Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101018029/gg1079sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101018029/gg1079Isup2.hkl |
CCDC reference: 180164
Compound (1) was synthesized and purified by the method of Albert & Barlin (1959). Single crystals suitable for X-ray data collection were obtained on slow evaporation from a ethyl acetate solution.
The H atoms were treated as riding atoms using the SHELXL97 (Sheldrick, 1997) defaults, d(C—H) = 0.93 Å for the aromatic and 0.96 Å for methyl-H atoms.
Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software (Enraf-Nonius, 1989); data reduction: SDP (B. A. Frenz & Associates Inc., 1985); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).
| SCHEME 1 SCHEME 2 Fig. 1. Molecular structures of the two symmetrically independent molecules of compound (I) at the 50% probability level (Farrugia, 1997). SCHEME 3 |
C6H7NS | Z = 4 |
Mr = 125.19 | F(000) = 264 |
Triclinic, P1 | Dx = 1.312 Mg m−3 |
a = 7.544 (1) Å | Cu Kα radiation, λ = 1.54178 Å |
b = 9.085 (1) Å | Cell parameters from 25 reflections |
c = 9.302 (1) Å | θ = 7–19° |
α = 89.84 (1)° | µ = 3.59 mm−1 |
β = 84.03 (1)° | T = 293 K |
γ = 87.98 (1)° | Block, yellow |
V = 633.7 (1) Å3 | 0.32 × 0.28 × 0.26 mm |
Enraf-Nonius CAD4 diffractometer | Rint = 0.022 |
Radiation source: fine-focus sealed tube | θmax = 78.2°, θmin = 4.8° |
Graphite monochromator | h = 0→9 |
ω–2θ scans | k = −11→11 |
2861 measured reflections | l = −11→11 |
2654 independent reflections | 3 standard reflections every 60 min |
2012 reflections with I > 2σ(I) | intensity decay: <1% |
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)] = 0.046 | H-atom parameters constrained |
wR(F2) = 0.135 | w = 1/[σ2(Fo2) + (0.0893P)2 + 0.0559P] where P = (Fo2 + 2Fc2)/3 |
S = 1.04 | (Δ/σ)max = 0.018 |
2654 reflections | Δρmax = 0.47 e Å−3 |
148 parameters | Δρmin = −0.37 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.012 (2) |
C6H7NS | γ = 87.98 (1)° |
Mr = 125.19 | V = 633.7 (1) Å3 |
Triclinic, P1 | Z = 4 |
a = 7.544 (1) Å | Cu Kα radiation |
b = 9.085 (1) Å | µ = 3.59 mm−1 |
c = 9.302 (1) Å | T = 293 K |
α = 89.84 (1)° | 0.32 × 0.28 × 0.26 mm |
β = 84.03 (1)° |
Enraf-Nonius CAD4 diffractometer | Rint = 0.022 |
2861 measured reflections | 3 standard reflections every 60 min |
2654 independent reflections | intensity decay: <1% |
2012 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.046 | 0 restraints |
wR(F2) = 0.135 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.47 e Å−3 |
2654 reflections | Δρmin = −0.37 e Å−3 |
148 parameters |
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 | ||
N1A | −0.2188 (2) | 0.64031 (19) | 0.38365 (18) | 0.0449 (4) | |
C2A | −0.0653 (3) | 0.6837 (2) | 0.4314 (2) | 0.0474 (5) | |
H2A | −0.0708 | 0.7490 | 0.5087 | 0.057* | |
C3A | 0.0951 (3) | 0.6346 (2) | 0.3697 (2) | 0.0471 (4) | |
H3A | 0.1974 | 0.6665 | 0.4061 | 0.057* | |
C4A | 0.1131 (3) | 0.5359 (2) | 0.2512 (2) | 0.0429 (4) | |
C5A | −0.0512 (3) | 0.4955 (2) | 0.2038 (2) | 0.0522 (5) | |
H5A | −0.0503 | 0.4318 | 0.1256 | 0.063* | |
C6A | −0.2091 (3) | 0.5474 (2) | 0.2697 (3) | 0.0532 (5) | |
H6A | −0.3141 | 0.5183 | 0.2356 | 0.064* | |
S41A | 0.31282 (8) | 0.47185 (6) | 0.17014 (7) | 0.0587 (2) | |
C11A | −0.3913 (3) | 0.6968 (3) | 0.4530 (3) | 0.0637 (6) | |
H11A | −0.4856 | 0.6602 | 0.4028 | 0.095* | |
H11B | −0.3951 | 0.8025 | 0.4498 | 0.095* | |
H11C | −0.4062 | 0.6648 | 0.5519 | 0.095* | |
N1B | −0.7288 (2) | 0.9911 (2) | 1.10807 (17) | 0.0470 (4) | |
C2B | −0.6816 (3) | 0.8587 (2) | 1.0474 (2) | 0.0512 (5) | |
H2B | −0.6389 | 0.7839 | 1.1044 | 0.061* | |
C3B | −0.6946 (3) | 0.8321 (2) | 0.9061 (2) | 0.0512 (5) | |
H3B | −0.6583 | 0.7401 | 0.8680 | 0.061* | |
C4B | −0.7621 (3) | 0.9408 (2) | 0.8143 (2) | 0.0435 (4) | |
C5B | −0.8102 (3) | 1.0766 (2) | 0.8837 (2) | 0.0494 (5) | |
H5B | −0.8557 | 1.1531 | 0.8304 | 0.059* | |
C6B | −0.7923 (3) | 1.0991 (2) | 1.0248 (2) | 0.0505 (5) | |
H6B | −0.8244 | 1.1908 | 1.0657 | 0.061* | |
S41B | −0.78108 (9) | 0.91137 (8) | 0.63710 (6) | 0.0669 (2) | |
C11B | −0.7161 (4) | 1.0181 (4) | 1.2623 (2) | 0.0708 (7) | |
H11D | −0.8287 | 1.0005 | 1.3164 | 0.106* | |
H11E | −0.6852 | 1.1184 | 1.2758 | 0.106* | |
H11F | −0.6259 | 0.9531 | 1.2956 | 0.106* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1A | 0.0404 (9) | 0.0451 (8) | 0.0498 (9) | −0.0043 (7) | −0.0076 (7) | −0.0022 (7) |
C2A | 0.0496 (11) | 0.0475 (10) | 0.0469 (10) | −0.0056 (8) | −0.0125 (8) | −0.0079 (8) |
C3A | 0.0440 (10) | 0.0464 (10) | 0.0534 (10) | −0.0059 (8) | −0.0149 (8) | −0.0066 (8) |
C4A | 0.0429 (10) | 0.0363 (8) | 0.0510 (10) | −0.0043 (7) | −0.0107 (8) | 0.0003 (7) |
C5A | 0.0494 (12) | 0.0508 (10) | 0.0586 (12) | −0.0065 (9) | −0.0138 (9) | −0.0164 (9) |
C6A | 0.0447 (11) | 0.0547 (11) | 0.0631 (12) | −0.0091 (9) | −0.0161 (9) | −0.0116 (9) |
S41A | 0.0464 (3) | 0.0529 (3) | 0.0766 (4) | 0.0024 (2) | −0.0067 (2) | −0.0151 (2) |
C11A | 0.0464 (12) | 0.0706 (15) | 0.0726 (15) | 0.0004 (11) | 0.0000 (10) | −0.0113 (12) |
N1B | 0.0467 (9) | 0.0561 (10) | 0.0389 (8) | −0.0082 (7) | −0.0058 (7) | −0.0029 (7) |
C2B | 0.0515 (12) | 0.0478 (10) | 0.0553 (11) | −0.0024 (9) | −0.0102 (9) | 0.0078 (9) |
C3B | 0.0542 (12) | 0.0382 (9) | 0.0609 (12) | 0.0005 (8) | −0.0059 (9) | −0.0084 (8) |
C4B | 0.0411 (10) | 0.0477 (10) | 0.0419 (9) | −0.0083 (8) | −0.0038 (7) | −0.0060 (7) |
C5B | 0.0590 (12) | 0.0409 (9) | 0.0485 (10) | 0.0002 (9) | −0.0074 (9) | 0.0022 (8) |
C6B | 0.0587 (12) | 0.0420 (9) | 0.0502 (11) | −0.0028 (9) | −0.0027 (9) | −0.0090 (8) |
S41B | 0.0719 (4) | 0.0870 (5) | 0.0437 (3) | −0.0132 (3) | −0.0108 (2) | −0.0170 (3) |
C11B | 0.0709 (16) | 0.102 (2) | 0.0407 (11) | −0.0151 (15) | −0.0086 (10) | −0.0077 (12) |
N1A—C6A | 1.351 (3) | N1B—C2B | 1.351 (3) |
N1A—C2A | 1.354 (3) | N1B—C6B | 1.353 (3) |
N1A—C11A | 1.468 (3) | N1B—C11B | 1.470 (3) |
C2A—C3A | 1.346 (3) | C2B—C3B | 1.351 (3) |
C2A—H2A | 0.9300 | C2B—H2B | 0.9300 |
C3A—C4A | 1.415 (3) | C3B—C4B | 1.419 (3) |
C3A—H3A | 0.9300 | C3B—H3B | 0.9300 |
C4A—C5A | 1.418 (3) | C4B—C5B | 1.412 (3) |
C4A—S41A | 1.697 (2) | C4B—S41B | 1.6922 (19) |
C5A—C6A | 1.352 (3) | C5B—C6B | 1.350 (3) |
C5A—H5A | 0.9300 | C5B—H5B | 0.9300 |
C6A—H6A | 0.9300 | C6B—H6B | 0.9300 |
C11A—H11A | 0.9600 | C11B—H11D | 0.9600 |
C11A—H11B | 0.9600 | C11B—H11E | 0.9600 |
C11A—H11C | 0.9600 | C11B—H11F | 0.9600 |
C6A—N1A—C2A | 118.71 (19) | C2B—N1B—C6B | 118.80 (17) |
C6A—N1A—C11A | 121.21 (19) | C2B—N1B—C11B | 121.2 (2) |
C2A—N1A—C11A | 120.07 (19) | C6B—N1B—C11B | 120.0 (2) |
C3A—C2A—N1A | 121.57 (18) | N1B—C2B—C3B | 121.77 (19) |
C3A—C2A—H2A | 119.2 | N1B—C2B—H2B | 119.1 |
N1A—C2A—H2A | 119.2 | C3B—C2B—H2B | 119.1 |
C2A—C3A—C4A | 122.11 (18) | C2B—C3B—C4B | 121.76 (19) |
C2A—C3A—H3A | 118.9 | C2B—C3B—H3B | 119.1 |
C4A—C3A—H3A | 118.9 | C4B—C3B—H3B | 119.1 |
C3A—C4A—C5A | 114.18 (19) | C5B—C4B—C3B | 113.95 (18) |
C3A—C4A—S41A | 123.53 (16) | C5B—C4B—S41B | 122.90 (16) |
C5A—C4A—S41A | 122.29 (15) | C3B—C4B—S41B | 123.14 (15) |
C6A—C5A—C4A | 121.52 (19) | C6B—C5B—C4B | 122.29 (19) |
C6A—C5A—H5A | 119.2 | C6B—C5B—H5B | 118.9 |
C4A—C5A—H5A | 119.2 | C4B—C5B—H5B | 118.9 |
N1A—C6A—C5A | 121.90 (19) | C5B—C6B—N1B | 121.40 (18) |
N1A—C6A—H6A | 119.1 | C5B—C6B—H6B | 119.3 |
C5A—C6A—H6A | 119.1 | N1B—C6B—H6B | 119.3 |
N1A—C11A—H11A | 109.5 | N1B—C11B—H11D | 109.5 |
N1A—C11A—H11B | 109.5 | N1B—C11B—H11E | 109.5 |
H11A—C11A—H11B | 109.5 | H11D—C11B—H11E | 109.5 |
N1A—C11A—H11C | 109.5 | N1B—C11B—H11F | 109.5 |
H11A—C11A—H11C | 109.5 | H11D—C11B—H11F | 109.5 |
H11B—C11A—H11C | 109.5 | H11E—C11B—H11F | 109.5 |
C6A—N1A—C2A—C3A | −1.1 (3) | C6B—N1B—C2B—C3B | 0.6 (3) |
C11A—N1A—C2A—C3A | −179.6 (2) | C11B—N1B—C2B—C3B | 179.3 (2) |
N1A—C2A—C3A—C4A | 0.4 (3) | N1B—C2B—C3B—C4B | −1.3 (4) |
C2A—C3A—C4A—C5A | 0.5 (3) | C2B—C3B—C4B—C5B | 0.9 (3) |
C2A—C3A—C4A—S41A | 179.83 (16) | C2B—C3B—C4B—S41B | −179.77 (18) |
C3A—C4A—C5A—C6A | −0.7 (3) | C3B—C4B—C5B—C6B | 0.1 (3) |
S41A—C4A—C5A—C6A | 179.92 (18) | S41B—C4B—C5B—C6B | −179.19 (18) |
C2A—N1A—C6A—C5A | 0.9 (3) | C4B—C5B—C6B—N1B | −0.8 (4) |
C11A—N1A—C6A—C5A | 179.4 (2) | C2B—N1B—C6B—C5B | 0.5 (3) |
C4A—C5A—C6A—N1A | 0.1 (4) | C11B—N1B—C6B—C5B | −178.2 (2) |
Experimental details
Crystal data | |
Chemical formula | C6H7NS |
Mr | 125.19 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 7.544 (1), 9.085 (1), 9.302 (1) |
α, β, γ (°) | 89.84 (1), 84.03 (1), 87.98 (1) |
V (Å3) | 633.7 (1) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 3.59 |
Crystal size (mm) | 0.32 × 0.28 × 0.26 |
Data collection | |
Diffractometer | Enraf-Nonius CAD4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2861, 2654, 2012 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.635 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.046, 0.135, 1.04 |
No. of reflections | 2654 |
No. of parameters | 148 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.47, −0.37 |
Computer programs: CAD-4 Software (Enraf-Nonius, 1989), SDP (B. A. Frenz & Associates Inc., 1985), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976).
N1A—C6A | 1.351 (3) | N1B—C2B | 1.351 (3) |
N1A—C2A | 1.354 (3) | N1B—C6B | 1.353 (3) |
N1A—C11A | 1.468 (3) | N1B—C11B | 1.470 (3) |
C2A—C3A | 1.346 (3) | C2B—C3B | 1.351 (3) |
C3A—C4A | 1.415 (3) | C3B—C4B | 1.419 (3) |
C4A—C5A | 1.418 (3) | C4B—C5B | 1.412 (3) |
C4A—S41A | 1.697 (2) | C4B—S41B | 1.6922 (19) |
C5A—C6A | 1.352 (3) | C5B—C6B | 1.350 (3) |
C6A—N1A—C2A | 118.71 (19) | C2B—N1B—C11B | 121.2 (2) |
C6A—N1A—C11A | 121.21 (19) | C6B—N1B—C11B | 120.0 (2) |
C2A—N1A—C11A | 120.07 (19) | N1B—C2B—C3B | 121.77 (19) |
C3A—C2A—N1A | 121.57 (18) | C2B—C3B—C4B | 121.76 (19) |
C2A—C3A—C4A | 122.11 (18) | C5B—C4B—C3B | 113.95 (18) |
C3A—C4A—C5A | 114.18 (19) | C5B—C4B—S41B | 122.90 (16) |
C3A—C4A—S41A | 123.53 (16) | C3B—C4B—S41B | 123.14 (15) |
C5A—C4A—S41A | 122.29 (15) | C6B—C5B—C4B | 122.29 (19) |
C6A—C5A—C4A | 121.52 (19) | C5B—C6B—N1B | 121.40 (18) |
C2B—N1B—C6B | 118.80 (17) |
Subscribe to Acta Crystallographica Section C: Structural Chemistry
The full text of this article is available to subscribers to the journal.
- Information on subscribing
- Sample issue
- Purchase subscription
- Reduced-price subscriptions
- If you have already subscribed, you may need to register
Insight into the nature of the thiocarbonyl group in thiolactams is important, i.e. for the evaluation of biological significance of pyrimidinethiones and pyrimidine-dithiones as rare-bases in RNA or purinethiones (e.g. thioguanine) as anticancer drugs (Reynolds, 1989). The synthetic application of thiolactams also seems to depend on their structural features. Due to electronic interactions expressed by mesomerism of the thiocarbonyl group in thioamides: the length of carbon sulfur bonds in thioamides are a little longer than those in thiones (Rozsondai, 1993) and vary from 1.622 (2) Å in thiocarbonylo-1,1'-bis(2-methylbenzimidazole) (II) (Dolling et al., 1995) to 1.692 (2) or 1.698 (2) Å in 2(1H)-pyridinethione (III) (Ohms et al., 1982), or from 1.677 (3) Å up to 1.691 (4) Å for 3-substituted 1-methyl-2(1H)-pyridinethiones (IVa,b) (Dupont et al., 1983, Dupont et al., 1984). γ-azinethiones can be considered as vinylogous analogs of thiolactams. Several papers deal with the study on dibenzo- and benzo-γ-pyridinethiones, i.e. on derivatives of 9(10H)-acridinethione (VI) (Jaud et al., 1995) or 4(1H)-quinolinethione (V) (Maślankiewicz et al., 1998), respectively. This paper presents the data for the parent γ-pyridinethione as exemplified by the title 1-methyl-4(1H)-pyridinethione (I).
The atom-numbering scheme is shown in the ORTEPII drawing in Fig. 1 (Johnson, 1976) with selected bond lengths and angles are given in Table 1. There are two symmetrically independent molecules in the unit cell which exhibit similar values of bond lengths and angles at the 2σ level. The pyridine rings of (I) are planar for both independent molecules (r.m.s. deviations of the ring atoms are 0.004 (3) and 0.005 (3) Å for molecules A and B, respectively); exo-substituents S41A, C11A and S41B are in plane of the appropriate rings within 3σ except for C11B which deviates out of the plane by 0.030 (4) Å. The two planar molecules are inclined by the angle 67.75 (7)°. There is one intermolecular C—H···π interaction between molecules A and B, C5B—H5B···(N1A/C2A/C3A/C4A/C5A/C6A)i and a H···Cg distance of 2.69 Å where Cg1 is the aromatic ring centroid and symmetry operator (i) = -1 - x,2y,1 - z.
The most interesting molecular feature of (I) is the planarity around the endocyclic-N atom indicating sp2 hybridization of the N1 atom. Thus, the planar tricoordinated N1 atom should bear a positive charge and, furthermore, a pyridinium-type resonance form (Ia) should be the major contributor to the true molecular structure of (I).
It is well known (Witanowski et al., 1973) that a N atom bearing a formal positive charge tends to produce a relatively sharp 14N NMR signal. In fact the 14N NMR spectrum (in CDCl3 solution) of the title compound 1-methyl-4(1H)-pyridinethione (I) reveals an N atom signal at δ = -220 p.p.m. with half-height of linewidths Δν1/2 = 286 Hz (Zi\,eba & Maślankiewicz, 1996). It has led us to the conclusion that for compound (I), a pyridinium-type resonance form (Ia) is the major contributor to the real molecular structure of (I). The occurrence of a positively charged endocyclic N atom should be accompanied by elongation of the C–S bond of the thiocarbonyl group as shown in formula (Ia). However, the value of the the endocyclic C–N–C bond angle of 118.7 (2) and 118.8 (2)° in (I) is below the generally accepted limit (120°) (Pauling, 1960) for the endocyclic C–N–C bond angle in pyridinium salts.