5-Iodo­benzofurazan 1-oxide: polymorphs, pseudosymmetry and disorder

5-Iodo­benzofurazan 1-oxide (systematic name: 5-iodo­benzo-1,2,5-oxadiazole 1-oxide), C₆H₃IN₂O₂, occurs in two polymorphic forms, both monoclinic in P2₁/c with Z′ = 2. The inter­molecular inter­actions in the two polymorphs are quite different. In polymorph (I), there are strong inter­molecular I...O inter­actions, with I...O distances of 3.114 (8) and 3.045 (8) Å. In polymorph (II), there are strong inter­mol­ecular I...N inter­actions, with I...N distances of 3.163 (4) and 3.175 (5) Å. In (I), there is about 15% disorder in one mol­ecule and about 5% in the other. In both polymorphs, there are pseudosymmetric relationships between the crystal­log­raphically independent mol­ecules.

S1. Comment

The structure of 5-iodobenzofurazan 1-oxide was originally determined at room temperature (Gehrz & Britton, 1972). Diffractometer data were used, but no measurable data were found above θ = 18° (Mo Kα radiation). The limited number of intensity measurements, combined with the dominance of the I atoms, led to large errors in the light-atom parameters. This structure, polymorph (I), has been redetermined to improve the accuracy. In the course of the redetermination a second polymorph, (II), was discovered, the structure of which is also reported.

Both molecules in polymorph (I) are disordered (Fig. 1), but there is no disorder in polymorph (II) (Fig. 2). All of the bond distances and angles are normal.

Molecules of (I) form chains parallel to [010] held together by intermolecular I···O interactions (Fig. 3). Each chain involves one or other of the two independent molecules. The geometric data for these interactions are given in Table 1.

The chains grow together in irregular sheets parallel to the (101) plane, with molecule A tilted by 11.2 (1)° and molecule B tilted by 10.8 (1)° with respect to the sheet; the molecules are 2.5 (1)° away from being parallel to each other. There are H···O interactions between adjacent chains. The geometric data for the H interactions are given in Table 2; only contacts with distances less than the sum of the van der Waals radii (Bondi, 1964; Rowland & Taylor, 1996) are included. See Desiraju & Steiner (1999) for a discussion of C—H···X hydrogen bonds.

The sheets stack so that columns occur parallel to the [001] direction, with each molecule A in contact with two other A molecules and each B with two other B molecules. The A molecules are tilted by 16.3 (1)° and the B molecules by 16.9 (1)° with respect to the direction of the stacks. The perpendicular distances between molecules alternate between 3.59 (3) and 3.62 (3) Å in both stacks.

In the preceding discussion of the packing only the major components of the disorder were considered. The disorder appears to arise from both kinds of chains shifting half a unit-cell length in the b direction. This seems a reasonable model, although all that can be said from the X-ray data is that there is disorder in the individual molecules.

Molecules of (II) form zigzag chains parallel to [100] (Fig. 4), held together by intermolecular I···N interactions. Each chain involves, alternately, the two kinds of independent molecules. The geometric data for these interactions are given in Table 1.

The chains grow together in irregular sheets parallel to the (001) plane, with molecule A tilted by 18.6 (1)° and molecule B tilted by 19.3 (1)° with respect to the sheet; the two molecules are 27.7 (1)° away from being parallel to each other. There are H···O interactions between adjacent chains; the geometric data for these are given in Table 2.

The sheets stack so that columns occur parallel to the [101] direction, with each molecule A in contact with one A molecule and one B molecule, and vice versa. The A molecules are tilted by 22.0 (1)° and the B molecules by 20.5 (1)° with respect to the direction of the stack. The perpendicular distances between molecules are A···A = 3.736 (7) Å, A···B = 3.53 (3) Å and B···B = 3.770 (6) Å.

There are no I···I contacts in either structure shorter than 4.4 Å. The expected van der Waals distance (Bondi, 1964; Rowland & Taylor, 1996) is 3.96 Å.

The pseudosymmetry in (I) can be seen in Fig. 3. Molecule A is converted to molecule B by a pseudo-translation (all non-H atoms weighted equally): x_B = -0.489 (3) + x_A; y_B = 0.258 (1) + y_A; z_B = -0.490 (12) + z_A. It can be converted to the other three molecules in Wyckoff position e of molecule B by a pseudo center: x_B = 1.489 (3) - x_A; y_B = 0.742 (1) - y_A; z_B = 1.490 (12) -z_A; a pseudo twofold screw axis: x_B = 1.489 (3) - x_A; y_B = 0.758 (1) + y_A; z_B = 0.990 (12) - z_A; and a pseudo a-glide: x_B = -0.489 (3) +x_A; y_B = 0.242 (1) - y_A; z_B = 0.010 (12) + z_A.

Similar relationships hold for the other molecules in the Wyckoff position of molecule A. As a measure of the preciseness of the pseudosymmetry, if molecules A and B are matched as well as possible using OFIT in SHELXTL (Sheldrick, 2008), the r.m.s. devation between the atoms is 0.028 Å; if the translation above is used, the r.m.s.deviation is 0.079 Å; and if an idealized translation of -a/2, b/4, -c/2 is used, the r.m.s. deviation is 0.218 Å.

The pseudosymmetry in (II) can be seen in Fig. 4. Molecule A is converted to molecule B by a pseudo a-glide: x_B = 0.506 (4) + x_A; y_B = 0.411 (10) - y_A; z_B = 0.015 (7) + z_A. It can be converted to the other three molecules in the Wyckoff position of molecule B by a pseudo center: x_B = 0.494 (4) - x_A; y_B = 0.911 (10) - y_A; z_B = 0.485 (7) -z_A; a pseudo translation: x_B = 0.506 (4) + x_A; y_B = 0.089 (10) + y_A; z_B = 0.515 (7) + z_A; and a pseudo twofold axis: x_B = 0.494 (4) - x_A; y_B = 0.589 (10) + y_A; z_B = 0.985 (7) - z_A.

Similar relationships hold for the other molecules in the Wyckoff position of molecule A. Again, as a measure of the preciseness of the pseudosymmetry, if molecules A and B are matched as well as possible using OFIT in SHELXTL, the r.m.s. deviation between the atoms is 0.008 Å; if the translation above is used, the r.m.s. deviation is 0.123 Å. In this case, there is no idealized translation; although the a and c translations can both be idealized as 1/2, the translation in y is not close to any rational fraction.

Polymorph (II) is isomorphous with the low-temperature form of 5-bromobenzofurazan 1-oxide (Pink & Britton, 2002). The pseudosymmetry relationships above are virtually identical with those for the bromo analog, except that the translation in y, 0.089 (10) in the iodo compound, is 0.114 (7) in the bromo compound, marginally different.

Although both polymorphs have the same four supersymmetry relationships, namely translation, inversion, screw and glide, there are significant differences between the two. In A [(I)?], the two types of molecules in a layer are related alternately by a pseudo-translation and a pseudo-screw. In B [(II)?], the two types of molecules are all related by a pseudo-glide. Supersymmetry has been discussed extensively by Zorky and coworkers (see Zorky, 1996, and references therein).

Related literature

For related literature, see: Bondi (1964); Bradfield et al. (1928); Brenans (1914a, 1914b); Deorha et al. (1962); Desiraju & Steiner (1999); Garden et al. (2002); Gehrz & Britton (1972); Kavalek et al. (1967, 1969); Michael & Norton (1878); Pink & Britton (2002); Rowland & Taylor (1996); Sheldrick (2008); Zorky (1996).

S2. Experimental

A sample of 4-iodo-2-nitroaniline, (1), from the chemical collection of W. E. Noland, was converted to 4-iodo-2-nitrophenylazide, (2), by the method of Deorha et al. (1962). Compound (2) was then converted to the title compound, (3). Compound (1) (2.00 g, 7.57 mmol) [m.p. 396.6 K, cf. 396.2 K (Deorha et al., 1962; Brenans, 1914a,b), 395–396 K (Garden et al., 2002), 395.2 K (Bradfield et al., 1928; Michael & Norton, 1878) and 394.6–395.2 K (Kavalek et al., 1967, 1969)] was dissolved in boiling glacial acetic acid (50 ml) and then cooled to 298 K. A solution of NaNO₂ (0.575 g, 8.33 mmol) in concentrated H₂SO₄ (20 ml) was stirred into the acetic acid solution and the mixture was poured over crushed ice (150 g). An aqueous solution of NaN₃ (0.227 M) was added slowly until the evolution of N₂ ceased, giving a light-yellow precipitate, which was crystallized from ⁱPrOH–H₂O (Ratio of solvents?) giving (2) as light-yellow needles (2.10 g, 7.24 mmol, 96%) [m.p. 345.5 K, cf. 345.2 K (Deorha et al., 1962)]. Compound (2) (1.00 g, 3.45 mmol) was dissolved in toluene (50 ml) and the solution was refluxed until the evolution of N₂ ceased. The solvent was removed in a rotating evaporator, leaving (3) as a light-yellow precipitate (0.90 g, 3.4 mmol, 100%). Crystallization from ⁱPrOH–H₂O (Ratio of solvents?) gave light-yellow needles (0.85 g, 3.2 mmol, 94%). Spectroscopic analysis: IR (KBr, cm^-1): 3089, 1604, 1517, 1466, 1267, 1194, 1123, 1018, 785, 613, 574, 545; ¹H NMR (acetone-d₆, δ, p.p.m.): 8.20 (bs, 7H), 765 (bs, 6H), 7.45 (bs, 4H). Recrystallization from benzene gave polymorph (I), previously obtained by sublimation (Gehrz & Britton, 1972). Recrystallization from acetone, chloroform, carbon tetrachloride or ⁱPrOH–H₂O (Ratio of solvents?) gave polymorph (II). Polymorph (I) melted at 348.5–348.8 K, while polymorph (II) turned opaque at 346.8 and melted at 348.5 K. Presumably the opacity at 346.8 K indicates the transition from (II) to (I).

S3. Refinement

The first crystal of (I), after refinement as an ordered structure, showed peaks in the final difference map of of 10 and 5 e Å^-3 near the I atoms. To make sure this was real, a second data set was collected, with the same results. At this point, the two large peaks were considered as disordered I atoms. The ordered structure had R = 0.095 and wR2 = 0.169. Considering only the I to be disordered reduced R to 0.052 and wR2 to 0.093. After consideration of various models, the arrangement shown in Fig. 1 seemed most reasonable, and refinement with the geometry in the minor components constrained to be the same as in the major components, with identical isotropic displacement parameters for the atoms of the minor components, led to R = 0.049 and wR2 = 0.087. Occupancies for the major components were 0.849 (3) for molecule 1 [A?] and 0.944 (4) for molecule 2 [B?]. Similar refinement of the first data set led to corresponding occupancies of 0.829 (3) and 0.920 (4). A reasonable model for the disorder would be one in which entire chains of molecules (Fig. 3) are shifted one molecule along in the chain direction, although this cannot be determined from the diffraction data. The minor components of the disorder have been ignored in the discussion of the packing.

H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C).

Computing details

For both compounds, data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. Polymorph (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. The minor components of the disorder are shown with open bonds.
	Fig. 2. Polymorph (II), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 3. The packing of polymorph (I), showing one layer viewed normal to the (101) plane. Molecules in each vertical column are crystallographically equivalent. I···O contacts are shown as double-dashed lines and H···X contacts as single-dashed lines. Atom I1A' is related to atom I1A by the symmetry code (2 - x,-1/2 + y,3/2 - z) and atom I1B' is related to atom I1B by the symmetry code (1 - x,-1/2 + y,1/2 - z).
	Fig. 4. The packing of polymorph (II), showing one layer viewed normal to the (001) plane. Molecules in each horizontal row are crystallographically equivalent. I···N contacts are shown as double-dashed lines and H···O contacts as single-dashed lines. Atom I1A' is related to atom I1A by the symmetry code (x, 1 + y, z) and atom I1B' is related to atom I1B by the symmetry code (x, -1 + y, z).

(I) 5-iodobenzo-1,2,5-oxadiazole 1-oxide

Crystal data

C6H3IN2O2	F(000) = 976
Mr = 262.00	Dx = 2.328 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3530 reflections
a = 10.344 (3) Å	θ = 2.2–27.2°
b = 19.804 (6) Å	µ = 4.23 mm^−1
c = 7.489 (2) Å	T = 174 K
β = 102.95 (1)°	Needle, yellow
V = 1495.1 (7) Å^3	0.35 × 0.08 × 0.04 mm
Z = 8

Data collection

Siemens SMART 1K CCD area-detector diffractometer	2929 independent reflections
Radiation source: fine-focus sealed tube	2078 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.071
ω scans	θmax = 26.0°, θmin = 2.0°
Absorption correction: multi-scan [SADABS (Sheldrick, 1996; Blessing, 1995)]	h = −12→12
Tmin = 0.68, Tmax = 0.84	k = −24→24
15378 measured reflections	l = −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)] = 0.049	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.087	H-atom parameters constrained
S = 0.99	w = 1/[σ^2(Fo^2) + (0.013P)^2 + 13.6P] where P = (Fo^2 + 2Fc^2)/3
2929 reflections	(Δ/σ)max = 0.004
270 parameters	Δρmax = 0.77 e Å^−3
58 restraints	Δρmin = −0.80 e Å^−3

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
I1A	1.03110 (12)	0.39626 (3)	0.77605 (10)	0.0344 (3)	0.850 (3)
O1A	0.8661 (8)	0.0442 (4)	0.6664 (10)	0.050 (2)	0.850 (3)
O2A	1.0801 (8)	0.0687 (3)	0.8118 (16)	0.0391 (18)	0.850 (3)
N1A	0.9459 (8)	0.0892 (3)	0.7240 (11)	0.0299 (17)	0.850 (3)
N2A	1.1554 (8)	0.1266 (4)	0.8622 (12)	0.043 (2)	0.850 (3)
C1A	0.9471 (9)	0.1567 (4)	0.7211 (12)	0.029 (2)	0.850 (3)
C2A	1.0725 (9)	0.1779 (4)	0.8094 (13)	0.027 (2)	0.850 (3)
C3A	1.1047 (8)	0.2486 (5)	0.8284 (13)	0.027 (2)	0.850 (3)
H3A	1.1903	0.2651	0.8855	0.033*	0.850 (3)
C4A	0.9978 (11)	0.2903 (4)	0.7548 (17)	0.039 (3)	0.850 (3)
C5A	0.8734 (9)	0.2679 (4)	0.6655 (19)	0.025 (2)	0.850 (3)
H5A	0.8070	0.3001	0.6158	0.030*	0.850 (3)
C6A	0.8440 (9)	0.2019 (4)	0.6473 (13)	0.030 (2)	0.850 (3)
H6A	0.7582	0.1865	0.5878	0.036*	0.850 (3)
I1B	0.54822 (14)	0.65334 (3)	0.25942 (12)	0.0287 (3)	0.943 (4)
O1B	0.3741 (6)	0.3015 (3)	0.1867 (10)	0.0382 (16)	0.943 (4)
O2B	0.5872 (6)	0.3268 (3)	0.3366 (8)	0.0346 (15)	0.943 (4)
N1B	0.4548 (7)	0.3471 (3)	0.2399 (9)	0.0289 (15)	0.943 (4)
N2B	0.6643 (7)	0.3836 (3)	0.3864 (10)	0.0362 (18)	0.943 (4)
C1B	0.4549 (8)	0.4151 (3)	0.2326 (11)	0.0241 (17)	0.943 (4)
C2B	0.5853 (8)	0.4355 (3)	0.3216 (12)	0.0236 (18)	0.943 (4)
C3B	0.6183 (8)	0.5070 (4)	0.3371 (14)	0.027 (2)	0.943 (4)
H3B	0.7027	0.5238	0.3982	0.033*	0.943 (4)
C4B	0.5141 (7)	0.5476 (4)	0.2538 (11)	0.0221 (19)	0.943 (4)
C5B	0.3855 (8)	0.5262 (4)	0.1679 (12)	0.0270 (19)	0.943 (4)
H5B	0.3198	0.5588	0.1188	0.032*	0.943 (4)
C6B	0.3543 (8)	0.4599 (4)	0.1544 (12)	0.032 (2)	0.943 (4)
H6B	0.2684	0.4446	0.0947	0.039*	0.943 (4)
I1A'	0.9546 (7)	0.4088 (2)	0.7461 (7)	0.0414 (15)*	0.150 (3)
O1A'	1.080 (4)	0.0520 (6)	0.804 (9)	0.0414 (15)*	0.150 (3)
O2A'	0.875 (3)	0.0844 (6)	0.641 (5)	0.0414 (15)*	0.150 (3)
N1A'	1.008 (3)	0.0999 (5)	0.747 (5)	0.0414 (15)*	0.150 (3)
N2A'	0.808 (3)	0.1448 (7)	0.594 (5)	0.0414 (15)*	0.150 (3)
C1A'	1.012 (3)	0.1670 (5)	0.767 (6)	0.0414 (15)*	0.150 (3)
C2A'	0.890 (2)	0.1926 (5)	0.679 (7)	0.0414 (15)*	0.150 (3)
C3A'	0.864 (3)	0.2641 (6)	0.674 (12)	0.0414 (15)*	0.150 (3)
H3A'	0.7812	0.2835	0.6174	0.050*	0.150 (3)
C4A'	0.974 (3)	0.3019 (5)	0.759 (9)	0.0414 (15)*	0.150 (3)
C5A'	1.095 (3)	0.2752 (6)	0.850 (8)	0.0414 (15)*	0.150 (3)
H5A'	1.1629	0.3048	0.9099	0.050*	0.150 (3)
C6A'	1.118 (3)	0.2084 (7)	0.854 (7)	0.0414 (15)*	0.150 (3)
H6A'	1.2017	0.1901	0.9124	0.050*	0.150 (3)
I1B'	0.491 (2)	0.6415 (7)	0.215 (2)	0.028 (4)*	0.057 (4)
O1B'	0.565 (6)	0.2830 (11)	0.326 (11)	0.028 (4)*	0.057 (4)
O2B'	0.357 (6)	0.3213 (11)	0.190 (14)	0.028 (4)*	0.057 (4)
N1B'	0.495 (5)	0.3333 (10)	0.281 (10)	0.028 (4)*	0.057 (4)
N2B'	0.294 (5)	0.3824 (13)	0.146 (11)	0.028 (4)*	0.057 (4)
C1B'	0.512 (4)	0.4008 (10)	0.290 (9)	0.028 (4)*	0.057 (4)
C2B'	0.387 (4)	0.4290 (11)	0.202 (10)	0.028 (4)*	0.057 (4)
C3B'	0.372 (4)	0.5020 (12)	0.188 (17)	0.028 (4)*	0.057 (4)
H3B'	0.2913	0.5239	0.1333	0.034*	0.057 (4)
C4B'	0.488 (4)	0.5359 (10)	0.262 (11)	0.028 (4)*	0.057 (4)
C5B'	0.608 (8)	0.5069 (13)	0.36 (2)	0.028 (4)*	0.057 (4)
H5B'	0.6802	0.5353	0.4117	0.034*	0.057 (4)
C6B'	0.622 (6)	0.4391 (13)	0.371 (18)	0.028 (4)*	0.057 (4)
H6B'	0.7029	0.4188	0.4330	0.034*	0.057 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1A	0.0533 (7)	0.0185 (3)	0.0322 (4)	−0.0053 (4)	0.0111 (4)	−0.0022 (3)
O1A	0.053 (5)	0.036 (4)	0.058 (5)	−0.006 (4)	0.005 (4)	0.001 (4)
O2A	0.036 (4)	0.029 (4)	0.047 (5)	0.005 (4)	−0.001 (3)	−0.002 (4)
N1A	0.037 (5)	0.023 (4)	0.032 (4)	0.008 (4)	0.011 (4)	0.001 (4)
N2A	0.037 (5)	0.041 (5)	0.047 (5)	−0.005 (4)	0.001 (4)	−0.005 (4)
C1A	0.043 (5)	0.021 (4)	0.026 (5)	−0.010 (5)	0.012 (4)	−0.009 (4)
C2A	0.027 (5)	0.023 (5)	0.031 (5)	0.015 (4)	0.008 (4)	0.009 (4)
C3A	0.017 (5)	0.033 (5)	0.030 (5)	−0.015 (4)	0.001 (4)	−0.014 (5)
C4A	0.063 (8)	0.026 (5)	0.039 (7)	−0.013 (5)	0.038 (7)	−0.003 (5)
C5A	0.020 (5)	0.030 (5)	0.023 (5)	0.005 (4)	0.000 (4)	0.005 (4)
C6A	0.033 (6)	0.028 (5)	0.026 (5)	−0.004 (4)	0.001 (4)	0.001 (4)
I1B	0.0353 (6)	0.0186 (3)	0.0320 (4)	−0.0009 (3)	0.0072 (4)	−0.0003 (3)
O1B	0.054 (4)	0.014 (3)	0.047 (4)	0.000 (3)	0.011 (3)	−0.003 (3)
O2B	0.045 (4)	0.016 (3)	0.045 (4)	0.005 (3)	0.015 (3)	0.004 (3)
N1B	0.041 (4)	0.019 (3)	0.026 (4)	0.005 (4)	0.007 (3)	0.000 (3)
N2B	0.040 (4)	0.024 (4)	0.044 (4)	0.010 (3)	0.010 (4)	0.008 (3)
C1B	0.035 (4)	0.015 (3)	0.022 (4)	0.005 (4)	0.004 (3)	0.002 (3)
C2B	0.027 (5)	0.018 (4)	0.027 (5)	0.008 (3)	0.009 (4)	0.003 (3)
C3B	0.030 (5)	0.023 (4)	0.028 (5)	0.000 (4)	0.007 (4)	−0.004 (3)
C4B	0.012 (4)	0.025 (4)	0.028 (5)	−0.003 (3)	0.001 (4)	−0.002 (3)
C5B	0.019 (4)	0.024 (4)	0.033 (5)	−0.003 (3)	−0.002 (4)	0.009 (4)
C6B	0.032 (5)	0.022 (4)	0.039 (5)	−0.008 (4)	−0.003 (4)	0.005 (4)

Geometric parameters (Å, º)

I1A—C4A	2.126 (8)	I1A'—C4A'	2.126 (8)
O1A—N1A	1.226 (10)	O1A'—N1A'	1.226 (10)
O2A—N2A	1.390 (10)	O2A'—N2A'	1.390 (10)
O2A—N1A	1.454 (12)	O2A'—N1A'	1.454 (11)
N1A—C1A	1.336 (10)	N1A'—C1A'	1.337 (10)
N2A—C2A	1.332 (11)	N2A'—C2A'	1.332 (11)
C1A—C2A	1.384 (12)	C1A'—C2A'	1.384 (12)
C1A—C6A	1.407 (12)	C1A'—C6A'	1.407 (12)
C2A—C3A	1.438 (12)	C2A'—C3A'	1.438 (12)
C3A—C4A	1.391 (13)	C3A'—C4A'	1.391 (14)
C3A—H3A	0.9500	C3A'—H3A'	0.9500
C4A—C5A	1.384 (14)	C4A'—C5A'	1.384 (14)
C5A—C6A	1.343 (12)	C5A'—C6A'	1.343 (12)
C5A—H5A	0.9500	C5A'—H5A'	0.9500
C6A—H6A	0.9500	C6A'—H6A'	0.9500
I1B—C4B	2.121 (7)	I1B'—C4B'	2.122 (7)
O1B—N1B	1.234 (8)	O1B'—N1B'	1.234 (8)
O2B—N2B	1.381 (9)	O2B'—N2B'	1.381 (9)
O2B—N1B	1.454 (9)	O2B'—N1B'	1.454 (9)
N1B—C1B	1.349 (9)	N1B'—C1B'	1.349 (9)
N2B—C2B	1.334 (9)	N2B'—C2B'	1.334 (9)
C1B—C6B	1.393 (11)	C1B'—C6B'	1.393 (11)
C1B—C2B	1.422 (11)	C1B'—C2B'	1.422 (11)
C2B—C3B	1.456 (10)	C2B'—C3B'	1.456 (10)
C3B—C4B	1.378 (10)	C3B'—C4B'	1.379 (10)
C3B—H3B	0.9500	C3B'—H3B'	0.9500
C4B—C5B	1.407 (10)	C4B'—C5B'	1.407 (10)
C5B—C6B	1.351 (10)	C5B'—C6B'	1.352 (11)
C5B—H5B	0.9500	C5B'—H5B'	0.9500
C6B—H6B	0.9500	C6B'—H6B'	0.9500
N2A—O2A—N1A	108.3 (6)	N2A'—O2A'—N1A'	108.2 (6)
O1A—N1A—C1A	136.8 (8)	O1A'—N1A'—C1A'	136.7 (9)
O1A—N1A—O2A	117.2 (6)	O1A'—N1A'—O2A'	117.1 (7)
C1A—N1A—O2A	106.0 (7)	C1A'—N1A'—O2A'	106.0 (7)
C2A—N2A—O2A	105.3 (7)	C2A'—N2A'—O2A'	105.3 (7)
N1A—C1A—C2A	107.9 (7)	N1A'—C1A'—C2A'	107.9 (7)
N1A—C1A—C6A	129.3 (8)	N1A'—C1A'—C6A'	129.3 (8)
C2A—C1A—C6A	122.7 (7)	C2A'—C1A'—C6A'	122.7 (7)
N2A—C2A—C1A	112.5 (8)	N2A'—C2A'—C1A'	112.4 (8)
N2A—C2A—C3A	126.5 (8)	N2A'—C2A'—C3A'	126.4 (8)
C1A—C2A—C3A	121.0 (7)	C1A'—C2A'—C3A'	121.0 (8)
C4A—C3A—C2A	113.1 (8)	C4A'—C3A'—C2A'	113.1 (8)
C4A—C3A—H3A	123.4	C4A'—C3A'—H3A'	123.4
C2A—C3A—H3A	123.4	C2A'—C3A'—H3A'	123.4
C5A—C4A—C3A	124.9 (8)	C5A'—C4A'—C3A'	124.9 (8)
C5A—C4A—I1A	118.0 (7)	C5A'—C4A'—I1A'	118.0 (7)
C3A—C4A—I1A	117.1 (7)	C3A'—C4A'—I1A'	117.1 (7)
C6A—C5A—C4A	121.7 (9)	C6A'—C5A'—C4A'	121.7 (9)
C6A—C5A—H5A	119.1	C6A'—C5A'—H5A'	119.1
C4A—C5A—H5A	119.1	C4A'—C5A'—H5A'	119.1
C5A—C6A—C1A	116.5 (8)	C5A'—C6A'—C1A'	116.5 (8)
C5A—C6A—H6A	121.8	C5A'—C6A'—H6A'	121.8
C1A—C6A—H6A	121.8	C1A'—C6A'—H6A'	121.8
N2B—O2B—N1B	109.4 (5)	N2B'—O2B'—N1B'	109.4 (5)
O1B—N1B—C1B	136.4 (7)	O1B'—N1B'—C1B'	136.4 (7)
O1B—N1B—O2B	116.9 (6)	O1B'—N1B'—O2B'	116.9 (6)
C1B—N1B—O2B	106.6 (6)	C1B'—N1B'—O2B'	106.6 (6)
C2B—N2B—O2B	105.0 (6)	C2B'—N2B'—O2B'	105.0 (6)
N1B—C1B—C6B	130.3 (8)	N1B'—C1B'—C6B'	130.2 (8)
N1B—C1B—C2B	105.9 (7)	N1B'—C1B'—C2B'	105.9 (7)
C6B—C1B—C2B	123.9 (7)	C6B'—C1B'—C2B'	123.8 (7)
N2B—C2B—C1B	113.0 (7)	N2B'—C2B'—C1B'	113.0 (7)
N2B—C2B—C3B	127.3 (7)	N2B'—C2B'—C3B'	127.3 (8)
C1B—C2B—C3B	119.7 (7)	C1B'—C2B'—C3B'	119.6 (7)
C4B—C3B—C2B	112.7 (7)	C4B'—C3B'—C2B'	112.7 (7)
C4B—C3B—H3B	123.6	C4B'—C3B'—H3B'	123.7
C2B—C3B—H3B	123.6	C2B'—C3B'—H3B'	123.7
C3B—C4B—C5B	126.5 (7)	C3B'—C4B'—C5B'	126.4 (7)
C3B—C4B—I1B	117.2 (5)	C3B'—C4B'—I1B'	117.2 (5)
C5B—C4B—I1B	116.3 (5)	C5B'—C4B'—I1B'	116.2 (5)
C6B—C5B—C4B	120.8 (7)	C6B'—C5B'—C4B'	120.8 (8)
C6B—C5B—H5B	119.6	C6B'—C5B'—H5B'	119.6
C4B—C5B—H5B	119.6	C4B'—C5B'—H5B'	119.6
C5B—C6B—C1B	116.4 (7)	C5B'—C6B'—C1B'	116.4 (8)
C5B—C6B—H6B	121.8	C5B'—C6B'—H6B'	121.8
C1B—C6B—H6B	121.8	C1B'—C6B'—H6B'	121.8
N2A—O2A—N1A—O1A	178.3 (9)	N2A'—O2A'—N1A'—O1A'	178 (3)
N2A—O2A—N1A—C1A	1.5 (11)	N2A'—O2A'—N1A'—C1A'	3 (3)
N1A—O2A—N2A—C2A	0.3 (11)	N1A'—O2A'—N2A'—C2A'	−5 (2)
O1A—N1A—C1A—C2A	−178.5 (10)	O1A'—N1A'—C1A'—C2A'	−174 (4)
O2A—N1A—C1A—C2A	−2.6 (10)	O2A'—N1A'—C1A'—C2A'	0 (3)
O1A—N1A—C1A—C6A	2.3 (17)	O1A'—N1A'—C1A'—C6A'	8 (6)
O2A—N1A—C1A—C6A	178.2 (9)	O2A'—N1A'—C1A'—C6A'	−178 (5)
O2A—N2A—C2A—C1A	−2.0 (11)	O2A'—N2A'—C2A'—C1A'	5 (3)
O2A—N2A—C2A—C3A	−178.7 (9)	O2A'—N2A'—C2A'—C3A'	−180 (2)
N1A—C1A—C2A—N2A	3.0 (11)	N1A'—C1A'—C2A'—N2A'	−3 (3)
C6A—C1A—C2A—N2A	−177.7 (8)	C6A'—C1A'—C2A'—N2A'	175 (5)
N1A—C1A—C2A—C3A	180.0 (8)	N1A'—C1A'—C2A'—C3A'	−179 (2)
C6A—C1A—C2A—C3A	−0.8 (13)	C6A'—C1A'—C2A'—C3A'	−1 (5)
N2A—C2A—C3A—C4A	178.1 (9)	N2A'—C2A'—C3A'—C4A'	−173 (5)
C1A—C2A—C3A—C4A	1.6 (12)	C1A'—C2A'—C3A'—C4A'	2 (4)
C2A—C3A—C4A—C5A	−2.3 (13)	C2A'—C3A'—C4A'—C5A'	−3 (4)
C2A—C3A—C4A—I1A	179.4 (7)	C2A'—C3A'—C4A'—I1A'	176 (4)
C3A—C4A—C5A—C6A	2.2 (16)	C3A'—C4A'—C5A'—C6A'	3 (5)
I1A—C4A—C5A—C6A	−179.5 (9)	I1A'—C4A'—C5A'—C6A'	−176 (6)
C4A—C5A—C6A—C1A	−1.0 (15)	C4A'—C5A'—C6A'—C1A'	−2 (7)
N1A—C1A—C6A—C5A	179.5 (9)	N1A'—C1A'—C6A'—C5A'	179 (5)
C2A—C1A—C6A—C5A	0.4 (13)	C2A'—C1A'—C6A'—C5A'	1 (7)
N2B—O2B—N1B—O1B	−179.9 (6)	N2B'—O2B'—N1B'—O1B'	−179 (8)
N2B—O2B—N1B—C1B	0.3 (7)	N2B'—O2B'—N1B'—C1B'	0 (7)
N1B—O2B—N2B—C2B	−1.1 (7)	N1B'—O2B'—N2B'—C2B'	1 (7)
O1B—N1B—C1B—C6B	−0.4 (16)	O1B'—N1B'—C1B'—C6B'	−6 (11)
O2B—N1B—C1B—C6B	179.4 (8)	O2B'—N1B'—C1B'—C6B'	176 (8)
O1B—N1B—C1B—C2B	−179.2 (9)	O1B'—N1B'—C1B'—C2B'	177 (9)
O2B—N1B—C1B—C2B	0.6 (8)	O2B'—N1B'—C1B'—C2B'	−1 (5)
O2B—N2B—C2B—C1B	1.5 (9)	O2B'—N2B'—C2B'—C1B'	−2 (6)
O2B—N2B—C2B—C3B	180.0 (8)	O2B'—N2B'—C2B'—C3B'	−180 (6)
N1B—C1B—C2B—N2B	−1.3 (10)	N1B'—C1B'—C2B'—N2B'	2 (5)
C6B—C1B—C2B—N2B	179.8 (8)	C6B'—C1B'—C2B'—N2B'	−175 (8)
N1B—C1B—C2B—C3B	−179.9 (7)	N1B'—C1B'—C2B'—C3B'	180 (5)
C6B—C1B—C2B—C3B	1.1 (12)	C6B'—C1B'—C2B'—C3B'	2 (7)
N2B—C2B—C3B—C4B	179.6 (8)	N2B'—C2B'—C3B'—C4B'	179 (7)
C1B—C2B—C3B—C4B	−2.0 (11)	C1B'—C2B'—C3B'—C4B'	1 (9)
C2B—C3B—C4B—C5B	2.8 (11)	C2B'—C3B'—C4B'—C5B'	−5 (5)
C2B—C3B—C4B—I1B	−178.6 (6)	C2B'—C3B'—C4B'—I1B'	170 (6)
C3B—C4B—C5B—C6B	−2.5 (12)	C3B'—C4B'—C5B'—C6B'	5 (7)
I1B—C4B—C5B—C6B	178.9 (7)	I1B'—C4B'—C5B'—C6B'	−170 (9)
C4B—C5B—C6B—C1B	1.2 (12)	C4B'—C5B'—C6B'—C1B'	−1 (12)
N1B—C1B—C6B—C5B	−179.3 (8)	N1B'—C1B'—C6B'—C5B'	−180 (7)
C2B—C1B—C6B—C5B	−0.7 (12)	C2B'—C1B'—C6B'—C5B'	−3 (9)

(II) 5-iodobenzo-1,2,5-oxadiazole 1-oxide

Crystal data

C6H3IN2O2	F(000) = 976
Mr = 262.00	Dx = 2.312 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2956 reflections
a = 14.392 (4) Å	θ = 2.6–27.4°
b = 7.640 (2) Å	µ = 4.20 mm^−1
c = 15.284 (4) Å	T = 174 K
β = 116.39 (1)°	Needle, yellow
V = 1505.4 (7) Å^3	0.50 × 0.10 × 0.05 mm
Z = 8

Data collection

Siemens SMART 1K CCD area-detector diffractometer	3437 independent reflections
Radiation source: fine-focus sealed tube	2916 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
ω scans	θmax = 27.5°, θmin = 1.6°
Absorption correction: multi-scan [SADABS (Sheldrick, 1996; Blessing, 1995)]	h = −18→18
Tmin = 0.63, Tmax = 0.81	k = −9→9
17038 measured reflections	l = −19→19

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)] = 0.031	H-atom parameters constrained
wR(F^2) = 0.065	w = 1/[σ^2(Fo^2) + (0.021P)^2 + 2.97P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max = 0.002
3437 reflections	Δρmax = 1.29 e Å^−3
200 parameters	Δρmin = −0.95 e Å^−3
0 restraints	Extinction correction: SHELXTL (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0064 (2)

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

	x	y	z	Uiso*/Ueq
I1A	−0.01769 (2)	−0.33005 (4)	0.110736 (18)	0.03802 (10)
O1A	0.2861 (3)	0.4321 (5)	0.1432 (3)	0.0655 (10)
O2A	0.3342 (2)	0.1781 (5)	0.0927 (2)	0.0543 (8)
N1A	0.2700 (3)	0.2754 (5)	0.1273 (3)	0.0461 (9)
N2A	0.3026 (3)	0.0066 (5)	0.0773 (3)	0.0489 (9)
C1A	0.2026 (3)	0.1601 (5)	0.1317 (3)	0.0375 (9)
C2A	0.2239 (3)	−0.0031 (5)	0.1010 (3)	0.0351 (9)
C3A	0.1621 (3)	−0.1514 (5)	0.0953 (3)	0.0358 (9)
H3A	0.1746	−0.2627	0.0749	0.043*
C4A	0.0840 (3)	−0.1250 (5)	0.1209 (3)	0.0311 (8)
C5A	0.0643 (3)	0.0406 (6)	0.1537 (3)	0.0390 (9)
H5A	0.0091	0.0499	0.1715	0.047*
C6A	0.1216 (3)	0.1829 (6)	0.1597 (3)	0.0419 (10)
H6A	0.1088	0.2926	0.1816	0.050*
I1B	0.49171 (2)	0.75493 (4)	0.113192 (19)	0.04070 (10)
O1B	0.7859 (3)	−0.0264 (5)	0.1662 (3)	0.0631 (9)
O2B	0.8422 (2)	0.2182 (5)	0.1165 (2)	0.0510 (8)
N1B	0.7734 (3)	0.1306 (5)	0.1481 (3)	0.0449 (9)
N2B	0.8141 (3)	0.3914 (5)	0.0979 (3)	0.0453 (9)
C1B	0.7068 (3)	0.2517 (5)	0.1486 (3)	0.0355 (9)
C2B	0.7324 (3)	0.4088 (5)	0.1171 (3)	0.0328 (8)
C3B	0.6725 (3)	0.5625 (5)	0.1081 (3)	0.0334 (8)
H3B	0.6885	0.6713	0.0878	0.040*
C4B	0.5916 (3)	0.5443 (5)	0.1301 (2)	0.0304 (8)
C5B	0.5670 (3)	0.3836 (6)	0.1632 (3)	0.0354 (9)
H5B	0.5098	0.3802	0.1785	0.042*
C6B	0.6231 (3)	0.2362 (6)	0.1734 (3)	0.0402 (9)
H6B	0.6075	0.1292	0.1956	0.048*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1A	0.03993 (15)	0.04093 (17)	0.03396 (15)	0.00184 (12)	0.01712 (12)	0.00477 (11)
O1A	0.072 (2)	0.043 (2)	0.068 (2)	−0.0121 (18)	0.0194 (19)	−0.0055 (17)
O2A	0.0438 (17)	0.059 (2)	0.061 (2)	−0.0057 (16)	0.0241 (16)	0.0047 (17)
N1A	0.043 (2)	0.041 (2)	0.039 (2)	0.0006 (17)	0.0057 (16)	0.0021 (16)
N2A	0.045 (2)	0.046 (2)	0.060 (2)	0.0011 (17)	0.0276 (18)	0.0022 (19)
C1A	0.035 (2)	0.036 (2)	0.031 (2)	−0.0012 (18)	0.0058 (16)	0.0044 (17)
C2A	0.0332 (19)	0.040 (2)	0.0305 (19)	0.0069 (17)	0.0127 (16)	0.0034 (16)
C3A	0.041 (2)	0.033 (2)	0.034 (2)	0.0057 (17)	0.0179 (17)	−0.0016 (16)
C4A	0.0323 (18)	0.036 (2)	0.0261 (18)	0.0067 (16)	0.0138 (15)	0.0045 (15)
C5A	0.036 (2)	0.044 (2)	0.039 (2)	0.0096 (18)	0.0183 (17)	−0.0006 (18)
C6A	0.045 (2)	0.038 (2)	0.040 (2)	0.0119 (19)	0.0157 (19)	−0.0015 (18)
I1B	0.04232 (16)	0.03983 (17)	0.03675 (16)	0.00492 (12)	0.01469 (12)	−0.01025 (12)
O1B	0.073 (2)	0.0411 (19)	0.065 (2)	0.0183 (17)	0.0213 (18)	0.0095 (17)
O2B	0.0388 (16)	0.059 (2)	0.0541 (19)	0.0081 (15)	0.0199 (15)	−0.0048 (16)
N1B	0.046 (2)	0.040 (2)	0.0374 (19)	0.0074 (16)	0.0089 (16)	−0.0001 (16)
N2B	0.0389 (18)	0.051 (2)	0.046 (2)	−0.0017 (17)	0.0183 (16)	−0.0064 (18)
C1B	0.0313 (19)	0.039 (2)	0.0278 (19)	0.0044 (17)	0.0057 (16)	−0.0019 (17)
C2B	0.0276 (17)	0.039 (2)	0.0296 (18)	−0.0056 (16)	0.0108 (15)	−0.0065 (17)
C3B	0.038 (2)	0.030 (2)	0.0340 (19)	−0.0072 (16)	0.0176 (17)	−0.0030 (16)
C4B	0.0290 (17)	0.034 (2)	0.0248 (17)	−0.0022 (15)	0.0093 (14)	−0.0064 (15)
C5B	0.0310 (19)	0.042 (2)	0.035 (2)	−0.0074 (17)	0.0160 (16)	0.0000 (17)
C6B	0.047 (2)	0.034 (2)	0.038 (2)	−0.0087 (19)	0.0173 (19)	0.0029 (18)

Geometric parameters (Å, º)

I1A—C4A	2.102 (4)	I1B—C4B	2.096 (4)
O1A—N1A	1.223 (5)	O1B—N1B	1.226 (5)
O2A—N2A	1.373 (5)	O2B—N2B	1.376 (5)
O2A—N1A	1.455 (5)	O2B—N1B	1.444 (5)
N1A—C1A	1.334 (5)	N1B—C1B	1.334 (5)
N2A—C2A	1.335 (5)	N2B—C2B	1.339 (5)
C1A—C2A	1.413 (6)	C1B—C2B	1.402 (6)
C1A—C6A	1.420 (6)	C1B—C6B	1.420 (6)
C2A—C3A	1.419 (6)	C2B—C3B	1.427 (6)
C3A—C4A	1.359 (5)	C3B—C4B	1.356 (5)
C3A—H3A	0.9500	C3B—H3B	0.9500
C4A—C5A	1.435 (6)	C4B—C5B	1.432 (5)
C5A—C6A	1.343 (6)	C5B—C6B	1.354 (6)
C5A—H5A	0.9500	C5B—H5B	0.9500
C6A—H6A	0.9500	C6B—H6B	0.9500
N2A—O2A—N1A	109.5 (3)	N2B—O2B—N1B	109.5 (3)
O1A—N1A—C1A	135.6 (4)	O1B—N1B—C1B	135.3 (4)
O1A—N1A—O2A	118.5 (4)	O1B—N1B—O2B	118.4 (4)
C1A—N1A—O2A	105.9 (3)	C1B—N1B—O2B	106.3 (3)
C2A—N2A—O2A	105.2 (3)	C2B—N2B—O2B	104.8 (3)
N1A—C1A—C2A	107.2 (4)	N1B—C1B—C2B	107.1 (4)
N1A—C1A—C6A	130.3 (4)	N1B—C1B—C6B	129.8 (4)
C2A—C1A—C6A	122.4 (4)	C2B—C1B—C6B	123.1 (4)
N2A—C2A—C1A	112.1 (4)	N2B—C2B—C1B	112.3 (4)
N2A—C2A—C3A	127.7 (4)	N2B—C2B—C3B	127.7 (4)
C1A—C2A—C3A	120.2 (3)	C1B—C2B—C3B	119.9 (3)
C4A—C3A—C2A	116.1 (4)	C4B—C3B—C2B	116.1 (4)
C4A—C3A—H3A	121.9	C4B—C3B—H3B	121.9
C2A—C3A—H3A	121.9	C2B—C3B—H3B	121.9
C3A—C4A—C5A	123.3 (4)	C3B—C4B—C5B	123.4 (4)
C3A—C4A—I1A	120.4 (3)	C3B—C4B—I1B	120.6 (3)
C5A—C4A—I1A	116.3 (3)	C5B—C4B—I1B	116.0 (3)
C6A—C5A—C4A	121.8 (4)	C6B—C5B—C4B	121.7 (3)
C6A—C5A—H5A	119.1	C6B—C5B—H5B	119.2
C4A—C5A—H5A	119.1	C4B—C5B—H5B	119.2
C5A—C6A—C1A	116.2 (4)	C5B—C6B—C1B	115.7 (4)
C5A—C6A—H6A	121.9	C5B—C6B—H6B	122.1
C1A—C6A—H6A	121.9	C1B—C6B—H6B	122.1
N2A—O2A—N1A—O1A	−178.6 (4)	N2B—O2B—N1B—O1B	178.6 (3)
N2A—O2A—N1A—C1A	0.1 (4)	N2B—O2B—N1B—C1B	−0.5 (4)
N1A—O2A—N2A—C2A	−0.1 (4)	N1B—O2B—N2B—C2B	0.0 (4)
O1A—N1A—C1A—C2A	178.4 (4)	O1B—N1B—C1B—C2B	−178.1 (5)
O2A—N1A—C1A—C2A	0.0 (4)	O2B—N1B—C1B—C2B	0.7 (4)
O1A—N1A—C1A—C6A	−1.0 (8)	O1B—N1B—C1B—C6B	1.0 (8)
O2A—N1A—C1A—C6A	−179.4 (4)	O2B—N1B—C1B—C6B	179.8 (4)
O2A—N2A—C2A—C1A	0.1 (5)	O2B—N2B—C2B—C1B	0.5 (4)
O2A—N2A—C2A—C3A	178.1 (4)	O2B—N2B—C2B—C3B	−178.9 (4)
N1A—C1A—C2A—N2A	−0.1 (5)	N1B—C1B—C2B—N2B	−0.8 (5)
C6A—C1A—C2A—N2A	179.4 (4)	C6B—C1B—C2B—N2B	−180.0 (4)
N1A—C1A—C2A—C3A	−178.2 (3)	N1B—C1B—C2B—C3B	178.7 (3)
C6A—C1A—C2A—C3A	1.3 (6)	C6B—C1B—C2B—C3B	−0.5 (6)
N2A—C2A—C3A—C4A	−177.9 (4)	N2B—C2B—C3B—C4B	178.5 (4)
C1A—C2A—C3A—C4A	0.0 (5)	C1B—C2B—C3B—C4B	−0.9 (5)
C2A—C3A—C4A—C5A	−1.1 (6)	C2B—C3B—C4B—C5B	1.7 (5)
C2A—C3A—C4A—I1A	177.5 (3)	C2B—C3B—C4B—I1B	−176.7 (2)
C3A—C4A—C5A—C6A	1.1 (6)	C3B—C4B—C5B—C6B	−1.1 (6)
I1A—C4A—C5A—C6A	−177.6 (3)	I1B—C4B—C5B—C6B	177.4 (3)
C4A—C5A—C6A—C1A	0.2 (6)	C4B—C5B—C6B—C1B	−0.3 (6)
N1A—C1A—C6A—C5A	178.1 (4)	N1B—C1B—C6B—C5B	−177.9 (4)
C2A—C1A—C6A—C5A	−1.3 (6)	C2B—C1B—C6B—C5B	1.1 (6)