The molecule of the title compound, C
18H
24N
2O
2, resides on a crystallographic inversion centre. The molecule adopts a
transoid conformation with respect to the central C—C single bond and is in the
meso form. A polarimetric study of the compound did not show any optical activity, indicating that the compound is a racemic mixture entirely consistent with the centrosymmetric
space group. In the molecule, there is one intramolecular N—H
O interaction, resulting in the formation of a five-membered ring. In the crystal structure, intermolecular O—H
N and C—H
O interactions are also observed. These interactions form an
R22(9) ring and one-dimensional linear chains of edge-fused rings running parallel to the [010] direction, which stabilize the crystal packing.
Supporting information
CCDC reference: 299640
The synthesis of the title compound was performed with minor modifications of the literature method of Koçak (2000), as follows. Benzaldehyde (10.6 g, 0.1 mol) and 2-aminoethanol (6.1 g, 0.1 mol) were mixed and heated in a water bath for 1 h. The mixture was then cooled to room temperature and a mixture of aluminium amalgam (7.0 g) in THF [ether in scheme?] (400 ml) and distilled water (7.5 ml) was added slowly. The reaction mixture was kept at room temperature for 24 h with stirring and the precipitate which formed was removed by suction filtration. The compound was extracted from the precipitate with benzene by the use of a Soxhlet extractor. The white crystalline compound which formed was removed by filtration and recrystallized from ethanol [yield: 6.90 g, 46%; m.p. 362 K, literature value 363 K (Jeyaprabha et al., 2005)]. Spectroscopic analysis: 1H NMR (DMSO-d6, δ, p.p.m.): 7.16 (m, 10H, Ar—H), 4.19 (t, 2H, OH, D2O exchangeable), 3.77 (s, 2H, >CH–), 3.31 (t, 4H, O—CH2–), 2.31 (t, 4H, N—CH2), 1.92 (s, 2H, –NH–, D2O exchangeable); characteristic IR bands are: 3410 cm−1 ν(O—H); 2800–3000 cm−1 aliphatic ν(C—H); 3000–3100 cm−1 aromatic ν(C—H); 3292 cm−1 ν(N—H); 1619 cm−1 ν(C═N). The compound is soluble in common organic solvents such as benzene, toluene, ethanol and methanol.
The H atoms were located in a difference map and refined isotropically, with distances of C—H = 0.93 (3)–1.036 (16) Å, O—H = 0.91 (3) Å and N—H = 0.922 (16) Å.
Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2003).
meso-4,5-diphenyl-3,6-diazaoctane-1,8-diol
top
Crystal data top
C18H24N2O2 | F(000) = 648 |
Mr = 300.39 | Dx = 1.217 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 4012 reflections |
a = 17.585 (2) Å | θ = 2.4–27.9° |
b = 6.8615 (5) Å | µ = 0.08 mm−1 |
c = 13.9453 (16) Å | T = 296 K |
β = 103.035 (10)° | Prism, colourless |
V = 1639.3 (3) Å3 | 0.57 × 0.51 × 0.44 mm |
Z = 4 | |
Data collection top
Stoe IPDS 2 diffractometer | 1388 reflections with I > 2σ(I) |
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus | Rint = 0.096 |
Plane graphite monochromator | θmax = 26.0°, θmin = 3.0° |
Detector resolution: 6.67 pixels mm-1 | h = −16→21 |
ω scans | k = −8→8 |
4103 measured reflections | l = −17→17 |
1597 independent reflections | |
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)] = 0.053 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.148 | All H-atom parameters refined |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0838P)2 + 0.3333P] where P = (Fo2 + 2Fc2)/3 |
1597 reflections | (Δ/σ)max < 0.001 |
148 parameters | Δρmax = 0.31 e Å−3 |
0 restraints | Δρmin = −0.20 e Å−3 |
Crystal data top
C18H24N2O2 | V = 1639.3 (3) Å3 |
Mr = 300.39 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 17.585 (2) Å | µ = 0.08 mm−1 |
b = 6.8615 (5) Å | T = 296 K |
c = 13.9453 (16) Å | 0.57 × 0.51 × 0.44 mm |
β = 103.035 (10)° | |
Data collection top
Stoe IPDS 2 diffractometer | 1388 reflections with I > 2σ(I) |
4103 measured reflections | Rint = 0.096 |
1597 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.053 | 0 restraints |
wR(F2) = 0.148 | All H-atom parameters refined |
S = 1.09 | Δρmax = 0.31 e Å−3 |
1597 reflections | Δρmin = −0.20 e Å−3 |
148 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 | Uiso*/Ueq | |
O1 | 0.77459 (8) | 0.18875 (17) | 0.83400 (9) | 0.0530 (4) | |
H1O | 0.7709 (15) | 0.060 (4) | 0.8484 (19) | 0.091 (8)* | |
N1 | 0.72996 (7) | 0.28089 (16) | 0.62583 (8) | 0.0324 (3) | |
H1 | 0.7797 (9) | 0.250 (2) | 0.6601 (11) | 0.029 (4)* | |
C1 | 0.63681 (8) | 0.2576 (2) | 0.46694 (10) | 0.0361 (4) | |
C2 | 0.61316 (9) | 0.4512 (2) | 0.44849 (11) | 0.0457 (4) | |
H2 | 0.6531 (12) | 0.556 (3) | 0.4760 (14) | 0.058 (5)* | |
C3 | 0.53819 (11) | 0.4947 (3) | 0.39781 (13) | 0.0610 (5) | |
H3 | 0.5235 (16) | 0.634 (4) | 0.388 (2) | 0.098 (8)* | |
C4 | 0.48535 (11) | 0.3493 (4) | 0.36535 (14) | 0.0678 (6) | |
H4 | 0.4310 (15) | 0.380 (3) | 0.3305 (18) | 0.081 (7)* | |
C5 | 0.50762 (12) | 0.1572 (4) | 0.38361 (16) | 0.0691 (6) | |
H5 | 0.4727 (15) | 0.058 (4) | 0.360 (2) | 0.092 (8)* | |
C6 | 0.58280 (10) | 0.1115 (3) | 0.43360 (13) | 0.0523 (5) | |
H6 | 0.6018 (13) | −0.022 (3) | 0.4498 (17) | 0.074 (6)* | |
C7 | 0.71821 (8) | 0.20736 (17) | 0.52392 (9) | 0.0323 (4) | |
H7 | 0.7226 (9) | 0.057 (2) | 0.5238 (11) | 0.038 (4)* | |
C8 | 0.67639 (9) | 0.1881 (2) | 0.67946 (11) | 0.0374 (4) | |
H8A | 0.6232 (10) | 0.235 (2) | 0.6483 (13) | 0.039 (4)* | |
H8B | 0.6766 (10) | 0.044 (2) | 0.6725 (11) | 0.040 (4)* | |
C9 | 0.69785 (10) | 0.2420 (2) | 0.78736 (11) | 0.0443 (4) | |
H9A | 0.6941 (10) | 0.389 (3) | 0.7939 (13) | 0.052 (5)* | |
H9B | 0.6594 (11) | 0.177 (3) | 0.8185 (15) | 0.058 (5)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0701 (8) | 0.0400 (6) | 0.0442 (7) | −0.0046 (5) | 0.0028 (6) | 0.0070 (4) |
N1 | 0.0371 (6) | 0.0331 (6) | 0.0291 (6) | −0.0018 (4) | 0.0119 (5) | −0.0010 (4) |
C1 | 0.0387 (7) | 0.0440 (7) | 0.0290 (7) | −0.0045 (5) | 0.0144 (6) | −0.0039 (5) |
C2 | 0.0466 (8) | 0.0498 (8) | 0.0421 (8) | 0.0039 (7) | 0.0127 (6) | 0.0021 (6) |
C3 | 0.0515 (10) | 0.0805 (13) | 0.0507 (9) | 0.0139 (9) | 0.0109 (8) | 0.0095 (9) |
C4 | 0.0415 (9) | 0.1130 (18) | 0.0474 (10) | 0.0056 (10) | 0.0068 (7) | 0.0031 (10) |
C5 | 0.0489 (10) | 0.1004 (16) | 0.0567 (11) | −0.0274 (11) | 0.0091 (8) | −0.0142 (11) |
C6 | 0.0485 (9) | 0.0596 (10) | 0.0501 (9) | −0.0166 (8) | 0.0140 (7) | −0.0104 (7) |
C7 | 0.0383 (7) | 0.0297 (6) | 0.0319 (7) | −0.0039 (5) | 0.0143 (6) | −0.0040 (5) |
C8 | 0.0410 (8) | 0.0369 (7) | 0.0383 (8) | −0.0010 (6) | 0.0173 (6) | 0.0034 (5) |
C9 | 0.0619 (10) | 0.0390 (7) | 0.0384 (8) | 0.0005 (6) | 0.0246 (7) | 0.0030 (6) |
Geometric parameters (Å, º) top
O1—C9 | 1.408 (2) | C4—C5 | 1.382 (4) |
O1—H1O | 0.91 (3) | C4—H4 | 0.99 (2) |
N1—C8 | 1.4732 (16) | C5—C6 | 1.384 (3) |
N1—C7 | 1.4781 (16) | C5—H5 | 0.93 (3) |
N1—H1 | 0.922 (16) | C6—H6 | 0.98 (2) |
C1—C6 | 1.387 (2) | C7—C7i | 1.541 (2) |
C1—C2 | 1.398 (2) | C7—H7 | 1.036 (16) |
C1—C7 | 1.512 (2) | C8—C9 | 1.512 (2) |
C2—C3 | 1.381 (2) | C8—H8A | 0.992 (17) |
C2—H2 | 1.02 (2) | C8—H8B | 0.991 (17) |
C3—C4 | 1.369 (3) | C9—H9A | 1.013 (19) |
C3—H3 | 0.99 (3) | C9—H9B | 0.99 (2) |
| | | |
C9—O1—H1O | 104.1 (16) | C5—C6—H6 | 124.2 (13) |
C8—N1—C7 | 111.95 (10) | C1—C6—H6 | 115.2 (13) |
C8—N1—H1 | 106.2 (9) | N1—C7—C1 | 109.75 (10) |
C7—N1—H1 | 109.3 (9) | N1—C7—C7i | 109.20 (13) |
C6—C1—C2 | 118.18 (15) | C1—C7—C7i | 112.29 (13) |
C6—C1—C7 | 120.45 (14) | N1—C7—H7 | 110.4 (9) |
C2—C1—C7 | 121.35 (13) | C1—C7—H7 | 106.8 (8) |
C3—C2—C1 | 120.64 (17) | C7i—C7—H7 | 108.4 (9) |
C3—C2—H2 | 122.5 (11) | N1—C8—C9 | 110.78 (12) |
C1—C2—H2 | 116.8 (11) | N1—C8—H8A | 106.6 (10) |
C4—C3—C2 | 120.7 (2) | C9—C8—H8A | 110.8 (10) |
C4—C3—H3 | 121.3 (16) | N1—C8—H8B | 111.3 (9) |
C2—C3—H3 | 118.0 (16) | C9—C8—H8B | 109.6 (9) |
C3—C4—C5 | 119.41 (18) | H8A—C8—H8B | 107.7 (13) |
C3—C4—H4 | 121.0 (14) | O1—C9—C8 | 113.23 (12) |
C5—C4—H4 | 119.6 (14) | O1—C9—H9A | 106.9 (10) |
C4—C5—C6 | 120.49 (19) | C8—C9—H9A | 109.0 (10) |
C4—C5—H5 | 119.9 (16) | O1—C9—H9B | 111.1 (11) |
C6—C5—H5 | 119.6 (16) | C8—C9—H9B | 106.7 (12) |
C5—C6—C1 | 120.59 (18) | H9A—C9—H9B | 109.9 (15) |
| | | |
C6—C1—C2—C3 | −0.5 (2) | C8—N1—C7—C1 | 62.79 (14) |
C7—C1—C2—C3 | −178.87 (13) | C8—N1—C7—C7i | −173.71 (13) |
C1—C2—C3—C4 | 0.6 (3) | C6—C1—C7—N1 | −114.33 (14) |
C2—C3—C4—C5 | −0.1 (3) | C2—C1—C7—N1 | 64.03 (15) |
C3—C4—C5—C6 | −0.5 (3) | C6—C1—C7—C7i | 124.00 (15) |
C4—C5—C6—C1 | 0.6 (3) | C2—C1—C7—C7i | −57.63 (18) |
C2—C1—C6—C5 | −0.1 (2) | C7—N1—C8—C9 | 171.19 (11) |
C7—C1—C6—C5 | 178.33 (15) | N1—C8—C9—O1 | −58.46 (16) |
Symmetry code: (i) −x+3/2, −y+1/2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.92 (2) | 2.48 (2) | 2.901 (2) | 107.8 (11) |
O1—H1O···N1ii | 0.91 (3) | 1.95 (3) | 2.859 (2) | 175 (2) |
C8—H8B···O1ii | 0.99 (2) | 2.60 (2) | 3.548 (2) | 161 (2) |
Symmetry code: (ii) −x+3/2, y−1/2, −z+3/2. |
Experimental details
Crystal data |
Chemical formula | C18H24N2O2 |
Mr | 300.39 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 296 |
a, b, c (Å) | 17.585 (2), 6.8615 (5), 13.9453 (16) |
β (°) | 103.035 (10) |
V (Å3) | 1639.3 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.57 × 0.51 × 0.44 |
|
Data collection |
Diffractometer | Stoe IPDS 2 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4103, 1597, 1388 |
Rint | 0.096 |
(sin θ/λ)max (Å−1) | 0.617 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.053, 0.148, 1.09 |
No. of reflections | 1597 |
No. of parameters | 148 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.31, −0.20 |
Selected geometric parameters (Å, º) topO1—C9 | 1.408 (2) | C1—C7 | 1.512 (2) |
N1—C8 | 1.4732 (16) | C7—C7i | 1.541 (2) |
N1—C7 | 1.4781 (16) | C8—C9 | 1.512 (2) |
| | | |
C8—N1—C7 | 111.95 (10) | N1—C7—C7i | 109.20 (13) |
C6—C1—C7 | 120.45 (14) | C1—C7—C7i | 112.29 (13) |
C2—C1—C7 | 121.35 (13) | N1—C8—C9 | 110.78 (12) |
N1—C7—C1 | 109.75 (10) | O1—C9—C8 | 113.23 (12) |
Symmetry code: (i) −x+3/2, −y+1/2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.92 (2) | 2.48 (2) | 2.901 (2) | 107.8 (11) |
O1—H1O···N1ii | 0.91 (3) | 1.95 (3) | 2.859 (2) | 175 (2) |
C8—H8B···O1ii | 0.99 (2) | 2.60 (2) | 3.548 (2) | 161 (2) |
Symmetry code: (ii) −x+3/2, y−1/2, −z+3/2. |
The generation of different types of packing motifs in crystalline lattices has been illustrated in detail in the literature. Hydrogen-bonding motifs play an important role in the interaction, recognition and conformation of both small and large molecules, e.g. in biologically active molecules (Watson & Crick, 1953; Zeng et al., 2000). These motifs have frequently been used as supramolecular synthons to direct solid-state structures (crystal engineering; Steiner, 2002; Aakeröy & Seddon, 1993) and for the synthesis of complex supramolecules. The molecular assembly in a crystal is predominantly governed by intermolecular forces, conventionally described by strong and directional N—H···O, O—H···O and O—H···N hydrogen bonds (Desiraju, 2002). In molecules lacking these hydrogen-bond donors and acceptors, other types of weak and less directional forces, such as C—H···O, C—H···π and π–π interactions, become important in generating supramolecular architectures (Desiraju & Steiner, 1999; Hunder & Sanders, 1990; Nishio et al., 1998; Umezawa et al., 1998; Calhorda, 2000). The title compound, (I), is the intermediate product obtained during the synthesis of macromolecular metal complexes, which is an ongoing project. We present here the complete geometric characterization of (I) in the solid state, together with an analysis of the intermolecular interactions in the crystal structure.
The structure of (I), together with the atom-labelling scheme, is shown in Fig. 1. Both phenyl and 2-hydroxyethylamino moieties adopt a transoid configuration with respect to the C7—C7i bond [symmetry code: (i) −x + 1/2, −y + 1/2, −z], which minimizes the steric hinderance in the molecule. The compound crystallizes in space group C2/c and the molecules reside on inversion centres located at the midpoint of the C7—C7i bond. Selected bond lengths and angles are listed in Table 1. The imine bond lengths N1—C7 and N1—C8 are 1.478 (2) and 1.473 (2) Å, respectively, and are in the accepted range for covalent single bonds (Allen et al., 1987). The ΦNC torsion angle (C7—N1—C8—C9) is 171.2 (2)°, which shows that the conformation about the N1—C8 bond is (+)antiperiplanar. However, the ΦCC torsion angle (N1—C8—C9—O1) is −54.5 (2)°, indicating that the conformation about the C8—C9 bond is (-)synclinal. As can be seen from these torsion angles, the C7—N1—C8—C9 backbone is in zigzag chain form. However, the hydroxy group O atom does not lie in the plane of this chain and is oriented towards the imine N atom. This orientation leads to an intramolecular N—H···O hydrogen bond, resulting in the formation of a five-membered ring.
In the crystal lattice, the 1,2-diphenylethane part of the molecule resides along the a axis of the unit cell, while two symmetry-related 2-methylaminoethanol parts of the molecule lie along the c axis of the unit cell. In this arrangement, the molecules are connected to each other by means of hydrogen bonds between 2-hydroxyethylamino tails. There are no intermolecular interactions between molecules in the a or c direction. In the construction of this connection, two 2-hydroxyethylamino tails of the 21 screw symmetry-related molecules, which interdigitate with [Rephrasing OK?] the 2-hydroxyethylamino tails of two neighbouring molecules translated linearly along the b axis of the unit cell, play an active role, in which each tail is connected to the neighbouring tails by means of one O—H···N and one leading C—H···O hydrogen bond (Taylor & Kennard, 1982; Steiner & Desiraju, 1998), in which the hydroxy group O atom acts both donor and acceptor in two different hydrogen bonds. Atom O1 acts as a hydrogen-bond donor, via atom H1O, to atom N1 at (−x + 3/2, y − 1/2, −z + 3/2), while atom C8 acts as a hydrogen-bond donor, via atom H8B, to atom O1 at (−x + 3/2, y − 1/2, −z + 3/2), so generating a centrosymmetric R22(9) ring (Bernstein et al., 1995). The geometric parameters of the C—H···O bonds are well within the accepted ranges (Desiraju, 1991, 1996) and the C—H···O angle is close to the optimally observed value of 160°. A similiar type of graph set produced by intermolecular interactions of these types is also observed in the literature (Howie et al., 2003). Propagation of this hydrogen-bonding motif generates one-dimensional linear chains of edge-fused rings running parallel to the [010] direction (Fig. 2). In addition, as can be seen in Fig. 2, this arrangement forms another one-dimensional linear chain of edge-fused rings running parallel to the [010] direction between two chains of fused R22(9) rings, graph set R44(16). The detailed geometry of the intra- and intermolecular interactions is given in Table 2. There are no other significant interactions, such as π–π and C—H···π interactions, in the crystal structure.