Nontypical iodine–halogen bonds in the crystal structure of (3E)-8-chloro-3-iodo­methyl­idene-2,3-di­hydro-1,4-oxazino[2,3,4-ij]quinolin-4-ium triiodide

Two kinds of iodine–iodine halogen bonds are the focus of our attention in the crystal structure of the title salt, C₁₂H₈ClINO⁺·I₃⁻, described by X-ray diffraction. The first kind is a halogen bond, reinforced by charges, between the I atom of the heterocyclic cation and the triiodide anion. The second kind is the rare case of a halogen bond between the terminal atoms of neighbouring triiodide anions. The influence of relatively weakly bound iodine inside an asymmetric triiodide anion on the thermal and Raman spectroscopic properties has been demonstrated.

Computing details

Data collection: APEX2 (Bruker, 2013); cell refinement: SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015); molecular graphics: SHELXTL (Bruker, 2013) and ACD/ChemSketch (Advanced Chemistry Development Inc., 2015); software used to prepare material for publication: SHELXTL (Bruker, 2013).

(3E)-8-Chloro-3-iodomethylidene-2,3-dihydro-1,4-oxazino[2,3,4-ij]quinolin-4-ium triiodide

Crystal data

C12H8ClINO^+·I3^−	F(000) = 1296
Mr = 725.24	Dx = 2.889 Mg m^−3
Monoclinic, P21/n	Synchrotron radiation, λ = 0.41328 Å
a = 7.6227 (2) Å	Cell parameters from 9796 reflections
b = 13.9464 (4) Å	θ = 2.3–17.2°
c = 16.0161 (4) Å	µ = 1.75 mm^−1
β = 101.6439 (7)°	T = 100 K
V = 1667.62 (8) Å^3	Prism, brown
Z = 4	0.04 × 0.03 × 0.01 mm

Data collection

Bruker APEXII CCD diffractometer	5066 independent reflections
Radiation source: Advanced photon source	4500 reflections with I > 2σ(I)
Diamond (111) monochromator	Rint = 0.048
φ–scan	θmax = 17.2°, θmin = 1.5°
Absorption correction: multi-scan (SADABS; Bruker, 2013)	h = −10→10
Tmin = 0.842, Tmax = 0.955	k = −19→19
45635 measured reflections	l = −22→20

Refinement

Refinement on F^2	Primary atom site location: difference Fourier map
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.016	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.035	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0066P)^2 + 1.3647P] where P = (Fo^2 + 2Fc^2)/3
5066 reflections	(Δ/σ)max = 0.002
172 parameters	Δρmax = 0.59 e Å^−3
0 restraints	Δρmin = −0.52 e Å^−3

Special details

Experimental. The crystal was cooled to 100 (2) K using the Cryojet N2 cold stream. The data collection was performed in φ-scan mode using steps of 0.5° and with fixed ω and χ angles.

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.

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

	x	y	z	Uiso*/Ueq
I1	0.66498 (2)	0.62361 (2)	0.89967 (2)	0.01440 (3)
I2	0.73791 (2)	0.93112 (2)	0.88024 (2)	0.01641 (3)
I3	0.56775 (2)	0.82664 (2)	0.72026 (2)	0.01462 (3)
I4	0.41517 (2)	0.71760 (2)	0.57124 (2)	0.01730 (4)
Cl1	0.31958 (7)	0.08762 (4)	0.56172 (3)	0.01759 (10)
O1	0.5294 (2)	0.31342 (10)	0.87713 (9)	0.0146 (3)
N1	0.3789 (2)	0.40884 (12)	0.72295 (11)	0.0122 (3)
C1	0.2998 (3)	0.45397 (14)	0.65133 (13)	0.0151 (4)
H1	0.2873	0.5217	0.6516	0.018*
C2	0.2358 (3)	0.40311 (15)	0.57665 (14)	0.0166 (4)
H2	0.1778	0.4360	0.5267	0.020*
C3	0.2567 (3)	0.30512 (15)	0.57515 (14)	0.0153 (4)
H3	0.2150	0.2705	0.5239	0.018*
C4	0.3397 (3)	0.25623 (14)	0.64956 (13)	0.0117 (4)
C5	0.3740 (3)	0.15615 (14)	0.65342 (13)	0.0138 (4)
C6	0.4558 (3)	0.11316 (14)	0.72781 (14)	0.0172 (4)
H6	0.4793	0.0462	0.7286	0.021*
C7	0.5055 (3)	0.16687 (14)	0.80322 (14)	0.0166 (4)
H7	0.5597	0.1356	0.8547	0.020*
C8	0.4766 (3)	0.26435 (14)	0.80322 (13)	0.0129 (4)
C9	0.3973 (3)	0.30951 (14)	0.72569 (12)	0.0110 (3)
C10	0.4431 (3)	0.40542 (14)	0.87812 (13)	0.0140 (4)
H101	0.5007	0.4417	0.9295	0.017*
H102	0.3154	0.3961	0.8803	0.017*
C11	0.4574 (3)	0.46079 (14)	0.79981 (13)	0.0122 (4)
C12	0.5393 (3)	0.54442 (14)	0.79424 (13)	0.0137 (4)
H12	0.5404	0.5692	0.7391	0.016*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.01625 (7)	0.01324 (6)	0.01395 (6)	−0.00313 (5)	0.00358 (5)	−0.00033 (5)
I2	0.01699 (7)	0.01690 (6)	0.01509 (7)	0.00253 (5)	0.00264 (5)	−0.00017 (5)
I3	0.01396 (6)	0.01403 (6)	0.01650 (7)	0.00317 (5)	0.00456 (5)	0.00226 (5)
I4	0.02154 (7)	0.01424 (6)	0.01651 (7)	0.00171 (5)	0.00477 (6)	0.00024 (5)
Cl1	0.0181 (2)	0.0159 (2)	0.0182 (2)	−0.00220 (18)	0.00227 (19)	−0.00602 (18)
O1	0.0193 (7)	0.0118 (6)	0.0118 (7)	0.0022 (5)	0.0013 (6)	0.0010 (5)
N1	0.0136 (8)	0.0117 (7)	0.0114 (8)	−0.0001 (6)	0.0033 (6)	0.0008 (6)
C1	0.0169 (9)	0.0137 (8)	0.0145 (9)	0.0020 (7)	0.0024 (8)	0.0026 (7)
C2	0.0173 (10)	0.0192 (9)	0.0128 (9)	0.0016 (8)	0.0017 (8)	0.0022 (8)
C3	0.0133 (9)	0.0192 (9)	0.0135 (9)	−0.0011 (8)	0.0025 (8)	−0.0016 (8)
C4	0.0089 (8)	0.0133 (8)	0.0135 (9)	−0.0014 (7)	0.0034 (7)	−0.0002 (7)
C5	0.0131 (9)	0.0129 (8)	0.0163 (9)	−0.0023 (7)	0.0050 (8)	−0.0036 (7)
C6	0.0189 (10)	0.0110 (8)	0.0218 (11)	−0.0008 (7)	0.0040 (9)	0.0012 (8)
C7	0.0191 (10)	0.0142 (9)	0.0161 (10)	0.0014 (8)	0.0030 (8)	0.0030 (7)
C8	0.0123 (8)	0.0126 (8)	0.0137 (9)	−0.0008 (7)	0.0023 (7)	0.0010 (7)
C9	0.0102 (8)	0.0114 (8)	0.0119 (9)	0.0007 (7)	0.0033 (7)	0.0003 (7)
C10	0.0158 (9)	0.0116 (8)	0.0148 (9)	0.0001 (7)	0.0040 (8)	0.0000 (7)
C11	0.0135 (9)	0.0117 (8)	0.0112 (8)	0.0007 (7)	0.0018 (7)	0.0020 (7)
C12	0.0151 (9)	0.0128 (8)	0.0133 (9)	−0.0009 (7)	0.0032 (8)	−0.0010 (7)

Geometric parameters (Å, º)

I1—C12	2.082 (2)	C3—H3	0.9500
I2—I3	3.0048 (2)	C4—C5	1.419 (3)
I3—I4	2.8708 (2)	C4—C9	1.420 (3)
Cl1—C5	1.731 (2)	C5—C6	1.367 (3)
O1—C8	1.356 (2)	C6—C7	1.407 (3)
O1—C10	1.443 (2)	C6—H6	0.9500
N1—C1	1.340 (3)	C7—C8	1.377 (3)
N1—C9	1.392 (2)	C7—H7	0.9500
N1—C11	1.450 (3)	C8—C9	1.414 (3)
C1—C2	1.391 (3)	C10—C11	1.496 (3)
C1—H1	0.9500	C10—H101	0.9900
C2—C3	1.377 (3)	C10—H102	0.9900
C2—H2	0.9500	C11—C12	1.334 (3)
C3—C4	1.408 (3)	C12—H12	0.9500
I4—I3—I2	176.897 (6)	C7—C6—H6	119.6
C8—O1—C10	113.73 (15)	C8—C7—C6	120.67 (19)
C1—N1—C9	121.30 (17)	C8—C7—H7	119.7
C1—N1—C11	121.96 (17)	C6—C7—H7	119.7
C9—N1—C11	116.66 (16)	O1—C8—C7	118.60 (18)
N1—C1—C2	121.02 (19)	O1—C8—C9	122.72 (17)
N1—C1—H1	119.5	C7—C8—C9	118.66 (19)
C2—C1—H1	119.5	N1—C9—C8	119.55 (17)
C3—C2—C1	119.96 (19)	N1—C9—C4	118.81 (17)
C3—C2—H2	120.0	C8—C9—C4	121.62 (18)
C1—C2—H2	120.0	O1—C10—C11	109.83 (17)
C2—C3—C4	119.99 (19)	O1—C10—H101	109.7
C2—C3—H3	120.0	C11—C10—H101	109.7
C4—C3—H3	120.0	O1—C10—H102	109.7
C3—C4—C5	124.10 (19)	C11—C10—H102	109.7
C3—C4—C9	118.81 (18)	H101—C10—H102	108.2
C5—C4—C9	117.08 (18)	C12—C11—N1	119.93 (18)
C6—C5—C4	121.13 (19)	C12—C11—C10	128.45 (19)
C6—C5—Cl1	119.11 (16)	N1—C11—C10	111.49 (16)
C4—C5—Cl1	119.72 (16)	C11—C12—I1	123.66 (16)
C5—C6—C7	120.76 (19)	C11—C12—H12	118.2
C5—C6—H6	119.6	I1—C12—H12	118.2