Dimethyl 2,2′-(4,5-dicyano-o-phenylenedithio)diacetate

The title compound, 4,5-di­(mercapto­acetic acid methyl ester)­phthalo­nitrile, C₁₄H₁₂N₂O₄S₂, exhibits five intermolecular hydrogen bonds, four of them C—H...O bonds and the other a C—H...N bond. The mol­ecule contains three different molecular planes, two of which pass through the ester groups, while the other includes the aromatic ring. The dihedral angles between the ester-group planes and the aromatic ring plane are 74.98  (1) and 58.55 (1)°, while the dihedral angle between the two ester-group planes is 63.55 (1)°.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.046
• wR factor = 0.134
• Data-to-parameter ratio = 14.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_371  Alert C Long   C(sp2)-C(sp1) Bond  C(6)   -   C(13)  =       1.44 Ang.

PLAT_371  Alert C Long   C(sp2)-C(sp1) Bond  C(7)   -   C(14)  =       1.43 Ang.

PLAT_725  Alert C D-H     Calc     0.96992, Rep     0.98000, Dev.      0.01 Ang.
                     C3   -H3B     1.555   1.555

PLAT_747  Alert C D...A   Calc    3.321(4), Rep     3.32000 ....    Missing s.u.
                     C10  -O2      1.555   2.655

PLAT_747  Alert C D...A   Calc    3.137(5), Rep     3.14000 ....    Missing s.u.
                     C8   -O4      1.555   1.545

PLAT_747  Alert C D...A   Calc    3.410(5), Rep     3.41000 ....    Missing s.u.
                     C10  -O4      1.555   1.545

PLAT_747  Alert C D...A   Calc    3.424(4), Rep     3.42000 ....    Missing s.u.
                     C5   -N1      1.555   3.646

PLAT_747  Alert C D...A   Calc    3.342(4), Rep     3.34000 ....    Missing s.u.
                     C3   -O2      1.555   1.565


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 8 Alert Level C = Please check

---

S1. Comment

Phthalonitriles have been used as starting materials for phthalocyanines (Leznoff & Lever, 1996), which are important components for dyes, pigments, gas sensors, optical limiters and liquid crystals, and are also used in medicine, as singlet oxygen photosensitizors for photodynamic therapy (PDT) (McKeown, 1998). Some phthalocyanines have also been used as catalysts for the oxidation of sulfur compounds in the gasoline fraction by the petroleum industry. Applications as photoconductors in the xerographic double layers of laser printers and copy machines, and as active materials in writable disks, are also known (Wöhrle, 2001).

The title molecule, (I), is shown in Fig. 1, with selected bond angles and hydrogen-bond parameters in Tables 1 and 2, respectively. The structure shows that the N1≡C13 and N2≡C14 distances of 1.143 (4) and 1.128 (4) Å, respectively, correspond to literature values (Öztürk et al., 2000). All bond lengths in the ester groups of (I) are similar to those in recently reported structures containing ester groups (Armelin, Urpi et al., 2001; Armelin, Escudero et al., 2001; Bujak, 2002). The C3—S1—C4 and C9—S2—C10 angles of 103.62 (16) and 103.82 (15)°, respectively, show good agreement, whereas the C2—C3—S1—C4 and C9—S2—C10—C11 torsion angles of -90.1 (3) and -92.1 (3)°, respectively, show a small difference. The ester groups and the aromatic ring are planar to within experimental error, with a maximum deviation of 0.0152 (0) Å from the best planes defined by the ester groups, O1/O2/C1/C2/C3 and O3/O4/C10/C11/C12, and a maximum deviation of 0.0202 (1) Å from the best plane defined by the aromatic ring.

In the molecule of (I), the S1···S2 distance is 3.003 Å. Repulsion between C5—H5 and C3—H3A leads to an enlargement of the S1—C4—C5 angle. While the S1—C4—C5 angle is 123°, the S1—C4—C9 angle is 117°. Similarly, the S2—C9—C8 angle is 129°, whereas the S2—C9—C4 angle is 117°.

In the case of (I), the ester groups and the phenyl ring are able to form hydrogen bonds with the ester moieties and phenyl ring of a symmetry-related molecule. All details of the C—H···O and C—H···N types of intermolecular interaction found in the crystal, by which the crystal structure is stabilized, can be seen in Table 2. These contacts generate infinite chains along the [010] axis (Fig. 2) and seem to force the molecule to adopt a twisted conformation, with the dihedral angle between ester groups being far from 0°. This arrangement also explains the absence of intramolecular hydrogen bonds in (I). Considering atoms O2 and O4 as potential acceptors, the observed contacts are C1—H1C···O2 and C12—H12A···O4, with angles of 84.4 and 97.1°, respectively, i.e. with electrostatic interaction energies approaching zero.

Table 2. Short C—H···O and C—H···N contacts (Å, °) for compound (I)

S2. Experimental

Mercaptoacetic acid methyl ester and 1,2-dichloro-4,5-dicyanobenzene were dissolved in anhydrous dimethyl formamide under an N₂ atmosphere, and then dry fine-powdered potassium carbonate was added in several portions over a period of 2 h with efficient stirring. The product was then recrystallized from ethanol and dried. Single crystals of (I) were obtained via slow evaporation from absolute ethanol.

S3. Refinement

H atoms were located geometrically and then refined isotropically with fixed displacement parameters.

Computing details

Data collection: CAD-4-PC Software (Enraf-Nonius, 1992); cell refinement: CAD-4-PC Software; data reduction: XCAD4/PC (Harms, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. A view of (I) with the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The hydrogen-bond network observed in (I), viewed approximately along the [010] axis of the monoclinic cell.

Dimethyl 2,2'-(4,5-dicyano-o-phenylenedithio)diacetate

Crystal data

C14H12N2O4S2	F(000) = 696
Mr = 336.38	Dx = 1.463 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 12.1201 (1) Å	Cell parameters from 25 reflections
b = 5.148 (1) Å	θ = 8.2–12.2°
c = 24.944 (1) Å	µ = 0.37 mm^−1
β = 101.20 (1)°	T = 293 K
V = 1526.8 (3) Å^3	Plate, dark yellow
Z = 4	0.45 × 0.25 × 0.10 mm

Data collection

Enraf-Nonius CAD-4 MACH-3 diffractometer	Rint = 0.072
Radiation source: fine-focus sealed tube	θmax = 26.0°, θmin = 2.1°
Graphite monochromator	h = 0→14
ω/2θ scans	k = 0→6
3152 measured reflections	l = −30→30
3004 independent reflections	3 standard reflections every 60 min
1853 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.134	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0586P)^2 + 0.7252P] where P = (Fo^2 + 2Fc^2)/3
3004 reflections	(Δ/σ)max = 0.001
201 parameters	Δρmax = 0.36 e Å^−3
0 restraints	Δρmin = −0.30 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
C1	0.1049 (4)	−0.1140 (11)	0.4411 (2)	0.0919 (16)
H1A	0.0501	−0.1232	0.4077	0.110*
H1B	0.0692	−0.0566	0.4701	0.110*
H1C	0.1372	−0.2828	0.4497	0.110*
C2	0.2552 (3)	0.0045 (7)	0.39930 (14)	0.0440 (8)
C3	0.3418 (3)	0.2096 (6)	0.39885 (16)	0.0504 (9)
H3A	0.3973	0.1953	0.4325	0.060*
H3B	0.3056	0.3774	0.3993	0.060*
C4	0.5310 (2)	0.0070 (6)	0.36643 (13)	0.0361 (7)
C5	0.5339 (2)	−0.1749 (6)	0.40739 (13)	0.0380 (7)
H5	0.4717	−0.1966	0.4236	0.046*
C6	0.6286 (3)	−0.3242 (6)	0.42423 (12)	0.0364 (7)
C7	0.7222 (2)	−0.2908 (6)	0.40080 (12)	0.0384 (7)
C8	0.7194 (3)	−0.1107 (6)	0.35969 (14)	0.0419 (8)
H8	0.7828	−0.0872	0.3444	0.050*
C9	0.6240 (3)	0.0357 (6)	0.34082 (12)	0.0368 (7)
C10	0.7279 (3)	0.1851 (7)	0.25537 (14)	0.0474 (8)
H10A	0.7461	0.0022	0.2605	0.057*
H10B	0.7064	0.2161	0.2164	0.057*
C11	0.8300 (3)	0.3412 (7)	0.27745 (15)	0.0491 (9)
C12	1.0224 (3)	0.3307 (11)	0.3159 (2)	0.0859 (15)
H12A	1.0248	0.4877	0.2954	0.103*
H12B	1.0846	0.2214	0.3119	0.103*
H12C	1.0272	0.3726	0.3537	0.103*
O1	0.1923 (2)	0.0672 (5)	0.43463 (12)	0.0661 (8)
O2	0.2439 (2)	−0.1880 (5)	0.37181 (11)	0.0549 (6)
O3	0.9185 (2)	0.1965 (5)	0.29564 (12)	0.0670 (8)
O4	0.8327 (2)	0.5714 (5)	0.27765 (16)	0.0862 (10)
C13	0.6277 (3)	−0.5205 (7)	0.46509 (13)	0.0399 (7)
N1	0.6244 (2)	−0.6779 (6)	0.49699 (12)	0.0536 (8)
C14	0.8201 (3)	−0.4488 (8)	0.41763 (15)	0.0526 (9)
N2	0.8961 (3)	−0.5773 (8)	0.43011 (16)	0.0826 (12)
S1	0.41428 (7)	0.20581 (17)	0.34313 (4)	0.0490 (3)
S2	0.61099 (7)	0.25862 (17)	0.28700 (4)	0.0483 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.074 (3)	0.101 (4)	0.116 (4)	0.010 (3)	0.054 (3)	0.036 (3)
C2	0.0426 (18)	0.043 (2)	0.047 (2)	0.0110 (16)	0.0105 (16)	0.0088 (17)
C3	0.0469 (18)	0.0352 (18)	0.070 (2)	0.0097 (16)	0.0133 (17)	−0.0046 (18)
C4	0.0366 (16)	0.0282 (16)	0.0427 (18)	−0.0003 (13)	0.0057 (13)	−0.0032 (14)
C5	0.0380 (16)	0.0346 (17)	0.0430 (18)	−0.0024 (14)	0.0117 (14)	0.0015 (14)
C6	0.0407 (16)	0.0337 (16)	0.0345 (16)	−0.0015 (14)	0.0067 (13)	−0.0004 (13)
C7	0.0409 (17)	0.0365 (17)	0.0393 (17)	0.0006 (14)	0.0112 (14)	0.0018 (15)
C8	0.0382 (17)	0.0406 (18)	0.049 (2)	−0.0004 (15)	0.0131 (15)	0.0032 (15)
C9	0.0441 (17)	0.0298 (16)	0.0363 (17)	−0.0069 (14)	0.0072 (14)	−0.0009 (13)
C10	0.067 (2)	0.0364 (18)	0.0420 (19)	−0.0035 (17)	0.0182 (16)	0.0056 (15)
C11	0.063 (2)	0.039 (2)	0.053 (2)	0.0058 (17)	0.0290 (18)	0.0065 (16)
C12	0.055 (2)	0.110 (4)	0.091 (3)	−0.002 (3)	0.011 (2)	0.014 (3)
O1	0.0640 (16)	0.0649 (18)	0.0780 (19)	0.0147 (14)	0.0351 (15)	0.0019 (15)
O2	0.0624 (15)	0.0408 (14)	0.0643 (16)	−0.0082 (12)	0.0189 (13)	−0.0052 (13)
O3	0.0640 (17)	0.0589 (17)	0.0774 (19)	0.0070 (14)	0.0120 (14)	0.0129 (15)
O4	0.0720 (19)	0.0381 (16)	0.153 (3)	−0.0023 (14)	0.034 (2)	0.0005 (18)
C13	0.0372 (17)	0.0417 (19)	0.0414 (18)	0.0015 (15)	0.0093 (14)	−0.0004 (16)
N1	0.0616 (19)	0.0501 (18)	0.0516 (18)	0.0039 (15)	0.0172 (15)	0.0125 (16)
C14	0.0441 (19)	0.059 (2)	0.058 (2)	0.0098 (18)	0.0184 (17)	0.0199 (19)
N2	0.062 (2)	0.097 (3)	0.095 (3)	0.031 (2)	0.031 (2)	0.043 (2)
S1	0.0425 (5)	0.0412 (5)	0.0631 (6)	0.0051 (4)	0.0101 (4)	0.0147 (4)
S2	0.0507 (5)	0.0403 (5)	0.0541 (5)	−0.0001 (4)	0.0110 (4)	0.0160 (4)

Geometric parameters (Å, º)

C1—O1	1.444 (5)	C7—C8	1.379 (4)
C1—H1A	0.9600	C7—C14	1.432 (5)
C1—H1B	0.9600	C8—C9	1.384 (4)
C1—H1C	0.9600	C8—H8	0.9300
C2—O2	1.197 (4)	C9—S2	1.751 (3)
C2—O1	1.312 (4)	C10—C11	1.488 (5)
C2—C3	1.492 (5)	C10—S2	1.791 (3)
C3—S1	1.782 (4)	C10—H10A	0.9700
C3—H3A	0.9700	C10—H10B	0.9700
C3—H3B	0.9700	C11—O4	1.185 (4)
C4—C5	1.382 (4)	C11—O3	1.313 (4)
C4—C9	1.407 (4)	C12—O3	1.440 (5)
C4—S1	1.751 (3)	C12—H12A	0.9600
C5—C6	1.378 (4)	C12—H12B	0.9600
C5—H5	0.9300	C12—H12C	0.9600
C6—C7	1.384 (4)	C13—N1	1.143 (4)
C6—C13	1.437 (4)	C14—N2	1.128 (4)
O1—C1—H1A	109.5	C7—C8—C9	121.2 (3)
O1—C1—H1B	109.5	C7—C8—H8	119.4
H1A—C1—H1B	109.5	C9—C8—H8	119.4
O1—C1—H1C	109.5	C8—C9—C4	118.6 (3)
H1A—C1—H1C	109.5	C8—C9—S2	124.2 (2)
H1B—C1—H1C	109.5	C4—C9—S2	117.2 (2)
O2—C2—O1	124.8 (3)	C11—C10—S2	113.3 (2)
O2—C2—C3	125.7 (3)	C11—C10—H10A	108.9
O1—C2—C3	109.5 (3)	S2—C10—H10A	108.9
C2—C3—S1	117.0 (3)	C11—C10—H10B	108.9
C2—C3—H3A	108.1	S2—C10—H10B	108.9
S1—C3—H3A	108.1	H10A—C10—H10B	107.7
C2—C3—H3B	108.1	O4—C11—O3	123.1 (4)
S1—C3—H3B	108.1	O4—C11—C10	124.2 (4)
H3A—C3—H3B	107.3	O3—C11—C10	112.7 (3)
C5—C4—C9	120.0 (3)	O3—C12—H12A	109.5
C5—C4—S1	123.0 (2)	O3—C12—H12B	109.5
C9—C4—S1	117.0 (2)	H12A—C12—H12B	109.5
C6—C5—C4	120.3 (3)	O3—C12—H12C	109.5
C6—C5—H5	119.9	H12A—C12—H12C	109.5
C4—C5—H5	119.9	H12B—C12—H12C	109.5
C5—C6—C7	120.3 (3)	C2—O1—C1	116.8 (3)
C5—C6—C13	119.2 (3)	C11—O3—C12	116.7 (3)
C7—C6—C13	120.5 (3)	N1—C13—C6	178.4 (4)
C8—C7—C6	119.6 (3)	N2—C14—C7	178.5 (5)
C8—C7—C14	120.0 (3)	C4—S1—C3	103.62 (16)
C6—C7—C14	120.3 (3)	C9—S2—C10	103.82 (15)
O2—C2—C3—S1	14.5 (5)	S1—C4—C9—C8	177.4 (2)
O1—C2—C3—S1	−165.4 (2)	C5—C4—C9—S2	176.9 (2)
C9—C4—C5—C6	1.6 (5)	S1—C4—C9—S2	−2.1 (3)
S1—C4—C5—C6	−179.5 (2)	S2—C10—C11—O4	−57.3 (5)
C4—C5—C6—C7	0.9 (5)	S2—C10—C11—O3	124.4 (3)
C4—C5—C6—C13	−177.1 (3)	O2—C2—O1—C1	1.3 (5)
C5—C6—C7—C8	−1.3 (5)	C3—C2—O1—C1	−178.8 (3)
C13—C6—C7—C8	176.7 (3)	O4—C11—O3—C12	−0.7 (6)
C5—C6—C7—C14	−179.0 (3)	C10—C11—O3—C12	177.6 (3)
C13—C6—C7—C14	−1.0 (5)	C5—C4—S1—C3	22.6 (3)
C6—C7—C8—C9	−0.8 (5)	C9—C4—S1—C3	−158.4 (2)
C14—C7—C8—C9	176.9 (3)	C2—C3—S1—C4	−90.1 (3)
C7—C8—C9—C4	3.3 (5)	C8—C9—S2—C10	13.8 (3)
C7—C8—C9—S2	−177.3 (2)	C4—C9—S2—C10	−166.7 (2)
C5—C4—C9—C8	−3.6 (4)	C11—C10—S2—C9	−92.1 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10B···O2^i	0.97	2.44	3.32	151
C8—H8···O4^ii	0.93	2.57	3.14	120
C10—H10A···O4^ii	0.97	2.45	3.41	168
C5—H5···N1^iii	0.93	2.57	3.42	153
C3—H3B···O2^iv	0.98	2.42	3.34	160

Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) x, y−1, z; (iii) −x+1, −y−1, −z+1; (iv) x, y+1, z.