organic compounds
2,2′-(Diselane-1,2-diyl)bis(N,N-dimethylnicotinamide)
aScientific Instrument Center, Shanxi University, Taiyuan 030006, People's Republic of China, and bSchool of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, People's Republic of China
*Correspondence e-mail: gzq@sxu.edu.cn
The title compound, C16H18N4O2Se2, is centrosymmetric. The dihedral angle between the pyridine ring and the amide side chain is 56.20 (16)°. In the crystal, a weak C—H⋯O interaction links the molecules into [010] chains.
Keywords: crystal structure; diselenides; nicotinic acid derivatives.
CCDC reference: 1555913
Structure description
Many investigations have demonstrated that organoselenium compounds are less toxic than those of inorganic selenium compounds (Jalbout et al. 2008). However, to gain further insight into the role of organoselenium compounds, detailed studies are still needed. As part of our research in this area, we report herein the synthesis and of the title compound (Fig. 1).
The complete molecule is generated by a crystallographic centre of symmetry at the mid-point of the Se—Se bond. This implies, of course, that the C—Se—Se—C torsion angle is 180°, which minimizes repulsion of the Se lone pairs, and the dihedral angle between the pyridine rings is 0°. The pyridine ring is substituted at the 2-position [C1—Se = 1.923 (3) Å] and the 3-position [C2—C6 = 1.490 (4) Å]. The X—C—Se—Se torsion angles (X = C, N) are 14.01 (2) and −164.79 (2)°, respectively, indicating that the Se—Se bond lies close to the plane of each pyridine ring. In the crystal, weak C—H⋯O bonds (Table 1) link the molecules into [010] chains.
Synthesis and crystallization
The title compound was prepared follows a modified literature procedure (Feng et al., 2010). To a vigorously stirred solution of selenium powder (1.00 g, 12.6 mmol) and absolute ethanol (30 ml), sodium borohydride (0.35 g, 9.3 mmol) was added at 0°C. The mixture was warmed to room temperature and stirred for 2 h. 2-Chloro-N,N-dimethylnicotinamide (1.55 g, 8.4 mmol) was added and stirred for 7 d. O2 was passed through the solution slowly for 2 h after the reaction mixture was acidified by glacial acetic acid. The solvents were removed in vacuo and the residue was extracted with dichloromethane (CH2Cl2) and filtered. The filtrate was evaporated in vacuo. The precipitate was separated by filtration and recrystallized from C6H12–CHCl3 (1:2) mixed solvent to give the product as colorless block-shaped crystals, yield: 1.0 g, 52%.
1H NMR (300 MHz, DCCl3) δ(p.p.m.): 3.07 (s, 12H, Me), 7.10 (q, 2H, ArH), 7.44 (dd, 2H, ArH), 8.41 (dd, 2H, ArH). 13C NMR (75 MHz, DCCl3) δ(p.p.m.): 40.77 (Me), 41.69 (Me), 123.71, 135.47, 136.92, 153.18, 154.68, 171.27(C=O). 77Se NMR (57 MHz, DCCl3) δ(p.p.m.): 486.10. Analysis calculated for C16H18N4O2Se2: C: 42.12, H: 3.98, N: 12.28; found: C:41.74, H: 3.957, N: 12.03.
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2Structural data
CCDC reference: 1555913
https://doi.org/10.1107/S2414314617008823/hb4154sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617008823/hb4154Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314617008823/hb4154Isup3.cml
Data collection: APEX2 (Bruker, 2004); cell
SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015).C16H18N4O2Se2 | F(000) = 452 |
Mr = 456.26 | Dx = 1.748 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 7.167 (2) Å | Cell parameters from 2532 reflections |
b = 8.726 (3) Å | θ = 2.8–27.5° |
c = 13.947 (4) Å | µ = 4.28 mm−1 |
β = 96.375 (4)° | T = 293 K |
V = 866.8 (4) Å3 | Block, colorless |
Z = 2 | 0.50 × 0.20 × 0.20 mm |
Bruker APEXII CCD diffractometer | 1300 reflections with I > 2σ(I) |
phi and ω scans | Rint = 0.035 |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | θmax = 25.0°, θmin = 2.8° |
Tmin = 0.223, Tmax = 0.481 | h = −8→6 |
3376 measured reflections | k = −8→10 |
1524 independent reflections | l = −16→15 |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.030 | H-atom parameters constrained |
wR(F2) = 0.077 | w = 1/[σ2(Fo2) + (0.0337P)2 + 0.0053P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.001 |
1524 reflections | Δρmax = 0.64 e Å−3 |
111 parameters | Δρmin = −0.43 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. |
Refinement. All H atoms were positioned geometrically(C—H = 0.93–0.96 Å), and refined as riding with Uiso(H) = 1.2Ueq of the adjacent carbon atom (1.5Ueq for methyl H atoms). |
x | y | z | Uiso*/Ueq | ||
Se | 0.52041 (4) | 0.56001 (3) | 0.92626 (2) | 0.04189 (16) | |
N1 | 0.1797 (4) | 0.6437 (3) | 0.99097 (18) | 0.0386 (6) | |
N2 | 0.4942 (4) | 0.9794 (3) | 0.79999 (18) | 0.0403 (6) | |
O | 0.4595 (4) | 0.7382 (3) | 0.74625 (17) | 0.0541 (7) | |
C1 | 0.2981 (4) | 0.6827 (3) | 0.9288 (2) | 0.0313 (6) | |
C2 | 0.2725 (4) | 0.8092 (3) | 0.8665 (2) | 0.0341 (7) | |
C3 | 0.1072 (5) | 0.8902 (4) | 0.8669 (2) | 0.0423 (8) | |
H3 | 0.0823 | 0.9734 | 0.8257 | 0.051* | |
C4 | −0.0211 (5) | 0.8469 (4) | 0.9289 (2) | 0.0450 (8) | |
H4 | −0.1344 | 0.8987 | 0.9289 | 0.054* | |
C5 | 0.0220 (4) | 0.7258 (4) | 0.9903 (2) | 0.0433 (8) | |
H5 | −0.0627 | 0.6996 | 1.0335 | 0.052* | |
C6 | 0.4161 (4) | 0.8408 (3) | 0.7996 (2) | 0.0349 (7) | |
C7 | 0.4669 (5) | 1.1022 (4) | 0.8681 (3) | 0.0546 (9) | |
H7A | 0.3853 | 1.1787 | 0.8368 | 0.082* | |
H7B | 0.5860 | 1.1477 | 0.8902 | 0.082* | |
H7C | 0.4116 | 1.0610 | 0.9222 | 0.082* | |
C8 | 0.6280 (5) | 1.0111 (4) | 0.7320 (3) | 0.0535 (9) | |
H8A | 0.7067 | 0.9231 | 0.7268 | 0.080* | |
H8B | 0.7042 | 1.0973 | 0.7541 | 0.080* | |
H8C | 0.5619 | 1.0339 | 0.6699 | 0.080* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Se | 0.0395 (2) | 0.0410 (2) | 0.0480 (2) | 0.01035 (14) | 0.01743 (16) | 0.01223 (14) |
N1 | 0.0347 (14) | 0.0393 (15) | 0.0434 (14) | 0.0022 (12) | 0.0121 (12) | 0.0045 (11) |
N2 | 0.0425 (16) | 0.0382 (15) | 0.0405 (14) | −0.0051 (12) | 0.0072 (12) | 0.0041 (11) |
O | 0.0702 (17) | 0.0403 (13) | 0.0569 (14) | −0.0031 (12) | 0.0293 (13) | −0.0065 (11) |
C1 | 0.0288 (15) | 0.0274 (15) | 0.0377 (15) | 0.0003 (12) | 0.0044 (13) | −0.0021 (12) |
C2 | 0.0380 (17) | 0.0283 (16) | 0.0358 (15) | 0.0008 (13) | 0.0039 (13) | −0.0018 (12) |
C3 | 0.046 (2) | 0.0345 (17) | 0.0469 (19) | 0.0062 (15) | 0.0049 (15) | 0.0037 (14) |
C4 | 0.0374 (19) | 0.0432 (19) | 0.055 (2) | 0.0098 (15) | 0.0097 (16) | 0.0010 (15) |
C5 | 0.0362 (18) | 0.0479 (19) | 0.0479 (18) | 0.0017 (15) | 0.0139 (15) | 0.0012 (15) |
C6 | 0.0378 (17) | 0.0301 (17) | 0.0365 (16) | 0.0040 (13) | 0.0028 (13) | 0.0045 (13) |
C7 | 0.064 (3) | 0.0413 (19) | 0.058 (2) | −0.0088 (18) | 0.0045 (18) | −0.0050 (16) |
C8 | 0.052 (2) | 0.055 (2) | 0.055 (2) | −0.0063 (18) | 0.0144 (18) | 0.0171 (17) |
Se—C1 | 1.923 (3) | C3—C4 | 1.383 (4) |
Se—Sei | 2.3551 (8) | C3—H3 | 0.9300 |
N1—C1 | 1.324 (4) | C4—C5 | 1.373 (4) |
N1—C5 | 1.338 (4) | C4—H4 | 0.9300 |
N2—C6 | 1.332 (4) | C5—H5 | 0.9300 |
N2—C8 | 1.449 (4) | C7—H7A | 0.9600 |
N2—C7 | 1.460 (4) | C7—H7B | 0.9600 |
O—C6 | 1.226 (3) | C7—H7C | 0.9600 |
C1—C2 | 1.403 (4) | C8—H8A | 0.9600 |
C2—C3 | 1.381 (4) | C8—H8B | 0.9600 |
C2—C6 | 1.490 (4) | C8—H8C | 0.9600 |
C1—Se—Sei | 92.77 (8) | N1—C5—H5 | 118.4 |
C1—N1—C5 | 117.4 (3) | C4—C5—H5 | 118.4 |
C6—N2—C8 | 118.6 (3) | O—C6—N2 | 122.0 (3) |
C6—N2—C7 | 125.6 (3) | O—C6—C2 | 118.9 (3) |
C8—N2—C7 | 115.6 (3) | N2—C6—C2 | 119.0 (3) |
N1—C1—C2 | 124.0 (3) | N2—C7—H7A | 109.5 |
N1—C1—Se | 117.5 (2) | N2—C7—H7B | 109.5 |
C2—C1—Se | 118.6 (2) | H7A—C7—H7B | 109.5 |
C3—C2—C1 | 117.0 (3) | N2—C7—H7C | 109.5 |
C3—C2—C6 | 124.1 (3) | H7A—C7—H7C | 109.5 |
C1—C2—C6 | 118.8 (3) | H7B—C7—H7C | 109.5 |
C2—C3—C4 | 119.5 (3) | N2—C8—H8A | 109.5 |
C2—C3—H3 | 120.2 | N2—C8—H8B | 109.5 |
C4—C3—H3 | 120.2 | H8A—C8—H8B | 109.5 |
C5—C4—C3 | 118.8 (3) | N2—C8—H8C | 109.5 |
C5—C4—H4 | 120.6 | H8A—C8—H8C | 109.5 |
C3—C4—H4 | 120.6 | H8B—C8—H8C | 109.5 |
N1—C5—C4 | 123.2 (3) | ||
C5—N1—C1—C2 | 3.6 (4) | C3—C4—C5—N1 | −2.4 (5) |
C5—N1—C1—Se | −177.7 (2) | C8—N2—C6—O | 2.9 (5) |
N1—C1—C2—C3 | −4.4 (4) | C7—N2—C6—O | −172.7 (3) |
Se—C1—C2—C3 | 176.9 (2) | C8—N2—C6—C2 | −177.5 (3) |
N1—C1—C2—C6 | −179.9 (3) | C7—N2—C6—C2 | 6.9 (5) |
Se—C1—C2—C6 | 1.4 (4) | C3—C2—C6—O | −121.7 (3) |
C1—C2—C3—C4 | 1.6 (4) | C1—C2—C6—O | 53.5 (4) |
C6—C2—C3—C4 | 176.9 (3) | C3—C2—C6—N2 | 58.7 (4) |
C2—C3—C4—C5 | 1.5 (5) | C1—C2—C6—N2 | −126.1 (3) |
C1—N1—C5—C4 | −0.1 (5) |
Symmetry code: (i) −x+1, −y+1, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C3—H3···Oii | 0.93 | 2.52 | 3.431 (4) | 165 |
Symmetry code: (ii) −x+1/2, y+1/2, −z+3/2. |
Funding information
Financial support from the Special Fund for Agro-scientific Research in the Public Interest (No. 201303106) is gratefully acknowledged.
References
Bruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Feng, A., Xu, Y. & Wei, X. (2010). Acta Cryst. E66, o1216. CSD CrossRef IUCr Journals Google Scholar
Jalbout, A. F., Hameed, A. J. & Essa, A. H. (2008). J. Organomet. Chem. 693, 2074–2078. CrossRef CAS 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
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