Isomorphous crystal structures of chlorodi-acetyl-ene and iododi-acetyl-ene derivatives: simultaneous hydrogen and halogen bonds on carbon-yl.

The crystal structures of tert-butyl (5-chloro-penta-2,4-diyn-1-yl)carbamate, C10H12ClNO2 (II), and tert-butyl (5-iodo-penta-2,4-diyn-1-yl)carbamate, C10H12INO2 (IV), are isomorphous to previously reported structures and accordingly their mol-ecular and supra-molecular structures are similar. In the crystals of (II) and (IV), mol-ecules are linked into very similar two-dimensional wall organizations with anti-parallel carbamate groups involved in a combination of hydrogen and halogen bonds (bifurcated N-H⋯O=C and C≡C-X⋯O=C inter-actions on the same carbonyl group). There is no long-range parallel stacking of diynes, so the topochemical polymerization of di-acetyl-ene is prevented. A Cambridge Structural Database search revealed that C≡C-X⋯O=C contacts shorter than the sum of the van der Waals radii are scarce (only one structure for the C≡C-Cl⋯O=C inter-action and 13 structures for the similar C≡C-I⋯O=C inter-action).

Chemical context

Hydrogen bonds (HBs) and <span class="Chemical">halogen bonds (XBs) are considered to be useful noncovalent synthetic tools in crystal engineering (Aakeröy et al., 2015 ▸; Grabowski, 2016 ▸; Resnati et al., 2015 ▸; Cinčić et al., 2008 ▸). Indeed, these directional inter­molecular inter­actions facilitate the preparation of the desired solid-state motifs and architectures (Gilday et al., 2015 ▸; Cavallo et al., 2016 ▸; Priimagi et al., 2013 ▸; Mukherjee et al., 2014 ▸; Shirman et al., 2015 ▸; Mukherjee et al., 2017 ▸). For example, using HBs and XBs, the specific organization of terminal di­acetyl­enes (Li et al., 2009 ▸; Ouyang et al., 2003 ▸), bromodi­acetyl­enes (Jin et al., 2015 ▸) and iododi­acetyl­enes (Jin et al., 2013 ▸; Sun et al., 2006 ▸) has been obtained to achieve the solid-state topochemical polymerization of di­acetyl­enes. On the other hand, to the best of our knowledge, no chlorodi­acetyl­ene topochemical polymerizations have been reported. Our results show that chlorodi­acetyl­ene (II) is isostructural to iododi­acetyl­ene (IV) and the previously reported bromodi­acetyl­ene (III) and terminal di­acetyl­ene (I) (Baillargeon et al., 2016 ▸) (see Scheme). Although the arrangement of diynes in the present article stands no chance of undergoing topochemical polymerization, we suggest that in other systems prone to polymerization, replacing Br, I or H atoms by Cl atoms in their diyne groups might result in successful PolyChloroDi­Acetyl­ene (PCDA) formation as well. This work also contributes to an emerging research theme, namely the concept of orthogonal mol­ecular inter­actions such as HBs and XBs (Kratzer et al., 2015 ▸; Takemura et al., 2014 ▸; Voth et al., 2009 ▸), which may find applications in medicinal chemistry and chemical biology (Wilcken et al., 2013 ▸).

Structural commentary

The mol­ecular structures of compounds (II) and (IV) are shown in Fig. 1 ▸. All bond lengths and angles are within normal ranges. For example, the inter­nal diyne C2—C3 bonds lengths [1.376 (3) Å for (II) and 1.385 (4) Å for (IV)] follow the useful rule of thumb describing a C—C single-bond distance (1.54 Å) decreasing by 0.04 Å each time one of the participating C atoms changes hybridization from sp 3 to sp 2 or from sp 2 to sp (Bent, 1961 ▸). Moreover, the observed distances are almost identical to those found recently in the literature for similar <span class="Chemical">halodiynes (Hoheisel et al., 2013 ▸; Baillargeon et al., 2016 ▸). The relative orientation between the di­acetyl­enic moiety and the carbamate functional group can be established by the absolute value of the torsion angles C4—C5—N1—C6 [111.07 (19)°] for (II) and [103.8 (3)°] for (IV).

Figure 1

The mol­ecular structure of (A) compound (II) and (B) compound (IV), showing the atom-labelling schemes. Displacement ellipsoids are drawn at the 50% probability level. H atoms are shown as fixed-size spheres of 0.30 Å.

Supra­molecular features

In the crystals of compounds (II) and (IV), mol­ecules are linked via an N—H⋯O=C hydrogen bond between their respective <span class="Chemical">carbamate functionalities [N1—H1⋯O1i (Table 1 ▸) and N1—H1⋯O2i (Table 2 ▸)], generating an anti­parallel stacking pattern which orients the di­acetyl­ene skeleton on each side of the one-dimensional carbamate tape (parts B and D in Fig. 2 ▸). For both crystals, the simultaneous presence of halogen and hydrogen bonds with the carbamate O atom have been found. Indeed, additional halogen-bond inter­actions occur with the carbamate O atom [Cl1⋯O1ii for (II) and I1⋯O2ii for (IV)], resulting in an infinite two-dimensional network that can be considered as polar supra­molecular walls. This arrangement is similar to our previous work (Baillargeon et al., 2016 ▸) on the terminal di­acetyl­ene (I) (part A in Fig. 2 ▸) and the bromodi­acetyl­ene (III) (part C in Fig. 2 ▸). In fact, diynes (I)–(IV) (Fig. 2 ▸) constitute a complete set of truly isomorphous crystals that can be carefully examined to evaluate the differences and similarities that exist between halogen and hydrogen bonds. Thus, the X⋯O⋯H angle increases as the size of the halogen atom becomes larger. This angle, which is pretty open in the chlorine crystal (II) (Cl1⋯O1⋯H1; part B in Fig. 2 ▸; 69°) adopts a near orthogonal geometry with the iodine (I1⋯O2⋯H1; part D in Fig. 2 ▸; 83°). It is not a surprise that the bromine crystal (III) represents an inter­mediate case (part C in Fig. 2 ▸; 72°). The value for the terminal di­acetyl­ene (I) X = H (part A in Fig. 2 ▸; 76°) is closely related to the bromodi­acetyl­ene (Baillargeon et al., 2016 ▸).

Table 1

Hydrogen-bond and halogen-bond geometries (Å, °) for (II)

D—X⋯A	D—X	X⋯A	D⋯A	D—X⋯A
N1—H1⋯O1i	0.88	2.09	2.934 (2)	162
C1—Cl1⋯O1ii	1.665 (2)	3.127 (2)	4.792 (3)	179.01 (7)

Symmetry codes: (i) ; (ii) .

Table 2

Hydrogen-bond and halogen-bond geometries (Å, °) for (IV)

D—X⋯A	D—X	X⋯A	D⋯A	D—X⋯A
N1—H1⋯O2i	0.88	2.04	2.881 (2)	160
C1—I1⋯O2ii	1.999 (2)	2.945 (2)	4.919 (3)	168.31 (8)

Symmetry codes: (i) ; (ii) .

Figure 2

Halogen (green lines) and/or hydrogen bonds (blue lines) inside the supra­molecular walls of (A) diyne (I), (B) chloro­diyne (II), (C) bromo­diyne (III) and (D) iodo­diyne (IV). The nonpolar H atoms have been omitted for clarity.

Database survey

A survey of the Cambridge Structural Database (Conquest Version 1.19; CSD, Version 5.38, November 2016 plus 3 updates; Groom et al., 2016 ▸) furnished 404 hits of terminal <span class="Chemical">alkynes CC—H having close contacts with carbonyl O=C (shorter than the sum of their van der Waals radii). On the other hand, similar contacts from halogenoalkyne analogs are scarce (1 hit for the chloro­alkyne, 4 hits for the bromo­alkyne and 13 hits for the iodo­alkyne; Table 3 ▸). For the iodo­alkyne, results are limited to monovalent iodine and for a structure in which the carbonyl group is not involved in an organometallic complex.

Table 3

CSD data (Groom et al., 2016 ▸) retrieved for the C≡C—X⋯O=C contacts shorter than the sum of their van der Waals radii

C≡C—X⋯O=C contacts	CSD refcode	Space group	X⋯O distance (Å)	C—X⋯O angle (°)	Reference
C≡C—Cl⋯O=C	NIDWAA	P	3.111; 3.241	152.59; 158.76	Kawai et al. (2013 ▸)
C≡C—Br⋯O=C	HEVWAI	C2	2.959	158.12	Hoheisel et al. (2013 ▸)
C≡C—Br⋯O=C	HEVWAI01	P212121	2.966	166.70	Hoheisel et al. (2013 ▸)
C≡C—Br⋯O=C	NIDWII	P21/n	2.867	171.11	Kawai et al. (2013 ▸)
C≡C—Br⋯O=C	KAMXII	P21/c	3.060	178.26	Baillargeon et al. (2016 ▸)
C≡C—I⋯O=C	COHYUU	P	3.096	164.55	Luo et al. (2008 ▸)
C≡C—I⋯O=C	IYAYUC	Pca21	2.861	170.36	Hou et al. (2004 ▸)
C≡C—I⋯O=C	MASVUZ	P21/n	2.834; 2.887	170.72; 172.97	Perkins et al. (2012 ▸)
C≡C—I⋯O=C	TOYPUS	P21/c	2.933	175.36	Avtomonov et al. (1997 ▸)
C≡C—I⋯O=C	HOWXIC	P21/c	2.887	169.51	Dumele et al. (2014 ▸)
C≡C—I⋯O=C	LUNKOW	P2/c	2.791	174.12	Kratzer et al. (2015 ▸)
C≡C—I⋯O=C	LUNKUC	P21/c	2.754	172.63	Kratzer et al. (2015 ▸)
C≡C—I⋯O=C	LUNLAJ	P21/c	2.773	173.70	Kratzer et al. (2015 ▸)
C≡C—I⋯O=C	LUNLIR	Pca21	2.858	170.94	Kratzer et al. (2015 ▸)
C≡C—I⋯O=C	LUNLOX	C2/c	2.763	175.58	Kratzer et al. (2015 ▸)
C≡C—I⋯O=C	IBUYAI	P21/m	2.856	177.96	Dumele et al. (2017 ▸)
C≡C—I⋯O=C	IBUYOW	P21/c	2.830	176.52	Dumele et al. (2017 ▸)
C≡C—I⋯O=C	IBUYUC	P	2.878	177.89	Dumele et al. (2017 ▸)

Synthesis and crystallization

Compound (II)

Tetra-n-butylammonium fluoride (<span class="Chemical">TBAF, 0.437 ml, 1 M in THF, 0.437 mmol), AgNO3 (39 mg, 0.23 mmol) and NCS (190 mg, 1.42 mmol) were added to a solution of BocNHCH2—C≡C—C≡C—TMS (183 mg, 0.728 mmol) in aceto­nitrile (3 ml) at room temperature. The resulting mixture was stirred for 2.5 h under N2 in the absence of light. Purification of the crude product by flash chromatography on silica gel, eluting with mixtures of Hex/DCM/Et2O (gradient from 9:1:1 to 1:1:1), provided compound (II) as a beige solid (yield 72 mg, 46%). Single crystals suitable for X-ray diffraction were prepared by diffusion of pentane into a chloro­form solution of (II) at 263 K. R F = 0.43 (2:1:1 Hex/DCM/Et2O); IR (UATR, ν, cm−1): 3326, 2977, 2920, 2255, 2168, 1673, 1531, 1421, 1368, 1278, 1248, 1222, 1158, 1143, 1042, 1028, 933, 849, 761, 718, 655; 1H NMR (400 MHz, CDCl3): δ 4.72 (br, 1H), 3.99 (d, 2H), 1.45 (s, 9H); HRMS (m/z): calculated for C10H12ClNNaO2 [MNa+]: 236.0449, found: 236.0448.

Compound (IV)

TBAF (0.437 ml, 1 M in <span class="Chemical">THF, 0.437 mmol), AgNO3 (39 mg, 0.23 mmol) and NIS (328 mg, 1.46 mmol) were added to a solution of BocNHCH2—C≡C—C≡C—TMS (183 mg, 0.728 mmol) in aceto­nitrile (3 ml) at room temperature. The resulting mixture was stirred for 2.5 h under N2 in the absence of light. Purification of the crude product by flash chromatography on silica gel, eluting with mixtures of Hex/DCM/Et2O (gradient from 9:1:1 to 1:1:1) provided compound (IV) as a beige solid (yield 95 mg, 43%). Single crystals suitable for X-ray diffraction were prepared by slow evaporation from a chloro­form solution of (IV) at room temperature. R F = 0.48 (2:1:1 Hex/DCM/Et2O); IR (UATR, ν, cm−1): 3328, 2980, 2933, 2230, 2159, 1661, 1532, 1451, 1420, 1367, 1284, 1250, 1154, 1142, 1042, 1026, 929, 851, 762, 714, 647; 1H NMR (400 MHz, CDCl3): δ 4.73 (br, 1H), 4.02 (d, 2H), 1.44 (s, 9H).

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 4 ▸.

Table 4

Experimental details

	(II)	(IV)
Crystal data
Chemical formula	C10H12ClNO2	C10H12INO2
M r	213.66	305.11
Crystal system, space group	Monoclinic, P21/c	Monoclinic, P21/n
Temperature (K)	173	173
a, b, c (Å)	10.336 (3), 9.171 (3), 11.870 (3)	11.1587 (16), 9.0288 (13), 12.9899 (18)
β (°)	100.656 (5)	108.731 (2)
V (Å3)	1105.8 (5)	1239.4 (3)
Z	4	4
Radiation type	Mo Kα	Mo Kα
μ (mm−1)	0.32	2.56
Crystal size (mm)	0.34 × 0.22 × 0.02	0.36 × 0.3 × 0.28
Data collection
Diffractometer	Bruker APEXII	Bruker APEXII
Absorption correction	Multi-scan (SADABS; Bruker, 2008 ▸)	Multi-scan (SADABS; Bruker, 2008 ▸)
T min, T max	0.66, 0.745	0.675, 0.745
No. of measured, independent and observed [I > 2σ(I)] reflections	16132, 2249, 1755	17970, 2532, 2342
R int	0.045	0.02
(sin θ/λ)max (Å−1)	0.625	0.626
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.036, 0.089, 1.06	0.022, 0.054, 1.08
No. of reflections	2249	2532
No. of parameters	130	130
H-atom treatment	H-atom parameters constrained	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.22, −0.21	1.32, −0.69

Computer programs: APEX2 (Bruker, 2008 ▸), SAINT (Bruker, 2008 ▸), SORTAV (Blessing, 1995 ▸), SHELXS97 (Sheldrick, 2008 ▸), SHELXL2016 (Sheldrick, 2015 ▸), ORTEP-3 for Windows (Farrugia, 2012 ▸), Mercury (Macrae et al., 2006 ▸), WinGX (Farrugia, 2012 ▸) and publCIF (Westrip, 2010 ▸).

Crystal structure: contains datablock(s) global, II, IV. DOI: 10.1107/S2056989017010155/mw2133sup1.cif

Structure factors: contains datablock(s) II. DOI: 10.1107/S2056989017010155/mw2133IIsup2.hkl

Structure factors: contains datablock(s) IV. DOI: 10.1107/S2056989017010155/mw2133IVsup3.hkl

CCDC references: 1551031, 1551032

Additional supporting information: crystallographic information; 3D view; checkCIF report

C10H12ClNO2	F(000) = 448
Mr = 213.66	Dx = 1.283 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 8841 reflections
a = 10.336 (3) Å	θ = 2.8–26.4°
b = 9.171 (3) Å	µ = 0.32 mm−1
c = 11.870 (3) Å	T = 173 K
β = 100.656 (5)°	Plate, orange
V = 1105.8 (5) Å3	0.34 × 0.22 × 0.02 mm
Z = 4

Bruker APEXII diffractometer	2249 independent reflections
Radiation source: sealed x-ray tube	1755 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
φ or ω oscillation scans	θmax = 26.4°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −12→12
Tmin = 0.66, Tmax = 0.745	k = −11→11
16132 measured reflections	l = −9→14

Refinement on F2	0 constraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.036	H-atom parameters constrained
wR(F2) = 0.089	w = 1/[σ2(Fo2) + (0.0397P)2 + 0.2863P] where P = (Fo2 + 2Fc2)/3
S = 1.06	(Δ/σ)max < 0.001
2249 reflections	Δρmax = 0.22 e Å−3
130 parameters	Δρmin = −0.21 e Å−3
0 restraints

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

	x	y	z	Uiso*/Ueq
C1	0.40035 (19)	0.0211 (2)	0.15762 (16)	0.0343 (4)
C2	0.50716 (18)	−0.0266 (2)	0.15615 (16)	0.0336 (4)
C3	0.63096 (19)	−0.0798 (2)	0.15309 (16)	0.0336 (4)
C4	0.73990 (19)	−0.1223 (2)	0.15037 (16)	0.0334 (4)
C5	0.87519 (17)	−0.1687 (2)	0.14761 (17)	0.0339 (4)
H5A	0.882935	−0.274828	0.16243	0.041*
H5B	0.894345	−0.150569	0.070125	0.041*
C6	1.04144 (17)	−0.15939 (19)	0.32333 (15)	0.0271 (4)
C7	1.22986 (18)	−0.11065 (19)	0.47967 (15)	0.0304 (4)
C8	1.1748 (2)	−0.1841 (2)	0.57483 (17)	0.0439 (5)
H8A	1.106364	−0.122368	0.597047	0.066*
H8B	1.245644	−0.198955	0.641132	0.066*
H8C	1.136913	−0.278618	0.547923	0.066*
C9	1.32333 (19)	−0.2075 (2)	0.42986 (18)	0.0408 (5)
H9A	1.278745	−0.298815	0.40299	0.061*
H9B	1.400577	−0.228971	0.488902	0.061*
H9C	1.351283	−0.15766	0.365371	0.061*
C10	1.2953 (2)	0.0332 (2)	0.52078 (19)	0.0449 (5)
H10A	1.324136	0.082715	0.456527	0.067*
H10B	1.371735	0.014414	0.581378	0.067*
H10C	1.232365	0.095115	0.550916	0.067*
Cl1	0.24981 (4)	0.08590 (5)	0.15756 (4)	0.03061 (14)
N1	0.97160 (14)	−0.09282 (16)	0.23144 (13)	0.0314 (4)
H1	0.984766	0.000739	0.221551	0.038*
O1	1.03225 (13)	−0.28874 (13)	0.34594 (11)	0.0361 (3)
O2	1.12149 (12)	−0.06256 (12)	0.38708 (11)	0.0311 (3)

	U11	U22	U33	U12	U13	U23
C1	0.0342 (11)	0.0349 (11)	0.0334 (11)	−0.0009 (9)	0.0055 (8)	0.0009 (8)
C2	0.0337 (11)	0.0333 (10)	0.0323 (11)	−0.0036 (8)	0.0019 (8)	0.0007 (8)
C3	0.0333 (11)	0.0300 (10)	0.0346 (11)	−0.0005 (8)	−0.0011 (8)	0.0016 (8)
C4	0.0339 (11)	0.0279 (10)	0.0350 (11)	−0.0023 (8)	−0.0028 (8)	−0.0006 (8)
C5	0.0309 (10)	0.0311 (10)	0.0368 (11)	0.0013 (8)	−0.0014 (8)	−0.0030 (8)
C6	0.0264 (9)	0.0222 (9)	0.0323 (10)	−0.0014 (7)	0.0045 (7)	−0.0023 (7)
C7	0.0311 (10)	0.0269 (10)	0.0299 (10)	0.0017 (8)	−0.0026 (8)	0.0021 (8)
C8	0.0524 (13)	0.0429 (12)	0.0369 (12)	0.0014 (10)	0.0091 (10)	0.0049 (9)
C9	0.0344 (11)	0.0415 (12)	0.0451 (13)	0.0056 (9)	0.0037 (9)	0.0019 (9)
C10	0.0468 (13)	0.0339 (11)	0.0462 (13)	−0.0041 (10)	−0.0121 (10)	−0.0007 (9)
Cl1	0.0268 (2)	0.0320 (3)	0.0337 (3)	0.00451 (19)	0.00733 (18)	0.00090 (19)
N1	0.0303 (8)	0.0220 (8)	0.0381 (9)	−0.0024 (7)	−0.0036 (7)	0.0013 (7)
O1	0.0409 (8)	0.0217 (7)	0.0427 (8)	−0.0034 (6)	0.0003 (6)	0.0014 (6)
O2	0.0314 (7)	0.0220 (7)	0.0358 (8)	−0.0009 (5)	−0.0049 (6)	−0.0006 (5)

C1—C2	1.191 (3)	C6—N1	1.339 (2)
C1—Cl1	1.666 (2)	C6—O2	1.347 (2)
C2—C3	1.376 (3)	C7—O2	1.484 (2)
C3—C4	1.198 (3)	C7—C9	1.511 (3)
C4—C5	1.468 (3)	C7—C8	1.513 (3)
C5—N1	1.449 (2)	C7—C10	1.521 (3)
C6—O1	1.224 (2)
C2—C1—Cl1	178.9 (2)	O2—C7—C9	109.55 (15)
C1—C2—C3	179.0 (2)	O2—C7—C8	110.41 (15)
C4—C3—C2	178.2 (2)	C9—C7—C8	112.70 (16)
C3—C4—C5	177.8 (2)	O2—C7—C10	102.12 (14)
N1—C5—C4	112.49 (16)	C9—C7—C10	110.89 (17)
O1—C6—N1	124.66 (17)	C8—C7—C10	110.67 (17)
O1—C6—O2	125.48 (17)	C6—N1—C5	122.64 (16)
N1—C6—O2	109.86 (15)	C6—O2—C7	121.42 (13)
O1—C6—N1—C5	0.3 (3)	N1—C6—O2—C7	−166.78 (14)
O2—C6—N1—C5	−178.98 (15)	C9—C7—O2—C6	59.3 (2)
C4—C5—N1—C6	111.1 (2)	C8—C7—O2—C6	−65.4 (2)
O1—C6—O2—C7	13.9 (3)	C10—C7—O2—C6	176.85 (16)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1i	0.88	2.09	2.935	162
C1—Cl1···O1ii	1.67	3.13	4.793	179

C10H12INO2	F(000) = 592
Mr = 305.11	Dx = 1.635 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 9940 reflections
a = 11.1587 (16) Å	θ = 2.3–26.4°
b = 9.0288 (13) Å	µ = 2.56 mm−1
c = 12.9899 (18) Å	T = 173 K
β = 108.731 (2)°	Prism, yellow
V = 1239.4 (3) Å3	0.36 × 0.3 × 0.28 mm
Z = 4

Bruker APEXII diffractometer	2532 independent reflections
Radiation source: sealed x-ray tube	2342 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.02
φ or ω oscillation scans	θmax = 26.4°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −12→13
Tmin = 0.675, Tmax = 0.745	k = −11→11
17970 measured reflections	l = −15→16

Refinement on F2	0 constraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.022	H-atom parameters constrained
wR(F2) = 0.054	w = 1/[σ2(Fo2) + (0.0203P)2 + 1.7447P] where P = (Fo2 + 2Fc2)/3
S = 1.08	(Δ/σ)max = 0.001
2532 reflections	Δρmax = 1.32 e Å−3
130 parameters	Δρmin = −0.69 e Å−3
0 restraints

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

	x	y	z	Uiso*/Ueq
C1	0.2157 (2)	1.0340 (3)	0.3437 (2)	0.0328 (6)
C2	0.3210 (2)	1.0012 (3)	0.34873 (19)	0.0304 (5)
C3	0.4425 (2)	0.9623 (3)	0.35280 (19)	0.0279 (5)
C4	0.5465 (2)	0.9286 (3)	0.35525 (19)	0.0275 (5)
C5	0.6760 (2)	0.8938 (3)	0.35692 (19)	0.0282 (5)
H5A	0.736704	0.927089	0.42691	0.034*
H5B	0.684833	0.785076	0.352172	0.034*
C6	0.7111 (2)	0.8882 (2)	0.18051 (19)	0.0219 (4)
C7	0.7579 (3)	0.9226 (3)	0.0094 (2)	0.0344 (6)
C8	0.7976 (4)	1.0622 (3)	−0.0367 (3)	0.0511 (8)
H8A	0.730469	1.136625	−0.049832	0.077*
H8B	0.812386	1.038609	−0.105307	0.077*
H8C	0.875616	1.101212	0.015278	0.077*
C9	0.6338 (4)	0.8624 (4)	−0.0654 (3)	0.0559 (9)
H9A	0.611252	0.772368	−0.033698	0.084*
H9B	0.642508	0.839113	−0.136337	0.084*
H9C	0.567195	0.936832	−0.074587	0.084*
C10	0.8637 (3)	0.8100 (4)	0.0377 (3)	0.0506 (8)
H10A	0.936443	0.849222	0.095807	0.076*
H10B	0.888703	0.789497	−0.02666	0.076*
H10C	0.834626	0.718248	0.062297	0.076*
N1	0.7077 (2)	0.9636 (2)	0.26832 (16)	0.0263 (4)
H1	0.725256	1.058913	0.272455	0.032*
O1	0.73962 (17)	0.97953 (18)	0.11063 (13)	0.0272 (4)
O2	0.69111 (17)	0.75519 (18)	0.16743 (14)	0.0289 (4)
I1	0.04221 (2)	1.09875 (2)	0.33737 (2)	0.03907 (7)

	U11	U22	U33	U12	U13	U23
C1	0.0294 (14)	0.0398 (14)	0.0301 (13)	0.0020 (11)	0.0106 (10)	0.0027 (11)
C2	0.0333 (14)	0.0328 (13)	0.0263 (12)	−0.0012 (11)	0.0110 (10)	0.0031 (10)
C3	0.0312 (14)	0.0309 (13)	0.0250 (11)	−0.0015 (10)	0.0139 (10)	0.0011 (10)
C4	0.0337 (14)	0.0284 (12)	0.0236 (11)	−0.0036 (10)	0.0135 (10)	0.0005 (9)
C5	0.0298 (13)	0.0321 (13)	0.0259 (12)	0.0007 (10)	0.0132 (10)	0.0032 (10)
C6	0.0180 (11)	0.0216 (11)	0.0271 (11)	0.0013 (8)	0.0087 (9)	0.0020 (9)
C7	0.0490 (17)	0.0323 (13)	0.0293 (13)	−0.0017 (12)	0.0229 (12)	−0.0034 (10)
C8	0.085 (3)	0.0407 (17)	0.0437 (17)	−0.0055 (16)	0.0430 (18)	0.0016 (13)
C9	0.067 (2)	0.065 (2)	0.0325 (15)	−0.0141 (18)	0.0106 (15)	−0.0046 (15)
C10	0.065 (2)	0.0415 (17)	0.063 (2)	0.0074 (15)	0.0446 (18)	−0.0051 (15)
N1	0.0334 (11)	0.0215 (10)	0.0304 (10)	−0.0039 (8)	0.0191 (9)	−0.0015 (8)
O1	0.0396 (10)	0.0196 (8)	0.0293 (9)	0.0004 (7)	0.0209 (7)	0.0004 (7)
O2	0.0348 (10)	0.0197 (8)	0.0352 (9)	−0.0030 (7)	0.0157 (8)	−0.0001 (7)
I1	0.02499 (10)	0.04928 (12)	0.04157 (11)	0.00657 (8)	0.00878 (7)	0.00614 (8)

C1—C2	1.193 (4)	C7—C9	1.514 (4)
C1—I1	1.999 (3)	C7—C8	1.521 (4)
C2—C3	1.385 (4)	C8—H8A	0.98
C3—C4	1.191 (4)	C8—H8B	0.98
C4—C5	1.472 (3)	C8—H8C	0.98
C5—N1	1.452 (3)	C9—H9A	0.98
C5—H5A	0.99	C9—H9B	0.98
C5—H5B	0.99	C9—H9C	0.98
C6—O2	1.223 (3)	C10—H10A	0.98
C6—O1	1.338 (3)	C10—H10B	0.98
C6—N1	1.340 (3)	C10—H10C	0.98
C7—O1	1.486 (3)	N1—H1	0.88
C7—C10	1.512 (4)
C2—C1—I1	177.3 (3)	H8A—C8—H8B	109.5
C1—C2—C3	179.1 (3)	C7—C8—H8C	109.5
C4—C3—C2	179.4 (3)	H8A—C8—H8C	109.5
C3—C4—C5	177.4 (3)	H8B—C8—H8C	109.5
N1—C5—C4	112.5 (2)	C7—C9—H9A	109.5
N1—C5—H5A	109.1	C7—C9—H9B	109.5
C4—C5—H5A	109.1	H9A—C9—H9B	109.5
N1—C5—H5B	109.1	C7—C9—H9C	109.5
C4—C5—H5B	109.1	H9A—C9—H9C	109.5
H5A—C5—H5B	107.8	H9B—C9—H9C	109.5
O2—C6—O1	125.7 (2)	C7—C10—H10A	109.5
O2—C6—N1	124.3 (2)	C7—C10—H10B	109.5
O1—C6—N1	110.00 (19)	H10A—C10—H10B	109.5
O1—C7—C10	109.6 (2)	C7—C10—H10C	109.5
O1—C7—C9	109.6 (2)	H10A—C10—H10C	109.5
C10—C7—C9	113.4 (3)	H10B—C10—H10C	109.5
O1—C7—C8	101.7 (2)	C6—N1—C5	122.3 (2)
C10—C7—C8	110.5 (3)	C6—N1—H1	118.8
C9—C7—C8	111.5 (3)	C5—N1—H1	118.8
C7—C8—H8A	109.5	C6—O1—C7	121.17 (18)
C7—C8—H8B	109.5
O2—C6—N1—C5	−1.7 (4)	N1—C6—O1—C7	175.9 (2)
O1—C6—N1—C5	178.5 (2)	C10—C7—O1—C6	−58.9 (3)
C4—C5—N1—C6	−103.9 (3)	C9—C7—O1—C6	66.1 (3)
O2—C6—O1—C7	−3.9 (4)	C8—C7—O1—C6	−175.8 (2)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O2i	0.88	2.04	2.881	160
C1—I1···O2ii	2.00	2.95	4.919	168