
N1—C1—C2	118.6 (2)	C14—C13—C12	106.5 (3)
N1—C1—H1A	107.7	C14—C13—H13A	126.7
C2—C1—H1A	107.7	C12—C13—H13A	126.7
N1—C1—H1B	107.7	N5—C14—C13	108.8 (3)
C2—C1—H1B	107.7	N5—C14—H14A	125.6
H1A—C1—H1B	107.1	C13—C14—H14A	125.6
N2—C2—C1	113.5 (2)	N1—C15—C16	110.9 (2)
N2—C2—H2B	108.9	N1—C15—H15A	109.5
C1—C2—H2B	108.9	C16—C15—H15A	109.5
N2—C2—H2C	108.9	N1—C15—H15B	109.5
C1—C2—H2C	108.9	C16—C15—H15B	109.5
H2B—C2—H2C	107.7	H15A—C15—H15B	108.0
N2—C3—C4	123.7 (3)	N6—C16—C15	112.6 (2)
N2—C3—H3B	118.2	N6—C16—H16A	109.1
C4—C3—H3B	118.2	C15—C16—H16A	109.1
N3—C4—C5	107.0 (3)	N6—C16—H16B	109.1
N3—C4—C3	122.7 (3)	C15—C16—H16B	109.1
C5—C4—C3	130.3 (3)	H16A—C16—H16B	107.8
C4—C5—C6	108.2 (3)	N6—C17—C18	124.1 (3)
C4—C5—H5B	125.9	N6—C17—H17A	117.9
C6—C5—H5B	125.9	C18—C17—H17A	117.9
C7—C6—C5	106.9 (3)	N7—C18—C19	107.2 (3)
C7—C6—H6B	126.5	N7—C18—C17	123.8 (3)
C5—C6—H6B	126.5	C19—C18—C17	128.9 (3)
C6—C7—N3	109.0 (3)	C18—C19—C20	108.1 (3)
C6—C7—H7B	125.5	C18—C19—H19A	125.9
N3—C7—H7B	125.5	C20—C19—H19A	125.9
N1—C8—C9	112.7 (2)	C21—C20—C19	106.8 (3)
N1—C8—H8A	109.1	C21—C20—H20A	126.6
C9—C8—H8A	109.1	C19—C20—H20A	126.6
N1—C8—H8B	109.1	C20—C21—N7	108.9 (3)
C9—C8—H8B	109.1	C20—C21—H21A	125.5
H8A—C8—H8B	107.8	N7—C21—H21A	125.5

C15—N1—C1—C2	−87.6 (3)	N4—C10—C11—N5	−1.3 (5)
C8—N1—C1—C2	48.9 (3)	N4—C10—C11—C12	175.1 (3)
C3—N2—C2—C1	110.2 (3)	N5—C11—C12—C13	−0.3 (4)
N1—C1—C2—N2	56.6 (3)	C10—C11—C12—C13	−177.2 (3)
C2—N2—C3—C4	−178.6 (3)	C11—C12—C13—C14	0.4 (4)
C7—N3—C4—C5	0.0 (3)	C11—N5—C14—C13	0.1 (4)
C7—N3—C4—C3	−179.5 (2)	C12—C13—C14—N5	−0.3 (4)
N2—C3—C4—N3	3.4 (4)	C1—N1—C15—C16	−85.5 (3)
N2—C3—C4—C5	−175.9 (3)	C8—N1—C15—C16	137.4 (2)
N3—C4—C5—C6	−0.2 (4)	C17—N6—C16—C15	−129.8 (3)
C3—C4—C5—C6	179.2 (3)	N1—C15—C16—N6	−167.7 (2)
C4—C5—C6—C7	0.3 (4)	C16—N6—C17—C18	−177.0 (3)
C5—C6—C7—N3	−0.3 (4)	C21—N7—C18—C19	0.4 (3)
C4—N3—C7—C6	0.2 (3)	C21—N7—C18—C17	178.7 (3)
C1—N1—C8—C9	144.0 (3)	N6—C17—C18—N7	−4.9 (4)
C15—N1—C8—C9	−79.1 (3)	N6—C17—C18—C19	173.0 (3)
C10—N4—C9—C8	102.4 (3)	N7—C18—C19—C20	0.3 (3)
N1—C8—C9—N4	−73.9 (3)	C17—C18—C19—C20	−177.9 (3)
C9—N4—C10—C11	−177.0 (3)	C18—C19—C20—C21	−0.9 (4)
C14—N5—C11—C12	0.1 (3)	C19—C20—C21—N7	1.1 (4)
C14—N5—C11—C10	177.3 (3)	C18—N7—C21—C20	−0.9 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15B···N2	0.97	2.59	3.246 (4)	125
N3—H3A···N6ⁱ	0.86	2.14	2.956 (3)	159
N5—H5A···N4ⁱⁱ	0.86	2.20	3.029 (3)	163
N7—H7A···N2ⁱ	0.86	2.13	2.940 (3)	158

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

Experimental details

Crystal data
Chemical formula	C₂₁H₂₇N₇
M_r	377.50
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	11.494 (2), 9.4875 (19), 20.232 (4)
β (°)	105.97 (3)
V (Å³)	2121.1 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.80 × 0.08 × 0.05

Data collection
Diffractometer	Rigaku R-AXIS RAPID IP diffractometer
Absorption correction	Multi-scan (ABSCOR; Higashi, 1995)
T_min, T_max	0.943, 0.995
No. of measured, independent and observed [I > 2σ(I)] reflections	19300, 4832, 1905
R_int	0.069
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.049, 0.142, 1.01
No. of reflections	4832
No. of parameters	253
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.20, −0.19

Computer programs: RAPID-AUTO (Rigaku, 2001), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL/PC (Sheldrick, 1994).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15B···N2	0.97	2.59	3.246 (4)	124.8
N3—H3A···N6ⁱ	0.86	2.14	2.956 (3)	158.8
N5—H5A···N4ⁱⁱ	0.86	2.20	3.029 (3)	162.6
N7—H7A···N2ⁱ	0.86	2.13	2.940 (3)	157.5

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

Acknowledgements

This work was supported by the National Natural Science Foundation of China (grant Nos. 90301010, 50573084, 90606004).

References

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Rigaku (2001). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan. Google Scholar
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