2-(10′,10′-Dimethyl-3′-sulfanyl­idene-4′-aza­tri­cyclo­[5.2.1.01,5]decan-2′­-yl)-10,10-dimethyl-4-aza­tri­cyclo­[5.2.1.01,5]decane-3-thione

Walker, A.; Forsyth, C.M.; Perlmutter, P.

doi:10.1107/S1600536813019211

organic compounds

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Volume 69| Part 8| August 2013| Page o1282

doi:10.1107/S1600536813019211

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2-(10′,10′-Dimethyl-3′-sulfanylidene-4′-azatricyclo[5.2.1.0^1,5]decan-2′-yl)-10,10-dimethyl-4-azatricyclo[5.2.1.0^1,5]decane-3-thione

Ashley Walker,^a Craig M. Forsyth ^a ^* and Patrick Perlmutter ^a

^aSchool of Chemistry, Monash University, Clayton, Victoria 3800, Australia
^*Correspondence e-mail: craig.forsyth@sci.monash.edu.au

(Received 4 June 2013; accepted 11 July 2013; online 20 July 2013)

The title compound, C₂₈H₄₀N₂O₂S₂, was obtained as a minor product from an anti-aldol reaction between the corresponding N-propionylthiolactam and benzaldehyde. The asymmetric unit contains one half-molecule, which is completed by inversion symmetry. The molecule displays a nearly eclipsed conformation along the central C—C bond with a C—C—C—C— torsion angle of 20.4 (3)°.

Related literature

For chiral auxiliaries providing control over the sterochemical outcome of chemical transformations, see: Valezquez & Olivo (2002 ). For a related synthesis, see: Tamaru et al. (1978 ).

Experimental

Crystal data

C₂₈H₄₀N₂O₂S₂
M_r = 500.74
Tetragonal, P 4₁ 2₁ 2
a = 13.8159 (3) Å
c = 13.5221 (6) Å
V = 2581.09 (16) Å³
Z = 4
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 123 K
0.20 × 0.15 × 0.08 mm

Data collection

Bruker X8 APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ) T_min = 0.94, T_max = 0.98
18157 measured reflections
3814 independent reflections
3601 reflections with I > 2σ(I)
R_int = 0.052

Refinement

R[F² > 2σ(F²)] = 0.049
wR(F²) = 0.100
S = 1.19
3814 reflections
154 parameters
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.30 e Å⁻³
Absolute structure: Parsons & Flack (2004 ); Flack x determined using 1367 quotients [(I+)-(I-)]/[(I+)+(I-)]
Absolute structure parameter: 0.04 (4)

Data collection: APEX2 (Bruker, 2006 ); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001 ); software used to prepare material for publication: CIFTAB (Sheldrick, 1997 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536813019211/gw2136sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536813019211/gw2136Isup2.hkl

checkCIF report

Comment top

Chiral auxiliaries provide control over the sterochemical outcome of chemical transformations (Valezquez & Olivo, 2002). During the course of studies on a new type of chiral auxilliary, dimer I was obtained as the unexpected product of a Et₂BOTf-promoted anti-aldol reaction between the corresponding N-propionyl thiolactam and benzaldehyde. We postulate that the dimeristion occurs via initial deprotonation of the thiolactam α-carbon to give a thioenolate, followed by oxidative coupling and eventual [3,3]sigmatropic rearrangement of the resultant disulfide (Tamaru et al., 1978). The molecular structure comprises one half of the dimer in the ASU, the other half generated by the symmetry operator #1 - y,-x,1/2 - z. The thiolactam ring is non-planar with an S configuration at C(2) and a nearly eclipsed conformation along the central C—C bond (C(1)—C(2)—C(2)#1-C(1)#1 20.4 (3)°).

Related literature top

Chiral auxiliaries provide control over the sterochemical outcome of chemical transformations, see: Valezquez & Olivo (2002). For a related synthesis, see: Tamaru et al. (1978).

Experimental top

A freshly prepared solution of diethylboron trifluoromethanesulfonate in hexane (from triflic acid (60µL, 0.67 mmol) and triethylborane (0.67µL of a 1M solution in hexane, 0.67 mmol)) was cooled to -5 °C. A solution of N-propionyl-10',10'-dimethyl-4'-azatricyclo[5.2.1.0^1,5]decan -3'-thione (85 mg, 0.34 mmol) in CH₂Cl₂ (1.5 mL) was added dropwise, whilst maintaining temperature below 0 °C. After 10 min, i-Pr₂NEt (150µL, 0.84 mmol) was added dropwise and the reaction mixture was stirred for 30 min. After cooling to -78 °C, benzaldehyde (110/ml, 1.01 mmol) was added dropwise. The reaction was quenched by dropwise addition of pH 6 phosphate buffer (5 mL) and the resulting mixture was allowed to warm to room tempersture. The organic fraction was extracted into CH₂Cl₂ (3x5mL)and the combined extracts were dried over MgSO₄, filtered and the solvent removed in vacuo. The yellow residue was purified by flash chromatography (3:2 hexane/Et₂O) to afford the title compound as yellow prisms. ¹H NMR (300 MHz, CDCl₃ δ, p.p.m.): 0.91 (s, 6H), 0.93 (s, 6H), 1.11 (t, J 7.2 Hz, 6H), 1.41 (m, 2H), 1.71 (m, 2H), 2.07 (m, 4H), 3.04 (q, J 7.2 Hz, 4H), 3.19 (s, 2H), 4.62 (dd, J 5.4, 7.9 Hz, 2H). ¹³C NMR (75 MHz, CDCl₃ δ, p.p.m.): 8.58, 19.82, 20.63, 26.82, 29.07, 33.75, 38.27, 45.38, 48.62, 55.45, 61.33, 74.22, 175.65, 211.55. IR (ν, cm^-1): 2960(s), 1695(s), 1458(w), 1405(w), 1377(m), 1352(m), 1305(m), 1275(m), 1217(m), 1152(m), 1110(m), 1075(m), 1048(m), 958(w), 808(w), 707(w), 626(w). HRMS: Calcd for (C₂₈H₄₁N₂O₂S₂)⁺ m/z 501.2609; Found 501.2661

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: CIFTAB (Sheldrick, 1997).

Figures top

Fig. 1. Molecular diagram of the title compound. Displacement ellipsoids are drawn at the 50% probability level.

2-(10',10'-Dimethyl-3'-sulfanylidene-4'-azatricyclo[5.2.1.0^1,5]decan-2'-yl)-10,10-dimethyl-4-azatricyclo[5.2.1.0^1,5]decane-3-thione top

Crystal data top

C₂₈H₄₀N₂O₂S₂	D_x = 1.289 Mg m⁻³
M_r = 500.74	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P4₁2₁2	Cell parameters from 4395 reflections
a = 13.8159 (3) Å	θ = 2.6–29.9°
c = 13.5221 (6) Å	µ = 0.24 mm⁻¹
V = 2581.09 (16) Å³	T = 123 K
Z = 4	Prism, colourless
F(000) = 1080	0.20 × 0.15 × 0.08 mm

Data collection top

Bruker X8 APEX CCD diffractometer	3814 independent reflections
Radiation source: fine-focus sealed tube	3601 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.052
thin slice ϕ and ω scans	θ_max = 30.1°, θ_min = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2004)	h = −19→15
T_min = 0.94, T_max = 0.98	k = −18→19
18157 measured reflections	l = −19→18

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.049	w = 1/[σ²(F_o²) + (0.0302P)² + 0.8743P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.100	(Δ/σ)_max < 0.001
S = 1.19	Δρ_max = 0.26 e Å⁻³
3814 reflections	Δρ_min = −0.30 e Å⁻³
154 parameters	Absolute structure: Parsons & Flack (2004); Flack x determined using 1367 quotients [(I+)-(I-)]/[(I+)+(I-)]
0 restraints	Absolute structure parameter: 0.04 (4)

Crystal data top

C₂₈H₄₀N₂O₂S₂	Z = 4
M_r = 500.74	Mo Kα radiation
Tetragonal, P4₁2₁2	µ = 0.24 mm⁻¹
a = 13.8159 (3) Å	T = 123 K
c = 13.5221 (6) Å	0.20 × 0.15 × 0.08 mm
V = 2581.09 (16) Å³

Data collection top

Bruker X8 APEX CCD diffractometer	3814 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2004)	3601 reflections with I > 2σ(I)
T_min = 0.94, T_max = 0.98	R_int = 0.052
18157 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.049	H-atom parameters constrained
wR(F²) = 0.100	Δρ_max = 0.26 e Å⁻³
S = 1.19	Δρ_min = −0.30 e Å⁻³
3814 reflections	Absolute structure: Parsons & Flack (2004); Flack x determined using 1367 quotients [(I+)-(I-)]/[(I+)+(I-)]
154 parameters	Absolute structure parameter: 0.04 (4)
0 restraints

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
S1	−0.06533 (5)	0.15852 (5)	0.37365 (5)	0.01864 (15)
O1	0.06705 (15)	0.29052 (14)	0.09532 (15)	0.0238 (4)
N1	0.05153 (14)	0.17685 (14)	0.21226 (16)	0.0132 (4)
C1	0.00988 (17)	0.12335 (18)	0.28611 (19)	0.0129 (5)
C2	0.04889 (17)	0.02031 (17)	0.27992 (19)	0.0127 (5)
H2	0.0589	−0.0060	0.3481	0.015*
C3	0.14660 (17)	0.03484 (17)	0.22943 (18)	0.0128 (5)
C4	0.12967 (17)	0.12247 (18)	0.16116 (19)	0.0145 (5)
H4	0.1074	0.1005	0.0945	0.017*
C5	0.23097 (18)	0.1709 (2)	0.1537 (2)	0.0199 (6)
H5A	0.2513	0.1787	0.0840	0.024*
H5B	0.2318	0.2348	0.1868	0.024*
C6	0.29552 (18)	0.09742 (19)	0.2084 (2)	0.0188 (5)
H6	0.3607	0.1231	0.2270	0.023*
C7	0.2986 (2)	0.0036 (2)	0.1471 (2)	0.0218 (6)
H7A	0.3502	−0.0403	0.1712	0.026*
H7B	0.3098	0.0177	0.0763	0.026*
C8	0.19577 (19)	−0.04196 (19)	0.1637 (2)	0.0186 (5)
H8A	0.1608	−0.0504	0.1004	0.022*
H8B	0.2001	−0.1052	0.1979	0.022*
C9	0.23189 (17)	0.0686 (2)	0.29719 (19)	0.0163 (5)
C10	0.2748 (2)	−0.0132 (2)	0.3598 (2)	0.0230 (6)
H10A	0.2305	−0.0285	0.4142	0.035*
H10B	0.3374	0.0074	0.3867	0.035*
H10C	0.2839	−0.0707	0.3185	0.035*
C11	0.21142 (19)	0.1521 (2)	0.3678 (2)	0.0224 (6)
H11A	0.1701	0.1294	0.4219	0.034*
H11B	0.1785	0.2043	0.3320	0.034*
H11C	0.2726	0.1764	0.3949	0.034*
C12	0.02120 (18)	0.26367 (18)	0.1666 (2)	0.0159 (5)
C13	−0.06707 (19)	0.31563 (18)	0.2041 (2)	0.0184 (5)
H13A	−0.0560	0.3367	0.2731	0.022*
H13B	−0.1230	0.2708	0.2037	0.022*
C14	−0.0900 (2)	0.4034 (2)	0.1403 (2)	0.0304 (7)
H14A	−0.1476	0.4361	0.1664	0.046*
H14B	−0.1023	0.3825	0.0722	0.046*
H14C	−0.0350	0.4481	0.1413	0.046*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0187 (3)	0.0188 (3)	0.0184 (3)	0.0002 (2)	0.0045 (3)	−0.0031 (3)
O1	0.0213 (10)	0.0246 (10)	0.0256 (10)	0.0043 (8)	0.0038 (9)	0.0106 (8)
N1	0.0103 (9)	0.0134 (9)	0.0158 (10)	0.0010 (7)	0.0003 (8)	0.0006 (8)
C1	0.0112 (11)	0.0143 (11)	0.0132 (11)	−0.0012 (8)	−0.0024 (9)	−0.0006 (9)
C2	0.0121 (11)	0.0119 (11)	0.0140 (11)	−0.0005 (8)	0.0005 (9)	0.0010 (9)
C3	0.0113 (11)	0.0128 (10)	0.0144 (12)	0.0004 (8)	0.0001 (9)	0.0020 (9)
C4	0.0145 (11)	0.0152 (11)	0.0140 (11)	0.0020 (9)	0.0019 (9)	0.0026 (9)
C5	0.0139 (11)	0.0214 (13)	0.0245 (14)	0.0010 (10)	0.0030 (10)	0.0088 (11)
C6	0.0117 (11)	0.0227 (13)	0.0219 (14)	−0.0007 (9)	0.0026 (10)	0.0064 (11)
C7	0.0161 (12)	0.0245 (14)	0.0249 (15)	0.0044 (10)	0.0058 (11)	0.0037 (12)
C8	0.0174 (12)	0.0186 (13)	0.0197 (13)	0.0028 (10)	0.0048 (10)	−0.0011 (10)
C9	0.0117 (10)	0.0183 (12)	0.0188 (12)	−0.0019 (10)	−0.0023 (10)	0.0051 (11)
C10	0.0192 (13)	0.0268 (14)	0.0232 (16)	−0.0003 (10)	−0.0031 (11)	0.0068 (11)
C11	0.0192 (12)	0.0255 (13)	0.0224 (14)	−0.0048 (10)	−0.0042 (11)	−0.0016 (12)
C12	0.0146 (11)	0.0136 (11)	0.0195 (13)	−0.0007 (9)	−0.0021 (10)	0.0029 (10)
C13	0.0158 (12)	0.0167 (12)	0.0227 (13)	0.0031 (10)	−0.0008 (11)	0.0017 (10)
C14	0.0264 (15)	0.0270 (15)	0.0378 (18)	0.0123 (12)	0.0026 (13)	0.0085 (13)

Geometric parameters (Å, º) top

S1—C1	1.648 (3)	C7—C8	1.570 (4)
O1—C12	1.211 (3)	C7—H7A	0.9900
N1—C1	1.369 (3)	C7—H7B	0.9900
N1—C12	1.413 (3)	C8—H8A	0.9900
N1—C4	1.486 (3)	C8—H8B	0.9900
C1—C2	1.524 (3)	C9—C11	1.524 (4)
C2—C3	1.526 (3)	C9—C10	1.531 (4)
C2—C2ⁱ	1.576 (5)	C10—H10A	0.9800
C2—H2	1.0000	C10—H10B	0.9800
C3—C4	1.540 (3)	C10—H10C	0.9800
C3—C8	1.542 (3)	C11—H11A	0.9800
C3—C9	1.564 (3)	C11—H11B	0.9800
C4—C5	1.554 (3)	C11—H11C	0.9800
C4—H4	1.0000	C12—C13	1.503 (4)
C5—C6	1.540 (4)	C13—C14	1.521 (4)
C5—H5A	0.9900	C13—H13A	0.9900
C5—H5B	0.9900	C13—H13B	0.9900
C6—C7	1.539 (4)	C14—H14A	0.9800
C6—C9	1.540 (4)	C14—H14B	0.9800
C6—H6	1.0000	C14—H14C	0.9800

C1—N1—C12	130.7 (2)	H7A—C7—H7B	109.0
C1—N1—C4	111.81 (19)	C3—C8—C7	101.8 (2)
C12—N1—C4	116.2 (2)	C3—C8—H8A	111.4
N1—C1—C2	108.4 (2)	C7—C8—H8A	111.4
N1—C1—S1	129.01 (19)	C3—C8—H8B	111.4
C2—C1—S1	122.52 (19)	C7—C8—H8B	111.4
C1—C2—C3	102.38 (18)	H8A—C8—H8B	109.3
C1—C2—C2ⁱ	112.35 (13)	C11—C9—C10	106.5 (2)
C3—C2—C2ⁱ	112.8 (2)	C11—C9—C6	113.5 (2)
C1—C2—H2	109.7	C10—C9—C6	113.6 (2)
C3—C2—H2	109.7	C11—C9—C3	116.9 (2)
C2ⁱ—C2—H2	109.7	C10—C9—C3	113.3 (2)
C2—C3—C4	103.72 (19)	C6—C9—C3	92.89 (19)
C2—C3—C8	123.9 (2)	C9—C10—H10A	109.5
C4—C3—C8	105.2 (2)	C9—C10—H10B	109.5
C2—C3—C9	116.3 (2)	H10A—C10—H10B	109.5
C4—C3—C9	103.4 (2)	C9—C10—H10C	109.5
C8—C3—C9	102.2 (2)	H10A—C10—H10C	109.5
N1—C4—C3	103.25 (19)	H10B—C10—H10C	109.5
N1—C4—C5	117.8 (2)	C9—C11—H11A	109.5
C3—C4—C5	103.89 (19)	C9—C11—H11B	109.5
N1—C4—H4	110.4	H11A—C11—H11B	109.5
C3—C4—H4	110.4	C9—C11—H11C	109.5
C5—C4—H4	110.4	H11A—C11—H11C	109.5
C6—C5—C4	102.0 (2)	H11B—C11—H11C	109.5
C6—C5—H5A	111.4	O1—C12—N1	116.9 (2)
C4—C5—H5A	111.4	O1—C12—C13	123.1 (2)
C6—C5—H5B	111.4	N1—C12—C13	119.9 (2)
C4—C5—H5B	111.4	C12—C13—C14	111.0 (2)
H5A—C5—H5B	109.2	C12—C13—H13A	109.4
C7—C6—C5	108.2 (2)	C14—C13—H13A	109.4
C7—C6—C9	102.6 (2)	C12—C13—H13B	109.4
C5—C6—C9	102.3 (2)	C14—C13—H13B	109.4
C7—C6—H6	114.1	H13A—C13—H13B	108.0
C5—C6—H6	114.1	C13—C14—H14A	109.5
C9—C6—H6	114.1	C13—C14—H14B	109.5
C6—C7—C8	103.6 (2)	H14A—C14—H14B	109.5
C6—C7—H7A	111.0	C13—C14—H14C	109.5
C8—C7—H7A	111.0	H14A—C14—H14C	109.5
C6—C7—H7B	111.0	H14B—C14—H14C	109.5
C8—C7—H7B	111.0

C12—N1—C1—C2	158.2 (2)	C4—C5—C6—C9	−41.2 (3)
C4—N1—C1—C2	−8.3 (3)	C5—C6—C7—C8	−73.3 (3)
C12—N1—C1—S1	−24.9 (4)	C9—C6—C7—C8	34.4 (3)
C4—N1—C1—S1	168.63 (19)	C2—C3—C8—C7	−171.0 (2)
N1—C1—C2—C3	25.5 (2)	C4—C3—C8—C7	70.4 (2)
S1—C1—C2—C3	−151.66 (18)	C9—C3—C8—C7	−37.3 (2)
N1—C1—C2—C2ⁱ	−95.8 (3)	C6—C7—C8—C3	2.1 (3)
S1—C1—C2—C2ⁱ	87.1 (3)	C7—C6—C9—C11	−176.3 (2)
C1—C2—C2ⁱ—C1ⁱ	−20.4 (3)	C5—C6—C9—C11	−64.1 (3)
C1—C2—C3—C4	−31.9 (2)	C7—C6—C9—C10	61.8 (3)
C2ⁱ—C2—C3—C4	89.1 (2)	C5—C6—C9—C10	174.0 (2)
C1—C2—C3—C8	−151.2 (2)	C7—C6—C9—C3	−55.2 (2)
C2ⁱ—C2—C3—C8	−30.2 (3)	C5—C6—C9—C3	57.0 (2)
C1—C2—C3—C9	80.8 (2)	C2—C3—C9—C11	−46.9 (3)
C2ⁱ—C2—C3—C9	−158.2 (2)	C4—C3—C9—C11	66.0 (3)
C1—N1—C4—C3	−12.4 (3)	C8—C3—C9—C11	175.1 (2)
C12—N1—C4—C3	179.0 (2)	C2—C3—C9—C10	77.6 (3)
C1—N1—C4—C5	−126.1 (2)	C4—C3—C9—C10	−169.5 (2)
C12—N1—C4—C5	65.2 (3)	C8—C3—C9—C10	−60.4 (3)
C2—C3—C4—N1	27.5 (2)	C2—C3—C9—C6	−165.2 (2)
C8—C3—C4—N1	158.87 (19)	C4—C3—C9—C6	−52.2 (2)
C9—C3—C4—N1	−94.3 (2)	C8—C3—C9—C6	56.9 (2)
C2—C3—C4—C5	151.0 (2)	C1—N1—C12—O1	−172.5 (2)
C8—C3—C4—C5	−77.6 (2)	C4—N1—C12—O1	−6.5 (3)
C9—C3—C4—C5	29.2 (2)	C1—N1—C12—C13	4.8 (4)
N1—C4—C5—C6	120.1 (2)	C4—N1—C12—C13	170.8 (2)
C3—C4—C5—C6	6.7 (3)	O1—C12—C13—C14	0.7 (4)
C4—C5—C6—C7	66.7 (3)	N1—C12—C13—C14	−176.4 (2)

Symmetry code: (i) −y, −x, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₂₈H₄₀N₂O₂S₂
M_r	500.74
Crystal system, space group	Tetragonal, P4₁2₁2
Temperature (K)	123
a, c (Å)	13.8159 (3), 13.5221 (6)
V (Å³)	2581.09 (16)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.24
Crystal size (mm)	0.20 × 0.15 × 0.08

Data collection
Diffractometer	Bruker X8 APEX CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2004)
T_min, T_max	0.94, 0.98
No. of measured, independent and observed [I > 2σ(I)] reflections	18157, 3814, 3601
R_int	0.052
(sin θ/λ)_max (Å⁻¹)	0.707

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.049, 0.100, 1.19
No. of reflections	3814
No. of parameters	154
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.26, −0.30
Absolute structure	Parsons & Flack (2004); Flack x determined using 1367 quotients [(I+)-(I-)]/[(I+)+(I-)]
Absolute structure parameter	0.04 (4)

Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL2013 (Sheldrick, 2008), X-SEED (Barbour, 2001), CIFTAB (Sheldrick, 1997).

Acknowledgements

We acknowledge support from Monash University and the Australian Research Council for funding this work.

References

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