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The crystal structures of the title compounds, alternatively called 2,2'-(2,2'-biimidazole-1,1'-diyl)diacetohydrazide monohydrate, C10H14N8O2·H2O, (I), and 3,3'-(2,2'-biimidazole-1,1'-diyl)dipropionohydrazide, C12H18N8O2, (II), respectively, have been determined. The molecules consist of half-molecule asymmetric units related by a twofold rotation in (I) and by a center of inversion in (II). The imidazole rings of both molecules crystallize in a nearly coplanar fashion [dihedral angles of 5.91 (3) and 0.0 (1)° for (I) and (II), respectively]. Both planar hydrazinocarbonylalkyl substituents are essentially planar and assume the E orientation.
Supporting information
CCDC references: 195624; 195625
The title compounds were prepared by separately reacting
1,1'-di(methylacetato)-2,2'-biimidazole (0.25 g, 0.898 mmol) or
1,1'-di(ethylpropionato)-2,2'-biimidazole (0.25 g, 0.748 mmol) with 64%
hydrazine (10 ml, 200 mmol) in a 25 ml round-bottomed flask with stirring. The
mixtures were stirred for a minimum of 3 d, after which, the white powdery
products were washed with water, filtered and crystallized by slow cooling
from hot aqueous solutions. Yields were \sim60 and 78% for (I) and (II),
respectively. The crystal of (I) was sealed with mother liquor in a capillary
to minimize possible gain or loss of water.
The C—H bond lengths were constrained at 0.96 Å, N—H at 0.90 Å and O—H
at 0.85 Å.
For both compounds, data collection: P3/P4-PC Diffractometer Program (Siemens, 1991); cell refinement: P3/P4-PC Diffractometer Program; data reduction: XDISK (Siemens, 1991); program(s) used to solve structure: SHELXS86 (Sheldrick, 1990a); program(s) used to refine structure: SHELXL93 (Sheldrick, 1993); molecular graphics: SHELXTL/PC (Sheldrick, 1990b); software used to prepare material for publication: SHELXTL/PC and SHELXL93.
(I) 1,1'-di(hydrazinoethanoyl)2,2'-biimidazole monohydrate
top
Crystal data top
C10H14N8O2·H2O | Dx = 1.462 Mg m−3 |
Mr = 296.29 | Mo Kα radiation, λ = 0.71073 Å |
Tetragonal, I41 | Cell parameters from 100 reflections |
Hall symbol: I 4bw | θ = 6.4–19.7° |
a = 9.7451 (3) Å | µ = 0.11 mm−1 |
c = 14.1764 (6) Å | T = 293 K |
V = 1346.30 (8) Å3 | Block cut from larger crystal, colorless |
Z = 4 | 0.59 × 0.50 × 0.45 mm |
F(000) = 624 | |
Data collection top
Siemens–Bruker P4 diffractometer | Rint = 0.015 |
Radiation source: normal-focus sealed tube | θmax = 25.0°, θmin = 2.5° |
Graphite monochromator | h = −11→1 |
θ/2θ scans | k = −1→11 |
939 measured reflections | l = −16→1 |
620 independent reflections | 3 standard reflections every 100 reflections |
562 reflections with I > 2σ(I) | intensity decay: ave. in σ(I)'s of 1.7% |
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)] = 0.032 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.077 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.12 | w = 1/[σ2(Fo2) + (0.038P)2 + 0.5103P] where P = (Fo2 + 2Fc2)/3 |
620 reflections | (Δ/σ)max < 0.001 |
99 parameters | Δρmax = 0.14 e Å−3 |
3 restraints | Δρmin = −0.16 e Å−3 |
Crystal data top
C10H14N8O2·H2O | Z = 4 |
Mr = 296.29 | Mo Kα radiation |
Tetragonal, I41 | µ = 0.11 mm−1 |
a = 9.7451 (3) Å | T = 293 K |
c = 14.1764 (6) Å | 0.59 × 0.50 × 0.45 mm |
V = 1346.30 (8) Å3 | |
Data collection top
Siemens–Bruker P4 diffractometer | Rint = 0.015 |
939 measured reflections | 3 standard reflections every 100 reflections |
620 independent reflections | intensity decay: ave. in σ(I)'s of 1.7% |
562 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.032 | 3 restraints |
wR(F2) = 0.077 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.12 | Δρmax = 0.14 e Å−3 |
620 reflections | Δρmin = −0.16 e Å−3 |
99 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.
planes. |
Refinement. Refinement on F2 for ALL reflections except for 4 with very negative
F2 or flagged by the user for potential systematic errors. Weighted
R-factors wR and all goodnesses of fit S are based on
F2, conventional R-factors R are based on F,
with F set to zero for negative F2. The observed criterion of
F2 > σ(F2) is used only for calculating R factor obs
etc. and is not relevant to the choice of reflections for refinement.
R-factors based on F2 are statistically about twice as large
as those based on F, and R- factors based on ALL data will be
even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.5130 (2) | 0.2547 (2) | 0.5599 (2) | 0.0384 (5) | |
O2 | 0.5000 | 0.0000 | 0.41219 (13) | 0.0676 (13) | |
H2A | 0.503 (6) | 0.0691 (2) | 0.3757 (3) | 0.080* | |
N1 | 0.4009 (2) | 0.3361 (2) | 0.7275 (2) | 0.0314 (5) | |
N2 | 0.3170 (3) | 0.5473 (3) | 0.7237 (3) | 0.0395 (7) | |
N3 | 0.6668 (2) | 0.1164 (3) | 0.6313 (3) | 0.0338 (6) | |
H3A | 0.6945 (2) | 0.0809 (3) | 0.6870 (3) | 0.080* | |
N4 | 0.7422 (3) | 0.0819 (3) | 0.5499 (2) | 0.0402 (6) | |
H4D | 0.6858 (3) | 0.0402 (3) | 0.5084 (2) | 0.080* | |
H4C | 0.7767 (3) | 0.1584 (3) | 0.5234 (2) | 0.080* | |
C1 | 0.4306 (3) | 0.4728 (3) | 0.7275 (3) | 0.0302 (6) | |
C2 | 0.2607 (3) | 0.3242 (3) | 0.7222 (3) | 0.0397 (7) | |
H2 | 0.2071 (3) | 0.2414 (3) | 0.7198 (3) | 0.080* | |
C3 | 0.2128 (3) | 0.4538 (4) | 0.7201 (3) | 0.0448 (8) | |
H3 | 0.1173 (3) | 0.4782 (4) | 0.7174 (3) | 0.080* | |
C4 | 0.4940 (3) | 0.2194 (3) | 0.7275 (3) | 0.0320 (7) | |
H4A | 0.4453 (3) | 0.1374 (3) | 0.7450 (3) | 0.080* | |
H4B | 0.5650 (3) | 0.2348 (3) | 0.7735 (3) | 0.080* | |
C5 | 0.5589 (3) | 0.2002 (3) | 0.6308 (3) | 0.0276 (6) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0381 (11) | 0.0450 (13) | 0.0321 (11) | 0.0104 (9) | 0.0037 (10) | 0.0089 (10) |
O2 | 0.099 (3) | 0.058 (2) | 0.046 (2) | −0.025 (2) | 0.000 | 0.000 |
N1 | 0.0289 (12) | 0.0284 (12) | 0.0367 (13) | −0.0004 (10) | 0.0056 (11) | −0.0003 (12) |
N2 | 0.0298 (13) | 0.0344 (14) | 0.054 (2) | 0.0040 (10) | 0.0030 (13) | −0.0013 (14) |
N3 | 0.0335 (13) | 0.0349 (14) | 0.0331 (12) | 0.0082 (11) | 0.0011 (11) | 0.0030 (11) |
N4 | 0.0372 (14) | 0.0402 (15) | 0.0430 (15) | 0.0095 (10) | 0.0067 (13) | −0.0004 (13) |
C1 | 0.0301 (14) | 0.0284 (14) | 0.032 (2) | 0.0004 (12) | 0.0007 (14) | −0.0002 (13) |
C2 | 0.0294 (15) | 0.041 (2) | 0.049 (2) | −0.0050 (14) | 0.0074 (15) | −0.005 (2) |
C3 | 0.0250 (14) | 0.046 (2) | 0.063 (2) | −0.0011 (14) | 0.006 (2) | −0.005 (2) |
C4 | 0.036 (2) | 0.0238 (14) | 0.036 (2) | 0.0007 (11) | 0.0063 (15) | 0.0053 (13) |
C5 | 0.0276 (14) | 0.0228 (15) | 0.0324 (15) | −0.0033 (11) | 0.0004 (13) | 0.0030 (12) |
Geometric parameters (Å, º) top
O1—C5 | 1.222 (4) | N4—H4D | 0.90 |
O2—H2A | 0.850 (5) | N4—H4C | 0.90 |
N1—C1 | 1.364 (4) | C1—C1i | 1.453 (5) |
N1—C2 | 1.374 (4) | C2—C3 | 1.346 (5) |
N1—C4 | 1.455 (3) | C2—H2 | 0.96 |
N2—C1 | 1.325 (4) | C3—H3 | 0.96 |
N2—C3 | 1.366 (4) | C4—C5 | 1.521 (4) |
N3—C5 | 1.331 (4) | C4—H4A | 0.96 |
N3—N4 | 1.410 (4) | C4—H4B | 0.96 |
N3—H3A | 0.90 | | |
| | | |
C1—N1—C2 | 107.1 (2) | N1—C2—H2 | 127.8 |
C1—N1—C4 | 129.2 (2) | C2—C3—N2 | 111.6 (3) |
C2—N1—C4 | 123.7 (3) | C2—C3—H3 | 124.7 |
C1—N2—C3 | 104.9 (3) | N2—C3—H3 | 123.8 |
C5—N3—N4 | 123.6 (3) | N1—C4—C5 | 110.8 (2) |
C5—N3—H3A | 118.4 | N1—C4—H4A | 109.98 |
N4—N3—H3A | 117.96 | C5—C4—H4A | 109.65 |
N3—N4—H4D | 108.9 | N1—C4—H4B | 109.1 |
N3—N4—H4C | 109.8 | C5—C4—H4B | 109.33 |
H4D—N4—H4C | 109.2 | H4A—C4—H4B | 108.0 |
N2—C1—N1 | 111.0 (2) | O1—C5—N3 | 124.0 (3) |
N2—C1—C1i | 125.3 (3) | O1—C5—C4 | 122.4 (2) |
N1—C1—C1i | 123.6 (3) | N3—C5—C4 | 113.5 (3) |
C3—C2—N1 | 105.5 (3) | H4D—O2—H2A | 102 |
C3—C2—H2 | 126.7 | H4D—O2—H2Aii | 122 |
Symmetry codes: (i) −x+1, −y+1, z; (ii) −x+1, −y, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2a···N4iii | 0.85 (1) | 2.27 (2) | 3.080 (3) | 161 (4) |
N3—H3a···O1iv | 0.90 | 1.93 | 2.830 (3) | 176 |
N4—H4c···N2v | 0.90 | 2.41 | 3.260 (4) | 157 |
N4—H4d···O2 | 0.90 | 2.30 | 3.165 (4) | 161 |
Symmetry codes: (iii) y+1/2, −x+1, z−1/4; (iv) −y+1, x−1/2, z+1/4; (v) −y+3/2, x, z−1/4. |
(II) 1,1'-di(hydrazinopropanoyl)-2,2'-biimidazole
top
Crystal data top
C12H18N8O2 | F(000) = 324 |
Mr = 306.33 | Dx = 1.387 Mg m−3 Dm = not determined Mg m−3 Dm measured by ? |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 100 reflections |
a = 10.0505 (5) Å | θ = 7.7–19.7° |
b = 4.9326 (2) Å | µ = 0.10 mm−1 |
c = 15.4663 (7) Å | T = 293 K |
β = 106.904 (3)° | Rectangular block, colorless |
V = 733.61 (6) Å3 | 0.50 × 0.36 × 0.30 mm |
Z = 2 | |
Data collection top
Siemens–Bruker P4 diffractometer | Rint = 0.026 |
Radiation source: normal-focus sealed tube | θmax = 25.0°, θmin = 2.1° |
Graphite monochromator | h = −11→1 |
θ/2θ scans | k = −5→1 |
1899 measured reflections | l = −17→18 |
1287 independent reflections | 3 standard reflections every 100 reflections |
1078 reflections with I > 2 σ(I) | intensity decay: ave. of 1.7 % in σ(I)s |
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)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.101 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0496P)2 + 0.2482P] where P = (Fo2 + 2Fc2)/3 |
1283 reflections | (Δ/σ)max < 0.001 |
100 parameters | Δρmax = 0.18 e Å−3 |
0 restraints | Δρmin = −0.19 e Å−3 |
Crystal data top
C12H18N8O2 | V = 733.61 (6) Å3 |
Mr = 306.33 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 10.0505 (5) Å | µ = 0.10 mm−1 |
b = 4.9326 (2) Å | T = 293 K |
c = 15.4663 (7) Å | 0.50 × 0.36 × 0.30 mm |
β = 106.904 (3)° | |
Data collection top
Siemens–Bruker P4 diffractometer | Rint = 0.026 |
1899 measured reflections | 3 standard reflections every 100 reflections |
1287 independent reflections | intensity decay: ave. of 1.7 % in σ(I)s |
1078 reflections with I > 2 σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.101 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.18 e Å−3 |
1283 reflections | Δρmin = −0.19 e Å−3 |
100 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.
planes. |
Refinement. Refinement on F2 for ALL reflections except for 4 with very negative
F2 or flagged by the user for potential systematic errors. Weighted
R-factors wR and all goodnesses of fit S are based on
F2, conventional R-factors R are based on F,
with F set to zero for negative F2. The observed criterion of
F2 > σ(F2) is used only for calculating R factor obs
etc. and is not relevant to the choice of reflections for refinement.
R-factors based on F2 are statistically about twice as large
as those based on F, and R- factors based on ALL data will be
even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.84779 (13) | 1.0937 (2) | 0.87916 (9) | 0.0451 (4) | |
N1 | 0.56996 (15) | 0.7806 (3) | 0.94387 (9) | 0.0388 (4) | |
N2 | 0.3743 (2) | 0.5492 (3) | 0.88759 (10) | 0.0447 (4) | |
N3 | 0.8717 (2) | 0.6660 (3) | 0.83692 (11) | 0.0442 (4) | |
H3A | 0.8687 (2) | 0.4891 (3) | 0.85044 (11) | 0.080* | |
N4 | 0.9002 (2) | 0.7358 (3) | 0.75521 (12) | 0.0526 (4) | |
H4C | 0.8281 (2) | 0.8303 (3) | 0.72000 (12) | 0.080* | |
H4D | 0.9776 (2) | 0.8382 (3) | 0.76777 (12) | 0.080* | |
C1 | 0.4855 (2) | 0.5785 (3) | 0.95835 (11) | 0.0356 (4) | |
C2 | 0.5070 (2) | 0.8814 (4) | 0.85903 (12) | 0.0471 (5) | |
H2 | 0.5411 (2) | 1.0261 (4) | 0.82984 (12) | 0.080* | |
C3 | 0.3888 (2) | 0.7385 (4) | 0.82599 (13) | 0.0498 (5) | |
H3 | 0.3239 (2) | 0.7658 (4) | 0.76737 (13) | 0.080* | |
C4 | 0.7041 (2) | 0.8773 (4) | 1.00172 (12) | 0.0457 (5) | |
H4A | 0.7096 (2) | 0.8431 (4) | 1.06378 (12) | 0.080* | |
H4B | 0.7105 (2) | 1.0695 (4) | 0.99418 (12) | 0.080* | |
C5 | 0.8255 (2) | 0.7397 (4) | 0.97986 (12) | 0.0440 (5) | |
H5A | 0.8075 (2) | 0.5485 (4) | 0.97329 (12) | 0.080* | |
H5B | 0.9086 (2) | 0.7653 (4) | 1.02893 (12) | 0.080* | |
C6 | 0.8484 (2) | 0.8480 (3) | 0.89408 (11) | 0.0348 (4) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0572 (8) | 0.0255 (7) | 0.0574 (8) | −0.0039 (5) | 0.0240 (6) | 0.0030 (5) |
N1 | 0.0434 (8) | 0.0360 (8) | 0.0413 (8) | −0.0038 (6) | 0.0193 (6) | −0.0002 (6) |
N2 | 0.0431 (8) | 0.0426 (9) | 0.0472 (8) | 0.0008 (7) | 0.0111 (7) | 0.0019 (7) |
N3 | 0.0506 (9) | 0.0278 (8) | 0.0577 (9) | −0.0011 (7) | 0.0211 (7) | 0.0014 (7) |
N4 | 0.0595 (10) | 0.0459 (10) | 0.0607 (10) | 0.0020 (8) | 0.0302 (8) | −0.0024 (8) |
C1 | 0.0390 (9) | 0.0311 (9) | 0.0400 (8) | 0.0003 (7) | 0.0168 (7) | −0.0024 (7) |
C2 | 0.0574 (11) | 0.0443 (11) | 0.0453 (10) | 0.0019 (9) | 0.0239 (9) | 0.0080 (8) |
C3 | 0.0541 (11) | 0.0514 (12) | 0.0432 (10) | 0.0065 (9) | 0.0130 (8) | 0.0052 (9) |
C4 | 0.0551 (11) | 0.0424 (10) | 0.0433 (9) | −0.0160 (9) | 0.0203 (8) | −0.0069 (8) |
C5 | 0.0428 (10) | 0.0393 (10) | 0.0464 (10) | −0.0074 (8) | 0.0073 (8) | 0.0069 (8) |
C6 | 0.0276 (8) | 0.0275 (9) | 0.0480 (9) | −0.0048 (6) | 0.0090 (7) | 0.0013 (7) |
Geometric parameters (Å, º) top
O1—C6 | 1.233 (2) | C1—C1i | 1.458 (3) |
N1—C1 | 1.369 (2) | C2—C3 | 1.348 (3) |
N1—C2 | 1.374 (2) | C2—H2 | 0.96 |
N1—C4 | 1.464 (2) | C3—H3 | 0.96 |
N2—C1 | 1.325 (2) | C4—C5 | 1.518 (3) |
N2—C3 | 1.372 (2) | C4—H4A | 0.96 |
N3—C6 | 1.328 (2) | C4—H4B | 0.96 |
N3—N4 | 1.417 (2) | C5—C6 | 1.509 (2) |
N3—H3A | 0.90 | C5—H5A | 0.96 |
N4—H4C | 0.90 | C5—H5B | 0.96 |
N4—H4D | 0.90 | | |
| | | |
C1—N1—C2 | 106.51 (15) | C2—C3—H3 | 124.48 |
C1—N1—C4 | 129.90 (15) | N2—C3—H3 | 124.87 |
C2—N1—C4 | 123.6 (2) | N1—C4—C5 | 112.03 (14) |
C1—N2—C3 | 105.4 (2) | N1—C4—H4A | 109.25 |
C6—N3—N4 | 123.37 (15) | C5—C4—H4A | 109.09 |
C6—N3—H3A | 118.44 | N1—C4—H4B | 109.28 |
N4—N3—H3A | 118.19 | C5—C4—H4B | 109.11 |
N3—N4—H4C | 109.24 | H4A—C4—H4B | 108.0 |
N3—N4—H4D | 109.25 | C6—C5—C4 | 112.07 (15) |
H4C—N4—H4D | 109.5 | C6—C5—H5A | 109.11 |
N2—C1—N1 | 111.01 (15) | C4—C5—H5A | 108.88 |
N2—C1—C1i | 125.1 (2) | C6—C5—H5B | 109.15 |
N1—C1—C1i | 123.9 (2) | C4—C5—H5B | 109.65 |
C3—C2—N1 | 106.5 (2) | H5A—C5—H5B | 107.9 |
C3—C2—H2 | 127.38 | O1—C6—N3 | 122.2 (2) |
N1—C2—H2 | 126.14 | O1—C6—C5 | 121.3 (2) |
C2—C3—N2 | 110.6 (2) | N3—C6—C5 | 116.58 (15) |
Symmetry code: (i) −x+1, −y+1, −z+2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N4—H4C···N2ii | 0.90 | 2.47 | 3.367 (2) | 174 |
N4—H4D···N4iii | 0.90 | 2.40 | 3.213 (2) | 151 |
N3—H3A···O1iv | 0.90 | 2.03 | 2.923 (2) | 176 |
C3—H3···O1v | 0.96 | 2.56 | 3.441 (2) | 152 |
C4—H4A···N2i | 0.96 | 2.32 | 2.960 (2) | 123 |
C4—H4B···O1 | 0.96 | 2.55 | 2.900 (2) | 102 |
C5—H5B···O1vi | 0.96 | 2.54 | 3.471 (2) | 162 |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x+1, y+1/2, −z+3/2; (iii) −x+2, y+1/2, −z+3/2; (iv) x, y−1, z; (v) −x+1, y−1/2, −z+3/2; (vi) −x+2, −y+2, −z+2. |
Experimental details
| (I) | (II) |
Crystal data |
Chemical formula | C10H14N8O2·H2O | C12H18N8O2 |
Mr | 296.29 | 306.33 |
Crystal system, space group | Tetragonal, I41 | Monoclinic, P21/c |
Temperature (K) | 293 | 293 |
a, b, c (Å) | 9.7451 (3), 9.7451 (3), 14.1764 (6) | 10.0505 (5), 4.9326 (2), 15.4663 (7) |
α, β, γ (°) | 90, 90, 90 | 90, 106.904 (3), 90 |
V (Å3) | 1346.30 (8) | 733.61 (6) |
Z | 4 | 2 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.11 | 0.10 |
Crystal size (mm) | 0.59 × 0.50 × 0.45 | 0.50 × 0.36 × 0.30 |
|
Data collection |
Diffractometer | Siemens–Bruker P4 diffractometer | Siemens–Bruker P4 diffractometer |
Absorption correction | – | – |
No. of measured, independent and observed reflections | 939, 620, 562 [I > 2σ(I)] | 1899, 1287, 1078 [I > 2 σ(I)] |
Rint | 0.015 | 0.026 |
(sin θ/λ)max (Å−1) | 0.594 | 0.594 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.077, 1.12 | 0.040, 0.101, 1.05 |
No. of reflections | 620 | 1283 |
No. of parameters | 99 | 100 |
No. of restraints | 3 | 0 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.14, −0.16 | 0.18, −0.19 |
Selected geometric parameters (Å, º) for (I) topO1—C5 | 1.222 (4) | N3—N4 | 1.410 (4) |
N1—C4 | 1.455 (3) | C1—C1i | 1.453 (5) |
N3—C5 | 1.331 (4) | C4—C5 | 1.521 (4) |
| | | |
C1—N1—C4 | 129.2 (2) | O1—C5—N3 | 124.0 (3) |
C2—N1—C4 | 123.7 (3) | O1—C5—C4 | 122.4 (2) |
C5—N3—N4 | 123.6 (3) | N3—C5—C4 | 113.5 (3) |
N2—C1—C1i | 125.3 (3) | H4D—O2—H2A | 102 |
N1—C1—C1i | 123.6 (3) | H4D—O2—H2Aii | 122 |
N1—C4—C5 | 110.8 (2) | | |
Symmetry codes: (i) −x+1, −y+1, z; (ii) −x+1, −y, z. |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2a···N4iii | 0.850 (5) | 2.27 (2) | 3.080 (3) | 161 (4) |
N3—H3a···O1iv | 0.90 | 1.93 | 2.830 (3) | 176 |
N4—H4c···N2v | 0.90 | 2.41 | 3.260 (4) | 157 |
N4—H4d···O2 | 0.90 | 2.30 | 3.165 (4) | 161 |
Symmetry codes: (iii) y+1/2, −x+1, z−1/4; (iv) −y+1, x−1/2, z+1/4; (v) −y+3/2, x, z−1/4. |
Selected geometric parameters (Å, º) for (II) topO1—C6 | 1.233 (2) | C1—C1i | 1.458 (3) |
N1—C4 | 1.464 (2) | C4—C5 | 1.518 (3) |
N3—C6 | 1.328 (2) | C5—C6 | 1.509 (2) |
N3—N4 | 1.417 (2) | | |
| | | |
C1—N1—C4 | 129.90 (15) | N1—C4—C5 | 112.03 (14) |
C2—N1—C4 | 123.6 (2) | C6—C5—C4 | 112.07 (15) |
C6—N3—N4 | 123.37 (15) | O1—C6—N3 | 122.2 (2) |
N2—C1—C1i | 125.1 (2) | O1—C6—C5 | 121.3 (2) |
N1—C1—C1i | 123.9 (2) | N3—C6—C5 | 116.58 (15) |
Symmetry code: (i) −x+1, −y+1, −z+2. |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
N4—H4C···N2ii | 0.90 | 2.47 | 3.367 (2) | 174 |
N4—H4D···N4iii | 0.90 | 2.40 | 3.213 (2) | 151 |
N3—H3A···O1iv | 0.90 | 2.03 | 2.923 (2) | 176 |
C3—H3···O1v | 0.96 | 2.56 | 3.441 (2) | 152 |
C4—H4A···N2i | 0.96 | 2.32 | 2.960 (2) | 123 |
C4—H4B···O1 | 0.96 | 2.55 | 2.900 (2) | 102 |
C5—H5B···O1vi | 0.96 | 2.54 | 3.471 (2) | 162 |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x+1, y+1/2, −z+3/2; (iii) −x+2, y+1/2, −z+3/2; (iv) x, y−1, z; (v) −x+1, y−1/2, −z+3/2; (vi) −x+2, −y+2, −z+2. |
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Compounds containing the 2,2'-biimidazole moiety have been the focus of several investigations due to their biological activity as cardiotonics (Matthews et al., 1990), antiprotozoals (Melloni et al., 1975), and enzyme active-site models (Overberger & Vorchheimer, 1963; Kirchner & Krebs, 1987). In addition to its physiological activity, the aromatic biheterocyclic structure has also been incorporated into a variety of polymer systems (Chi & Collier, 1988; Lui, et al., 1988; Elmer & Collier, 1993; Lister & Collier, 1993; Barnett, 1997) in a series of attempts to imbue polymers with thermal stability, conductivity and metal-ion binding selectivity. Recently, a new class of 2,2'-biimidazole compounds, the 1,1'-diester derivatives (Barnett, 1997; Barnett et al., 1996, 1997, 1999; Secondo et al., 1996), has been developed. Ready acylation of primary amines or hydrazine with these diesters proceeds with excellent yields. The hydrazide macromolecules 1,1'-di(hydrazinecarbonylmethyl)-2,2'-biimidazole, (I), and 1,1'-di(hydrazinecarbonylethyl)-2,2'-biimidazole, (II), illustrated in the Scheme below, were prepared as monomers for subsequent polymer syntheses.
As with similar unconjugated disubstituted biimidazole derivatives, the imidazole rings of both structures (I) and (II) are coplanar, with r.m.s. deviations of 0.003 and 0.001 Å, respectively. The N1/C1/N2/C3/C2 planes and their associated symmetry partners, as shown in Figs. 1 and 2, are essentially coplanar as they exhibit dihedral angles of 5.91 (3) and 0.0 (1)° for (I) and (II), respectively. Previously reported derivatives (Barnett, 1997; Barnett et al., 1999; Secondo et al., 1996) have torsion angles along the ring-bridging C atoms of less than 1°, while the dihedral angle for the ring planes of the unsubstituted 2,2'-biimidazole has been reported to be 4.6° (Cromer et al., 1987). So biimidazoles (I) and (II) represent the greatest disparity between imidazole plane torsion angles for similar derivatives.
The N1/C4/C5 least-squares plane of (I) possesses a dihedral angle of 76.7 (2)° with respect to the adjacent imidazole ring, while the same plane in (II) is 84.9 (1)° (cf. Figs. 1 and 2). Both dihedral angles are comparable to those observed in analogous compounds. Each hydrazinoalkanoyl (R) group is in the zigzag conformation and is essentially planar, as the r.m.s. deviations for the non-H atoms (including N1) are 0.092 and 0.550 Å for (I) and (II), respectively. Fig. 1 shows hydrogen bonding to the water molecules entrained in the crystal lattice of (I). The remaining bond angles and lengths do not differ significantly from 1,1'-disubstituted biimidazole structures reported previously. Selected distances and angles, together with hydrogen-bonding parameters, for (I) and (II) are given in Tables 1–4.
Extensive hydrogen-bonding networks exist in (I) and (II), as both compounds take advantage of the presence of various amine and amide H atoms and a carbonyl O atom. These are supplemented in (I) with the presence of a water of hydration. In this crystal, an intra-asymmetric unit hydrogen bond exists between atoms H4d and O2 (dashed lines in Fig. 1), while inter-asymmetric unit hydrogen bonds are present between H2a and N4, and H3a and O1, as well as between H4c and N2 (cf. Table 2). Thus, the presence of water in the crystal is an important contributor to the overall packing of this biimidazole derivative. In contrast, no strong intramolecular hydrogen bond is present in (II), although a number of intermolecular bonds, similar to those in (I), do exist (cf. Table 4). While both compounds were crystallized from water, only (I) draws on the hydrogen-bonding potential of the water in crystal formation.