research communications
H-imidazol-2-yl)methylidene]hydrazine and its one-dimensional hydrogen-bonding network
of 1,2-bis[(1aDepartment of Chemistry, National Taiwan University, Taipei, Taiwan, and bInstrumentation Center, National Taiwan University, Taipei, Taiwan
*Correspondence e-mail: ghlee@ntu.edu.tw
In the title compound, C8H8N6, two imidazolyl groups are separated by a zigzag –CH=N—N=CH– linkage. An inversion center is located at the mid-point of the N—N single bond and the complete molecule is generated by symmetry. In the crystal, each molecule forms four N—H⋯N hydrogen bonds with two neighbouring molecules to constitute a one-dimensional ladder-like structure propagating along the a-axis direction.
CCDC reference: 1468833
1. Chemical context
Supramolecular chemistry is a fascinating topic, and molecular assemblies via intermolecular non-covalent binding interactions (i.e. hydrogen bonding, ionic and π–π stacking interactions) have attracted much attentions in the field of crystal engineering over the last decade. In particular, hydrogen bonding, which is a powerful organizing force in designing a variety of supramolecular and solid-state architectures (Subramanian & Zaworotko, 1994), is not only used extensively to generate numerous network structures consisting of discrete organic and organometallic compounds (Desiraju, 2000), but is also responsible for interesting physical properties of these supramolecular arrangements, such as electrical, optical, magnetic, etc. (Bacchi & Pelagatti, 2016; Lindoy & Atkinson, 2000; Létard et al., 1998).
Imidazoles, containing two nitrogen atoms, possess both hydrogen-bond donating and accepting sites and are superior building blocks for supramolecular architectures. Many imidazole-containing polydentate ligands derived from hydrazine find a wide range of applications in coordination chemistry owing to their chelating ability (Zhou et al., 2012). In this paper we report the synthesis of 1,2-bis[(1H-imidazol-2-yl)methylene]hydrazine (I), designed to consist of nitrogen donors and acceptors, and the supramolecular architecture it gives rise to via hydrogen bonds. The functionality of molecule (I) as a bridge between metal centers for the formation of multi-dimensional structures will be discussed in subsequent publications.
2. Structural commentary
The molecular structure of the title compound consists of two imidazolyl groups linked by a zigzag –CH=N—N=CH– linkage (Fig. 1) and with C5⋯C5i = 5.937 (3) Å [the distance between the centroids of the imidazolyl groups is 8.103 (3) Å]. The molecule possesses an inversion center located in the mid-point of the N—N single bond and the complete molecule is generated by symmetry. The molecule appears in a Z(EE)Z configuration and its geometry is similar to that of 1,2-bis[(1H-imidazol-5-yl)methylene]hydrazine (Pinto et al., 2013) and 1,2-bis[(thiophene-3-yl)methylene]hydrazine (Kim & Lee, 2008).
The molecule (I) has a planar (r.m.s. deviation = 0.012 Å) structure which, in addition to the observed bond distances, suggests partial delocalization of the π electrons over the whole molecule. The geometric parameters, viz., the N—N single bond [N7—N7i = 1.409 (2) Å; symmetry code: (i) –x, −y + 1, −z + 2] , C=N double bond [C6—N7 = 1.2795 (19) Å] and C=N—N bond angle [C6=N7—N7i = 111.41 (15)°], are comparable to the corresponding parameters found in 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene [Dong et al., 2000] and 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene [Ciurtin et al., 2001].
3. Supramolecular features
In the , each molecule is involved in four N—H⋯N hydrogen bonds (i.e.: two donor and two acceptor interactions) and interacts with two neighboring molecules, resulting in a one-dimensional ladder-like structure along the a axis (Fig. 2). Numerical details of the hydrogen-bonding geometry are tabulated in Table 1.
of (I)
|
As a comparison, the related compound 1,2-bis[(1H-imidazol-5-yl)methylene]hydrazine (Pinto et al., 2013) is a planar molecule which constitutes corrugated layers parallel to the (101) plane, as a result of both hydrogen bonding and π–π stacking interactions with adjacent molecules. In the present case of (I), instead, there are no significant π–π stacking interactions.
4. Synthesis and crystallization
A methanol solution (10 mL) of imidazole-2-carboxaldehyde (2.48 g, 25.8 mmol) was added to a methanol solution (10 mL) of hydrazine monohydrate (0.64 ml, 12.9 mmol). The mixture was stirred for 3 h and the precipitate was collected by filtration. Single crystals suitable for X-ray diffraction studies were obtained by diffusion of diethyl ether into a DMSO solution of the title compound (I). Yield: 2.21 g (91%).
5. Refinement
Crystal data, data collection and structure . All the H atoms were located in difference-Fourier maps. For the H atom bounded to atom N1, the atomic coordinates and Uiso were refined, giving an N—H distance of 0.95 (2) Å. The C-bound H atoms were subsequently treated as riding atoms in geometrically idealized positions: C—H distances of 0.95 Å with Uiso(H) = 1.2Ueq(C).
details are summarized in Table 2Supporting information
CCDC reference: 1468833
https://doi.org/10.1107/S2056989016004497/bg2582sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989016004497/bg2582Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2056989016004497/bg2582Isup3.cml
Data collection: APEX3 (Bruker, 2015); cell
SAINT (Bruker, 2015); data reduction: SAINT (Bruker, 2015); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C8H8N6 | F(000) = 196 |
Mr = 188.20 | Dx = 1.435 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 5.0618 (3) Å | Cell parameters from 2074 reflections |
b = 14.6282 (8) Å | θ = 2.8–27.5° |
c = 6.1294 (4) Å | µ = 0.10 mm−1 |
β = 106.321 (2)° | T = 150 K |
V = 435.56 (5) Å3 | Needle, colourless |
Z = 2 | 0.35 × 0.10 × 0.03 mm |
Bruker D8 VENTURE diffractometer | 903 reflections with I > 2σ(I) |
φ and ω scans | Rint = 0.014 |
Absorption correction: multi-scan (SADABS; Bruker, 2015) | θmax = 27.5°, θmin = 2.8° |
Tmin = 0.702, Tmax = 0.746 | h = −6→6 |
2614 measured reflections | k = −18→19 |
999 independent reflections | l = −7→6 |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: mixed |
R[F2 > 2σ(F2)] = 0.042 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.117 | w = 1/[σ2(Fo2) + (0.0528P)2 + 0.2863P] where P = (Fo2 + 2Fc2)/3 |
S = 1.12 | (Δ/σ)max < 0.001 |
999 reflections | Δρmax = 0.31 e Å−3 |
68 parameters | Δρmin = −0.26 e Å−3 |
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 | ||
N1 | −0.1374 (2) | 0.62851 (8) | 0.4802 (2) | 0.0175 (3) | |
H1 | 0.055 (5) | 0.6193 (14) | 0.515 (4) | 0.037 (6)* | |
C2 | −0.2801 (3) | 0.67725 (10) | 0.2944 (2) | 0.0204 (4) | |
H2 | −0.2082 | 0.7044 | 0.1823 | 0.025* | |
C3 | −0.5481 (3) | 0.67920 (10) | 0.3022 (2) | 0.0197 (3) | |
H3 | −0.6956 | 0.7084 | 0.1937 | 0.024* | |
N4 | −0.5714 (2) | 0.63279 (8) | 0.4899 (2) | 0.0187 (3) | |
C5 | −0.3193 (3) | 0.60313 (10) | 0.5944 (2) | 0.0162 (3) | |
C6 | −0.2539 (3) | 0.55035 (10) | 0.8020 (2) | 0.0180 (3) | |
H6 | −0.3975 | 0.5336 | 0.8659 | 0.022* | |
N7 | −0.0068 (3) | 0.52574 (8) | 0.9014 (2) | 0.0195 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0139 (6) | 0.0223 (6) | 0.0170 (6) | 0.0001 (5) | 0.0052 (5) | 0.0008 (5) |
C2 | 0.0187 (7) | 0.0264 (8) | 0.0165 (7) | 0.0001 (6) | 0.0055 (5) | 0.0039 (5) |
C3 | 0.0168 (7) | 0.0227 (7) | 0.0187 (7) | 0.0013 (5) | 0.0037 (5) | 0.0040 (5) |
N4 | 0.0152 (6) | 0.0220 (6) | 0.0188 (6) | 0.0006 (5) | 0.0046 (5) | 0.0027 (5) |
C5 | 0.0141 (7) | 0.0180 (7) | 0.0167 (7) | −0.0007 (5) | 0.0049 (5) | −0.0013 (5) |
C6 | 0.0166 (7) | 0.0205 (7) | 0.0173 (7) | −0.0005 (5) | 0.0054 (5) | 0.0004 (5) |
N7 | 0.0198 (6) | 0.0224 (6) | 0.0159 (6) | 0.0003 (5) | 0.0043 (5) | 0.0030 (5) |
N1—C5 | 1.3557 (18) | C3—H3 | 0.9500 |
N1—C2 | 1.3656 (18) | N4—C5 | 1.3295 (18) |
N1—H1 | 0.95 (2) | C5—C6 | 1.445 (2) |
C2—C3 | 1.371 (2) | C6—N7 | 1.2795 (19) |
C2—H2 | 0.9500 | C6—H6 | 0.9500 |
C3—N4 | 1.3689 (19) | N7—N7i | 1.409 (2) |
C5—N1—C2 | 107.26 (12) | C5—N4—C3 | 105.60 (12) |
C5—N1—H1 | 130.4 (13) | N4—C5—N1 | 111.18 (13) |
C2—N1—H1 | 122.3 (13) | N4—C5—C6 | 123.37 (13) |
N1—C2—C3 | 106.15 (12) | N1—C5—C6 | 125.46 (13) |
N1—C2—H2 | 126.9 | N7—C6—C5 | 121.43 (13) |
C3—C2—H2 | 126.9 | N7—C6—H6 | 119.3 |
N4—C3—C2 | 109.81 (13) | C5—C6—H6 | 119.3 |
N4—C3—H3 | 125.1 | C6—N7—N7i | 111.41 (15) |
C2—C3—H3 | 125.1 | ||
C5—N1—C2—C3 | −0.35 (16) | C2—N1—C5—N4 | 0.38 (17) |
N1—C2—C3—N4 | 0.21 (17) | C2—N1—C5—C6 | −179.95 (14) |
C2—C3—N4—C5 | 0.02 (17) | N4—C5—C6—N7 | −177.58 (13) |
C3—N4—C5—N1 | −0.25 (16) | N1—C5—C6—N7 | 2.8 (2) |
C3—N4—C5—C6 | −179.93 (13) | C5—C6—N7—N7i | −179.35 (14) |
Symmetry code: (i) −x, −y+1, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···N4ii | 0.95 (2) | 1.95 (2) | 2.8493 (17) | 157.9 (19) |
Symmetry code: (ii) x+1, y, z. |
Acknowledgements
GHL thanks the Instrumentation Center, National Taiwan University, for support of this work.
References
Bacchi, A. & Pelagatti, P. (2016). Chem. Commun. 52, 1327–1337. CrossRef CAS Google Scholar
Bruker (2015). APEX3, SAINT and SADABS. Bruker AXS Inc, Madison , Wisconsin, USA. Google Scholar
Ciurtin, D. M., Dong, Y.-B., Smith, M. D., Barclay, T. & zur Loye, H.-C. (2001). Inorg. Chem. 40, 2825–2834. Web of Science CSD CrossRef PubMed CAS Google Scholar
Desiraju, G. R. (2000). Stimulating Concepts in Chemistry, edited by F. Vogtle, J. F. Stoddart & M. Shibasaki, pp. 293–302. Weinheim: Wiley VCH. Google Scholar
Dong, Y.-B., Smith, M. D., Layland, R. C. & zur Loye, H.-C. (2000). Chem. Mater. 12, 1156–1161. Web of Science CSD CrossRef CAS Google Scholar
Kim, S. H. & Lee, S. W. (2008). Inorg. Chim. Acta, 361, 137–144. Web of Science CSD CrossRef CAS Google Scholar
Létard, J. F., Guionneau, P., Rabardel, L., Howard, J. A. K., Goeta, A. E., Chasseau, D. & Kahn, O. (1998). Inorg. Chem. 37, 4432–4441. Web of Science CSD CrossRef PubMed CAS Google Scholar
Lindoy, L. F. & Atkinson, I. M. (2000). In Self-assembly in Supramolecular Systems, pp. 8–46. Cambridge: RSC. Google Scholar
Pinto, J., Silva, V. L. M., Silva, A. M. S., Claramunt, R. M., Sanz, D., Torralba, M. C., Torres, M. R., Reviriego, F., Alkorta, I. & Elguero, J. (2013). Magn. Reson. Chem. 51, 203–221. CrossRef CAS PubMed Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Subramanian, S. & Zaworotko, M. J. (1994). Coord. Chem. Rev. 137, 357–401. CrossRef CAS Web of Science Google Scholar
Zhou, X.-P., Li, M., Liu, J. & Li, D. (2012). J. Am. Chem. Soc. 134, 67–70. CrossRef CAS PubMed Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.