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The title structure (commonly known as 2,2′,5,5′-tetra­selenafulvalene or tetra­selenafulvalene), C6H4Se4, contains two independent mol­ecules, one of which is planar and centrosymmetric. The other mol­ecule has a pronounced boat conformation and no imposed crystallographic symmetry. Corresponding bond lengths in the two mol­ecules are similar. A few short inter­molecular Se...Se contacts are present.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807018582/ez2074sup1.cif
Contains datablocks global, TSF

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807018582/ez2074TSFsup2.hkl
Contains datablock TSF

CCDC reference: 647193

Key indicators

  • Single-crystal X-ray study
  • T = 120 K
  • Mean [sigma](C-C) = 0.004 Å
  • R factor = 0.020
  • wR factor = 0.051
  • Data-to-parameter ratio = 23.1

checkCIF/PLATON results

No syntax errors found




Alert level B ABSTM02_ALERT_3_B The ratio of expected to reported Tmax/Tmin(RR) is > 1.50 Tmin and Tmax reported: 0.170 0.262 Tmin and Tmax expected: 0.086 0.262 RR = 1.972 Please check that your absorption correction is appropriate. PLAT060_ALERT_3_B Ratio Tmax/Tmin (Exp-to-Rep) (too) Large ....... 1.98
Alert level C PLAT153_ALERT_1_C The su's on the Cell Axes are Equal (x 100000) . 30 Ang. PLAT154_ALERT_1_C The su's on the Cell Angles are Equal (x 10000) 100 Deg. PLAT180_ALERT_3_C Check Cell Rounding: # of Values Ending with 0 = 3
0 ALERT level A = In general: serious problem 2 ALERT level B = Potentially serious problem 3 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 3 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Computing details top

Data collection: SMART (Bruker, 2002); cell refinement: SAINT-Plus (Bruker, 2003); data reduction: SAINT-Plus; program(s) used to solve structure: DIRDIF99 (Beurskens et al., 1999); program(s) used to refine structure: SHELXTL (Sheldrick, 2001); molecular graphics: SHELXTL and PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL and PLATON.

2,2'-bi-1,3-diselenole top
Crystal data top
C6H4Se4Z = 3
Mr = 391.93F(000) = 528
Triclinic, P1Dx = 2.985 Mg m3
Hall symbol: -P 1Melting point: 406 K
a = 8.6303 (3) ÅMo Kα radiation, λ = 0.71073 Å
b = 8.6454 (3) ÅCell parameters from 5298 reflections
c = 10.4231 (3) Åθ = 2.7–28.0°
α = 105.245 (1)°µ = 16.75 mm1
β = 106.382 (1)°T = 120 K
γ = 108.221 (1)°Block, red
V = 653.98 (4) Å30.16 × 0.15 × 0.08 mm
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
3143 independent reflections
Radiation source: fine-focus sealed tube2844 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.019
ω scansθmax = 28.0°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
h = 1111
Tmin = 0.170, Tmax = 0.262k = 1111
7739 measured reflectionsl = 1313
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.020Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.051H-atom parameters constrained
S = 1.04 w = 1/[σ2(Fo2) + (0.03P)2 + 0.1634P]
where P = (Fo2 + 2Fc2)/3
3143 reflections(Δ/σ)max = 0.002
136 parametersΔρmax = 0.69 e Å3
0 restraintsΔρmin = 0.76 e Å3
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.

Short Se···Se distances

3.5329 (0.0004) Se1 - Se5_$3 3.5829 (0.0004) Se3 - Se5_$4 3.3797 (0.0005) Se4 - Se4_$5

EQIV $3 x, y, z + 1 EQIV $4 x, y - 1, z EQIV $5 - x + 1, -y + 1, -z + 2

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

0.3874 (0.0097) x - 6.4715 (0.0042) y + 8.6839 (0.0049) z = 7.2877 (0.0062)

* 0.0006 (0.0007) Se1 * -0.0006 (0.0007) Se2 * -0.0014 (0.0017) C3 * 0.0014 (0.0017) C4

Rms deviation of fitted atoms = 0.0011

2.6881 (0.0016) x - 7.0863 (0.0005) y + 7.2732 (0.0013) z = 5.6094 (0.0013)

Angle to previous plane (with approximate e.s.d.) = 15.76 (0.07)

* -0.0108 (0.0006) Se1 * 0.0007 (0.0006) Se2 * -0.0132 (0.0007) Se3 * -0.0015 (0.0007) Se4 * 0.0063 (0.0020) C1 * 0.0185 (0.0020) C2 - 0.4543 (0.0029) C3 - 0.4470 (0.0028) C4 - 0.7967 (0.0028) C5 - 0.7961 (0.0028) C6

Rms deviation of fitted atoms = 0.0106

6.2376 (0.0066) x - 6.8145 (0.0033) y + 3.4479 (0.0101) z = 3.2446 (0.0067)

Angle to previous plane (with approximate e.s.d.) = 28.54 (0.07)

* 0.0003 (0.0007) Se3 * -0.0002 (0.0007) Se4 * -0.0006 (0.0016) C5 * 0.0006 (0.0016) C6

Rms deviation of fitted atoms = 0.0005

- 1.8511 (0.0082) x + 5.9848 (0.0041) y + 4.7538 (0.0091) z = 5.4306 (0.0007)

Angle to previous plane (with approximate e.s.d.) = 73.31 (0.07)

* 0.0003 (0.0007) Se5 * -0.0003 (0.0007) Se6 * -0.0007 (0.0016) C8 * 0.0007 (0.0016) C9

Rms deviation of fitted atoms = 0.0005

- 2.1118 (0.0146) x + 5.8723 (0.0065) y + 5.0395 (0.0157) z = 5.4491 (0.0009)

Angle to previous plane (with approximate e.s.d.) = 2.29 (0.23)

* 0.0000 (0.0000) Se5 * 0.0000 (0.0000) Se6 * 0.0000 (0.0000) C7 - 0.0663 (0.0046) C8 - 0.0645 (0.0045) C9

Rms deviation of fitted atoms = 0.0000

2.6881 (0.0016) x - 7.0863 (0.0005) y + 7.2732 (0.0013) z = 5.6094 (0.0013)

Angle to previous plane (with approximate e.s.d.) = 81.90 (0.07)

* -0.0108 (0.0006) Se1 * 0.0007 (0.0006) Se2 * -0.0132 (0.0007) Se3 * -0.0015 (0.0007) Se4 * 0.0063 (0.0020) C1 * 0.0185 (0.0020) C2 - 0.4543 (0.0029) C3 - 0.4470 (0.0028) C4 - 0.7967 (0.0028) C5 - 0.7961 (0.0028) C6

Rms deviation of fitted atoms = 0.0106

Refinement. Friedel pairs were merged before refinement.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Se10.01014 (3)0.28911 (3)1.05519 (3)0.01379 (7)
Se20.26604 (3)0.08138 (3)0.79037 (3)0.01477 (7)
Se30.07536 (3)0.06305 (3)0.68016 (3)0.01535 (7)
Se40.32861 (3)0.30248 (3)0.94430 (3)0.01401 (7)
C10.0356 (3)0.1074 (3)0.8899 (3)0.0109 (4)
C20.0978 (3)0.1124 (3)0.8471 (3)0.0127 (5)
C30.2588 (3)0.2015 (4)1.0008 (3)0.0184 (5)
H30.30760.26751.05180.022*
C40.3651 (3)0.0479 (4)0.8913 (3)0.0191 (5)
H40.49010.00300.86390.023*
C50.2644 (3)0.1012 (4)0.6626 (3)0.0169 (5)
H50.28290.07410.57530.020*
C60.3708 (3)0.2538 (4)0.7721 (3)0.0164 (5)
H60.46650.33750.76470.020*
Se50.02616 (3)0.64448 (3)0.34125 (3)0.01437 (7)
Se60.29945 (3)0.55665 (4)0.55812 (3)0.01782 (7)
C70.0632 (3)0.5391 (3)0.4796 (3)0.0116 (5)
C80.2605 (4)0.7085 (4)0.3518 (3)0.0184 (5)
H80.29760.76640.29290.022*
C90.3741 (3)0.6719 (4)0.4423 (3)0.0193 (5)
H90.49240.70410.44820.023*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Se10.01285 (12)0.01268 (12)0.01578 (13)0.00605 (10)0.00673 (10)0.00340 (10)
Se20.00852 (12)0.01447 (13)0.01706 (13)0.00230 (9)0.00372 (9)0.00429 (10)
Se30.01540 (13)0.01191 (12)0.01503 (13)0.00303 (10)0.00771 (10)0.00117 (10)
Se40.00950 (12)0.01339 (12)0.01402 (13)0.00120 (9)0.00481 (9)0.00193 (10)
C10.0101 (11)0.0090 (11)0.0126 (11)0.0040 (9)0.0038 (9)0.0033 (9)
C20.0099 (11)0.0120 (11)0.0135 (11)0.0034 (9)0.0036 (9)0.0032 (9)
C30.0144 (12)0.0236 (14)0.0227 (13)0.0114 (10)0.0100 (10)0.0099 (11)
C40.0127 (12)0.0247 (14)0.0250 (14)0.0100 (11)0.0091 (10)0.0127 (11)
C50.0150 (12)0.0219 (13)0.0156 (12)0.0065 (10)0.0091 (10)0.0082 (10)
C60.0127 (12)0.0212 (13)0.0203 (13)0.0071 (10)0.0113 (10)0.0102 (11)
Se50.01445 (13)0.01702 (13)0.01601 (12)0.00880 (10)0.00757 (10)0.00849 (10)
Se60.01077 (12)0.02520 (15)0.02210 (14)0.00833 (10)0.00734 (10)0.01406 (11)
C70.0100 (11)0.0095 (11)0.0132 (11)0.0039 (9)0.0037 (9)0.0026 (9)
C80.0182 (13)0.0230 (13)0.0200 (13)0.0084 (11)0.0124 (10)0.0121 (11)
C90.0138 (12)0.0234 (14)0.0222 (13)0.0050 (10)0.0113 (10)0.0100 (11)
Geometric parameters (Å, º) top
Se1—C31.890 (3)C5—C61.321 (4)
Se1—C11.906 (2)C5—H50.9500
Se2—C41.890 (3)C6—H60.9500
Se2—C11.900 (2)Se5—C81.885 (3)
Se3—C51.889 (3)Se5—C71.904 (2)
Se3—C21.898 (2)Se6—C91.881 (3)
Se4—C61.897 (3)Se6—C71.910 (2)
Se4—C21.906 (2)C7—C7i1.333 (5)
C1—C21.340 (3)C8—C91.333 (4)
C3—C41.326 (4)C8—H80.9500
C3—H30.9500C9—H90.9500
C4—H40.9500
C3—Se1—C191.96 (11)C6—C5—H5120.1
C4—Se2—C192.24 (11)Se3—C5—H5120.1
C5—Se3—C291.21 (11)C5—C6—Se4118.6 (2)
C6—Se4—C291.32 (11)C5—C6—H6120.7
C2—C1—Se2122.7 (2)Se4—C6—H6120.7
C2—C1—Se1122.79 (19)C8—Se5—C793.10 (11)
Se2—C1—Se1114.48 (12)C9—Se6—C793.04 (11)
C1—C2—Se3123.89 (19)C7i—C7—Se5123.4 (2)
C1—C2—Se4123.2 (2)C7i—C7—Se6122.3 (3)
Se3—C2—Se4112.90 (12)Se5—C7—Se6114.25 (12)
C4—C3—Se1119.9 (2)C9—C8—Se5119.7 (2)
C4—C3—H3120.0C9—C8—H8120.2
Se1—C3—H3120.0Se5—C8—H8120.2
C3—C4—Se2119.5 (2)C8—C9—Se6119.9 (2)
C3—C4—H4120.2C8—C9—H9120.1
Se2—C4—H4120.2Se6—C9—H9120.1
C6—C5—Se3119.9 (2)
C4—Se2—C1—C2166.8 (2)Se1—C3—C4—Se20.3 (3)
C4—Se2—C1—Se113.07 (14)C1—Se2—C4—C37.9 (3)
C3—Se1—C1—C2166.7 (2)C2—Se3—C5—C614.7 (2)
C3—Se1—C1—Se213.14 (14)Se3—C5—C6—Se40.1 (3)
Se2—C1—C2—Se31.6 (3)C2—Se4—C6—C514.5 (2)
Se1—C1—C2—Se3178.23 (12)C8—Se5—C7—C7i178.7 (3)
Se2—C1—C2—Se4179.08 (12)C8—Se5—C7—Se62.02 (14)
Se1—C1—C2—Se40.8 (3)C9—Se6—C7—C7i178.7 (3)
C5—Se3—C2—C1154.2 (2)C9—Se6—C7—Se51.97 (14)
C5—Se3—C2—Se423.44 (14)C7—Se5—C8—C91.3 (2)
C6—Se4—C2—C1154.2 (2)Se5—C8—C9—Se60.1 (3)
C6—Se4—C2—Se323.46 (14)C7—Se6—C9—C81.1 (2)
C1—Se1—C3—C48.3 (3)
Symmetry code: (i) x, y+1, z+1.
 

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