4,4′-Di-3-pyridyl-2,2′-dithio­dipyrimidine

Abstract

The asymmetric unit of the title compound, C₁₈H₁₂N₆S₂, contains one half-mol­ecule situated on a twofold rotational axis that passes through the mid-point of the S—S bond. In the mol­ecule, the C—S—S—C torsion angle is 81.33 (7)°. The crystal packing exhibits no significantly short inter­molecular contacts.

Related literature

For general background to heterocyclic disulfides, see Horikoshi & Mochida (2006 ▶). For related crystal structures, see: Higashi et al. (1978 ▶); Tabellion et al. (2001 ▶).

Experimental

Crystal data

• C₁₈H₁₂N₆S₂

• M _r = 376.48

• Monoclinic,

• a = 19.480 (3) Å

• b = 5.4192 (9) Å

• c = 17.979 (3) Å

• β = 115.034 (2)°

• V = 1719.6 (5) ų

• Z = 4

• Mo Kα radiation

• μ = 0.33 mm⁻¹

• T = 298 K

• 0.12 × 0.11 × 0.09 mm

Data collection

• Bruker APEXII CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.884, T _max = 0.920 (expected range = 0.933–0.971)

• 5331 measured reflections

• 2091 independent reflections

• 1590 reflections with I > 2σ(I)

• R _int = 0.054

Refinement

• R[F ² > 2σ(F ²)] = 0.039

• wR(F ²) = 0.106

• S = 1.07

• 2091 reflections

• 118 parameters

• H-atom parameters constrained

• Δρ_max = 0.20 e Å⁻³

• Δρ_min = −0.25 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT-Plus (Bruker, 2007 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

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

supplementary crystallographic information

Comment

Heterocyclic disulfide ligands have attracted considerable attention due to its conformationally defined torison angle and axial chirality (Horikoshi & Mochida, 2006). Herein, we report the molecular structure of the title compound (I) - the newly synthesized disulfide ligand.

In (I) (Fig. 1), the dihedral angle between the pyrimidinyl and pyrdinyl rings is 17.62 (6)°. The C—S—S—C torsion angle of 81.33 (7)° and S—S bond length of 2.0148 (8) Å are comparable to those of typical aromatic disulfides (Higashi et al., 1978; Tabellion et al., 2001).

Experimental

A solution of SO₂Cl₂ (0.5 mL) in CH₂Cl₂ (20 ml) was added dropwise into the suspension containing 4-(pyridin-3-yl)pyrimidine-2-thiol (1.89 g) and 30 ml of CH₂Cl₂.Upon addition, the mixture was stirred at room temperature for 30 min. The solid was collected by filtration and dissolved into 30 ml of H₂O. The solution PH was adjusted into the range of 8–9 to give white precipitates. Single crystals suitable for X-ray diffraction analysis were obtained by slow evaporation of the CH₂Cl₂ solution of the title compound.

Refinement

All H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C).

Figures

Fig. 1.

The molecular structure of the title compound showing the atomic numbering and 40% probability displacement ellipsoids [symmetry code: (A) -x, y, 1/2 - z].

Crystal data

C18H12N6S2	F(000) = 776
Mr = 376.48	Dx = 1.454 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2091 reflections
a = 19.480 (3) Å	θ = 2.3–25.5°
b = 5.4192 (9) Å	µ = 0.33 mm−1
c = 17.979 (3) Å	T = 298 K
β = 115.034 (2)°	Block, yellow
V = 1719.6 (5) Å3	0.12 × 0.11 × 0.09 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer	2091 independent reflections
Radiation source: fine-focus sealed tube	1590 reflections with I > 2σ(I)
graphite	Rint = 0.054
φ and ω scans	θmax = 28.2°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −15→25
Tmin = 0.884, Tmax = 0.920	k = −7→6
5331 measured reflections	l = −23→21

Refinement

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.106	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.051P)2] where P = (Fo2 + 2Fc2)/3
2091 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 0.20 e Å−3
0 restraints	Δρmin = −0.25 e Å−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
S1	0.03745 (2)	0.82831 (7)	0.22489 (2)	0.05022 (17)
N3	0.09221 (7)	0.4611 (2)	0.33598 (7)	0.0431 (3)
C5	0.13449 (9)	0.1539 (3)	0.44158 (9)	0.0494 (4)
C6	0.14360 (8)	0.2851 (3)	0.37363 (9)	0.0449 (4)
N2	0.15519 (8)	0.5576 (3)	0.25070 (8)	0.0560 (4)
C9	0.10152 (8)	0.5858 (3)	0.27763 (8)	0.0436 (3)
C7	0.20210 (9)	0.2385 (3)	0.35106 (10)	0.0549 (4)
H7A	0.2380	0.1168	0.3769	0.066*
C8	0.20481 (10)	0.3797 (3)	0.28883 (11)	0.0599 (5)
H8A	0.2434	0.3493	0.2725	0.072*
C4	0.09033 (11)	0.2523 (4)	0.47734 (10)	0.0617 (5)
H4A	0.0642	0.3995	0.4582	0.074*
C1	0.17081 (12)	−0.0663 (3)	0.47231 (10)	0.0668 (5)
H1A	0.2002	−0.1334	0.4479	0.080*
N1	0.16688 (12)	−0.1900 (3)	0.53450 (11)	0.0827 (6)
C3	0.08571 (12)	0.1278 (5)	0.54219 (11)	0.0771 (6)
H3B	0.0569	0.1906	0.5679	0.092*
C2	0.12428 (14)	−0.0895 (5)	0.56778 (12)	0.0858 (7)
H2B	0.1204	−0.1720	0.6112	0.103*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
S1	0.0489 (3)	0.0576 (3)	0.0448 (2)	−0.00386 (18)	0.02041 (19)	0.00495 (17)
N3	0.0412 (7)	0.0496 (7)	0.0378 (6)	−0.0045 (6)	0.0159 (5)	−0.0041 (5)
C5	0.0477 (9)	0.0511 (9)	0.0405 (8)	−0.0095 (7)	0.0101 (7)	−0.0034 (6)
C6	0.0417 (8)	0.0475 (8)	0.0394 (8)	−0.0074 (7)	0.0113 (7)	−0.0102 (6)
N2	0.0466 (8)	0.0760 (10)	0.0524 (8)	−0.0031 (7)	0.0278 (7)	−0.0019 (7)
C9	0.0389 (7)	0.0533 (8)	0.0375 (7)	−0.0080 (7)	0.0150 (6)	−0.0080 (6)
C7	0.0427 (9)	0.0596 (9)	0.0578 (10)	0.0013 (8)	0.0170 (8)	−0.0079 (8)
C8	0.0454 (9)	0.0795 (12)	0.0626 (10)	−0.0025 (9)	0.0304 (8)	−0.0114 (9)
C4	0.0586 (11)	0.0721 (11)	0.0550 (10)	−0.0076 (9)	0.0246 (9)	0.0058 (8)
C1	0.0716 (12)	0.0599 (11)	0.0551 (10)	−0.0021 (10)	0.0133 (9)	0.0008 (9)
N1	0.0928 (14)	0.0723 (11)	0.0631 (10)	−0.0090 (10)	0.0137 (10)	0.0172 (8)
C3	0.0734 (14)	0.1040 (16)	0.0558 (11)	−0.0123 (12)	0.0292 (10)	0.0095 (10)
C2	0.0838 (16)	0.1026 (17)	0.0541 (11)	−0.0319 (14)	0.0129 (11)	0.0196 (11)

Geometric parameters (Å, °)

S1—C9	1.7840 (16)	C7—H7A	0.9300
S1—S1i	2.0148 (8)	C8—H8A	0.9300
N3—C9	1.3233 (17)	C4—C3	1.383 (2)
N3—C6	1.3402 (19)	C4—H4A	0.9300
C5—C1	1.378 (2)	C1—N1	1.333 (2)
C5—C4	1.380 (2)	C1—H1A	0.9300
C5—C6	1.488 (2)	N1—C2	1.328 (3)
C6—C7	1.385 (2)	C3—C2	1.367 (3)
N2—C9	1.334 (2)	C3—H3B	0.9300
N2—C8	1.332 (2)	C2—H2B	0.9300
C7—C8	1.375 (2)
C9—S1—S1i	103.78 (5)	N2—C8—H8A	118.2
C9—N3—C6	116.12 (13)	C7—C8—H8A	118.2
C1—C5—C4	117.59 (17)	C5—C4—C3	118.7 (2)
C1—C5—C6	121.58 (16)	C5—C4—H4A	120.7
C4—C5—C6	120.81 (15)	C3—C4—H4A	120.7
N3—C6—C7	120.87 (14)	N1—C1—C5	124.72 (19)
N3—C6—C5	115.57 (13)	N1—C1—H1A	117.6
C7—C6—C5	123.53 (15)	C5—C1—H1A	117.6
C9—N2—C8	113.93 (13)	C2—N1—C1	116.12 (18)
N3—C9—N2	128.37 (15)	C2—C3—C4	118.8 (2)
N3—C9—S1	119.86 (11)	C2—C3—H3B	120.6
N2—C9—S1	111.77 (11)	C4—C3—H3B	120.6
C8—C7—C6	117.17 (16)	N1—C2—C3	124.10 (19)
C8—C7—H7A	121.4	N1—C2—H2B	118.0
C6—C7—H7A	121.4	C3—C2—H2B	118.0
N2—C8—C7	123.54 (15)

Symmetry codes: (i) −x, y, −z+1/2.