Diquino[4,3-b;3′,4′-e][1,4]thia­selenine

The title compound, C₁₈H₁₀N₂SSe, is a penta­cyclic ring system folded along the S...Se vector. The central thia­selenine ring adopts a boat conformation and the two halves of the mol­ecule are related by a crystallographic mirror plane.

Key indicators

• Single-crystal synchrotron study
• T = 293 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.024
• wR factor = 0.052
• Data-to-parameter ratio = 7.4

checkCIF/PLATON results

No syntax errors found



Alert level A
THETM01_ALERT_3_A  The value of sine(theta_max)/wavelength is less than 0.550
            Calculated sin(theta_max)/wavelength =    0.4958

Author Response: The setting used was far away from optimal. The diffractometer available at the time of our experiment was a protein set-up with a single phi axis.

PLAT023_ALERT_3_A Resolution (too) Low [sin(th)/Lambda < 0.6].....      32.68 Deg.

Author Response: The setting used was far away from optimal. The diffractometer available at the time of our experiment was a protein set-up with a single phi axis.

PLAT027_ALERT_3_A _diffrn_reflns_theta_full (too) Low ............      32.68 Deg.

Author Response: The setting used was far away from optimal. The diffractometer available at the time of our experiment was a protein set-up with a single phi axis.

Alert level B
REFNR01_ALERT_3_B  Ratio of reflections to parameters is < 8 for a
            non-centrosymmetric structure, where ZMAX > 18
            sine(theta)/lambda                0.4958
            Proportion of unique data used    0.9948
            Ratio reflections to parameters   7.3654
PLAT029_ALERT_3_B _diffrn_measured_fraction_theta_full Low .......       0.94

Alert level C
STRVA01_ALERT_4_C           Flack test results are ambiguous.
           From the CIF: _refine_ls_abs_structure_Flack    0.420
           From the CIF: _refine_ls_abs_structure_Flack_su    0.019
PLAT033_ALERT_2_C Flack Parameter Value Deviates from Zero .......       0.42
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       7.37
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K
PLAT230_ALERT_2_C Hirshfeld Test Diff for    Se     -   C4      ..       6.99 su
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          7

Alert level G
  ABSMU_01  Radiation type not identified. Calculation of
            _exptl_absorpt_correction_mu not performed.
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           32.68
           From the CIF: _reflns_number_total                770
           Count of symmetry unique reflns          443
           Completeness (_total/calc)            173.81%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       327
           Fraction of Friedel pairs measured     0.738
           Are heavy atom types Z>Si present        yes

   3 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
   7 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   7 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: TWINSOLVE (Rigaku/MSC & Prekat, 2002); cell refinement: TWINSOLVE; data reduction: TWINSOLVE; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: ORTEP-3 (Burnett & Johnson, 1996) and ATOMS (Dowty, 1994); software used to prepare material for publication: CRYSTALS and enCIFer (Allen et al., 2004).

Diquino[4,3 - b;3',4'-e][1,4]thiaselenine

Crystal data

C18H10N2SSe	F(000) = 364
Mr = 365.32	Dx = 1.696 Mg m^−3
Orthorhombic, Pmn21	Synchrotron radiation, λ = 1.08900 Å
Hall symbol: P 2ac -2	Cell parameters from 0 reflections
a = 23.625 (3) Å	θ = 0–0°
b = 7.3299 (9) Å	µ = 2.77 mm^−1
c = 4.1297 (5) Å	T = 293 K
V = 715.13 (15) Å^3	Needle, yellow
Z = 2	0.03 × 0.001 × 0.001 mm

Data collection

Mar CCD area-detector diffractometer	Rint = 0.030
Graphite monochromator	θmax = 32.7°, θmin = 4.0°
φ scans	h = −23→23
3727 measured reflections	k = −7→7
770 independent reflections	l = −4→4
684 reflections with I > 2σ(I)

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.024	w = [1-(Fo-Fc)^2/36σ^2(F)]^2/[23.9To(x)-32.3T1(x) + 11.2T2(x)] where Ti are the Chebychev polynomials and x = Fc/Fmax (Prince, 1982; Watkin, 1994)
wR(F^2) = 0.052	(Δ/σ)max = 0.000169
S = 1.04	Δρmax = 0.14 e Å^−3
770 reflections	Δρmin = −0.20 e Å^−3
104 parameters	Absolute structure: Flack (1983), with 72 Friedel pairs
1 restraint	Absolute structure parameter: 0.420 (19)
Primary atom site location: structure-invariant direct methods

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

	x	y	z	Uiso*/Ueq
N1	0.6499 (2)	0.4209 (6)	0.9810 (11)	0.0638
C2	0.6039 (2)	0.3715 (7)	0.8314 (16)	0.0610
C3	0.55764 (16)	0.4888 (6)	0.7703 (17)	0.0478
C4	0.56015 (18)	0.6649 (7)	0.8649 (10)	0.0464
C5	0.6085 (2)	0.7276 (7)	1.0402 (12)	0.0504
C6	0.6162 (2)	0.9055 (7)	1.1625 (12)	0.0546
C7	0.6644 (2)	0.9538 (7)	1.3186 (17)	0.0616
C8	0.7081 (2)	0.8289 (10)	1.3588 (14)	0.0733
C9	0.70237 (19)	0.6534 (8)	1.2495 (19)	0.0654
C10	0.6532 (2)	0.5966 (8)	1.0877 (13)	0.0531
Se	0.5000	0.83098 (10)	0.7698 (3)	0.0676
S	0.5000	0.3993 (3)	0.5433 (5)	0.0638
H21	0.6000	0.2560	0.7088	0.0875*
H61	0.5876	0.9887	1.0846	0.0788*
H71	0.6681	1.0729	1.3498	0.0888*
H81	0.7419	0.8635	1.4177	0.1059*
H91	0.7317	0.5694	1.2281	0.0935*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.058 (3)	0.067 (3)	0.066 (3)	0.016 (3)	0.002 (3)	0.007 (3)
C2	0.065 (3)	0.058 (3)	0.060 (4)	0.009 (3)	0.025 (4)	0.003 (3)
C3	0.047 (2)	0.057 (3)	0.039 (3)	0.001 (2)	0.009 (4)	−0.004 (4)
C4	0.035 (2)	0.058 (3)	0.046 (4)	0.009 (2)	0.006 (2)	0.020 (3)
C5	0.043 (3)	0.065 (3)	0.043 (3)	0.005 (3)	0.018 (3)	0.017 (3)
C6	0.045 (3)	0.061 (4)	0.057 (4)	−0.003 (3)	0.007 (3)	0.011 (3)
C7	0.052 (3)	0.072 (3)	0.060 (4)	−0.004 (3)	0.011 (4)	0.014 (4)
C8	0.046 (3)	0.108 (5)	0.066 (6)	−0.009 (4)	0.001 (3)	0.004 (4)
C9	0.046 (3)	0.094 (4)	0.056 (4)	0.013 (3)	0.010 (5)	0.014 (4)
C10	0.045 (3)	0.072 (4)	0.043 (3)	0.011 (3)	0.011 (3)	0.012 (3)
Se	0.0558 (4)	0.0635 (5)	0.0836 (6)	0.0000	0.0000	0.0239 (6)
S	0.0731 (13)	0.0684 (13)	0.0498 (12)	0.0000	0.0000	−0.0075 (13)

Geometric parameters (Å, º)

N1—C2	1.303 (6)	C5—C10	1.440 (7)
N1—C10	1.363 (7)	C6—C7	1.357 (7)
C2—C3	1.413 (6)	C6—H61	0.964
C2—H21	0.990	C7—C8	1.388 (7)
C3—C4	1.350 (6)	C7—H71	0.887
C3—S	1.779 (5)	C8—C9	1.370 (8)
C4—C5	1.429 (7)	C8—H81	0.873
C4—Se	1.912 (4)	C9—C10	1.404 (7)
C5—C6	1.410 (7)	C9—H91	0.932
C2—N1—C10	117.6 (5)	C7—C6—H61	125.5
N1—C2—C3	124.1 (5)	C6—C7—C8	120.6 (6)
N1—C2—H21	123.9	C6—C7—H71	114.1
C3—C2—H21	111.0	C8—C7—H71	124.0
C2—C3—C4	119.8 (5)	C7—C8—C9	120.5 (5)
C2—C3—S	117.5 (4)	C7—C8—H81	121.4
C4—C3—S	122.6 (4)	C9—C8—H81	117.0
C3—C4—C5	119.3 (4)	C8—C9—C10	121.1 (5)
C3—C4—Se	121.1 (4)	C8—C9—H91	125.4
C5—C4—Se	119.6 (4)	C10—C9—H91	112.0
C4—C5—C6	125.6 (4)	C5—C10—C9	118.3 (5)
C4—C5—C10	116.1 (5)	C5—C10—N1	123.0 (5)
C6—C5—C10	118.3 (5)	C9—C10—N1	118.7 (5)
C5—C6—C7	121.3 (5)	C3—S—C3^i	99.9 (4)
C5—C6—H61	112.0	C4—Se—C4^i	96.0 (3)

Symmetry code: (i) −x+1, y, z.