2-(Pyridin-2-yl)-1,3-oxathiane

David Turner; Albert Fratini; Claudia Turro; Michael Check; Chad Hunter

doi:10.1107/S1600536812018661

. 2012 May 12;68(Pt 6):o1675. doi: 10.1107/S1600536812018661

2-(Pyridin-2-yl)-1,3-oxathiane

David Turner ^a,^b,^*, Albert Fratini ^c, Claudia Turro ^d, Michael Check ^a,^b, Chad Hunter ^a

PMCID: PMC3379271 PMID: 22719469

Abstract

The title compound, C₉H₁₁NOS, exhibits a unique structural motif, with free rotation of the aliphatic oxathiane ring about the C—C bond connecting this moiety to the aromatic pyridine ring. The structure elucidation was undertaken due to its potential as a bidentate ligand for organometallic complexes. The oxathiane ring adopts the expected chair conformation, with the S atom in proximity to the N atom on the pyridine ring. The corresponding S—C—C—N torsion angle is 69.07 (14)°. In the crystal, molecules aggregate as centrosymmetric pairs connected by pairs of C—H⋯N hydrogen bonds.

Related literature

The corresponding organic compound, 2-(2-pyridyl)-1,3-oxathiane, forms dimers via weak intermolecular C—H⋯N hydrogen bonds, exhibiting similar photophysical properties as previously observed (Rachford et al., 2005 ▶; Rachford & Rack, 2006 ▶). graphic file with name e-68-o1675-scheme1.jpg

Experimental

Crystal data

C₉H₁₁NOS
M _r = 181.26
Monoclinic,
a = 7.5329 (3) Å
b = 11.8099 (5) Å
c = 9.7632 (4) Å
β = 92.940 (3)°
V = 867.42 (6) Å³
Z = 4
Cu Kα radiation
μ = 2.89 mm⁻¹
T = 110 K
0.48 × 0.46 × 0.36 mm

Data collection

Oxford Diffraction Xcalibur Sapphire3 diffractometer
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2010 ▶), based on expressions derived by Clark & Reid (1995 ▶)] T _min = 0.344, T _max = 0.519
3675 measured reflections
1708 independent reflections
1656 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.085
S = 1.07
1708 reflections
154 parameters
All H-atom parameters refined
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.30 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) ▶; molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812018661/nr2024sup1.cif

e-68-o1675-sup1.cif^{(21.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812018661/nr2024Isup2.hkl

e-68-o1675-Isup2.hkl^{(84.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812018661/nr2024Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯N1ⁱ	0.979 (19)	2.586 (19)	3.5399 (19)	164.8 (14)

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Symmetry code: (i) Inline graphic .

Acknowledgments

Funding from the US Air Force Office of Scientific Research, Thermal Sciences (Program Manager: Dr Joan Fuller) is gratefully acknowledged. In addition, the authors would like to acknowledge Dr Andrey Voevodin at the Air Force Research Laboratory, Thermal Sciences and Materials Branch, for helpful advice and guidance.

supplementary crystallographic information

Comment

Photo-induced or photo-triggered molecular isomerizations employ the stored energy in an electronic excited state for rapid bond-breaking and bond-making reactions. One of the most well studied examples of this type of reaction is photo-isomerization of stilbene and its derivatives, where phenyl group rotation occurs following π→π^* excitation on an ultrafast time scale. Photo-induced or photo-triggered linkage isomerizations have also been observed in certain late transition metal complexes containing NO⁺, NO^2-, N₂, SO₂, and DMSO (dimethylsulfoxide). Rack et al. has worked on ruthenium complexes with DMSO ligands and has observed photo- isomerization between the S-bound to the O-bound state upon uv/visible irradiation. However, this conversion can only be demonstrated in a solvent of DMSO (Rachford et al., 2005; Rachford & Rack, 2006). The development of photo-switchable molecules is of interest due to potential use in applications such as optical molecular information storage, optical limiting devices, and molecular sensing. For photonic devices, the design of such molecules requires the efficient conversion of light energy to potential energy. Thus, bistable molecules are also of a fundamental interest in that the design of such molecules requires specific electronic structures in order to exhibit two stable interconvertible states. Rack et al. has worked on ruthenium complexes with DMSO ligands and has observed photo-isomerization between the S-bound to the O-bound state upon uv/visible irradiation. However, this conversion can only be demonstrated in a solvent of DMSO (Rachford et al., 2005; Rachford & Rack, 2006). The synthesis and bonding of 2-(2-pyridyl)-1,3-oxathiane to a ruthenium metal center would still allow for the photo-isomerization between a S-bound to an O-bound state upon uv/visible irradiation due to the ability of the bidentate ligand to rotate about the C—C bond between the aliphatic, oxathiane moiety and the aromatic, pyridyl moiety. The major benefit of using this bidentate ligand would be that the photo-isomerization could be performed in a wide variety of solvents.

Experimental

The title compound was synthesized as follows: A solution of 3.34 g (31.2 mmol) of 2-pyridinecarbaldehyde, 10.0 g (109 mmol) of 3-mercapto-1-propanol, and 0.475 g (2.50 mmol) of p-toluenesulfonic acid monohydrate in 400 ml of 1,2-dichloroethane were refluxed for 24 h with a Dean-Stark trap to collect the azeotroped water. After cooling, the azeotroped water was disposed of. The reacted mixture was washed with 70 ml of 7 M KOH and water. The aqueous and organic layers were separated in a separatory funnel. The organic layer was then dried over anhydrous sodium sulfate and filtered to remove the Na₂SO₄. The resulting solution was evaporated under reduced pressure to yield a brown oil. The brown oil was then passed through a silica column with diethyl ether. The 2-(2-pyridyl)-1,3-oxathiane was collected from the column and dried in air with a yield of 4.29 g (76%): ¹H-NMR (400 MHz Bruker, CDCl₃) δ(p.p.m.) 1.58 (d, 1 H), 1.92 (dd, 1 H), 2.68 (d, 1 H), 3.05 (dd, 1 H), 3.64 (dd, 1 H), 4.17 (d, 1 H), 5.80 (s, 1 H), 7.04 (t, 1 H), 7.41 (d, 1 H), 7.54 (t, 1 H), 8.41 (d, 1 H). ¹³C-NMR (400 MHz Bruker, CDCl₃) δ(p.p.m.) 24.8 (CH₂), 27.9 (CH₂), 69.6 (CH₂), 84.3 (CH), 120.1 (CH), 122.4 (CH), 136.0 (CH), 148.0 (CH), 157.2 (C). The experimental protocol for recrystallizing the title compound was as follows: 100 mg of 2-(2-pyridyl)-1,3-oxathiane was dissolved in 0.5 ml of methylene chloride, followed by the addition of 2.0 ml of hexane to the solution. The solution was filtered and then placed in a vial, covered with parafilm, and allowed to evaporate at room temperature over the course of days, after which time large crystals were obtained.