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The two imine moieties of the title compound, C18H20N4, are positioned equatorially on the chair-conformation cyclohexane ring. Both also show a trans configuration with respect to the C=N double bond. The molecule lies on a crystallographic twofold rotation in a non-centrosymmetric space group. The dihedral angle between the two least-squares planes of the pyridine rings is 56.6 (2)°.
Supporting information
CCDC reference: 189381
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.003 Å
- R factor = 0.053
- wR factor = 0.143
- Data-to-parameter ratio = 14.7
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
General Notes
REFLT_03
From the CIF: _diffrn_reflns_theta_max 25.00
From the CIF: _reflns_number_total 1473
Count of symmetry unique reflns 889
Completeness (_total/calc) 165.69%
TEST3: Check Friedels for noncentro structure
Estimate of Friedel pairs measured 584
Fraction of Friedel pairs measured 0.657
Are heavy atom types Z>Si present no
ALERT: MoKa measured Friedel data cannot be used to
determine absolute structure in a light-atom
study EXCEPT under VERY special conditions.
It is preferred that Friedel data is merged in such cases.
Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SHELXTL (Bruker, 1997); program(s) used to solve structure: SHELXTL; program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
(1
R,2
R)-Bis(4-pyridylmethyleneamino)cyclohexane
top
Crystal data top
C18H20N4 | Dx = 1.170 Mg m−3 |
Mr = 292.38 | Melting point = 407–409 K |
Orthorhombic, P21212 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2 2ab | Cell parameters from 1006 reflections |
a = 15.230 (4) Å | θ = 2.6–25.5° |
b = 5.789 (1) Å | µ = 0.07 mm−1 |
c = 9.415 (2) Å | T = 293 K |
V = 830.0 (3) Å3 | Block, colorless |
Z = 2 | 0.3 × 0.2 × 0.2 mm |
F(000) = 312 | |
Data collection top
Bruker CCD area-detector diffractometer | 1473 independent reflections |
Radiation source: sealed tube | 1288 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.051 |
φ and ω scans | θmax = 25.0°, θmin = 2.2° |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | h = −17→18 |
Tmin = 0.983, Tmax = 0.986 | k = −6→6 |
4258 measured reflections | l = −11→6 |
Refinement top
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)] = 0.053 | H-atom parameters constrained |
wR(F2) = 0.143 | w = 1/[σ2(Fo2) + (0.1P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.01 | (Δ/σ)max < 0.001 |
1473 reflections | Δρmax = 0.13 e Å−3 |
100 parameters | Δρmin = −0.26 e Å−3 |
0 restraints | Absolute structure: Flack (1983); 584 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.0018 (3) |
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 | |
C1 | 0.36087 (19) | 0.5747 (5) | 0.2450 (3) | 0.0958 (9) | |
H1 | 0.3864 | 0.7185 | 0.2297 | 0.115* | |
C2 | 0.38240 (14) | 0.4610 (4) | 0.3675 (3) | 0.0738 (6) | |
H2 | 0.4208 | 0.5272 | 0.4326 | 0.089* | |
C3 | 0.34617 (12) | 0.2459 (4) | 0.3930 (2) | 0.0593 (6) | |
C4 | 0.28680 (13) | 0.1598 (5) | 0.2941 (2) | 0.0738 (7) | |
H4 | 0.2590 | 0.0186 | 0.3081 | 0.089* | |
C5 | 0.27040 (18) | 0.2919 (7) | 0.1735 (3) | 0.0927 (9) | |
H5 | 0.2314 | 0.2329 | 0.1067 | 0.111* | |
C6 | 0.37032 (11) | 0.1118 (4) | 0.5197 (2) | 0.0560 (5) | |
H6 | 0.3391 | −0.0218 | 0.5412 | 0.067* | |
C7 | 0.45115 (12) | 0.0325 (3) | 0.72348 (19) | 0.0542 (5) | |
H7 | 0.4156 | −0.1086 | 0.7206 | 0.065* | |
C8 | 0.42892 (12) | 0.1681 (4) | 0.8567 (2) | 0.0659 (6) | |
H8A | 0.4608 | 0.3132 | 0.8558 | 0.079* | |
H8B | 0.3666 | 0.2033 | 0.8570 | 0.079* | |
C9 | 0.45190 (14) | 0.0359 (5) | 0.9902 (2) | 0.0738 (7) | |
H9A | 0.4152 | −0.1006 | 0.9968 | 0.089* | |
H9B | 0.4402 | 0.1318 | 1.0725 | 0.089* | |
N1 | 0.30656 (18) | 0.4962 (6) | 0.1469 (2) | 0.1044 (9) | |
N2 | 0.43171 (10) | 0.1731 (3) | 0.59912 (18) | 0.0612 (5) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.111 (2) | 0.1001 (19) | 0.0759 (17) | 0.0366 (16) | 0.0153 (16) | 0.0260 (15) |
C2 | 0.0718 (13) | 0.0825 (14) | 0.0672 (14) | 0.0128 (12) | 0.0071 (11) | 0.0115 (13) |
C3 | 0.0472 (10) | 0.0775 (13) | 0.0532 (11) | 0.0140 (9) | 0.0062 (8) | 0.0003 (10) |
C4 | 0.0577 (12) | 0.1015 (16) | 0.0622 (13) | 0.0223 (11) | −0.0040 (9) | −0.0129 (13) |
C5 | 0.0758 (16) | 0.140 (3) | 0.0623 (16) | 0.0455 (18) | −0.0089 (12) | −0.0145 (18) |
C6 | 0.0466 (10) | 0.0662 (11) | 0.0552 (11) | −0.0033 (9) | 0.0035 (8) | 0.0034 (9) |
C7 | 0.0507 (10) | 0.0590 (10) | 0.0528 (10) | −0.0094 (8) | −0.0013 (8) | 0.0061 (9) |
C8 | 0.0528 (10) | 0.0818 (13) | 0.0632 (12) | 0.0045 (9) | 0.0011 (9) | −0.0023 (12) |
C9 | 0.0637 (12) | 0.1081 (17) | 0.0497 (12) | 0.0045 (13) | 0.0041 (9) | −0.0030 (13) |
N1 | 0.1075 (18) | 0.139 (2) | 0.0667 (14) | 0.0576 (18) | 0.0014 (13) | 0.0165 (18) |
N2 | 0.0581 (10) | 0.0686 (10) | 0.0569 (10) | −0.0084 (8) | −0.0031 (8) | 0.0060 (8) |
Geometric parameters (Å, º) top
C1—N1 | 1.321 (4) | C6—H6 | 0.9300 |
C1—C2 | 1.368 (3) | C7—N2 | 1.456 (2) |
C1—H1 | 0.9300 | C7—C8 | 1.518 (3) |
C2—C3 | 1.383 (3) | C7—C7i | 1.535 (4) |
C2—H2 | 0.9300 | C7—H7 | 0.9800 |
C3—C4 | 1.390 (3) | C8—C9 | 1.513 (3) |
C3—C6 | 1.470 (3) | C8—H8A | 0.9700 |
C4—C5 | 1.392 (4) | C8—H8B | 0.9700 |
C4—H4 | 0.9300 | C9—C9i | 1.523 (4) |
C5—N1 | 1.328 (5) | C9—H9A | 0.9700 |
C5—H5 | 0.9300 | C9—H9B | 0.9700 |
C6—N2 | 1.249 (2) | | |
| | | |
N1—C1—C2 | 125.0 (3) | N2—C7—C7i | 109.51 (13) |
N1—C1—H1 | 117.5 | C8—C7—C7i | 110.06 (13) |
C2—C1—H1 | 117.5 | N2—C7—H7 | 109.3 |
C1—C2—C3 | 119.0 (3) | C8—C7—H7 | 109.3 |
C1—C2—H2 | 120.5 | C7i—C7—H7 | 109.3 |
C3—C2—H2 | 120.5 | C9—C8—C7 | 111.90 (17) |
C2—C3—C4 | 117.8 (2) | C9—C8—H8A | 109.2 |
C2—C3—C6 | 121.1 (2) | C7—C8—H8A | 109.2 |
C4—C3—C6 | 121.1 (2) | C9—C8—H8B | 109.2 |
C3—C4—C5 | 117.8 (2) | C7—C8—H8B | 109.2 |
C3—C4—H4 | 121.1 | H8A—C8—H8B | 107.9 |
C5—C4—H4 | 121.1 | C8—C9—C9i | 111.14 (16) |
N1—C5—C4 | 124.6 (3) | C8—C9—H9A | 109.4 |
N1—C5—H5 | 117.7 | C9i—C9—H9A | 109.4 |
C4—C5—H5 | 117.7 | C8—C9—H9B | 109.4 |
N2—C6—C3 | 121.56 (19) | C9i—C9—H9B | 109.4 |
N2—C6—H6 | 119.2 | H9A—C9—H9B | 108.0 |
C3—C6—H6 | 119.2 | C1—N1—C5 | 115.8 (2) |
N2—C7—C8 | 109.25 (15) | C6—N2—C7 | 118.36 (16) |
Symmetry code: (i) −x+1, −y, z. |
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