Tris{2-[(2-amino-benzyl-idene)amino]-ethyl}amine.

The title Schiff base, C(27)H(33)N(7), is a tripodal amine displaying C(3) symmetry, with the central tertiary N atom lying on the threefold crystallographic axis. The N-CH(2)-CH(2)-N conformation of the pendant arms is gauche [torsion angle = 76.1 (3)°], which results in a claw-like mol-ecule, with the terminal aniline groups wrapped around the symmetry axis. The lone pair of the apical N atom is clearly oriented inwards towards the cavity, and should thus be chemically inactive. The amine NH(2) substituents lie in the plane of the benzene ring to which they are bonded. With such an arrangement, one amine H atom forms an S(6) motif through a weak N-H⋯N hydrogen bond with the imine N atom, while the other is engaged in an inter-molecular N-H⋯π contact involving the benzene ring of a neighbouring mol-ecule related by inversion. The benzene rings also participate in an intra-molecular C-H⋯π contact of similar strength. In the crystal structure, mol-ecules are separated by empty voids (ca 5% of the crystal volume), although the crystal seems to be unsolvated.

Related literature

For applications of polyamines as metal extracta­nts, see: Wenzel (2008 ▶); Bernier et al. (2009 ▶); Galbraith et al. (2006 ▶). For other applications, see: Zibaseresht & Hartshorn (2005 ▶); Mercs et al. (2008 ▶). For similar C 3 tripodal structures, see: Weibel et al. (2002 ▶); Işıklan et al. (2010 ▶); McKee et al. (2006 ▶); Glidewell et al. (2005 ▶). The software used for analysis of the empty voids in the crystal structure was SQUEEZE in PLATON (Spek, 2009 ▶).

Experimental

Crystal data

C27H33N7

M = 455.60

Trigonal,

a = 13.1075 (18) Å

c = 25.985 (6) Å

V = 3866.3 (12) Å3

Z = 6

Mo Kα radiation

μ = 0.07 mm−1

T = 300 K

0.40 × 0.40 × 0.18 mm

Data collection

Siemens P4 diffractometer

6668 measured reflections

1507 independent reflections

838 reflections with I > 2σ(I)

R int = 0.033

2 standard reflections every 98 reflections intensity decay: 2%

Refinement

R[F 2 > 2σ(F 2)] = 0.058

wR(F 2) = 0.176

S = 1.81

1507 reflections

110 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.51 e Å−3

Δρmin = −0.21 e Å−3

Data collection: XSCANS (Siemens, 1996 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810043783/bq2243sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810043783/bq2243Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C27H33N7	Dx = 1.174 Mg m−3
Mr = 455.60	Melting point: 416 K
Trigonal, R3	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -R 3	Cell parameters from 70 reflections
a = 13.1075 (18) Å	θ = 4.8–12.3°
c = 25.985 (6) Å	µ = 0.07 mm−1
V = 3866.3 (12) Å3	T = 300 K
Z = 6	Prism, yellow
F(000) = 1464	0.40 × 0.40 × 0.18 mm

Siemens P4 diffractometer	Rint = 0.033
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.0°
graphite	h = −13→15
ω scans	k = −15→15
6668 measured reflections	l = −30→30
1507 independent reflections	2 standard reflections every 98 reflections
838 reflections with I > 2σ(I)	intensity decay: 2%

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.058	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.176	w = 1/[σ2(Fo2) + (0.05P)2] where P = (Fo2 + 2Fc2)/3
S = 1.81	(Δ/σ)max < 0.001
1507 reflections	Δρmax = 0.51 e Å−3
110 parameters	Δρmin = −0.21 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 constraints	Extinction coefficient: 0.0057 (9)
Primary atom site location: structure-invariant direct methods

	x	y	z	Uiso*/Ueq
N1	1.0000	1.0000	0.17108 (11)	0.0773 (10)
C2	0.9753 (3)	0.8840 (2)	0.15415 (9)	0.0952 (9)
H2A	1.0068	0.8904	0.1198	0.114*
H2B	0.8906	0.8322	0.1524	0.114*
C3	1.0266 (3)	0.8305 (3)	0.18909 (10)	0.0990 (10)
H3A	1.0287	0.7663	0.1714	0.119*
H3B	1.1069	0.8892	0.1978	0.119*
N4	0.95737 (19)	0.78635 (19)	0.23590 (8)	0.0821 (7)
C5	1.0077 (2)	0.8295 (2)	0.27831 (10)	0.0741 (7)
H5A	1.0862	0.8891	0.2776	0.089*
C6	0.9507 (2)	0.79175 (19)	0.32820 (9)	0.0680 (7)
C7	1.0149 (2)	0.8459 (2)	0.37218 (10)	0.0825 (8)
H7A	1.0933	0.9045	0.3688	0.099*
C8	0.9669 (3)	0.8163 (3)	0.42032 (11)	0.0985 (9)
H8A	1.0120	0.8540	0.4492	0.118*
C9	0.8505 (3)	0.7297 (3)	0.42536 (10)	0.0915 (9)
H9A	0.8165	0.7096	0.4579	0.110*
C10	0.7853 (3)	0.6738 (2)	0.38354 (10)	0.0820 (8)
H10A	0.7073	0.6147	0.3879	0.098*
C11	0.8319 (2)	0.7026 (2)	0.33419 (9)	0.0696 (7)
N12	0.7651 (2)	0.6450 (2)	0.29267 (9)	0.0958 (8)
H12A	0.792 (3)	0.670 (3)	0.2599 (10)	0.115*
H12B	0.692 (3)	0.597 (3)	0.2993 (11)	0.115*

	U11	U22	U33	U12	U13	U23
N1	0.0863 (15)	0.0863 (15)	0.0592 (18)	0.0432 (8)	0.000	0.000
C2	0.116 (2)	0.101 (2)	0.0686 (14)	0.0545 (18)	0.0064 (14)	−0.0093 (14)
C3	0.118 (2)	0.098 (2)	0.0928 (18)	0.0631 (19)	0.0324 (16)	0.0059 (15)
N4	0.0836 (15)	0.0817 (14)	0.0848 (14)	0.0442 (12)	0.0142 (12)	0.0027 (11)
C5	0.0668 (15)	0.0620 (14)	0.0941 (17)	0.0327 (12)	0.0095 (13)	0.0063 (13)
C6	0.0648 (15)	0.0560 (13)	0.0840 (16)	0.0307 (12)	0.0009 (12)	0.0046 (11)
C7	0.0821 (17)	0.0684 (16)	0.0913 (18)	0.0333 (14)	−0.0097 (14)	0.0050 (13)
C8	0.121 (3)	0.094 (2)	0.0859 (18)	0.058 (2)	−0.0204 (18)	−0.0012 (16)
C9	0.112 (2)	0.094 (2)	0.0842 (18)	0.063 (2)	0.0122 (16)	0.0217 (16)
C10	0.0820 (17)	0.0778 (17)	0.0947 (18)	0.0463 (14)	0.0110 (15)	0.0148 (14)
C11	0.0679 (15)	0.0647 (14)	0.0832 (15)	0.0384 (13)	0.0025 (13)	−0.0001 (13)
N12	0.0638 (14)	0.1025 (18)	0.1008 (16)	0.0263 (13)	0.0001 (13)	−0.0157 (14)

N1—C2	1.455 (3)	C6—C11	1.413 (3)
N1—C2i	1.455 (3)	C7—C8	1.366 (4)
N1—C2ii	1.455 (3)	C7—H7A	0.9300
C2—C3	1.498 (4)	C8—C9	1.379 (4)
C2—H2A	0.9700	C8—H8A	0.9300
C2—H2B	0.9700	C9—C10	1.350 (4)
C3—N4	1.454 (3)	C9—H9A	0.9300
C3—H3A	0.9700	C10—C11	1.389 (3)
C3—H3B	0.9700	C10—H10A	0.9300
N4—C5	1.264 (3)	C11—N12	1.356 (3)
C5—C6	1.454 (3)	N12—H12A	0.92 (3)
C5—H5A	0.9300	N12—H12B	0.86 (3)
C6—C7	1.386 (3)
C2—N1—C2i	111.28 (14)	C7—C6—C5	119.0 (2)
C2—N1—C2ii	111.28 (14)	C11—C6—C5	123.1 (2)
C2i—N1—C2ii	111.28 (14)	C8—C7—C6	122.3 (3)
N1—C2—C3	112.9 (2)	C8—C7—H7A	118.8
N1—C2—H2A	109.0	C6—C7—H7A	118.8
C3—C2—H2A	109.0	C7—C8—C9	118.9 (3)
N1—C2—H2B	109.0	C7—C8—H8A	120.5
C3—C2—H2B	109.0	C9—C8—H8A	120.5
H2A—C2—H2B	107.8	C10—C9—C8	120.7 (3)
N4—C3—C2	110.9 (2)	C10—C9—H9A	119.7
N4—C3—H3A	109.5	C8—C9—H9A	119.7
C2—C3—H3A	109.5	C9—C10—C11	121.5 (3)
N4—C3—H3B	109.5	C9—C10—H10A	119.2
C2—C3—H3B	109.5	C11—C10—H10A	119.2
H3A—C3—H3B	108.1	N12—C11—C10	120.6 (2)
C5—N4—C3	118.0 (2)	N12—C11—C6	120.7 (2)
N4—C5—C6	124.1 (2)	C10—C11—C6	118.7 (2)
N4—C5—H5A	117.9	C11—N12—H12A	120.7 (19)
C6—C5—H5A	117.9	C11—N12—H12B	115 (2)
C7—C6—C11	117.9 (2)	H12A—N12—H12B	123 (3)
C2i—N1—C2—C3	83.1 (3)	C6—C7—C8—C9	−0.1 (4)
C2ii—N1—C2—C3	−152.1 (3)	C7—C8—C9—C10	0.9 (4)
N1—C2—C3—N4	76.1 (3)	C8—C9—C10—C11	−1.1 (4)
C2—C3—N4—C5	−119.7 (3)	C9—C10—C11—N12	179.7 (2)
C3—N4—C5—C6	−178.2 (2)	C9—C10—C11—C6	0.6 (3)
N4—C5—C6—C7	−179.8 (2)	C7—C6—C11—N12	−178.9 (2)
N4—C5—C6—C11	−0.3 (4)	C5—C6—C11—N12	1.6 (3)
C11—C6—C7—C8	−0.3 (4)	C7—C6—C11—C10	0.1 (3)
C5—C6—C7—C8	179.1 (2)	C5—C6—C11—C10	−179.3 (2)

D—H···A	D—H	H···A	D···A	D—H···A
N12—H12A···N4	0.92 (3)	2.02 (3)	2.700 (3)	129 (2)
N12—H12B···Cgiii	0.86 (3)	2.70 (3)	3.430 (2)	143 (3)
C7—H7A···Cgi	0.93	2.71	3.494 (3)	143

Table 1

Hydrogen-bond geometry (Å, °)

Cg is the centroid of the benzene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N12—H12A⋯N4	0.92 (3)	2.02 (3)	2.700 (3)	129 (2)
N12—H12B⋯Cgi	0.86 (3)	2.70 (3)	3.430 (2)	143 (3)
C7—H7A⋯Cgii	0.93	2.71	3.494 (3)	143

Symmetry codes: (i) ; (ii) .