The structure of 1,3-bis(8-chlorotheophyllin-7-yl)propane, C
17H
18Cl
2N
8O
4, which has no acidic H atom for conventional hydrogen bonding, is described. The compound shows only intermolecular stacking, as found in many xanthines, and most importantly it does not show intramolecular stacking, unlike the closely related 1,3-bis(theophyllin-8-yl)propane which has an acidic NH group for conventional hydrogen bonding. The title compound, in addition, exhibits intermolecular Cl
O interactions.
Supporting information
CCDC reference: 177203
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.002 Å
- R factor = 0.037
- wR factor = 0.098
- Data-to-parameter ratio = 12.1
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXTL-NT (Bruker, 1997); program(s) used to refine structure: SHELXTL-NT; molecular graphics: SHELXTL-NT; software used to prepare material for publication: SHELXTL-NT.
1,3-bis(8-chlorotheophyllin-7-yl)propane
top
Crystal data top
C17H18Cl2N8O4 | Dx = 1.582 Mg m−3 |
Mr = 469.29 | Melting point: 180 K |
Monoclinic, I2/a | Mo Kα radiation, λ = 0.71073 Å |
a = 19.929 (1) Å | Cell parameters from 35 reflections |
b = 4.3417 (2) Å | θ = 5.2–12.5° |
c = 22.788 (2) Å | µ = 0.38 mm−1 |
β = 91.40 (1)° | T = 293 K |
V = 1970.8 (2) Å3 | Block, colourless |
Z = 4 | 0.35 × 0.25 × 0.14 mm |
F(000) = 968 | |
Data collection top
Bruker P4 diffractometer | Rint = 0.014 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 1.8° |
Graphite monochromator | h = −23→23 |
θ–2θ scans | k = −5→1 |
2379 measured reflections | l = −27→1 |
1724 independent reflections | 3 standard reflections every 97 reflections |
1436 reflections with I > 2σ(I) | intensity decay: none |
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.098 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0508P)2 + 0.8204P] where P = (Fo2 + 2Fc2)/3 |
1724 reflections | (Δ/σ)max = 0.001 |
143 parameters | Δρmax = 0.20 e Å−3 |
0 restraints | Δρmin = −0.27 e Å−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 | Occ. (<1) |
Cl1 | 0.32994 (2) | 0.27327 (15) | 0.34767 (3) | 0.0603 (2) | |
O1 | −0.01634 (7) | −0.2310 (3) | 0.33147 (7) | 0.0541 (4) | |
O2 | 0.08167 (7) | 0.4415 (4) | 0.46294 (6) | 0.0598 (4) | |
N1 | 0.03258 (7) | 0.1034 (4) | 0.39686 (7) | 0.0410 (4) | |
C2 | 0.03373 (9) | −0.0926 (4) | 0.34834 (8) | 0.0395 (4) | |
N3 | 0.09361 (7) | −0.1233 (4) | 0.31994 (6) | 0.0394 (4) | |
C4 | 0.14951 (8) | 0.0304 (4) | 0.34123 (7) | 0.0341 (4) | |
C5 | 0.14660 (9) | 0.2154 (4) | 0.38948 (7) | 0.0342 (4) | |
C6 | 0.08699 (9) | 0.2707 (4) | 0.42072 (8) | 0.0397 (5) | |
N7 | 0.21098 (7) | 0.3334 (4) | 0.39704 (6) | 0.0357 (4) | |
C8 | 0.24671 (9) | 0.2057 (5) | 0.35374 (8) | 0.0394 (5) | |
N9 | 0.21176 (7) | 0.0216 (4) | 0.31853 (6) | 0.0416 (4) | |
C10 | 0.23461 (10) | 0.5265 (4) | 0.44602 (7) | 0.0385 (4) | |
H10A | 0.2005 | 0.6774 | 0.4550 | 0.046* | |
H10B | 0.2747 | 0.6362 | 0.4349 | 0.046* | |
C11 | 0.2500 | 0.3316 (6) | 0.5000 | 0.0398 (6) | |
H11A | 0.2118 | 0.2001 | 0.5076 | 0.048* | 0.50 |
H11B | 0.2882 | 0.2001 | 0.4924 | 0.048* | 0.50 |
C12 | −0.03232 (10) | 0.1371 (6) | 0.42521 (10) | 0.0597 (6) | |
H12A | −0.0647 | 0.2194 | 0.3975 | 0.090* | |
H12B | −0.0275 | 0.2746 | 0.4580 | 0.090* | |
H12C | −0.0472 | −0.0605 | 0.4386 | 0.090* | |
C13 | 0.09598 (11) | −0.3047 (5) | 0.26595 (8) | 0.0496 (5) | |
H13A | 0.0717 | −0.4934 | 0.2709 | 0.074* | |
H13B | 0.1418 | −0.3503 | 0.2574 | 0.074* | |
H13C | 0.0760 | −0.1894 | 0.2341 | 0.074* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cl1 | 0.0401 (3) | 0.0828 (5) | 0.0583 (4) | −0.0075 (3) | 0.0046 (2) | −0.0088 (3) |
O1 | 0.0465 (8) | 0.0605 (9) | 0.0545 (9) | −0.0111 (7) | −0.0127 (7) | 0.0014 (7) |
O2 | 0.0575 (9) | 0.0707 (11) | 0.0517 (9) | 0.0000 (8) | 0.0100 (7) | −0.0259 (8) |
N1 | 0.0375 (8) | 0.0448 (9) | 0.0406 (8) | 0.0033 (7) | −0.0008 (7) | 0.0006 (8) |
C2 | 0.0410 (10) | 0.0403 (10) | 0.0368 (9) | 0.0016 (9) | −0.0085 (8) | 0.0060 (9) |
N3 | 0.0451 (8) | 0.0396 (9) | 0.0330 (8) | 0.0004 (7) | −0.0084 (7) | −0.0050 (7) |
C4 | 0.0389 (9) | 0.0341 (10) | 0.0288 (8) | 0.0041 (8) | −0.0059 (7) | 0.0011 (8) |
C5 | 0.0380 (9) | 0.0357 (10) | 0.0285 (9) | 0.0019 (8) | −0.0063 (7) | −0.0004 (8) |
C6 | 0.0429 (10) | 0.0401 (11) | 0.0360 (10) | 0.0039 (8) | −0.0013 (8) | 0.0011 (9) |
N7 | 0.0413 (8) | 0.0363 (8) | 0.0290 (7) | 0.0006 (7) | −0.0065 (6) | −0.0004 (6) |
C8 | 0.0399 (10) | 0.0452 (11) | 0.0331 (9) | 0.0027 (8) | −0.0013 (8) | 0.0010 (8) |
N9 | 0.0430 (8) | 0.0483 (10) | 0.0336 (8) | 0.0035 (7) | −0.0007 (6) | −0.0061 (7) |
C10 | 0.0498 (10) | 0.0326 (10) | 0.0326 (9) | −0.0032 (8) | −0.0093 (8) | −0.0008 (8) |
C11 | 0.0517 (15) | 0.0317 (14) | 0.0355 (14) | 0.000 | −0.0116 (11) | 0.000 |
C12 | 0.0436 (11) | 0.0729 (16) | 0.0629 (14) | 0.0033 (11) | 0.0076 (10) | −0.0027 (13) |
C13 | 0.0651 (13) | 0.0487 (12) | 0.0344 (10) | −0.0003 (10) | −0.0107 (9) | −0.0081 (9) |
Geometric parameters (Å, º) top
Cl1—C8 | 1.6932 (19) | C4—N9 | 1.356 (2) |
O1—C2 | 1.219 (2) | C4—C5 | 1.364 (2) |
O2—C6 | 1.221 (2) | C5—N7 | 1.388 (2) |
N1—C2 | 1.396 (3) | C5—C6 | 1.420 (3) |
N1—C6 | 1.404 (2) | N7—C8 | 1.350 (3) |
N1—C12 | 1.467 (2) | N7—C10 | 1.465 (2) |
C2—N3 | 1.378 (2) | C8—N9 | 1.319 (2) |
N3—C4 | 1.377 (2) | C10—C11 | 1.518 (2) |
N3—C13 | 1.462 (2) | C11—C10i | 1.518 (2) |
| | | |
C2—N1—C6 | 126.50 (16) | N7—C5—C6 | 131.08 (16) |
C2—N1—C12 | 116.19 (17) | O2—C6—N1 | 122.56 (18) |
C6—N1—C12 | 117.31 (17) | O2—C6—C5 | 125.97 (18) |
O1—C2—N3 | 121.05 (18) | N1—C6—C5 | 111.47 (16) |
O1—C2—N1 | 121.42 (18) | C8—N7—C5 | 105.08 (15) |
N3—C2—N1 | 117.53 (16) | C8—N7—C10 | 128.79 (16) |
C4—N3—C2 | 119.35 (15) | C5—N7—C10 | 125.80 (15) |
C4—N3—C13 | 121.00 (16) | N9—C8—N7 | 114.40 (16) |
C2—N3—C13 | 119.56 (16) | N9—C8—Cl1 | 123.98 (15) |
N9—C4—C5 | 112.41 (16) | N7—C8—Cl1 | 121.59 (15) |
N9—C4—N3 | 126.28 (16) | C8—N9—C4 | 103.02 (15) |
C5—C4—N3 | 121.31 (17) | N7—C10—C11 | 110.69 (15) |
C4—C5—N7 | 105.08 (16) | C10i—C11—C10 | 112.3 (2) |
C4—C5—C6 | 123.79 (17) | | |
| | | |
C6—N1—C2—O1 | 179.05 (17) | C4—C5—C6—O2 | −177.62 (19) |
C12—N1—C2—O1 | −1.2 (3) | N7—C5—C6—O2 | −0.7 (3) |
C6—N1—C2—N3 | −1.2 (3) | C4—C5—C6—N1 | 2.0 (3) |
C12—N1—C2—N3 | 178.51 (17) | N7—C5—C6—N1 | 178.90 (17) |
O1—C2—N3—C4 | −178.29 (17) | C4—C5—N7—C8 | −1.07 (19) |
N1—C2—N3—C4 | 2.0 (3) | C6—C5—N7—C8 | −178.38 (19) |
O1—C2—N3—C13 | 5.0 (3) | C4—C5—N7—C10 | −174.92 (16) |
N1—C2—N3—C13 | −174.74 (16) | C6—C5—N7—C10 | 7.8 (3) |
C2—N3—C4—N9 | 179.48 (17) | C5—N7—C8—N9 | 1.0 (2) |
C13—N3—C4—N9 | −3.9 (3) | C10—N7—C8—N9 | 174.64 (16) |
C2—N3—C4—C5 | −0.8 (3) | C5—N7—C8—Cl1 | −177.28 (13) |
C13—N3—C4—C5 | 175.87 (17) | C10—N7—C8—Cl1 | −3.7 (3) |
N9—C4—C5—N7 | 0.8 (2) | N7—C8—N9—C4 | −0.5 (2) |
N3—C4—C5—N7 | −178.94 (15) | Cl1—C8—N9—C4 | 177.74 (14) |
N9—C4—C5—C6 | 178.40 (17) | C5—C4—N9—C8 | −0.2 (2) |
N3—C4—C5—C6 | −1.4 (3) | N3—C4—N9—C8 | 179.53 (17) |
C2—N1—C6—O2 | 178.92 (19) | C8—N7—C10—C11 | −93.3 (2) |
C12—N1—C6—O2 | −0.8 (3) | C5—N7—C10—C11 | 79.1 (2) |
C2—N1—C6—C5 | −0.7 (3) | N7—C10—C11—C10i | −172.11 (17) |
C12—N1—C6—C5 | 179.56 (17) | | |
Symmetry code: (i) −x+1/2, y, −z+1. |