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Three polymorphs of 4,4′-diiodobenzalazine (systematic name: 4-iodobenzaldehyde azine), C14H10I2N2, have crystallographically imposed inversion symmetry. 4-Chloro-4′-iodobenzalazine [systematic name: 1-(4-chlorobenzylidene)-2-(4-iodobenzylidene)diazane], C14H10ClIN2, has a partially disordered pseudocentrosymmetric packing and is not isostructural with any of the polymorphs of 4,4′-diiodobenzalazine. All structures pack utilizing halogen–halogen interactions; some also have weak π (benzene ring) interactions. A comparison with previously published methylphenylketalazines (which differ by substitution of methyl for H at the azine C atoms) shows a fundamentally different geometry for these two classes, namely planar for the alazines and twisted for the ketalazines. Density functional theory calculations confirm that the difference is fundamental and not an artifact of packing forces.
Supporting information
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270107034786/ga3056sup1.cif Contains datablocks global, I,I-A, I,I-B, I,I-C, I,Cl |
| Structure factor file (CIF format) https://doi.org/10.1107/S0108270107034786/ga3056I,I-Asup2.hkl Contains datablock I,I-A |
| Structure factor file (CIF format) https://doi.org/10.1107/S0108270107034786/ga3056I,I-Bsup3.hkl Contains datablock I,I-B |
| Structure factor file (CIF format) https://doi.org/10.1107/S0108270107034786/ga3056I,I-Csup4.hkl Contains datablock I,I-C |
| Structure factor file (CIF format) https://doi.org/10.1107/S0108270107034786/ga3056I,Clsup5.hkl Contains datablock I,Cl |
CCDC references: 661806; 661807; 661808; 661809
For the preparation of 4-chlorobenzaldehyde hydrazone, a solution of
4-chlorobenzaldehyde (0.5 g, 3.6 mmol) dissolved in approximately 10 ml of
ethanol was added dropwise with stirring to an aqueous 8% hydrazine solution
(14.25 g, 3.6 mmol hydrazine). The milky solution was stirred for
approximately 30 min after the completion of the addition and then cooled in a
refrigerator overnight (at 277 K). The solid hydrazone was removed by
filtration and used without recrystallization.
For the preparation of 4-chloro-4'-iodobenzalazine, to a solution of
4-iodobenzaldehyde (0.2 g, 0.9 mmol) dissolved in 10 ml of absolute ethanol
was added 4-chlorobenzaldehyde hydrazone (0.15 g, 1.0 mmol). The mixture was
heated to 323 K with stirring for approximately 1 h, cooled, and then placed
in a refrigerator overnight. The crude azine was recrystallized from
chloroform.
For the preparation of 4-iodobenzaldehyde azine, a solution of
4-iodobenzaldehyde (0.1 g, 0.4 mmol) dissolved in approximately 5 ml of
ethanol was added dropwise with stirring to an aqueous 8% hydrazine solution
(3 g, 8 mmol hydrazine). The milky solution was heated (lower than 323 K) with
stirring for approximately 1 h and then was allowed to stand at room
temperature overnight. The solution was refrigerated and the crude azine was
recrystallized from chloroform. All three polymorphs were obtained in the
original recrystallization.
The solutions and refinements were straightforward, except for (I,Cl). This
structure was solved as an end-for-end disordered molecule in
P21/c; the refinement converged with R[F2>2σ(F2)]
= 0.043 and wR(F2) = 0.084. To test whether the disorder was complete
the structure was solved and partially refined in P1. At this point it
appeared that the disorder was not 50/50 and that Pc was the correct
space group; the final R and wR2 were 0.038 and 0.072 with
0.586 (2)/0.414 (2) disorder of the Cl and I. In all of the refinements C—Cl
was constrained to 1.746 (1) and C—I to 2.095 (1) Å; all of the
C6H4—CH—N fragments were constrained to be the same to 0.001 Å. The
atoms that would have overlapped in the pseudocentric arrangement were
constrained to have the same ADP's.
H atoms were placed at geometrically idealized positions and constrained to
ride on their parent atoms with C—H distances of 0.95 Å and with
Uiso(H) = 1.2 Ueq(C).
For all compounds, data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
(I,I-A) 4-iodobenzaldehyde azine
top
Crystal data top
C14H10I2N2 | F(000) = 428 |
Mr = 460.04 | Dx = 2.172 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 11.854 (2) Å | Cell parameters from 2671 reflections |
b = 7.7308 (13) Å | θ = 2.6–27.5° |
c = 7.6827 (13) Å | µ = 4.45 mm−1 |
β = 92.407 (3)° | T = 174 K |
V = 703.5 (2) Å3 | Plate, pale yellow |
Z = 2 | 0.45 × 0.35 × 0.06 mm |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 1602 independent reflections |
Radiation source: fine-focus sealed tube | 1442 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.031 |
ω scans | θmax = 27.5°, θmin = 1.7° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003; Blessing, 1995) | h = −15→15 |
Tmin = 0.32, Tmax = 0.77 | k = −9→10 |
7773 measured reflections | l = −9→9 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.022 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.054 | H-atom parameters constrained |
S = 1.11 | w = 1/[σ2(Fo2) + (0.027P)2 + 0.31P]
where P = (Fo2 + 2Fc2)/3 |
1602 reflections | (Δ/σ)max = 0.001 |
83 parameters | Δρmax = 0.86 e Å−3 |
0 restraints | Δρmin = −0.55 e Å−3 |
Crystal data top
C14H10I2N2 | V = 703.5 (2) Å3 |
Mr = 460.04 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 11.854 (2) Å | µ = 4.45 mm−1 |
b = 7.7308 (13) Å | T = 174 K |
c = 7.6827 (13) Å | 0.45 × 0.35 × 0.06 mm |
β = 92.407 (3)° | |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 1602 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003; Blessing, 1995) | 1442 reflections with I > 2σ(I) |
Tmin = 0.32, Tmax = 0.77 | Rint = 0.031 |
7773 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.022 | 0 restraints |
wR(F2) = 0.054 | H-atom parameters constrained |
S = 1.11 | Δρmax = 0.86 e Å−3 |
1602 reflections | Δρmin = −0.55 e Å−3 |
83 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
I1 | 0.114704 (15) | 0.42460 (2) | −0.33923 (2) | 0.03116 (9) | |
N1 | 0.4787 (2) | 0.4782 (3) | 0.4157 (3) | 0.0290 (5) | |
C1 | 0.2062 (2) | 0.4727 (3) | −0.1050 (3) | 0.0225 (5) | |
C2 | 0.1565 (2) | 0.5669 (3) | 0.0252 (4) | 0.0244 (5) | |
H2 | 0.0825 | 0.6125 | 0.0073 | 0.029* | |
C3 | 0.2167 (2) | 0.5937 (3) | 0.1822 (3) | 0.0258 (5) | |
H3 | 0.1837 | 0.6589 | 0.2717 | 0.031* | |
C4 | 0.3251 (2) | 0.5256 (3) | 0.2095 (3) | 0.0245 (5) | |
C5 | 0.3732 (2) | 0.4320 (3) | 0.0763 (4) | 0.0263 (5) | |
H5 | 0.4469 | 0.3853 | 0.0940 | 0.032* | |
C6 | 0.3148 (2) | 0.4064 (3) | −0.0814 (4) | 0.0268 (5) | |
H6 | 0.3485 | 0.3442 | −0.1724 | 0.032* | |
C7 | 0.3853 (2) | 0.5536 (3) | 0.3787 (4) | 0.0276 (6) | |
H7 | 0.3539 | 0.6290 | 0.4615 | 0.033* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
I1 | 0.03674 (14) | 0.03150 (13) | 0.02453 (12) | −0.00061 (7) | −0.00715 (8) | −0.00406 (6) |
N1 | 0.0338 (12) | 0.0315 (11) | 0.0212 (11) | −0.0037 (10) | −0.0057 (9) | −0.0010 (9) |
C1 | 0.0284 (13) | 0.0192 (10) | 0.0196 (11) | −0.0027 (10) | −0.0030 (10) | 0.0011 (9) |
C2 | 0.0259 (13) | 0.0217 (11) | 0.0252 (13) | 0.0016 (9) | −0.0027 (10) | 0.0013 (9) |
C3 | 0.0318 (14) | 0.0229 (12) | 0.0226 (13) | 0.0033 (10) | 0.0005 (11) | −0.0028 (9) |
C4 | 0.0284 (13) | 0.0229 (11) | 0.0217 (12) | −0.0036 (10) | −0.0038 (10) | 0.0033 (10) |
C5 | 0.0236 (13) | 0.0283 (13) | 0.0268 (13) | 0.0015 (10) | −0.0008 (10) | 0.0021 (10) |
C6 | 0.0298 (14) | 0.0273 (12) | 0.0235 (13) | 0.0014 (10) | 0.0035 (11) | 0.0001 (10) |
C7 | 0.0315 (15) | 0.0269 (13) | 0.0241 (13) | −0.0034 (10) | −0.0034 (11) | 0.0000 (10) |
Geometric parameters (Å, º) top
I1—C1 | 2.095 (2) | C3—H3 | 0.9500 |
N1—C7 | 1.273 (4) | C4—C5 | 1.395 (4) |
N1—N1i | 1.411 (4) | C4—C7 | 1.472 (4) |
C1—C2 | 1.389 (4) | C5—C6 | 1.384 (4) |
C1—C6 | 1.391 (4) | C5—H5 | 0.9500 |
C2—C3 | 1.391 (4) | C6—H6 | 0.9500 |
C2—H2 | 0.9500 | C7—H7 | 0.9500 |
C3—C4 | 1.396 (4) | | |
| | | |
C7—N1—N1i | 111.7 (3) | C5—C4—C7 | 121.7 (2) |
C2—C1—C6 | 121.2 (2) | C3—C4—C7 | 119.1 (2) |
C2—C1—I1 | 119.47 (19) | C6—C5—C4 | 120.8 (2) |
C6—C1—I1 | 119.32 (18) | C6—C5—H5 | 119.6 |
C1—C2—C3 | 119.0 (2) | C4—C5—H5 | 119.6 |
C1—C2—H2 | 120.5 | C5—C6—C1 | 119.2 (2) |
C3—C2—H2 | 120.5 | C5—C6—H6 | 120.4 |
C2—C3—C4 | 120.6 (2) | C1—C6—H6 | 120.4 |
C2—C3—H3 | 119.7 | N1—C7—C4 | 121.0 (3) |
C4—C3—H3 | 119.7 | N1—C7—H7 | 119.5 |
C5—C4—C3 | 119.2 (2) | C4—C7—H7 | 119.5 |
| | | |
C6—C1—C2—C3 | −0.5 (4) | C4—C5—C6—C1 | −1.1 (4) |
I1—C1—C2—C3 | 178.09 (18) | C2—C1—C6—C5 | 1.4 (4) |
C1—C2—C3—C4 | −0.6 (4) | I1—C1—C6—C5 | −177.25 (18) |
C2—C3—C4—C5 | 0.8 (4) | N1i—N1—C7—C4 | −179.4 (3) |
C2—C3—C4—C7 | −178.8 (2) | C5—C4—C7—N1 | −7.3 (4) |
C3—C4—C5—C6 | 0.0 (4) | C3—C4—C7—N1 | 172.3 (2) |
C7—C4—C5—C6 | 179.6 (2) | | |
Symmetry code: (i) −x+1, −y+1, −z+1. |
(I,I-B) 4-iodobenzaldehyde azine
top
Crystal data top
C14H10I2N2 | F(000) = 428 |
Mr = 460.04 | Dx = 2.173 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 8.4303 (17) Å | Cell parameters from 2860 reflections |
b = 5.6453 (12) Å | θ = 2.5–25.5° |
c = 15.248 (3) Å | µ = 4.46 mm−1 |
β = 104.346 (3)° | T = 174 K |
V = 703.0 (3) Å3 | Needle, pale yellow |
Z = 2 | 0.30 × 0.06 × 0.03 mm |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 1600 independent reflections |
Radiation source: fine-focus sealed tube | 1189 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.052 |
ω scans | θmax = 27.5°, θmin = 2.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003; Blessing, 1995) | h = −10→10 |
Tmin = 0.54, Tmax = 0.87 | k = −7→7 |
7699 measured reflections | l = −19→19 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.031 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.061 | H-atom parameters constrained |
S = 1.02 | w = 1/[σ2(Fo2) + (0.028P)2] where P = (Fo2 + 2Fc2)/3 |
1600 reflections | (Δ/σ)max = 0.001 |
83 parameters | Δρmax = 0.48 e Å−3 |
0 restraints | Δρmin = −0.61 e Å−3 |
Crystal data top
C14H10I2N2 | V = 703.0 (3) Å3 |
Mr = 460.04 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.4303 (17) Å | µ = 4.46 mm−1 |
b = 5.6453 (12) Å | T = 174 K |
c = 15.248 (3) Å | 0.30 × 0.06 × 0.03 mm |
β = 104.346 (3)° | |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 1600 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003; Blessing, 1995) | 1189 reflections with I > 2σ(I) |
Tmin = 0.54, Tmax = 0.87 | Rint = 0.052 |
7699 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.031 | 0 restraints |
wR(F2) = 0.061 | H-atom parameters constrained |
S = 1.02 | Δρmax = 0.48 e Å−3 |
1600 reflections | Δρmin = −0.61 e Å−3 |
83 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
I1 | 1.14291 (3) | 1.16954 (5) | 0.306393 (19) | 0.03499 (13) | |
N1 | 0.5738 (4) | 0.5302 (7) | 0.4884 (2) | 0.0301 (8) | |
C1 | 0.9511 (5) | 1.0231 (7) | 0.3531 (3) | 0.0251 (9) | |
C2 | 0.8041 (5) | 1.1403 (7) | 0.3377 (3) | 0.0289 (9) | |
C3 | 0.6780 (5) | 1.0432 (7) | 0.3695 (3) | 0.0274 (9) | |
C4 | 0.6982 (5) | 0.8283 (7) | 0.4157 (3) | 0.0263 (9) | |
C5 | 0.8486 (5) | 0.7121 (7) | 0.4307 (3) | 0.0286 (9) | |
C6 | 0.9762 (5) | 0.8064 (7) | 0.4003 (3) | 0.0299 (10) | |
C7 | 0.5607 (5) | 0.7274 (7) | 0.4465 (3) | 0.0285 (10) | |
H2 | 0.7890 | 1.2862 | 0.3057 | 0.035* | |
H3 | 0.5764 | 1.1244 | 0.3596 | 0.033* | |
H5 | 0.8633 | 0.5656 | 0.4623 | 0.034* | |
H6 | 1.0786 | 0.7271 | 0.4109 | 0.036* | |
H7 | 0.4598 | 0.8109 | 0.4348 | 0.034* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
I1 | 0.02812 (17) | 0.0440 (2) | 0.03479 (19) | −0.00089 (15) | 0.01144 (12) | 0.00570 (16) |
N1 | 0.0252 (18) | 0.030 (2) | 0.036 (2) | −0.0060 (16) | 0.0102 (16) | 0.0003 (17) |
C1 | 0.027 (2) | 0.024 (2) | 0.026 (2) | −0.0049 (18) | 0.0097 (18) | −0.0032 (18) |
C2 | 0.034 (2) | 0.026 (2) | 0.026 (2) | −0.001 (2) | 0.0059 (18) | −0.0007 (18) |
C3 | 0.022 (2) | 0.029 (2) | 0.031 (2) | 0.0006 (18) | 0.0066 (18) | −0.0029 (19) |
C4 | 0.029 (2) | 0.026 (2) | 0.023 (2) | −0.001 (2) | 0.0056 (17) | −0.0042 (19) |
C5 | 0.030 (2) | 0.024 (2) | 0.029 (2) | 0.0019 (18) | 0.0032 (18) | 0.0056 (18) |
C6 | 0.027 (2) | 0.033 (2) | 0.029 (2) | 0.006 (2) | 0.0056 (18) | 0.005 (2) |
C7 | 0.027 (2) | 0.030 (2) | 0.028 (2) | −0.0017 (18) | 0.0059 (19) | −0.0073 (19) |
Geometric parameters (Å, º) top
I1—C1 | 2.091 (4) | C6—C1 | 1.409 (5) |
C4—C3 | 1.392 (6) | C6—H6 | 0.9500 |
C4—C5 | 1.395 (5) | C1—C2 | 1.373 (5) |
C4—C7 | 1.468 (6) | C2—C3 | 1.386 (5) |
N1—C7 | 1.275 (5) | C2—H2 | 0.9500 |
N1—N1i | 1.418 (6) | C3—H3 | 0.9500 |
C5—C6 | 1.380 (6) | C7—H7 | 0.9500 |
C5—H5 | 0.9500 | | |
| | | |
C3—C4—C5 | 119.0 (4) | C2—C1—I1 | 119.5 (3) |
C3—C4—C7 | 119.5 (4) | C6—C1—I1 | 119.1 (3) |
C5—C4—C7 | 121.5 (4) | C1—C2—C3 | 119.2 (4) |
C7—N1—N1i | 111.3 (4) | C1—C2—H2 | 120.4 |
C6—C5—C4 | 121.1 (4) | C3—C2—H2 | 120.4 |
C6—C5—H5 | 119.5 | C2—C3—C4 | 120.9 (4) |
C4—C5—H5 | 119.5 | C2—C3—H3 | 119.6 |
C5—C6—C1 | 118.4 (4) | C4—C3—H3 | 119.6 |
C5—C6—H6 | 120.8 | N1—C7—C4 | 121.4 (4) |
C1—C6—H6 | 120.8 | N1—C7—H7 | 119.3 |
C2—C1—C6 | 121.3 (4) | C4—C7—H7 | 119.3 |
| | | |
C3—C4—C5—C6 | −0.2 (6) | C1—C2—C3—C4 | −0.6 (6) |
C7—C4—C5—C6 | 179.0 (4) | C5—C4—C3—C2 | 0.7 (6) |
C4—C5—C6—C1 | −0.3 (6) | C7—C4—C3—C2 | −178.5 (4) |
C5—C6—C1—C2 | 0.4 (6) | N1i—N1—C7—C4 | 179.7 (4) |
C5—C6—C1—I1 | 180.0 (3) | C3—C4—C7—N1 | 179.5 (4) |
C6—C1—C2—C3 | 0.1 (6) | C5—C4—C7—N1 | 0.3 (6) |
I1—C1—C2—C3 | −179.5 (3) | | |
Symmetry code: (i) −x+1, −y+1, −z+1. |
(I,I-C) 4-iodobenzaldehyde azine
top
Crystal data top
C14H10I2N2 | F(000) = 428 |
Mr = 460.04 | Dx = 2.188 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 7.2077 (17) Å | Cell parameters from 3960 reflections |
b = 4.1543 (10) Å | θ = 2.8–27.5° |
c = 23.317 (6) Å | µ = 4.49 mm−1 |
β = 90.314 (4)° | T = 174 K |
V = 698.2 (3) Å3 | Needle, pale yellow |
Z = 2 | 0.45 × 0.10 × 0.04 mm |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 1601 independent reflections |
Radiation source: fine-focus sealed tube | 1290 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.085 |
ω scans | θmax = 27.5°, θmin = 1.8° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003; Blessing, 1995) | h = −9→9 |
Tmin = 0.24, Tmax = 0.84 | k = −5→5 |
7115 measured reflections | l = −30→30 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.047 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.122 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.064P)2 + 3.31P]
where P = (Fo2 + 2Fc2)/3 |
1601 reflections | (Δ/σ)max = 0.001 |
82 parameters | Δρmax = 3.00 e Å−3 |
0 restraints | Δρmin = −1.34 e Å−3 |
Crystal data top
C14H10I2N2 | V = 698.2 (3) Å3 |
Mr = 460.04 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.2077 (17) Å | µ = 4.49 mm−1 |
b = 4.1543 (10) Å | T = 174 K |
c = 23.317 (6) Å | 0.45 × 0.10 × 0.04 mm |
β = 90.314 (4)° | |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 1601 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003; Blessing, 1995) | 1290 reflections with I > 2σ(I) |
Tmin = 0.24, Tmax = 0.84 | Rint = 0.085 |
7115 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.047 | 0 restraints |
wR(F2) = 0.122 | H-atom parameters constrained |
S = 1.05 | Δρmax = 3.00 e Å−3 |
1601 reflections | Δρmin = −1.34 e Å−3 |
82 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
I1 | −0.36110 (6) | 0.86627 (12) | 0.308402 (18) | 0.02813 (19) | |
C1 | −0.1234 (9) | 0.7210 (17) | 0.3534 (3) | 0.0217 (13) | |
N1 | 0.4138 (8) | 0.5574 (16) | 0.4905 (2) | 0.0305 (14) | |
C2 | 0.0112 (9) | 0.5424 (17) | 0.3250 (3) | 0.0245 (14) | |
H2 | −0.0065 | 0.4805 | 0.2861 | 0.029* | |
C3 | 0.1724 (9) | 0.4558 (19) | 0.3545 (3) | 0.0270 (14) | |
H3 | 0.2649 | 0.3335 | 0.3355 | 0.032* | |
C4 | 0.1998 (9) | 0.5447 (18) | 0.4110 (3) | 0.0259 (14) | |
C5 | 0.0624 (10) | 0.7242 (19) | 0.4393 (3) | 0.0288 (15) | |
H5 | 0.0803 | 0.7867 | 0.4781 | 0.035* | |
C6 | −0.0992 (10) | 0.8102 (18) | 0.4105 (3) | 0.0291 (16) | |
H6 | −0.1928 | 0.9294 | 0.4296 | 0.035* | |
C7 | 0.3726 (10) | 0.4583 (19) | 0.4403 (3) | 0.0284 (15) | |
H7 | 0.4579 | 0.3221 | 0.4211 | 0.034* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
I1 | 0.0228 (3) | 0.0252 (3) | 0.0363 (3) | 0.00290 (19) | −0.00815 (17) | −0.00015 (18) |
C1 | 0.016 (3) | 0.018 (3) | 0.031 (3) | 0.000 (3) | −0.007 (2) | 0.003 (2) |
N1 | 0.026 (3) | 0.034 (4) | 0.032 (3) | 0.004 (3) | −0.005 (2) | 0.000 (3) |
C2 | 0.025 (3) | 0.019 (3) | 0.030 (3) | −0.003 (3) | −0.004 (2) | 0.003 (3) |
C3 | 0.019 (3) | 0.032 (4) | 0.030 (3) | 0.003 (3) | 0.002 (2) | −0.001 (3) |
C4 | 0.020 (3) | 0.028 (4) | 0.030 (3) | −0.004 (3) | −0.003 (2) | 0.001 (3) |
C5 | 0.028 (4) | 0.029 (4) | 0.030 (3) | 0.005 (3) | −0.002 (3) | −0.003 (3) |
C6 | 0.028 (3) | 0.032 (4) | 0.028 (3) | 0.010 (3) | −0.002 (3) | −0.001 (3) |
C7 | 0.022 (3) | 0.027 (4) | 0.036 (4) | 0.003 (3) | −0.002 (3) | 0.003 (3) |
Geometric parameters (Å, º) top
I1—C1 | 2.094 (6) | C3—H3 | 0.9500 |
C1—C6 | 1.391 (9) | C4—C5 | 1.406 (10) |
C1—C2 | 1.392 (10) | C4—C7 | 1.463 (9) |
N1—C7 | 1.274 (9) | C5—C6 | 1.388 (10) |
N1—N1i | 1.400 (12) | C5—H5 | 0.9500 |
C2—C3 | 1.395 (9) | C6—H6 | 0.9500 |
C2—H2 | 0.9500 | C7—H7 | 0.9500 |
C3—C4 | 1.381 (9) | | |
| | | |
C6—C1—C2 | 120.9 (6) | C3—C4—C7 | 119.8 (6) |
C6—C1—I1 | 120.0 (5) | C5—C4—C7 | 120.7 (6) |
C2—C1—I1 | 119.0 (5) | C6—C5—C4 | 120.1 (6) |
C7—N1—N1i | 112.4 (7) | C6—C5—H5 | 120.0 |
C1—C2—C3 | 118.8 (6) | C4—C5—H5 | 120.0 |
C1—C2—H2 | 120.6 | C5—C6—C1 | 119.6 (6) |
C3—C2—H2 | 120.6 | C5—C6—H6 | 120.2 |
C4—C3—C2 | 121.1 (6) | C1—C6—H6 | 120.2 |
C4—C3—H3 | 119.5 | N1—C7—C4 | 122.9 (7) |
C2—C3—H3 | 119.5 | N1—C7—H7 | 118.5 |
C3—C4—C5 | 119.5 (6) | C4—C7—H7 | 118.5 |
| | | |
C6—C1—C2—C3 | −0.5 (10) | C4—C5—C6—C1 | −0.7 (11) |
I1—C1—C2—C3 | 177.8 (5) | C2—C1—C6—C5 | 0.9 (11) |
C1—C2—C3—C4 | −0.1 (11) | I1—C1—C6—C5 | −177.3 (6) |
C2—C3—C4—C5 | 0.3 (11) | N1i—N1—C7—C4 | −180.0 (7) |
C2—C3—C4—C7 | −178.2 (7) | C3—C4—C7—N1 | 173.4 (7) |
C3—C4—C5—C6 | 0.1 (11) | C5—C4—C7—N1 | −5.1 (11) |
C7—C4—C5—C6 | 178.6 (7) | | |
Symmetry code: (i) −x+1, −y+1, −z+1. |
(I,Cl) 1-(4-Chlorobenzylidene)-2-(4-iodobenzylidene)diazane
top
Crystal data top
C14H10ClIN2 | F(000) = 356 |
Mr = 368.59 | Dx = 1.808 Mg m−3 |
Monoclinic, Pc | Mo Kα radiation, λ = 0.71073 Å |
a = 11.499 (2) Å | Cell parameters from 3282 reflections |
b = 4.0006 (7) Å | θ = 2.8–27.5° |
c = 14.717 (3) Å | µ = 2.55 mm−1 |
β = 90.900 (3)° | T = 174 K |
V = 676.9 (2) Å3 | Plate, yellow |
Z = 2 | 0.20 × 0.20 × 0.05 mm |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 3089 independent reflections |
Radiation source: fine-focus sealed tube | 2308 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.032 |
ω scans | θmax = 28.2°, θmin = 1.8° |
Absorption correction: multi-scan SADABS; Sheldrick, 2003; Blessing, 1995 | h = −15→15 |
Tmin = 0.42, Tmax = 0.88 | k = −5→5 |
7262 measured reflections | l = −19→18 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
wR(F2) = 0.072 | w = 1/[σ2(Fo2) + (0.017P)2 + 0.681P]
where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max = 0.02 |
3089 reflections | Δρmax = 0.50 e Å−3 |
164 parameters | Δρmin = −0.33 e Å−3 |
109 restraints | Absolute structure: Flack (1983),
1476 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.17 (7) |
Crystal data top
C14H10ClIN2 | V = 676.9 (2) Å3 |
Mr = 368.59 | Z = 2 |
Monoclinic, Pc | Mo Kα radiation |
a = 11.499 (2) Å | µ = 2.55 mm−1 |
b = 4.0006 (7) Å | T = 174 K |
c = 14.717 (3) Å | 0.20 × 0.20 × 0.05 mm |
β = 90.900 (3)° | |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 3089 independent reflections |
Absorption correction: multi-scan SADABS; Sheldrick, 2003; Blessing, 1995 | 2308 reflections with I > 2σ(I) |
Tmin = 0.42, Tmax = 0.88 | Rint = 0.032 |
7262 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
wR(F2) = 0.072 | Δρmax = 0.50 e Å−3 |
S = 1.05 | Δρmin = −0.33 e Å−3 |
3089 reflections | Absolute structure: Flack (1983),
1476 Friedel pairs |
164 parameters | Absolute structure parameter: 0.17 (7) |
109 restraints | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
C1 | 0.2105 (10) | 0.678 (4) | 0.2032 (6) | 0.0338 (13) | 0.5858 (17) |
C2 | 0.1493 (7) | 0.807 (5) | 0.2760 (8) | 0.0378 (14) | 0.5858 (17) |
H2 | 0.0687 | 0.8563 | 0.2700 | 0.045* | 0.5858 (17) |
C3 | 0.2079 (8) | 0.862 (5) | 0.3569 (7) | 0.0385 (13) | 0.5858 (17) |
H3 | 0.1678 | 0.9621 | 0.4060 | 0.046* | 0.5858 (17) |
C4 | 0.3247 (8) | 0.775 (5) | 0.3685 (6) | 0.0350 (8) | 0.5858 (17) |
C5 | 0.3808 (9) | 0.618 (4) | 0.2962 (7) | 0.0353 (13) | 0.5858 (17) |
H5 | 0.4582 | 0.5388 | 0.3044 | 0.042* | 0.5858 (17) |
C6 | 0.3250 (10) | 0.575 (4) | 0.2134 (6) | 0.0361 (12) | 0.5858 (17) |
H6 | 0.3646 | 0.4771 | 0.1639 | 0.043* | 0.5858 (17) |
C7 | 0.3862 (12) | 0.857 (6) | 0.4527 (8) | 0.0365 (12) | 0.5858 (17) |
H7 | 0.3520 | 1.0074 | 0.4945 | 0.044* | 0.5858 (17) |
N1 | 0.486 (2) | 0.728 (8) | 0.4713 (15) | 0.041 (2) | 0.5858 (17) |
I1 | 0.1235 (4) | 0.5523 (8) | 0.0819 (3) | 0.0389 (2) | 0.5858 (17) |
C11 | 0.8013 (12) | 0.858 (7) | 0.8289 (7) | 0.0338 (13) | 0.5858 (17) |
C12 | 0.8598 (12) | 0.697 (7) | 0.7595 (10) | 0.0378 (14) | 0.5858 (17) |
H12 | 0.9377 | 0.6235 | 0.7682 | 0.045* | 0.5858 (17) |
C13 | 0.8026 (12) | 0.647 (8) | 0.6777 (11) | 0.0385 (13) | 0.5858 (17) |
H13 | 0.8418 | 0.5362 | 0.6300 | 0.046* | 0.5858 (17) |
C14 | 0.6883 (11) | 0.755 (7) | 0.6634 (8) | 0.0350 (8) | 0.5858 (17) |
C15 | 0.6333 (13) | 0.927 (8) | 0.7338 (9) | 0.0353 (13) | 0.5858 (17) |
H15 | 0.5558 | 1.0037 | 0.7252 | 0.042* | 0.5858 (17) |
C16 | 0.6904 (16) | 0.985 (9) | 0.8154 (10) | 0.0361 (12) | 0.5858 (17) |
H16 | 0.6540 | 1.1109 | 0.8617 | 0.043* | 0.5858 (17) |
C17 | 0.6301 (17) | 0.695 (12) | 0.5765 (12) | 0.0365 (12) | 0.5858 (17) |
H17 | 0.6710 | 0.5874 | 0.5291 | 0.044* | 0.5858 (17) |
N2 | 0.5236 (17) | 0.785 (9) | 0.5630 (12) | 0.041 (2) | 0.5858 (17) |
Cl1 | 0.8762 (8) | 0.904 (2) | 0.9323 (5) | 0.0389 (2) | 0.5858 (17) |
C1A | 0.2116 (14) | 0.610 (6) | 0.1946 (10) | 0.0338 (13) | 0.4142 (17) |
C2A | 0.1596 (12) | 0.820 (7) | 0.2575 (12) | 0.0378 (14) | 0.4142 (17) |
H2A | 0.0858 | 0.9176 | 0.2449 | 0.045* | 0.4142 (17) |
C3A | 0.2173 (12) | 0.883 (7) | 0.3384 (11) | 0.0385 (13) | 0.4142 (17) |
H3A | 0.1825 | 1.0256 | 0.3818 | 0.046* | 0.4142 (17) |
C4A | 0.3259 (12) | 0.742 (7) | 0.3581 (9) | 0.0350 (8) | 0.4142 (17) |
C5A | 0.3787 (12) | 0.548 (6) | 0.2910 (10) | 0.0353 (13) | 0.4142 (17) |
H5A | 0.4532 | 0.4529 | 0.3026 | 0.042* | 0.4142 (17) |
C6A | 0.3237 (14) | 0.492 (6) | 0.2084 (9) | 0.0361 (12) | 0.4142 (17) |
H6A | 0.3621 | 0.3739 | 0.1616 | 0.043* | 0.4142 (17) |
C7A | 0.3816 (18) | 0.799 (9) | 0.4460 (11) | 0.0365 (12) | 0.4142 (17) |
H7A | 0.3431 | 0.9290 | 0.4904 | 0.044* | 0.4142 (17) |
N1A | 0.483 (3) | 0.675 (12) | 0.465 (2) | 0.041 (2) | 0.4142 (17) |
Cl1A | 0.1289 (14) | 0.585 (4) | 0.0944 (7) | 0.0389 (2) | 0.4142 (17) |
C11A | 0.8080 (17) | 0.860 (10) | 0.8115 (10) | 0.0338 (13) | 0.4142 (17) |
C12A | 0.8602 (16) | 0.668 (10) | 0.7448 (14) | 0.0378 (14) | 0.4142 (17) |
H12A | 0.9355 | 0.5759 | 0.7546 | 0.045* | 0.4142 (17) |
C13A | 0.8003 (16) | 0.613 (11) | 0.6644 (15) | 0.0385 (13) | 0.4142 (17) |
H13A | 0.8369 | 0.4926 | 0.6171 | 0.046* | 0.4142 (17) |
C14A | 0.6872 (14) | 0.732 (11) | 0.6507 (11) | 0.0350 (8) | 0.4142 (17) |
C15A | 0.6333 (17) | 0.897 (11) | 0.7228 (12) | 0.0353 (13) | 0.4142 (17) |
H15A | 0.5545 | 0.9658 | 0.7164 | 0.042* | 0.4142 (17) |
C16A | 0.693 (2) | 0.962 (12) | 0.8027 (15) | 0.0361 (12) | 0.4142 (17) |
H16A | 0.6565 | 1.0758 | 0.8511 | 0.043* | 0.4142 (17) |
C17A | 0.628 (3) | 0.682 (17) | 0.5638 (18) | 0.0365 (12) | 0.4142 (17) |
H17A | 0.6642 | 0.5516 | 0.5182 | 0.044* | 0.4142 (17) |
N2A | 0.527 (3) | 0.812 (13) | 0.5477 (18) | 0.041 (2) | 0.4142 (17) |
I1A | 0.8899 (4) | 0.9487 (8) | 0.9374 (3) | 0.0389 (2) | 0.4142 (17) |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0354 (17) | 0.023 (3) | 0.043 (2) | −0.0047 (17) | 0.0129 (18) | 0.002 (3) |
C2 | 0.0353 (17) | 0.033 (3) | 0.046 (4) | 0.0018 (16) | 0.018 (2) | 0.003 (3) |
C3 | 0.0428 (18) | 0.033 (3) | 0.041 (3) | 0.0040 (17) | 0.0230 (19) | 0.000 (3) |
C4 | 0.0390 (16) | 0.024 (3) | 0.042 (2) | −0.0001 (13) | 0.0165 (15) | 0.001 (2) |
C5 | 0.0330 (14) | 0.024 (4) | 0.049 (2) | −0.0001 (16) | 0.0131 (15) | −0.002 (2) |
C6 | 0.0422 (17) | 0.020 (4) | 0.047 (2) | −0.0018 (18) | 0.0201 (17) | −0.005 (2) |
C7 | 0.0396 (17) | 0.029 (4) | 0.042 (3) | −0.001 (2) | 0.0205 (18) | −0.003 (3) |
N1 | 0.0423 (17) | 0.041 (5) | 0.039 (3) | 0.001 (3) | 0.0161 (19) | 0.001 (4) |
I1 | 0.0397 (4) | 0.0424 (6) | 0.0346 (4) | −0.0062 (3) | 0.0009 (3) | −0.0015 (3) |
C11 | 0.0354 (17) | 0.023 (3) | 0.043 (2) | −0.0047 (17) | 0.0129 (18) | 0.002 (3) |
C12 | 0.0353 (17) | 0.033 (3) | 0.046 (4) | 0.0018 (16) | 0.018 (2) | 0.003 (3) |
C13 | 0.0428 (18) | 0.033 (3) | 0.041 (3) | 0.0040 (17) | 0.0230 (19) | 0.000 (3) |
C14 | 0.0390 (16) | 0.024 (3) | 0.042 (2) | −0.0001 (13) | 0.0165 (15) | 0.001 (2) |
C15 | 0.0330 (14) | 0.024 (4) | 0.049 (2) | −0.0001 (16) | 0.0131 (15) | −0.002 (2) |
C16 | 0.0422 (17) | 0.020 (4) | 0.047 (2) | −0.0018 (18) | 0.0201 (17) | −0.005 (2) |
C17 | 0.0396 (17) | 0.029 (4) | 0.042 (3) | −0.001 (2) | 0.0205 (18) | −0.003 (3) |
N2 | 0.0423 (17) | 0.041 (5) | 0.039 (3) | 0.001 (3) | 0.0161 (19) | 0.001 (4) |
Cl1 | 0.0397 (4) | 0.0424 (6) | 0.0346 (4) | −0.0062 (3) | 0.0009 (3) | −0.0015 (3) |
C1A | 0.0354 (17) | 0.023 (3) | 0.043 (2) | −0.0047 (17) | 0.0129 (18) | 0.002 (3) |
C2A | 0.0353 (17) | 0.033 (3) | 0.046 (4) | 0.0018 (16) | 0.018 (2) | 0.003 (3) |
C3A | 0.0428 (18) | 0.033 (3) | 0.041 (3) | 0.0040 (17) | 0.0230 (19) | 0.000 (3) |
C4A | 0.0390 (16) | 0.024 (3) | 0.042 (2) | −0.0001 (13) | 0.0165 (15) | 0.001 (2) |
C5A | 0.0330 (14) | 0.024 (4) | 0.049 (2) | −0.0001 (16) | 0.0131 (15) | −0.002 (2) |
C6A | 0.0422 (17) | 0.020 (4) | 0.047 (2) | −0.0018 (18) | 0.0201 (17) | −0.005 (2) |
C7A | 0.0396 (17) | 0.029 (4) | 0.042 (3) | −0.001 (2) | 0.0205 (18) | −0.003 (3) |
N1A | 0.0423 (17) | 0.041 (5) | 0.039 (3) | 0.001 (3) | 0.0161 (19) | 0.001 (4) |
Cl1A | 0.0397 (4) | 0.0424 (6) | 0.0346 (4) | −0.0062 (3) | 0.0009 (3) | −0.0015 (3) |
C11A | 0.0354 (17) | 0.023 (3) | 0.043 (2) | −0.0047 (17) | 0.0129 (18) | 0.002 (3) |
C12A | 0.0353 (17) | 0.033 (3) | 0.046 (4) | 0.0018 (16) | 0.018 (2) | 0.003 (3) |
C13A | 0.0428 (18) | 0.033 (3) | 0.041 (3) | 0.0040 (17) | 0.0230 (19) | 0.000 (3) |
C14A | 0.0390 (16) | 0.024 (3) | 0.042 (2) | −0.0001 (13) | 0.0165 (15) | 0.001 (2) |
C15A | 0.0330 (14) | 0.024 (4) | 0.049 (2) | −0.0001 (16) | 0.0131 (15) | −0.002 (2) |
C16A | 0.0422 (17) | 0.020 (4) | 0.047 (2) | −0.0018 (18) | 0.0201 (17) | −0.005 (2) |
C17A | 0.0396 (17) | 0.029 (4) | 0.042 (3) | −0.001 (2) | 0.0205 (18) | −0.003 (3) |
N2A | 0.0423 (17) | 0.041 (5) | 0.039 (3) | 0.001 (3) | 0.0161 (19) | 0.001 (4) |
I1A | 0.0397 (4) | 0.0424 (6) | 0.0346 (4) | −0.0062 (3) | 0.0009 (3) | −0.0015 (3) |
Geometric parameters (Å, º) top
C1—C6 | 1.384 (4) | C1A—C6A | 1.385 (4) |
C1—C2 | 1.390 (4) | C1A—C2A | 1.391 (4) |
C1—I1 | 2.0946 (10) | C1A—Cl1A | 1.7458 (10) |
C2—C3 | 1.377 (4) | C2A—C3A | 1.377 (4) |
C2—H2 | 0.9500 | C2A—H2A | 0.9500 |
C3—C4 | 1.396 (4) | C3A—C4A | 1.396 (4) |
C3—H3 | 0.9500 | C3A—H3A | 0.9500 |
C4—C5 | 1.403 (4) | C4A—C5A | 1.403 (4) |
C4—C7 | 1.453 (4) | C4A—C7A | 1.453 (4) |
C5—C6 | 1.379 (4) | C5A—C6A | 1.379 (4) |
C5—H5 | 0.9500 | C5A—H5A | 0.9500 |
C6—H6 | 0.9500 | C6A—H6A | 0.9500 |
C7—N1 | 1.289 (4) | C7A—N1A | 1.289 (4) |
C7—H7 | 0.9500 | C7A—H7A | 0.9500 |
N1—N2 | 1.427 (11) | N1A—N2A | 1.427 (11) |
C11—C16 | 1.384 (4) | C11A—C16A | 1.385 (4) |
C11—C12 | 1.390 (4) | C11A—C12A | 1.391 (4) |
C11—Cl1 | 1.7461 (10) | C11A—I1A | 2.0951 (11) |
C12—C13 | 1.377 (4) | C12A—C13A | 1.377 (4) |
C12—H12 | 0.9500 | C12A—H12A | 0.9500 |
C13—C14 | 1.396 (4) | C13A—C14A | 1.396 (4) |
C13—H13 | 0.9500 | C13A—H13A | 0.9500 |
C14—C15 | 1.403 (4) | C14A—C15A | 1.403 (4) |
C14—C17 | 1.453 (4) | C14A—C17A | 1.453 (4) |
C15—C16 | 1.379 (4) | C15A—C16A | 1.379 (4) |
C15—H15 | 0.9500 | C15A—H15A | 0.9500 |
C16—H16 | 0.9500 | C16A—H16A | 0.9500 |
C17—N2 | 1.289 (4) | C17A—N2A | 1.289 (4) |
C17—H17 | 0.9500 | C17A—H17A | 0.9500 |
| | | |
C6—C1—C2 | 121.3 (3) | C6A—C1A—C2A | 121.2 (3) |
C6—C1—I1 | 117.5 (6) | C6A—C1A—Cl1A | 126.6 (11) |
C2—C1—I1 | 120.3 (7) | C2A—C1A—Cl1A | 111.3 (11) |
C3—C2—C1 | 118.7 (3) | C3A—C2A—C1A | 118.6 (3) |
C3—C2—H2 | 120.7 | C3A—C2A—H2A | 120.7 |
C1—C2—H2 | 120.7 | C1A—C2A—H2A | 120.7 |
C2—C3—C4 | 121.5 (3) | C2A—C3A—C4A | 121.5 (3) |
C2—C3—H3 | 119.3 | C2A—C3A—H3A | 119.2 |
C4—C3—H3 | 119.3 | C4A—C3A—H3A | 119.2 |
C3—C4—C5 | 118.2 (3) | C3A—C4A—C5A | 118.2 (3) |
C3—C4—C7 | 120.1 (3) | C3A—C4A—C7A | 120.1 (3) |
C5—C4—C7 | 121.6 (3) | C5A—C4A—C7A | 121.6 (3) |
C6—C5—C4 | 120.8 (3) | C6A—C5A—C4A | 120.8 (3) |
C6—C5—H5 | 119.6 | C6A—C5A—H5A | 119.6 |
C4—C5—H5 | 119.6 | C4A—C5A—H5A | 119.6 |
C5—C6—C1 | 119.2 (3) | C5A—C6A—C1A | 119.1 (3) |
C5—C6—H6 | 120.4 | C5A—C6A—H6A | 120.5 |
C1—C6—H6 | 120.4 | C1A—C6A—H6A | 120.5 |
N1—C7—C4 | 120.9 (3) | N1A—C7A—C4A | 120.8 (3) |
N1—C7—H7 | 119.6 | N1A—C7A—H7A | 119.6 |
C4—C7—H7 | 119.6 | C4A—C7A—H7A | 119.6 |
C7—N1—N2 | 113.0 (10) | C7A—N1A—N2A | 110.2 (11) |
C16—C11—C12 | 121.3 (3) | C16A—C11A—C12A | 121.2 (3) |
C16—C11—Cl1 | 121.8 (8) | C16A—C11A—I1A | 116.5 (10) |
C12—C11—Cl1 | 116.8 (8) | C12A—C11A—I1A | 121.6 (11) |
C13—C12—C11 | 118.7 (3) | C13A—C12A—C11A | 118.6 (3) |
C13—C12—H12 | 120.7 | C13A—C12A—H12A | 120.7 |
C11—C12—H12 | 120.7 | C11A—C12A—H12A | 120.7 |
C12—C13—C14 | 121.5 (3) | C12A—C13A—C14A | 121.5 (3) |
C12—C13—H13 | 119.2 | C12A—C13A—H13A | 119.3 |
C14—C13—H13 | 119.2 | C14A—C13A—H13A | 119.3 |
C13—C14—C15 | 118.2 (3) | C13A—C14A—C15A | 118.2 (3) |
C13—C14—C17 | 120.1 (3) | C13A—C14A—C17A | 120.1 (3) |
C15—C14—C17 | 121.6 (3) | C15A—C14A—C17A | 121.6 (3) |
C16—C15—C14 | 120.9 (3) | C16A—C15A—C14A | 120.9 (3) |
C16—C15—H15 | 119.6 | C16A—C15A—H15A | 119.6 |
C14—C15—H15 | 119.6 | C14A—C15A—H15A | 119.6 |
C15—C16—C11 | 119.2 (3) | C15A—C16A—C11A | 119.1 (3) |
C15—C16—H16 | 120.4 | C15A—C16A—H16A | 120.4 |
C11—C16—H16 | 120.4 | C11A—C16A—H16A | 120.4 |
N2—C17—C14 | 120.8 (3) | N2A—C17A—C14A | 120.9 (3) |
N2—C17—H17 | 119.6 | N2A—C17A—H17A | 119.6 |
C14—C17—H17 | 119.6 | C14A—C17A—H17A | 119.6 |
C17—N2—N1 | 111.7 (11) | C17A—N2A—N1A | 108.2 (12) |
Experimental details
| (I,I-A) | (I,I-B) | (I,I-C) | (I,Cl) |
Crystal data |
Chemical formula | C14H10I2N2 | C14H10I2N2 | C14H10I2N2 | C14H10ClIN2 |
Mr | 460.04 | 460.04 | 460.04 | 368.59 |
Crystal system, space group | Monoclinic, P21/c | Monoclinic, P21/n | Monoclinic, P21/c | Monoclinic, Pc |
Temperature (K) | 174 | 174 | 174 | 174 |
a, b, c (Å) | 11.854 (2), 7.7308 (13), 7.6827 (13) | 8.4303 (17), 5.6453 (12), 15.248 (3) | 7.2077 (17), 4.1543 (10), 23.317 (6) | 11.499 (2), 4.0006 (7), 14.717 (3) |
β (°) | 92.407 (3) | 104.346 (3) | 90.314 (4) | 90.900 (3) |
V (Å3) | 703.5 (2) | 703.0 (3) | 698.2 (3) | 676.9 (2) |
Z | 2 | 2 | 2 | 2 |
Radiation type | Mo Kα | Mo Kα | Mo Kα | Mo Kα |
µ (mm−1) | 4.45 | 4.46 | 4.49 | 2.55 |
Crystal size (mm) | 0.45 × 0.35 × 0.06 | 0.30 × 0.06 × 0.03 | 0.45 × 0.10 × 0.04 | 0.20 × 0.20 × 0.05 |
|
Data collection |
Diffractometer | Bruker SMART 1K CCD area-detector diffractometer | Bruker SMART 1K CCD area-detector diffractometer | Bruker SMART 1K CCD area-detector diffractometer | Bruker SMART 1K CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2003; Blessing, 1995) | Multi-scan (SADABS; Sheldrick, 2003; Blessing, 1995) | Multi-scan (SADABS; Sheldrick, 2003; Blessing, 1995) | Multi-scan SADABS; Sheldrick, 2003; Blessing, 1995 |
Tmin, Tmax | 0.32, 0.77 | 0.54, 0.87 | 0.24, 0.84 | 0.42, 0.88 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7773, 1602, 1442 | 7699, 1600, 1189 | 7115, 1601, 1290 | 7262, 3089, 2308 |
Rint | 0.031 | 0.052 | 0.085 | 0.032 |
(sin θ/λ)max (Å−1) | 0.649 | 0.649 | 0.650 | 0.665 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.022, 0.054, 1.11 | 0.031, 0.061, 1.02 | 0.047, 0.122, 1.05 | 0.038, 0.072, 1.05 |
No. of reflections | 1602 | 1600 | 1601 | 3089 |
No. of parameters | 83 | 83 | 82 | 164 |
No. of restraints | 0 | 0 | 0 | 109 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.86, −0.55 | 0.48, −0.61 | 3.00, −1.34 | 0.50, −0.33 |
Absolute structure | ? | ? | ? | Flack (1983),
1476 Friedel pairs |
Absolute structure parameter | ? | ? | ? | 0.17 (7) |
Table 1. Distances and angles (Å, °) in the X···X contacts in (X,X)
and (X,X)*a
For comparison, the van der Waals contact distances
(Bondi, 1964; Rowland & Taylor, 1996) are Cl···Cl = 3.50 Å;
Br···Br = 3.70 Å; I···I = 3.96 Å. topCompound | temp(K) | X | X' | C-X···X' | X···X' | X···X'-C | ref. |
(Cl,Cl) | 173 | Cl1 | Cl1i | 74.1 (1) | 3.887 (1) | 105.9 (1) | b |
(Cl,Cl) | 173 | Cl1 | Cl1 | 73.8 (1) | 3.892 (1) | 105.9 (1) | c |
(Cl,Cl) | 294 | Cl1 | Cl1 | 74.1 (1) | 3.958 (1) | 106.2 (1) | d |
(Br,Br) | 173 | Br1 | Br1ii | 127.1 (1) | 3.812 (2) | 152.6 (1) | b |
| 173 | Br1 | Br1iii | 74.2 (1) | 3.977 (1) | 105.8 (1) | b |
(Br,Br) | 294 | Br1 | Br1 | 126.3 (3) | 3.861 (4) | 153.4 (3) | e |
| 294 | Br1 | Br1 | 73.3 (3) | 4.051 (4) | 106.7 (3) | e |
(I,I-A) | 173 | I1 | I1iv | 147.0 (2) | 3.781 (1) | 147.0 (2) | f |
(I,I-B) | 173 | I1 | I1v | 109.9 (3) | 3.965 (2) | 154.5 (3) | f |
(I,I-C) | 173 | I1 | I1vi | 127.1 (5) | 3.960 (4) | 154.9 (5) | f |
| 173 | I1 | I1iii | 73.2 (5) | 4.154 (1) | 106.8 (5) | f |
(Cl,Cl)* | 294 | Cl1 | Cl2 | 163.4 (2) | 3.340 (1) | 163.6 (2) | g |
(Br,Br)* | 294 | Br1 | Br2 | 168.8 (2) | 3.560 (1) | 97.0 (2) | g |
(I,I)* | 173 | I1 | I1' | 155.3 (3) | 4.122 (1) | 101.8 (3) | h |
(a) The (X,X)* structures are for analogous compounds where the
azine H atoms have
been replaced by methyl groups.
(b) Ojala et al. (2007a).
(c) Glaser et al. (2006).
(d) Zheng et al. (2005).
(e) Marignan et al. (1972).
(f) This work.
(g) Chen et al. (1994).
(h) Lewis et al. (1999).
Symmetry codes: (i) 1+x, y, z; (ii) 3/2-x, -1/2+y, 3/2-z; (iii) x, -1+y, z;
(iv) -x, 1-y, -1-z;(v) 3/2-x, -1/2+y, 1/2-z; (vi) -1-x, -1/2+y, 1/2-z. |
Table 3. π contacts: inter-ring distances (Å) and ring overlaps (%) topcompound | distance(Å) | overlap(%) | ref. |
(Cl,Cl) | 3.459 (4) | 17.8 (2) | a |
(Br,Br) | 3.479 (6) | 12.8 (2) | a |
(I,I-A) | no_overlap | | b |
(I,I-B) | 3.584 (8) | 12.7 (2) | b |
(I,I-C) | 3.522 (3) | 5.7 (2) | b |
(a) Ojala et al. (2007a).
(b) This work. |
Table 4. Cell constants (Å, °, Å3) for all (X,X) and (X,Y)
structures at 173 K. topCompound | a | b | c | β | V | reference |
(Cl,Cl) | 3.887 (1) | 6.990 (1) | 22.980 (2) | 90.77 (1) | 624.3 (1) | a |
(Br,Cl) | 6.995 (1) | 3.945 (1) | 22.971 (4) | 92.72 (1) | 633.1 (2) | b |
(Br,Br) | 7.027 (1) | 3.977 (1) | 23.141 (3) | 91.72 (1) | 646.5 (1) | a |
(I,Cl) | 11.499 (2) | 4.001 (1) | 14.717 (3) | 90.90 (1) | 676.9 (2) | c |
(I,Br) | 11.513 (5) | 4.044 (2) | 14.719 (4) | 90.34 (2) | 685.3 (3) | b |
(I,I-A) | 11.854 (2) | 7.731 (1) | 7.683 (1) | 92.41 (1) | 703.5 (2) | c |
(I,I-B) | 8.430 (2) | 5.645 (1) | 15.248 (3) | 104.35 (1) | 703.0 (3) | c |
(I,I-C) | 7.208 (2) | 4.154 (1) | 23.317 (6) | 90.31 (1) | 698.2 (3) | c |
(a) Ojala et al. (2007a).
(b) Ojala et al. (2007b).
(c) This work. |
Table 2. Comparison of N-N distances (Å) between (X,X) and (X-X)* topX | dist._in_(X,X) | reference | dist._in_(X,X)* | reference |
H | 1.418 (3) | a | 1.403 (3) | b |
| 1.412 (10) | c | 1.396 (2) | d |
Cl | 1.412 (2) | e | 1.398 (3) | b |
| 1.414 (3) | f | | |
| 1.409 (2)) | g | | |
Br | 1.450 (22) | h | 1.383 (6) | b |
| 1.411 (4) | g | | |
I | 1.411 (4) | i | 1.396 (6) | j |
| 1.418 (6) | i | | |
| 1.400 (12) | i | | |
(a) Mom & de With (1978).
(b) Chen et al. (1994).
(c) Burke-Laing & Laing (1976).
(d) Bolte & Ton (2003).
(e) Glaser et al. (2006
(f) Zheng et al. (2005).
(g) Ojala et al. (2007a).
(h) Marignan et al. (1972).This work.
(j) Lewis et al. (1999). |
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In this paper the descriptor (X,Y) is used as an abbreviation for 4-X-4'-Y-benzalazine, with the three title polymorphs designated as (I,I-A),(I,I-B) and (I,I-C). Crystals of the dichloro and dibromo analogs, (Cl,Cl) and (Br,Br), of the (I,I) title compound are not isostructural (Zheng et al., 2005; Marignan et al., 1972). The structure of (I,I) was undertaken to compare the packing with that of (Br,Br). When three polymorphs of (I,I) were found, the study was expanded to include (Br,Cl), (I,Cl) and (I,Br) to see if these were isostructural with one or another of the (X,X) compounds.
Fig. 1 shows the atom labeling and the anisotropic displacement ellipsoid plots for (I,I-A) and (I,Cl). Molecules of (I,I-A) lie on a center of symmetry. (I,Cl) is disordered about a pseudo-center of symmetry, with 0.586 (2) as the fraction for the major component of the disorder. In both structures, the bond lengths and angles are normal. The labelings for all of the compounds described here are the same; the anisotropic displacement ellipsoid plots for (I,I-B) and I,I-C) are similar to those of (I,I-A).
The packing of (I,I-A) is shown in Fig. 2. The molecules assemble in ribbons held together by I···I interactions and parallel to the [102] direction. The ribbons form sheets normal to the b axis, with the essentially planar molecules tilted 33.4 (1)° away from the plane of the sheet. Adjacent sheets form a herringbone pattern. Table 1 gives the geometric data for all of the I···I contacts.
The packing of (I,I-B) is shown in Fig. 3. The molecules assemble in layers held together by I···I interactions and parallel to the (103) plane. The molecules are tilted 34.9 (1)° away from the mean plane of the layer; alternate molecules are tilted in opposite directions away from the plane.
The packing of (I,I-C) is shown in Fig. 4. The molecules assemble in layers held together by I···I interactions and parallel to the (104) plane. The molecules are tilted 58.6 (1)° away from the mean plane of the layer; alternate molecules are tilted in opposite directions away from the plane. There are two kinds of I···I interactions, one lying across a 21 axis and the other lying along the b axis.
The packing of (I,Cl) is shown in Fig. 5. The disordered molecules (as noted above) assemble in layers held together by I···I, I···Cl or Cl···Cl interactions. The molecules are tilted 59.9 (1)° away from the mean plane. All of the molecules in a given layer have the same tilt; those in the adjacent layer tilt in the opposite sense. This leads to a herringbone pattern between the layers. There are two kinds of I···I interactions, one lying across a 21 axis and the other lying along the b axis. There is some similarity in this respect with the packing arrangement of (I,Cl) and (I,I-C).
Schmidt (1971) showed that dichloro aromatic compounds often crystallize with a short, approximately 4 Å axis, presumably, in part, as a consequence of weak intermolecular Cl···Cl interactions. Sakurai et al. (1963) pointed out two other kinds of Cl···Cl interactions, viz. an approximately linear arrangement across a center of symmetry, and an angular arrangement across a 21 axis or a glide plane. These interactions have been discussed by Desiraju (1987, 1989, 1995). Examples of all of these are shown in the four compounds reported here. (I,I-A) has the approximately linear arrangement across a center of symmetry. (I,I-B), (I,I-C), and (I,Cl) all adopt the angular arrangement across a 21 axis. In addition, (I,Cl) and (I,I-C) have short axial contacts of the type pointed out by Schmidt (1971). The distances and angles for all of the X···X interactions are listed in Table 1. Also included in Table 1 are the same data for the compounds (X,X)*, where X = Cl, Br or I and the * refers to the analogous molecules in which the aliphatic H atoms have been replaced by methyl groups (the methylphenylketalazines, hereafter referred to as simply ketalazines). In this latter series, the X···X distances are significantly shorter in every case except for the (I,I) case.
The (X,X) and (X,X)* molecules differ in that the (X,X) molecules are all planar while the (X,X)* molecules are not, even though they all have gauche configurations around the N—N bonds. A comparison of benzalazine structures with ketalazine structures (Chen et al., 1994; Bolte & Ton, 2003; Lewis et al., 1999) confirms the fundamentally different geometry for the two systems. In the benzalazine structures, including the non-para-substituted parent system, the molecules are effectively planar with fully conjugated π systems. By contrast, in the ketalazine structures, again including the parent system, the torsion angle about the central CNNC linkage is large, ranging from 50 to 100° depending on the para substitution.
To better understand this difference, we carried out density functional structure calculations using the M06 density functional (Zhao & Truhlar, 2007) and the MIDI! basis set (Easton et al., 1996). For the case of 4,4'-dichloro substitution, both the benzalazine and ketalazine systems were subjected to constrained optimizations where the CNNC torsion angle was varied and held fixed in increments of 15° (Fig. 7). Interestingly, while the ketalazine is predicted to have a double-well potential characterized by a minimum-energy geometry with a CNNC dihedral angle of 105.3° (in very good agreement with the experimental value of 103.1°), the benzalazine has a triple well potential, with very shallow minima predicted for the symmetrically related twisted geometries and a more stable planar minimum predicted for the fully planar geometry (i.e. having a CNNC torsion angle of 180°). In each instance, the torsional potential is relatively flat over the range of 75 to 285°; the total variation in energy is only about 2 kcal mol-1. The methyl groups in the ketalazine experience unfavorable steric repulsion that causes the energy in this system to rise steeply outside this range. A full rotational coordinate for the benzalazine system was computed; the energy of the system having a CNNC torsion angle of 0° is predicted to be about 15 kcal mol-1 above the trans planar minimum.
The relatively flat potentials are associated with a balance between full π conjugation, available to the planar geometry, and a push–pull resonance available to the rotated system, which also minimizes NN lone-pair–lone-pair repulsions analogous to those in hydrazine, which also adopts a twisted minimum-energy geometry (Fig. 8). The deeper well for the twisted geometry of the ketalazine compared with the benzalazine, relative to the planar structure, is associated with improved hyperconjugative interactions for the nitrogen lone pairs delocalizing into the eclipsed π system when the methyl groups are present. Thus, Natural Bond Orbital analysis (Reed et al., 1988) quantifies the nN → π* delocalization for each N lone pair as 16.5 kcal mol-1 in the ketalazine system, but only 13.5 kcal mol-1 in the benzalazine system. This is the largest difference in the filled/empty delocalization energies between the two systems. A consequence of this delocalization is that the NN bond should be shorter (because of some double-bond character) in the twisted systems than in the planar systems, and this is indeed borne out by the experimental structural data (see Table 2).
A second aspect of the packing in the azalazines is the π interaction between the benzene rings. The geometric aspects are given in Table 3, where the perpendicular distances between the rings and the overlap are given. The overlap is given as the percentage overlap of the areas in the adjacent C6 rings. The overlap for (I,I-C) is shown in Fig. 5; the molecules assemble in stacks along the short axis. With two exceptions, the others are similar; in (I,I-A) there is no overlap, and in (I,I-B) the molecules assemble in chains rather than stacks. (Br,Cl) and (Br,Br) appear to be isostructural with each other, as do (I,Cl) and (I,Br). These similarities would require disorder in (Br,Cl) and (I,Br). In view of the disorder in all of the (X,Y) structures, no data are included here for their π overlap. However, they all appear to be similar to that shown in Fig. 5.
The unit-cell dimensions for all of the (X,X) and (X,Y) structures are given in Table 4. The (Cl,Cl) structure is unique. (Br,Cl) and (Br,Br) are isostructural with (I,I-C). (I,Cl) and (I,Br) are isostructural only with each other. Thus there are five different structural types in this series of compounds. When three polymorphs of (I,I) were found, all the remaining compounds in Table 4 were examined to see if other polymorphs could be found. Each compound was recrystallized from acetone, benzene, methylene chloride, chloroform, carbon tetrachloride and acetonitrile. Although a variety of crystal habits were found for each compound, in no case were other polymorphs found.
Each of the five structure types in Table 4 gives a plausible packing arrangment for all of the benzalazine compounds. So this system, which involves only planar molecules, could provide a reasonable test for programs that predict crystal packing. It is surprising that in five of the six compounds no polymorphs were found, even though the search for polymorphs was not exhaustive.