Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270110039995/fg3200sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270110039995/fg3200Isup2.hkl |
CCDC reference: 804131
Chemicals were used as obtained from suppliers, ethanolamine and magnesium sulfate from Merck, cyclohexene oxide and 1, 2-dibromoethane from Aldrich, and potassium carbonate from Saarchem.
The reagent 2-[(2-hydroxyethyl)amino]cyclohexanol was synthesized as previously reported (de Sousa et al., 2010). A suspension of 2-[(2-hydroxyethyl)amino]cyclohexanol (0.6 g, 3.77 mmol) and potassium carbonate (0.2633 g, 1.89 mmol) in dried dimethylformamide (10 ml) was allowed to reflux, followed by the dropwise addition of an anhydrous 1,2-dibromoethane (0.3596 g, 1.89 mmol) dimethylformamide solution (4 ml) over 30 min. The reaction was allowed to reflux for a further 72 h before the solvent was removed under reduced pressure to obtain an orange–brown viscous oil. The oil was dissolved in chloroform (30 ml) and solid KBr removed by filtration. The chloroform solution was washed with deionized water (3 × 20 ml) and dried over magnesium sulfate. Filtration and removal of solvent down to dryness produced a clear orange oil which was characterized by NMR and FAB-MS to be the desired product. Addition of concentrated HCl to an ethanolic solution of this product afforded the dihydrochloride salt as an off-white powder that crystallized upon cooling from hot absolute ethanol (yield 31%). Spectroscopic analysis: 1H NMR (D2O, 300 MHz, δ, p.p.m.): 3.73–3.37 (6H, m, 2CH, 2CH2), 2.84–2.23 (10H, m, 2CH, 4CH2), 2.03–1.51 (8H, m, 4CH2), 1.29–0.99 (8H, m, 4CH2); 13C NMR (CDCl3, 300 MHz, δ, p.p.m.): 70.54, 69.59, 67.17, 64.31, 60.81, 59.69, 52.69, 51.68, 51.58, 46.80, 34.38, 25.91, 25.84, 24.79, 23.09, 22.15; MS, m/z (FAB) 345 (M+, 100%).
PLATON (Spek, 2009) indicated that there was a minor twinning problem and the TwinRotMax function was used to generate an HKLF 5 file for use in the final refinement; details are in the _refine_special_details section of the CIF. Final refinement gave a twining factor (BASF value) of 0.11872. H atoms were visible in the difference map and those bonded to C atoms were positioned geometrically and allowed for as riding, with C—H = 1.00 (CH) or 0.99 Å (CH2). The coordinates of the H atoms involved in hydrogen bonding were refined freely. For all H atoms, Uiso(H) = 1.2Ueq(C,N,O).
Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: SAINT-Plus (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
C18H38N2O42+·2Cl− | F(000) = 452 |
Mr = 417.40 | Dx = 1.287 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 5507 reflections |
a = 9.6668 (3) Å | θ = 2.7–28.2° |
b = 11.7616 (4) Å | µ = 0.33 mm−1 |
c = 9.5471 (3) Å | T = 173 K |
β = 97.210 (2)° | Prismic, colourless |
V = 1076.89 (6) Å3 | 0.30 × 0.22 × 0.10 mm |
Z = 2 |
Bruker APEXII CCD area-detector diffractometer | 2668 independent reflections |
Radiation source: fine-focus sealed tube | 2233 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.050 |
ϕ and ω scans | θmax = 28.3°, θmin = 2.1° |
Absorption correction: integration [face-indexed correction using XPREP in SHELXTL (Sheldrick, 2008)] | h = −12→12 |
Tmin = 0.918, Tmax = 0.969 | k = −15→15 |
13823 measured reflections | l = −12→12 |
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)] = 0.034 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.086 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0461P)2 + 0.0994P] where P = (Fo2 + 2Fc2)/3 |
2668 reflections | (Δ/σ)max = 0.001 |
128 parameters | Δρmax = 0.40 e Å−3 |
0 restraints | Δρmin = −0.22 e Å−3 |
C18H38N2O42+·2Cl− | V = 1076.89 (6) Å3 |
Mr = 417.40 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 9.6668 (3) Å | µ = 0.33 mm−1 |
b = 11.7616 (4) Å | T = 173 K |
c = 9.5471 (3) Å | 0.30 × 0.22 × 0.10 mm |
β = 97.210 (2)° |
Bruker APEXII CCD area-detector diffractometer | 2668 independent reflections |
Absorption correction: integration [face-indexed correction using XPREP in SHELXTL (Sheldrick, 2008)] | 2233 reflections with I > 2σ(I) |
Tmin = 0.918, Tmax = 0.969 | Rint = 0.050 |
13823 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.086 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.40 e Å−3 |
2668 reflections | Δρmin = −0.22 e Å−3 |
128 parameters |
Experimental. A no-twin refinement with MERG 2 was performed initially, followed by the TwinRotMax PLATON command to generate the HKLF5 twinned file used in the final refimnement. PLATON TwinRotMax output:- Criteria: DeltaI/SigmaI .GT. 4.0, DeltaTheta 0.10 Deg., NselMin = 50 Wavelength Used in this Analysis 0.71073 Ang. N(refl) = 2668, N(selected) = 50, IndMax = 5, CritI = 0.1, CritT = 0.10 2-axis ( 1 0 0 ) [ 5 0 1 ], Angle () [] = 4.15 Deg, Freq = 52 ************* ( 1.000 0.000 0.254) (h1) (h2) Nr Overlap = 694 ( 0.000 -1.000 0.000) * (k1) = (k2) BASF = 0.12 ( 0.000 0.000 -1.000) (l1) (l2) DEL-R =-0.021 |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.28376 (14) | 0.61296 (11) | 0.14366 (13) | 0.0181 (3) | |
H1 | 0.3006 | 0.6951 | 0.1248 | 0.022* | |
C2 | 0.30906 (13) | 0.59155 (11) | 0.30185 (13) | 0.0170 (3) | |
H2 | 0.2900 | 0.5093 | 0.3174 | 0.020* | |
C3 | 0.21104 (15) | 0.65984 (13) | 0.38195 (15) | 0.0237 (3) | |
H3A | 0.2292 | 0.7421 | 0.3718 | 0.028* | |
H3B | 0.2275 | 0.6405 | 0.4836 | 0.028* | |
C4 | 0.05959 (16) | 0.63316 (16) | 0.32370 (17) | 0.0336 (4) | |
H4A | 0.0388 | 0.5529 | 0.3443 | 0.040* | |
H4B | −0.0037 | 0.6819 | 0.3714 | 0.040* | |
C5 | 0.03307 (16) | 0.65315 (16) | 0.16522 (17) | 0.0336 (4) | |
H5A | −0.0640 | 0.6316 | 0.1298 | 0.040* | |
H5B | 0.0449 | 0.7349 | 0.1451 | 0.040* | |
C6 | 0.13352 (15) | 0.58353 (13) | 0.08964 (15) | 0.0250 (3) | |
H6A | 0.1174 | 0.5016 | 0.1049 | 0.030* | |
H6B | 0.1160 | 0.5986 | −0.0131 | 0.030* | |
C7 | 0.50288 (14) | 0.73759 (10) | 0.35862 (15) | 0.0184 (3) | |
H7A | 0.4416 | 0.7785 | 0.2843 | 0.022* | |
H7B | 0.4875 | 0.7704 | 0.4509 | 0.022* | |
C8 | 0.65226 (15) | 0.75620 (11) | 0.33590 (16) | 0.0244 (3) | |
H8A | 0.6791 | 0.8355 | 0.3610 | 0.029* | |
H8B | 0.7129 | 0.7051 | 0.3991 | 0.029* | |
C9 | 0.50718 (14) | 0.56419 (10) | 0.49963 (13) | 0.0165 (3) | |
H9A | 0.4496 | 0.5974 | 0.5680 | 0.020* | |
H9B | 0.6056 | 0.5851 | 0.5300 | 0.020* | |
N1 | 0.46219 (11) | 0.61282 (9) | 0.35565 (11) | 0.0144 (2) | |
H11 | 0.5131 (16) | 0.5772 (13) | 0.2998 (17) | 0.017* | |
O1 | 0.38296 (11) | 0.54598 (9) | 0.08336 (11) | 0.0266 (2) | |
H10 | 0.3600 (19) | 0.5404 (15) | 0.003 (2) | 0.032* | |
O2 | 0.67408 (12) | 0.73525 (10) | 0.19383 (13) | 0.0325 (3) | |
H12 | 0.698 (2) | 0.6697 (17) | 0.191 (2) | 0.039* | |
Cl1 | 0.71687 (4) | 0.47600 (3) | 0.24602 (4) | 0.02181 (11) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0182 (6) | 0.0219 (6) | 0.0141 (6) | 0.0005 (5) | 0.0017 (5) | 0.0006 (5) |
C2 | 0.0167 (6) | 0.0189 (6) | 0.0150 (6) | −0.0026 (5) | 0.0005 (5) | 0.0013 (5) |
C3 | 0.0213 (7) | 0.0310 (7) | 0.0194 (7) | −0.0013 (6) | 0.0054 (6) | −0.0037 (6) |
C4 | 0.0206 (8) | 0.0532 (10) | 0.0279 (8) | −0.0009 (7) | 0.0072 (6) | −0.0065 (7) |
C5 | 0.0178 (7) | 0.0533 (10) | 0.0292 (8) | 0.0032 (7) | 0.0007 (6) | −0.0041 (7) |
C6 | 0.0206 (7) | 0.0342 (8) | 0.0191 (7) | −0.0025 (6) | −0.0009 (6) | −0.0018 (6) |
C7 | 0.0238 (7) | 0.0121 (6) | 0.0192 (6) | −0.0002 (5) | 0.0022 (5) | 0.0013 (5) |
C8 | 0.0267 (8) | 0.0185 (6) | 0.0279 (8) | −0.0039 (6) | 0.0030 (6) | 0.0034 (5) |
C9 | 0.0226 (7) | 0.0151 (6) | 0.0111 (6) | −0.0017 (5) | −0.0003 (5) | 0.0010 (5) |
N1 | 0.0174 (5) | 0.0139 (5) | 0.0120 (5) | −0.0005 (4) | 0.0022 (4) | 0.0001 (4) |
O1 | 0.0240 (5) | 0.0403 (6) | 0.0153 (5) | 0.0058 (5) | 0.0014 (4) | −0.0067 (4) |
O2 | 0.0380 (7) | 0.0302 (6) | 0.0322 (6) | 0.0064 (5) | 0.0161 (5) | 0.0108 (5) |
Cl1 | 0.02367 (18) | 0.02351 (17) | 0.01895 (17) | −0.00074 (13) | 0.00537 (13) | −0.00219 (12) |
C1—O1 | 1.4179 (17) | C6—H6A | 0.9900 |
C1—C6 | 1.5188 (19) | C6—H6B | 0.9900 |
C1—C2 | 1.5203 (18) | C7—C8 | 1.503 (2) |
C1—H1 | 1.0000 | C7—N1 | 1.5186 (15) |
C2—C3 | 1.5197 (19) | C7—H7A | 0.9900 |
C2—N1 | 1.5254 (16) | C7—H7B | 0.9900 |
C2—H2 | 1.0000 | C8—O2 | 1.4200 (19) |
C3—C4 | 1.532 (2) | C8—H8A | 0.9900 |
C3—H3A | 0.9900 | C8—H8B | 0.9900 |
C3—H3B | 0.9900 | C9—N1 | 1.5019 (15) |
C4—C5 | 1.521 (2) | C9—C9i | 1.516 (2) |
C4—H4A | 0.9900 | C9—H9A | 0.9900 |
C4—H4B | 0.9900 | C9—H9B | 0.9900 |
C5—C6 | 1.520 (2) | N1—H11 | 0.877 (16) |
C5—H5A | 0.9900 | O1—H10 | 0.78 (2) |
C5—H5B | 0.9900 | O2—H12 | 0.806 (19) |
O1—C1—C6 | 113.71 (11) | C1—C6—H6A | 109.5 |
O1—C1—C2 | 106.18 (10) | C5—C6—H6A | 109.5 |
C6—C1—C2 | 109.11 (11) | C1—C6—H6B | 109.5 |
O1—C1—H1 | 109.2 | C5—C6—H6B | 109.5 |
C6—C1—H1 | 109.2 | H6A—C6—H6B | 108.0 |
C2—C1—H1 | 109.2 | C8—C7—N1 | 112.91 (11) |
C3—C2—C1 | 112.31 (11) | C8—C7—H7A | 109.0 |
C3—C2—N1 | 112.57 (10) | N1—C7—H7A | 109.0 |
C1—C2—N1 | 109.61 (10) | C8—C7—H7B | 109.0 |
C3—C2—H2 | 107.4 | N1—C7—H7B | 109.0 |
C1—C2—H2 | 107.4 | H7A—C7—H7B | 107.8 |
N1—C2—H2 | 107.4 | O2—C8—C7 | 111.91 (12) |
C2—C3—C4 | 109.69 (12) | O2—C8—H8A | 109.2 |
C2—C3—H3A | 109.7 | C7—C8—H8A | 109.2 |
C4—C3—H3A | 109.7 | O2—C8—H8B | 109.2 |
C2—C3—H3B | 109.7 | C7—C8—H8B | 109.2 |
C4—C3—H3B | 109.7 | H8A—C8—H8B | 107.9 |
H3A—C3—H3B | 108.2 | N1—C9—C9i | 111.56 (12) |
C5—C4—C3 | 111.32 (13) | N1—C9—H9A | 109.3 |
C5—C4—H4A | 109.4 | C9i—C9—H9A | 109.3 |
C3—C4—H4A | 109.4 | N1—C9—H9B | 109.3 |
C5—C4—H4B | 109.4 | C9i—C9—H9B | 109.3 |
C3—C4—H4B | 109.4 | H9A—C9—H9B | 108.0 |
H4A—C4—H4B | 108.0 | C9—N1—C7 | 107.84 (9) |
C6—C5—C4 | 110.55 (13) | C9—N1—C2 | 113.76 (10) |
C6—C5—H5A | 109.5 | C7—N1—C2 | 113.76 (10) |
C4—C5—H5A | 109.5 | C9—N1—H11 | 104.7 (10) |
C6—C5—H5B | 109.5 | C7—N1—H11 | 108.0 (10) |
C4—C5—H5B | 109.5 | C2—N1—H11 | 108.2 (10) |
H5A—C5—H5B | 108.1 | C1—O1—H10 | 109.0 (14) |
C1—C6—C5 | 110.90 (12) | C8—O2—H12 | 105.7 (14) |
O1—C1—C2—C3 | 179.04 (11) | C4—C5—C6—C1 | −58.09 (18) |
C6—C1—C2—C3 | −58.02 (14) | N1—C7—C8—O2 | 72.17 (14) |
O1—C1—C2—N1 | 53.12 (13) | C9i—C9—N1—C7 | −170.50 (13) |
C6—C1—C2—N1 | 176.06 (10) | C9i—C9—N1—C2 | 62.33 (17) |
C1—C2—C3—C4 | 56.42 (16) | C8—C7—N1—C9 | 83.14 (13) |
N1—C2—C3—C4 | −179.29 (12) | C8—C7—N1—C2 | −149.69 (11) |
C2—C3—C4—C5 | −54.97 (18) | C3—C2—N1—C9 | 70.17 (13) |
C3—C4—C5—C6 | 56.35 (19) | C1—C2—N1—C9 | −164.06 (10) |
O1—C1—C6—C5 | 176.42 (12) | C3—C2—N1—C7 | −53.86 (14) |
C2—C1—C6—C5 | 58.10 (15) | C1—C2—N1—C7 | 71.91 (13) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H10···Cl1ii | 0.78 (2) | 2.40 (2) | 3.1819 (11) | 178.6 (19) |
N1—H11···Cl1 | 0.877 (16) | 2.411 (16) | 3.2239 (12) | 154.4 (13) |
O2—H12···Cl1 | 0.806 (19) | 2.34 (2) | 3.1089 (12) | 160.0 (18) |
C7—H7A···Cl1iii | 0.99 | 2.78 | 3.5834 (13) | 139 |
C9—H9A···Cl1i | 0.99 | 2.68 | 3.4830 (14) | 138 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z; (iii) −x+1, y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C18H38N2O42+·2Cl− |
Mr | 417.40 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 173 |
a, b, c (Å) | 9.6668 (3), 11.7616 (4), 9.5471 (3) |
β (°) | 97.210 (2) |
V (Å3) | 1076.89 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.33 |
Crystal size (mm) | 0.30 × 0.22 × 0.10 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector diffractometer |
Absorption correction | Integration [face-indexed correction using XPREP in SHELXTL (Sheldrick, 2008)] |
Tmin, Tmax | 0.918, 0.969 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 13823, 2668, 2233 |
Rint | 0.050 |
(sin θ/λ)max (Å−1) | 0.667 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.086, 1.06 |
No. of reflections | 2668 |
No. of parameters | 128 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.40, −0.22 |
Computer programs: APEX2 (Bruker, 2005), SAINT-Plus (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H10···Cl1i | 0.78 (2) | 2.40 (2) | 3.1819 (11) | 178.6 (19) |
N1—H11···Cl1 | 0.877 (16) | 2.411 (16) | 3.2239 (12) | 154.4 (13) |
O2—H12···Cl1 | 0.806 (19) | 2.34 (2) | 3.1089 (12) | 160.0 (18) |
C7—H7A···Cl1ii | 0.99 | 2.78 | 3.5834 (13) | 138.9 |
C9—H9A···Cl1iii | 0.99 | 2.68 | 3.4830 (14) | 137.9 |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) −x+1, y+1/2, −z+1/2; (iii) −x+1, −y+1, −z+1. |
Work on solid-state structures of reinforced β-amino alcohols, where cyclohexyl bridges are fused onto pendent hydroxyethyl groups, has suggested these compounds are able to self-assemble (de Sousa et al., 2010). Relatively simply amino alcohols, such as diethanolamine, weakly assemble into tubular stacks through the linking of ring motifs (Bernstein et al., 1995) via N—H···O hydrogen bonds, defining internal cavities of a predominantly hydrophilic nature. Tubular stacks are preferentially formed by stronger O—H···O intermolecular hydrogen bonds favoured in anti conformations adopted by β-amino alcohols with fused cyclohexyl bridges (de Sousa et al., 2010). In these compounds the cyclohexyl bridge, between the amine N atom and a single hydroxy O-atom donor, promotes stronger intermolecular O—H···O hydrogen bonds that link the ring motifs into elaborate tubular stacks in the reinforced diethanolamine derivative {2-[(2-hydroxyethyl)amino]cyclohexanol, CyEA}. The hydrophilic inner cores in this structure arise from the stereospecificity of the intermolecular O—H···O hydrogen bonds, dependent on the cyclohexyl conformation defining the surrounding hydrophobic outer surface. The selective enhancement of the intermolecular interactions within the hydrophilic inner core, via N-alkyl substitution of the amino group or C-alkyl substitution of the hydroxyalkyl pendents, may prompt controlled self-assembly of β-amino alcohols.
The solid-state structures of the hydrochloride salts of enantiomers of the C-alkylated amino alcohol nebivolol (Tuchalski et al., 2006) and the N-substituted amino alcohol triethanolammonium chloride (Light & Gale, 2003; Mootz et al., 1990; Vollbrecht et al., 1997) largely suggest that conventional O—H···Cl and N—H···Cl interactions stabilize the crystallization of these compounds (Steiner, 1998). These interactions, often characteristic of ion pairs, accommodate the anion in distorted geometries: trigonal pyramidal (Linden et al., 1994; Koman et al., 2000; Henkel et al., 1999; Bi & Aggarwal, 2008), tetrahedral (Nash et al., 1988; Furneaux et al., 1997; Henkel et al., 1997a,b), trigonal planar (Zukerman-Schpector et al., 2005), square pyramidal (Nash et al., 1990; Huerta et al., 2004) and T-shaped (Chang et al., 2005). The halide anion, a strong hydrogen-bond acceptor, typically interacts with four donors, and the above-mentioned geometries, observed in the solid state, include weaker C—H···Cl interactions. Halides are amongst the strongest hydrogen-bond acceptors, and the analysis of hydrogen-bonding motifs described by O—H···Cl, N—H···Cl and weaker interactions permits investigation of the chloride ion as a suitable template for self-assembly of amino alcohols.
The title compound, (I), can be viewed as a chirally substituted derivative of ethylene diamine (Fig. 1). An inversion centre at (1/2, 1/2, 1/2) pairs cyclohexyl (S,S) groups bonded to an R amine N atom at (x, y, z) with (R,R) cyclohexyl groups bonded to an S amine N atom at (1 - x, 1 - y, 1 - z), affording the achiral diastereomer of (I). The CyEA fragments of (I) occur in distorted syn conformations, with torsion angles N1—C2—C1—O1 = 53.12 (13)° and N1—C7—C8—O2 = 72.17 (14)°, for the hydroxycyclohexyl and hydroxyethyl pendents, respectively. The hydroxyalkyl torsions in (I) show larger deviations from the strain-free values (de Sousa et al., 1991; Kemp & Vellacio, 1980) compared with the syn conformer [58.98 (10) and -65.06 (13)°] reported for CyEA (de Sousa et al., 2010).
R22(16) and R22(10) hydrogen-bonded dimers have been previously reported for syn and anti CyEA enantiomeric pairs (de Sousa et al., 2010). These ring motifs are observed for O—H···O and N—H···O interactions where the hydroxycyclohexyl O atom acts as a hydrogen-bond acceptor. In the presence of the chloride ion, acting as an additional strong hydrogen-bond acceptor, these interactions are not observed in the structure of (I). Hydroxycyclohexyl atom O1 and hydroxyethyl atom O2 interact with acceptors Cl1ii and Cl1 via atoms H10 and H12, respectively, to generate an R42(20) motif (Bernstein et al., 1995) (Table 1 and Fig 2) centred at (1/2, 1/2, 0) when combined with interactions O2ii—H12ii···Cl1ii and O1ii—H10ii···Cl1. Combining symmetrically equivalent interactions N1—H11···Cl (Table 1) and N1ii—H11ii···Cl1ii with hydroxycyclohexyl interactions O1ii—H10ii···Cl1 and O1—H10···Cl1ii, respectively, generates an R42(14) motif. R42(20) and R42(14) motifs observed in the structure of (I) may be viewed as enlarged R22(16) and R22(10) motifs, in which O—H···O and N—H···O interactions are replaced by O—H···Cl and N—H···Cl counterparts upon inclusion of the halide. The latter interactions play a predominant role in assembling molecules of (I) into chains along [001] (Fig 2). Chain motifs C21(13) and C21(10), defined along the ethylene backbone, join R42(20) and R42(14) dimers, respectively. The [001] motif is therefore best represented as a chain of rings, C21(13)R42(20)C21(10)R42(14).
Mean planes through syn CyEA fragments in (I) are separated by 2.0 Å, compared with the previously reported R22(16) counterparts (3.2 Å; de Sousa et al., 2010). However, tubular stacks are segmented by the trans ethylene bridge between CyEA fragments. An inner hydrophilic core is segmented into hydrophilic pockets that separate adjacent R42(20) and R42(14) inversion centres (9.55 Å). Chains of hydrophilic segments describing the dimeric hydrogen-bonding ring motifs are flanked by hydrophobic columns of stacked cyclohexyl rings. A survey of the Cambridge Structural Database (Version?; Allen, 2002) indicates that the trans conformation of ethylenediamine is subject to distortion in mono- and disubstituted derivatives of this compound (Fig. 3). Variations in N—C—C bond angle and ethylene chain length, as measured by N···N distance, are pronounced for substituted ethylenediamine compounds compared with the recent structure of ethylenediammonium dichloride (Dickman, 2007; Gabro et al., 2009; Kooijman et al., 2006; Seidel, 2008) and ethylenediammonium dinitrate (George et al., 1991). The N1—C9—C9i bond angle [111.56 (12)°; symmetry code: (i) 1 - x, 1 - y, 1 - z] is less than the calculated average bond angle (112.2°) for disubstituted ethylenediamine derivatives, comparing favourably with the value observed in ethylammonium dinitrate (111.19°) exhibiting nitrate hydrogen-bond bifurcation. However, the ethylene chain length as measured by the N1···N1i distance [3.830 (2) Å] compares with the calculated average length (3.82 Å). The conformations adopted in the hydrogen-bonded chain are largely influenced by O—H···Cl and N—H···Cl interactions; C—H···Cl contacts (Table 1) are of lesser significance. A very weak interaction, C7—H7A···Cl1iii (Table 1), of the hydroxyethyl pendent links adjacent [001] chains to form undulating layers along (011) in the solid state.
In conclusion, the influence of the chloride ion upon the hydrogen-bonding interactions of (I) confirms its role as a template for the assembly of β-amino alcohols bearing cyclohexyl pendents. Segmentation of the hydrophilic inner core is less desirable for the controlled synthesis of porous materials (Ishida et al., 2003). Congruency of N-alkyl chain conformation, linking CyEA molecules, with hydrogen-bond orientation is necessary for achieving a central hydrophilic core in synthesizing larger supramolecular amino alcohol structures.