Exploring the rare S—H...S hydrogen bond using charge density analysis in isomers of mercapto­benzoic acid

Experimental and theoretical charge density analyses on isomers of mercapto­benzoic acid have been carried out to quantify the hydrogen bonding of the hitherto less explored thiols, to assess the strength of the interactions using the topological features of the electron density. The electron density study offers interesting insights into the nature of the S—H...S interaction. The interaction energy is comparable with that of a weak hydrogen bond. The strength and directionality of the S—H...S hydrogen bond is demonstrated to be mainly due to the conformation locking potential of the intramolecular S...O chalcogen bond in 2-mercapto­benzoic acid and is stronger than in 3-mercapto­benzoic acid, which lacks the intramolecular S...O bond. The para-substituted mercapto­benzoic acid depicts a type I S...S interaction.

Computing details

For all structures, program(s) used to refine structure: SHELXL2016/6 (Sheldrick, 2016).

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Crystal data

C7H6O2S	F(000) = 320
Mr = 154.18	Dx = 1.531 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.84809 (13) Å	Cell parameters from 20270 reflections
b = 5.89857 (12) Å	θ = 2.6–57.0°
c = 14.6898 (3) Å	µ = 0.41 mm^−1
β = 100.3380 (18)°	T = 100 K
V = 668.99 (2) Å^3	Block, yellow
Z = 4	0.46 × 0.38 × 0.11 mm

Data collection

Xcalibur, Eos, Nova diffractometer	θmax = 56.6°, θmin = 2.6°
54095 measured reflections	h = −18→18
9033 independent reflections	k = −13→13
7317 reflections with I > 2σ(I)	l = −34→34
Rint = 0.045

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.033	All H-atom parameters refined
wR(F^2) = 0.093	w = 1/[σ^2(Fo^2) + (0.0494P)^2 + 0.0251P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.002
9033 reflections	Δρmax = 0.73 e Å^−3
115 parameters	Δρmin = −0.68 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	0.48393 (2)	1.12960 (2)	0.33658 (2)	0.01305 (2)
O2	0.48711 (4)	0.71685 (6)	0.42493 (2)	0.01583 (5)
C1	0.76421 (4)	0.84695 (6)	0.40247 (2)	0.01118 (4)
C2	0.70425 (4)	1.04679 (6)	0.35456 (2)	0.01123 (4)
O1	0.72484 (4)	0.53918 (6)	0.49854 (3)	0.01698 (5)
C7	0.64585 (4)	0.69646 (6)	0.44254 (2)	0.01197 (4)
C6	0.94077 (4)	0.79059 (7)	0.41448 (3)	0.01359 (5)
C3	0.82439 (5)	1.18540 (7)	0.32078 (3)	0.01492 (5)
C5	1.05806 (5)	0.92890 (8)	0.38067 (3)	0.01500 (5)
C4	0.99894 (5)	1.12765 (8)	0.33409 (3)	0.01606 (6)
H6	0.9702 (16)	0.657 (2)	0.4446 (8)	0.027 (3)*
H5	1.1677 (17)	0.884 (2)	0.3912 (8)	0.027 (3)*
H4	1.0787 (16)	1.226 (2)	0.3113 (7)	0.026 (3)*
H3	0.7798 (16)	1.327 (2)	0.2904 (8)	0.025 (3)*
H1	0.5046 (16)	1.310 (2)	0.2937 (8)	0.029 (3)*
H1A	0.648 (2)	0.446 (3)	0.5219 (10)	0.051 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.01004 (3)	0.01220 (4)	0.01701 (4)	0.00117 (2)	0.00266 (2)	0.00181 (2)
O2	0.00921 (7)	0.01676 (11)	0.02167 (11)	0.00014 (7)	0.00317 (7)	0.00699 (9)
C1	0.00941 (8)	0.01132 (10)	0.01313 (9)	−0.00002 (7)	0.00286 (7)	0.00155 (8)
C2	0.00994 (9)	0.01109 (10)	0.01290 (9)	−0.00016 (7)	0.00266 (7)	0.00111 (8)
O1	0.01081 (8)	0.01628 (11)	0.02417 (12)	0.00135 (7)	0.00397 (8)	0.00954 (9)
C7	0.00971 (9)	0.01157 (10)	0.01499 (10)	0.00019 (7)	0.00320 (7)	0.00246 (8)
C6	0.01000 (9)	0.01480 (12)	0.01641 (11)	0.00103 (8)	0.00357 (8)	0.00324 (9)
C3	0.01216 (10)	0.01427 (12)	0.01896 (12)	−0.00052 (8)	0.00448 (9)	0.00457 (10)
C5	0.00977 (9)	0.01823 (14)	0.01763 (12)	0.00016 (9)	0.00418 (8)	0.00323 (10)
C4	0.01177 (10)	0.01764 (14)	0.01956 (13)	−0.00140 (9)	0.00493 (9)	0.00460 (11)

Geometric parameters (Å, º)

S1—C2	1.7704 (3)	C2—C3	1.4041 (5)
O2—C7	1.2320 (4)	O1—C7	1.3186 (4)
C1—C6	1.4050 (5)	C6—C5	1.3869 (5)
C1—C2	1.4098 (5)	C3—C4	1.3909 (5)
C1—C7	1.4810 (5)	C5—C4	1.3943 (6)
C6—C1—C2	119.59 (3)	O2—C7—C1	122.73 (3)
C6—C1—C7	118.89 (3)	O1—C7—C1	114.30 (3)
C2—C1—C7	121.51 (3)	C5—C6—C1	121.25 (3)
C3—C2—C1	118.57 (3)	C4—C3—C2	120.97 (4)
C3—C2—S1	119.11 (3)	C6—C5—C4	119.12 (3)
C1—C2—S1	122.33 (2)	C3—C4—C5	120.50 (3)
O2—C7—O1	122.97 (3)

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Crystal data

C7H6O2S	V = 694.1 (2) Å^3
Mr = 154.18	Z = 4
Monoclinic, P21/n	F(000) = 320
a = 4.7811 (10) Å	Dx = 1.475 Mg m^−3
b = 5.7441 (9) Å	Mo Kα radiation, λ = 0.71073 Å
c = 25.353 (5) Å	µ = 0.39 mm^−1
β = 94.49 (2)°	T = 100 K

Data collection

Xcalibur, Eos, Nova diffractometer	θmax = 26.4°, θmin = 3.2°
4579 measured reflections	h = −5→4
1413 independent reflections	k = −7→7
895 reflections with I > 2σ(I)	l = −31→29
Rint = 0.102

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.072	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.178	w = 1/[σ^2(Fo^2) + (0.0621P)^2 + 0.5271P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max < 0.001
1413 reflections	Δρmax = 0.60 e Å^−3
99 parameters	Δρmin = −0.48 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	0.0344 (3)	0.3984 (2)	0.27843 (5)	0.0293 (4)
O1	0.8206 (6)	0.3890 (5)	0.44185 (12)	0.0217 (8)
O2	0.7548 (6)	0.7071 (5)	0.49050 (12)	0.0221 (8)
C2	0.3796 (9)	0.5056 (7)	0.36880 (16)	0.0163 (10)
H2	0.473471	0.366253	0.364120	0.020*
C7	0.6921 (9)	0.5803 (7)	0.45070 (17)	0.0181 (10)
C1	0.4593 (9)	0.6505 (7)	0.41180 (16)	0.0143 (9)
C4	0.0209 (9)	0.7817 (7)	0.34002 (17)	0.0197 (10)
H4	−0.126616	0.826337	0.316074	0.024*
C6	0.3209 (9)	0.8586 (7)	0.41854 (17)	0.0184 (10)
H6	0.374641	0.953725	0.447257	0.022*
C5	0.1042 (9)	0.9253 (7)	0.38291 (17)	0.0205 (10)
H5	0.012895	1.066038	0.387354	0.025*
C3	0.1584 (9)	0.5728 (7)	0.33320 (16)	0.0173 (10)
H1	0.224 (10)	0.250 (8)	0.2837 (17)	0.040 (14)*
H1A	0.972 (16)	0.364 (12)	0.468 (3)	0.11 (3)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0409 (9)	0.0190 (6)	0.0258 (7)	0.0003 (6)	−0.0119 (6)	−0.0040 (5)
O1	0.0187 (18)	0.0195 (15)	0.0261 (18)	0.0086 (14)	−0.0043 (15)	−0.0017 (14)
O2	0.0198 (18)	0.0228 (16)	0.0228 (17)	0.0022 (14)	−0.0029 (14)	−0.0054 (14)
C2	0.016 (2)	0.0081 (18)	0.025 (2)	0.0012 (18)	0.003 (2)	−0.0011 (17)
C7	0.014 (2)	0.015 (2)	0.025 (3)	0.0048 (19)	0.002 (2)	−0.0005 (19)
C1	0.011 (2)	0.0125 (19)	0.019 (2)	−0.0010 (17)	0.0012 (18)	0.0025 (17)
C4	0.017 (3)	0.017 (2)	0.024 (2)	0.0029 (19)	−0.006 (2)	0.0013 (19)
C6	0.017 (2)	0.018 (2)	0.021 (2)	−0.0019 (19)	0.0035 (19)	−0.0020 (19)
C5	0.019 (2)	0.014 (2)	0.028 (3)	0.0025 (19)	0.001 (2)	0.0009 (19)
C3	0.019 (2)	0.016 (2)	0.017 (2)	−0.0030 (19)	0.0007 (19)	0.0002 (18)

Geometric parameters (Å, º)

S1—C3	1.776 (4)	C7—C1	1.484 (6)
O1—C7	1.287 (5)	C1—C6	1.384 (5)
O2—C7	1.261 (5)	C4—C3	1.385 (6)
C2—C3	1.390 (6)	C4—C5	1.398 (6)
C2—C1	1.400 (6)	C6—C5	1.374 (6)
C3—C2—C1	119.2 (4)	C3—C4—C5	119.9 (4)
O2—C7—O1	123.0 (4)	C5—C6—C1	120.2 (4)
O2—C7—C1	119.6 (4)	C6—C5—C4	120.1 (4)
O1—C7—C1	117.4 (4)	C4—C3—C2	120.2 (4)
C6—C1—C2	120.4 (4)	C4—C3—S1	116.9 (3)
C6—C1—C7	119.6 (4)	C2—C3—S1	122.8 (3)
C2—C1—C7	120.0 (4)

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Crystal data

C7H6O2S	γ = 92.925 (8)°
Mr = 154.18	V = 336.28 (5) Å^3
Triclinic, P1	Z = 2
a = 3.8630 (3) Å	F(000) = 160
b = 6.0337 (6) Å	Dx = 1.523 Mg m^−3
c = 14.4721 (10) Å	Mo Kα radiation, λ = 0.71073 Å
α = 91.302 (7)°	µ = 0.41 mm^−1
β = 93.062 (7)°	T = 120 K

Data collection

Xcalibur, Eos, Nova diffractometer	θmax = 26.4°, θmin = 2.8°
4199 measured reflections	h = −4→4
1375 independent reflections	k = −7→7
1117 reflections with I > 2σ(I)	l = −18→18
Rint = 0.037

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.041	All H-atom parameters refined
wR(F^2) = 0.104	w = 1/[σ^2(Fo^2) + (0.0506P)^2 + 0.0164P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max < 0.001
1375 reflections	Δρmax = 0.31 e Å^−3
115 parameters	Δρmin = −0.22 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	0.91179 (15)	0.22586 (11)	0.07360 (4)	0.0292 (2)
O1	0.4419 (4)	0.9839 (3)	0.38571 (10)	0.0250 (4)
O2	0.7245 (4)	0.7546 (3)	0.47942 (10)	0.0285 (4)
C1	0.6939 (5)	0.6708 (4)	0.31941 (14)	0.0190 (5)
C4	0.8339 (5)	0.3972 (4)	0.17025 (14)	0.0203 (5)
C7	0.6089 (5)	0.8168 (4)	0.39730 (14)	0.0202 (5)
C5	0.9219 (6)	0.3353 (4)	0.26057 (15)	0.0213 (5)
C6	0.8527 (5)	0.4720 (4)	0.33414 (15)	0.0213 (5)
C3	0.6762 (5)	0.5969 (4)	0.15475 (14)	0.0228 (5)
C2	0.6071 (5)	0.7317 (4)	0.22878 (14)	0.0207 (5)
H1O	0.500 (6)	0.871 (4)	0.2185 (16)	0.029 (6)*
H6	0.906 (5)	0.434 (4)	0.3929 (16)	0.023 (6)*
H3	0.619 (6)	0.638 (4)	0.0918 (16)	0.027 (6)*
H5	1.029 (6)	0.201 (4)	0.2713 (16)	0.029 (7)*
H2	0.643 (8)	0.849 (6)	0.520 (2)	0.075 (11)*
H1S	1.116 (11)	0.104 (8)	0.110 (3)	0.149 (17)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0328 (4)	0.0314 (4)	0.0235 (3)	0.0059 (3)	0.0028 (2)	−0.0077 (2)
O1	0.0326 (9)	0.0239 (10)	0.0192 (8)	0.0088 (7)	0.0006 (6)	0.0004 (6)
O2	0.0393 (10)	0.0307 (10)	0.0163 (8)	0.0138 (8)	−0.0014 (7)	−0.0003 (7)
C1	0.0169 (11)	0.0210 (12)	0.0189 (10)	−0.0006 (9)	0.0010 (8)	−0.0009 (8)
C4	0.0148 (11)	0.0241 (13)	0.0216 (11)	−0.0017 (9)	0.0030 (8)	−0.0034 (9)
C7	0.0188 (11)	0.0213 (13)	0.0200 (10)	−0.0034 (10)	0.0010 (8)	0.0020 (9)
C5	0.0217 (11)	0.0188 (13)	0.0232 (11)	0.0010 (10)	0.0005 (9)	−0.0009 (9)
C6	0.0208 (11)	0.0243 (13)	0.0187 (11)	0.0007 (10)	−0.0016 (9)	0.0039 (9)
C3	0.0240 (12)	0.0274 (13)	0.0169 (11)	0.0015 (10)	−0.0009 (9)	0.0007 (9)
C2	0.0199 (11)	0.0210 (13)	0.0212 (11)	0.0022 (10)	−0.0006 (9)	0.0025 (9)

Geometric parameters (Å, º)

S1—C4	1.768 (2)	C4—C3	1.395 (3)
S1—H1S	1.21 (5)	C4—C5	1.397 (3)
O1—C7	1.234 (3)	C5—C6	1.378 (3)
O2—C7	1.317 (3)	C5—H5	0.94 (2)
O2—H2	0.88 (3)	C6—H6	0.90 (2)
C1—C6	1.390 (3)	C3—C2	1.376 (3)
C1—C2	1.398 (3)	C3—H3	0.97 (2)
C1—C7	1.476 (3)	C2—H1O	0.97 (2)
C4—S1—H1S	100 (2)	C6—C5—H5	119.9 (15)
C7—O2—H2	106 (2)	C4—C5—H5	120.3 (15)
C6—C1—C2	119.2 (2)	C5—C6—C1	120.6 (2)
C6—C1—C7	121.50 (19)	C5—C6—H6	121.0 (15)
C2—C1—C7	119.3 (2)	C1—C6—H6	118.4 (15)
C3—C4—C5	120.0 (2)	C2—C3—C4	119.7 (2)
C3—C4—S1	118.45 (16)	C2—C3—H3	121.2 (14)
C5—C4—S1	121.55 (18)	C4—C3—H3	119.1 (14)
O1—C7—O2	123.0 (2)	C3—C2—C1	120.7 (2)
O1—C7—C1	122.18 (19)	C3—C2—H1O	120.1 (14)
O2—C7—C1	114.8 (2)	C1—C2—H1O	119.2 (14)
C6—C5—C4	119.8 (2)