Structural characterization of protonated benzeneseleninic acid, the dihydroxyselenonium ion

The structure of the dihydroxyphenylselenonium ion (CHOSe) has been determined in its benzenesulfonate (CHOSe) and p-toluenesulfonate (CHOS) salts. Whereas the former salt is disordered, the latter less dense salt is well defined. This difference in crystallization behaviour is attributed to a C—H...O hydrogen bond involving the methyl group of the p-toluenesulfonate ion. The two salts display very similar hydrogen-bond arrangements and differ only with respect to the stacking of the phenyl groups. The dihydroxyselenonium ion is a strong acid with a pK value of −0.9 determined from the variation of the ⁷⁷Se chemical shift. A comparison with the two deprotonated species reveals a systematic increase in the Se—O bond lengths and the pyramidal configuration around Se with the number of protons attached.

Computing details

For both compounds, data collection: Enraf-Nonius XPRESS; cell refinement: Enraf-Nonius XPRESS; data reduction: DREADD (Blessing, 1987); program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976).

(TOL) dihydroxy phenylselenonium 4-methylphenyl sulfonate

Crystal data

C6H7O2Se^+·C7H7O3S^−	F(000) = 728
Mr = 361.26	Dx = 1.705 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54184 Å
a = 5.8838 (11) Å	Cell parameters from 23 reflections
b = 16.0925 (19) Å	θ = 39.5–42.3°
c = 14.929 (2) Å	µ = 5.17 mm^−1
β = 95.547 (15)°	T = 122 K
V = 1407.0 (4) Å^3	Needle, colourless
Z = 4	0.36 × 0.08 × 0.07 mm

Data collection

Enraf Nonius CAD-4 diffractometer	2820 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.033
Graphite monochromator	θmax = 74.9°, θmin = 4.1°
ω – 2θ scans	h = −7→4
Absorption correction: numerical (DeTitta, 1985)	k = 0→20
Tmin = 0.370, Tmax = 0.726	l = −18→18
5288 measured reflections	5 standard reflections every 166.7 min
2906 independent reflections	intensity decay: 9.9%

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)] = 0.027	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.075	All H-atom parameters refined
S = 2.39	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo^2)]
2906 reflections	(Δ/σ)max = 0.029
237 parameters	Δρmax = 0.44 e Å^−3
0 restraints	Δρmin = −0.86 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
Se	1.49991 (3)	0.440382 (11)	0.618334 (12)	0.01292 (9)
O11	1.3405 (3)	0.47988 (9)	0.70046 (9)	0.0189 (3)
H110	1.248 (6)	0.514 (2)	0.677 (2)	0.043 (9)*
O12	1.7698 (3)	0.45573 (10)	0.67323 (11)	0.0202 (3)
H120	1.806 (6)	0.492 (2)	0.656 (2)	0.048 (11)*
C11	1.4822 (3)	0.32727 (12)	0.65740 (13)	0.0153 (4)
C16	1.2894 (4)	0.30150 (13)	0.69657 (13)	0.0190 (4)
H16	1.188 (4)	0.3371 (16)	0.7080 (17)	0.023 (7)*
C15	1.2736 (4)	0.21839 (14)	0.72069 (14)	0.0247 (5)
H15	1.136 (5)	0.2013 (19)	0.7503 (19)	0.038 (8)*
C14	1.4465 (4)	0.16344 (13)	0.70460 (16)	0.0279 (5)
H14	1.429 (5)	0.110 (2)	0.721 (2)	0.041 (8)*
C13	1.6379 (4)	0.19051 (13)	0.66597 (16)	0.0267 (5)
H13	1.765 (6)	0.154 (2)	0.647 (2)	0.052 (9)*
C12	1.6578 (4)	0.27328 (13)	0.64188 (14)	0.0190 (4)
H12	1.782 (4)	0.2875 (16)	0.6191 (16)	0.020 (6)*
S	1.93426 (8)	0.37598 (3)	1.44917 (3)	0.01381 (11)
O21	1.6969 (2)	0.38869 (9)	1.46536 (9)	0.0185 (3)
O22	1.9798 (2)	0.41539 (9)	1.36250 (10)	0.0178 (3)
O23	2.0987 (3)	0.40097 (9)	1.52264 (10)	0.0233 (3)
C21	1.9715 (3)	0.26826 (11)	1.43297 (12)	0.0150 (4)
C26	1.7915 (4)	0.22094 (13)	1.39255 (14)	0.0204 (4)
H26	1.657 (5)	0.2461 (18)	1.3746 (17)	0.029 (7)*
C25	1.8240 (4)	0.13718 (13)	1.37779 (15)	0.0244 (4)
H25	1.692 (4)	0.1025 (16)	1.3469 (17)	0.024 (6)*
C24	2.0331 (4)	0.09914 (12)	1.40294 (14)	0.0220 (4)
C23	2.2106 (4)	0.14733 (14)	1.44372 (15)	0.0252 (5)
H23	2.354 (5)	0.1252 (16)	1.4607 (17)	0.023 (6)*
C22	2.1811 (4)	0.23179 (13)	1.45846 (14)	0.0213 (4)
H22	2.291 (5)	0.2601 (19)	1.4779 (19)	0.035 (8)*
C27	2.0666 (6)	0.00804 (15)	1.38557 (18)	0.0327 (6)
H27A	1.937 (8)	−0.024 (3)	1.400 (3)	0.086 (14)*
H27B	2.119 (7)	0.002 (3)	1.335 (3)	0.074 (13)*
H27C	2.206 (8)	−0.011 (3)	1.421 (3)	0.080 (13)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Se	0.01197 (13)	0.01193 (13)	0.01490 (13)	0.00112 (6)	0.00158 (8)	0.00137 (6)
O11	0.0202 (7)	0.0184 (7)	0.0186 (7)	0.0052 (6)	0.0042 (6)	−0.0003 (5)
O12	0.0142 (7)	0.0207 (7)	0.0253 (8)	−0.0046 (6)	−0.0012 (6)	0.0064 (6)
C11	0.0163 (9)	0.0132 (8)	0.0161 (8)	−0.0002 (7)	−0.0009 (7)	0.0023 (7)
C16	0.0168 (10)	0.0195 (9)	0.0205 (9)	−0.0010 (8)	0.0015 (7)	0.0020 (8)
C15	0.0234 (11)	0.0255 (11)	0.0242 (10)	−0.0100 (9)	−0.0024 (8)	0.0069 (8)
C14	0.0348 (13)	0.0139 (10)	0.0328 (12)	−0.0043 (9)	−0.0081 (10)	0.0078 (8)
C13	0.0265 (12)	0.0173 (10)	0.0347 (12)	0.0069 (9)	−0.0048 (9)	0.0013 (9)
C12	0.0151 (10)	0.0178 (9)	0.0235 (10)	0.0020 (8)	0.0000 (8)	0.0014 (7)
S	0.0121 (2)	0.0117 (2)	0.0176 (2)	0.00103 (15)	0.00140 (17)	−0.00106 (15)
O21	0.0135 (7)	0.0181 (7)	0.0246 (7)	0.0023 (5)	0.0052 (5)	0.0004 (5)
O22	0.0175 (7)	0.0137 (7)	0.0230 (7)	0.0000 (5)	0.0062 (5)	0.0020 (6)
O23	0.0211 (8)	0.0197 (7)	0.0273 (8)	0.0023 (6)	−0.0064 (6)	−0.0080 (6)
C21	0.0169 (9)	0.0122 (8)	0.0161 (8)	0.0012 (7)	0.0029 (7)	0.0005 (6)
C26	0.0183 (10)	0.0190 (10)	0.0233 (10)	0.0009 (8)	−0.0010 (8)	−0.0005 (8)
C25	0.0316 (12)	0.0172 (10)	0.0244 (10)	−0.0045 (9)	0.0022 (9)	−0.0018 (8)
C24	0.0365 (13)	0.0133 (9)	0.0172 (9)	0.0035 (8)	0.0080 (8)	0.0010 (7)
C23	0.0264 (12)	0.0217 (10)	0.0278 (11)	0.0110 (9)	0.0037 (9)	0.0003 (8)
C22	0.0173 (10)	0.0198 (10)	0.0262 (10)	0.0024 (8)	−0.0008 (8)	−0.0027 (8)
C27	0.0557 (17)	0.0162 (11)	0.0277 (12)	0.0054 (11)	0.0115 (11)	−0.0009 (9)

Geometric parameters (Å, º)

Se—O12	1.7331 (16)	S—O21	1.4546 (14)
Se—O11	1.7350 (14)	S—O22	1.4885 (14)
Se—C11	1.9173 (19)	S—C21	1.7668 (19)
C11—C12	1.387 (3)	C21—C22	1.385 (3)
C11—C16	1.389 (3)	C21—C26	1.394 (3)
C16—C15	1.390 (3)	C26—C25	1.382 (3)
C15—C14	1.386 (3)	C25—C24	1.393 (3)
C14—C13	1.385 (3)	C24—C23	1.393 (3)
C13—C12	1.387 (3)	C24—C27	1.505 (3)
S—O23	1.4477 (15)	C23—C22	1.390 (3)
O12—Se—O11	98.46 (8)	O23—S—C21	107.08 (9)
O12—Se—C11	93.76 (8)	O21—S—C21	107.12 (9)
O11—Se—C11	94.81 (8)	O22—S—C21	105.31 (8)
C12—C11—C16	122.37 (18)	C22—C21—C26	120.43 (19)
C12—C11—Se	118.74 (15)	C22—C21—S	119.79 (15)
C16—C11—Se	118.82 (15)	C26—C21—S	119.76 (15)
C11—C16—C15	118.3 (2)	C25—C26—C21	119.4 (2)
C14—C15—C16	120.0 (2)	C26—C25—C24	121.2 (2)
C13—C14—C15	120.8 (2)	C23—C24—C25	118.59 (19)
C14—C13—C12	120.2 (2)	C23—C24—C27	120.8 (2)
C11—C12—C13	118.4 (2)	C25—C24—C27	120.6 (2)
O23—S—O21	114.65 (9)	C22—C23—C24	120.9 (2)
O23—S—O22	112.15 (9)	C21—C22—C23	119.5 (2)
O21—S—O22	109.94 (8)
O12—Se—C11—C12	−52.97 (17)	O22—S—C21—C22	93.96 (17)
O11—Se—C11—C12	−151.80 (16)	O23—S—C21—C26	156.05 (16)
O12—Se—C11—C16	129.87 (16)	O21—S—C21—C26	32.60 (18)
O11—Se—C11—C16	31.04 (16)	O22—S—C21—C26	−84.41 (18)
C12—C11—C16—C15	−0.1 (3)	C22—C21—C26—C25	−0.2 (3)
Se—C11—C16—C15	176.96 (15)	S—C21—C26—C25	178.17 (16)
C11—C16—C15—C14	−0.7 (3)	C21—C26—C25—C24	0.3 (3)
C16—C15—C14—C13	1.1 (3)	C26—C25—C24—C23	0.1 (3)
C15—C14—C13—C12	−0.7 (4)	C26—C25—C24—C27	−179.4 (2)
C16—C11—C12—C13	0.5 (3)	C25—C24—C23—C22	−0.5 (3)
Se—C11—C12—C13	−176.58 (16)	C27—C24—C23—C22	178.9 (2)
C14—C13—C12—C11	−0.1 (3)	C26—C21—C22—C23	−0.2 (3)
O23—S—C21—C22	−25.57 (19)	S—C21—C22—C23	−178.60 (17)
O21—S—C21—C22	−149.03 (16)	C24—C23—C22—C21	0.6 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O11—H110···O22^i	0.83 (3)	1.81 (3)	2.633 (2)	172 (3)
O12—H120···O22^ii	0.68 (3)	1.99 (3)	2.628 (2)	157 (4)
C27—H27B···O11^iii	0.84 (4)	2.52 (4)	3.337 (3)	164 (4)

Symmetry codes: (i) −x+3, −y+1, −z+2; (ii) −x+4, −y+1, −z+2; (iii) x+1, −y+1/2, z+1/2.

(BEN) dihydroxy phenylselenonium benzene sulfonate

Crystal data

C6H7O2Se^+·C6H5O3S^−	Dx = 1.761 Mg m^−3
Mr = 347.24	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, Fdd2	Cell parameters from 20 reflections
a = 40.641 (5) Å	θ = 39.1–40.6°
b = 22.268 (3) Å	µ = 5.52 mm^−1
c = 5.7881 (13) Å	T = 122 K
V = 5238.4 (15) Å^3	Needle, colourless
Z = 16	0.36 × 0.08 × 0.07 mm
F(000) = 2784

Data collection

Enraf Nonius CAD-4 diffractometer	2552 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.038
Graphite monochromator	θmax = 74.9°, θmin = 4.4°
ω – 2θ scans	h = −50→50
Absorption correction: numerical (DeTitta, 1985)	k = −27→0
Tmin = 0.361, Tmax = 0.737	l = −7→6
5592 measured reflections	4 standard reflections every 166.7 min
2669 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.074	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.143	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo^2)]
S = 5.84	(Δ/σ)max = 0.036
2669 reflections	Δρmax = 1.19 e Å^−3
166 parameters	Δρmin = −1.13 e Å^−3
7 restraints	Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.01 (5)

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	Occ. (<1)
Se	0.00474 (2)	0.09172 (4)	0.0064 (3)	0.0466 (3)
O11	0.02224 (13)	0.1138 (2)	−0.2518 (14)	0.0434 (14)
O12	0.03535 (13)	0.1150 (3)	0.1938 (11)	0.056 (2)
C11	−0.02233 (17)	0.1620 (3)	0.0373 (17)	0.0313 (19)
C12	−0.02132 (17)	0.1957 (3)	0.2348 (18)	0.0316 (17)
H12	−0.0061	0.1859	0.3535	0.038*
C13	−0.0423 (2)	0.2437 (3)	0.262 (2)	0.0371 (19)
H13	−0.0418	0.2670	0.3996	0.045*
C14	−0.0640 (2)	0.2574 (3)	0.0854 (17)	0.039 (2)
H14	−0.0784	0.2907	0.1010	0.047*
C15	−0.0647 (2)	0.2225 (3)	−0.1168 (16)	0.0326 (19)
H15	−0.0798	0.2319	−0.2367	0.039*
C16	−0.04363 (19)	0.1752 (3)	−0.1404 (15)	0.0317 (19)
H16	−0.0437	0.1516	−0.2773	0.038*
S	−0.05331 (5)	0.02257 (9)	0.4980 (5)	0.0558 (8)
O21A	−0.0309 (3)	0.0534 (5)	0.3456 (19)	0.0458 (14)*	0.518 (8)
O22A	−0.0589 (3)	−0.0401 (3)	0.470 (3)	0.0458 (14)*	0.518 (8)
O23A	−0.0392 (3)	0.0195 (6)	0.7308 (14)	0.0458 (14)*	0.518 (8)
O21B	−0.0283 (3)	0.0660 (5)	0.436 (2)	0.0458 (14)*	0.482 (8)
O22B	−0.0659 (3)	−0.0202 (5)	0.327 (2)	0.0458 (14)*	0.482 (8)
O23B	−0.0467 (3)	−0.0107 (6)	0.7049 (16)	0.0458 (14)*	0.482 (8)
C21	−0.08864 (16)	0.0674 (3)	0.5451 (16)	0.0276 (19)
C22	−0.10690 (16)	0.0622 (3)	0.7457 (17)	0.0292 (17)
H22	−0.1010	0.0337	0.8604	0.035*
C23	−0.13386 (17)	0.0989 (3)	0.7774 (17)	0.0340 (19)
H23	−0.1468	0.0952	0.9135	0.041*
C24	−0.14224 (19)	0.1412 (4)	0.6122 (17)	0.035 (2)
H24	−0.1605	0.1671	0.6369	0.042*
C25	−0.12387 (19)	0.1457 (4)	0.4095 (17)	0.037 (2)
H25	−0.1299	0.1745	0.2960	0.045*
C26	−0.09723 (19)	0.1091 (4)	0.3716 (16)	0.0321 (19)
H26	−0.0849	0.1119	0.2326	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Se	0.0278 (4)	0.0292 (4)	0.0829 (7)	0.0071 (4)	0.0167 (6)	0.0188 (6)
O11	0.040 (3)	0.043 (3)	0.048 (4)	0.006 (3)	0.012 (4)	−0.003 (4)
O12	0.021 (3)	0.112 (6)	0.035 (4)	0.008 (3)	0.003 (3)	0.025 (4)
C11	0.027 (3)	0.014 (3)	0.054 (6)	−0.001 (3)	−0.005 (4)	0.015 (4)
C12	0.028 (3)	0.030 (4)	0.037 (5)	−0.006 (3)	−0.002 (4)	0.000 (4)
C13	0.048 (5)	0.031 (4)	0.032 (4)	−0.006 (3)	0.012 (5)	0.008 (4)
C14	0.044 (5)	0.025 (4)	0.049 (6)	0.004 (4)	0.007 (4)	0.001 (4)
C15	0.032 (4)	0.029 (4)	0.037 (5)	0.002 (3)	−0.007 (4)	0.004 (4)
C16	0.036 (4)	0.022 (4)	0.037 (5)	−0.003 (3)	−0.004 (4)	0.000 (4)
S	0.0322 (10)	0.0295 (10)	0.106 (2)	0.0074 (8)	0.0327 (15)	0.0197 (16)
C21	0.016 (3)	0.023 (3)	0.044 (6)	−0.003 (3)	0.000 (4)	−0.001 (4)
C22	0.024 (3)	0.027 (3)	0.037 (5)	−0.005 (3)	−0.007 (4)	0.007 (4)
C23	0.025 (4)	0.036 (4)	0.041 (5)	−0.002 (3)	0.014 (4)	−0.006 (5)
C24	0.029 (4)	0.026 (4)	0.049 (6)	0.006 (3)	−0.001 (4)	0.000 (4)
C25	0.021 (4)	0.046 (5)	0.045 (6)	0.003 (3)	−0.004 (4)	0.013 (4)
C26	0.027 (4)	0.032 (4)	0.037 (5)	−0.004 (3)	0.002 (4)	−0.003 (4)

Geometric parameters (Å, º)

Se—O11	1.727 (7)	S—O21A	1.443 (6)
Se—O12	1.730 (6)	S—O21B	1.447 (6)
Se—C11	1.922 (7)	S—O22B	1.465 (6)
C11—C12	1.368 (13)	S—O23A	1.466 (6)
C11—C16	1.376 (11)	S—C21	1.769 (7)
C12—C13	1.376 (11)	C21—C22	1.383 (11)
C13—C14	1.384 (14)	C21—C26	1.412 (12)
C14—C15	1.405 (11)	C22—C23	1.380 (9)
C15—C16	1.366 (10)	C23—C24	1.384 (12)
S—O22A	1.424 (6)	C24—C25	1.394 (13)
S—O23B	1.434 (6)	C25—C26	1.372 (11)
O11—Se—O12	99.3 (3)	O21B—S—O22B	120.7 (8)
O11—Se—C11	94.8 (3)	O22A—S—O23A	96.9 (8)
O12—Se—C11	96.2 (3)	O23B—S—O23A	30.1 (6)
C12—C11—C16	121.8 (7)	O21A—S—O23A	109.7 (7)
C12—C11—Se	120.5 (6)	O21B—S—O23A	89.1 (8)
C16—C11—Se	117.6 (6)	O22B—S—O23A	136.6 (8)
C11—C12—C13	120.2 (9)	O22A—S—C21	116.2 (5)
C12—C13—C14	118.7 (10)	O23B—S—C21	108.4 (7)
C13—C14—C15	120.5 (8)	O21A—S—C21	109.8 (6)
C16—C15—C14	119.8 (8)	O21B—S—C21	103.4 (6)
C15—C16—C11	119.0 (8)	O22B—S—C21	100.8 (6)
O22A—S—O23B	67.5 (8)	O23A—S—C21	101.7 (6)
O22A—S—O21A	119.8 (7)	C22—C21—C26	121.3 (7)
O23B—S—O21A	129.6 (8)	C22—C21—S	121.2 (6)
O22A—S—O21B	137.5 (8)	C26—C21—S	117.5 (6)
O23B—S—O21B	114.9 (8)	C23—C22—C21	119.2 (8)
O21A—S—O21B	24.1 (7)	C22—C23—C24	120.4 (8)
O22A—S—O22B	39.7 (7)	C23—C24—C25	119.9 (7)
O23B—S—O22B	107.0 (7)	C26—C25—C24	120.9 (8)
O21A—S—O22B	96.7 (7)	C25—C26—C21	118.2 (8)
O11—Se—C11—C12	−126.6 (6)	O22B—S—C21—C22	105.8 (8)
O12—Se—C11—C12	−26.7 (6)	O23B—S—C21—C22	−6.4 (9)
O11—Se—C11—C16	56.5 (6)	O21A—S—C21—C26	26.2 (9)
O12—Se—C11—C16	156.4 (6)	O22A—S—C21—C26	−113.8 (9)
C16—C11—C12—C13	1.0 (12)	O23A—S—C21—C26	142.3 (8)
Se—C11—C12—C13	−175.8 (6)	O21B—S—C21—C26	50.4 (9)
C11—C12—C13—C14	−0.7 (12)	O22B—S—C21—C26	−75.0 (8)
C12—C13—C14—C15	0.6 (13)	O23B—S—C21—C26	172.7 (8)
C13—C14—C15—C16	−0.7 (13)	C26—C21—C22—C23	−0.5 (11)
C14—C15—C16—C11	1.0 (13)	S—C21—C22—C23	178.6 (6)
C12—C11—C16—C15	−1.1 (12)	C21—C22—C23—C24	−1.1 (12)
Se—C11—C16—C15	175.7 (6)	C22—C23—C24—C25	1.7 (12)
O21A—S—C21—C22	−153.0 (8)	C23—C24—C25—C26	−0.7 (13)
O22A—S—C21—C22	67.0 (10)	C24—C25—C26—C21	−0.9 (12)
O23A—S—C21—C22	−36.8 (8)	C22—C21—C26—C25	1.5 (11)
O21B—S—C21—C22	−128.7 (8)	S—C21—C26—C25	−177.7 (6)