In the title compound, [Na(C
2H
3N
2O
3)], the Na
+ cation lies on a centre of inversion in space group
P2
1/
m and all the atoms of the anion lie on a mirror plane. Na is octahedrally coordinated by four O and two N atoms from six different anions and each anion is coordinated to six different Na
+ cations, forming chains of confacial octahedra which link the anion layers. Within these layers, the individual anions are linked by both O-H
O and C-H
O hydrogen bonds.
Supporting information
CCDC reference: 170178
The sodium salt of [3-(α-acetonylbenzyl)-4-hydroxycoumarin] was dissolved at
ambient temperature in water and then an equal volume of nitromethane was
added: when this solution was set aside to crystallize at ambient temperature,
a solid orange-brown mass resulted, from which thin orange plates of (I) were
isolated manually.
Compound (I) crystallized in the monoclinic system; space group
P21/m or P21 from the systematic absences;
P21/m was assumed and confirmed by the analysis. H atoms
bonded to C were treated as riding atoms with C—H 0.95 Å. The H atom
bonded to O1 was refined isotropically. The chemical types of all the atoms in
the anion were confirmed by refinement of their site occupation factors.
Data collection: Collect (Nonius, 1997-2000); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2001); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
Sodium 2-nitroethanaloximate
top
Crystal data top
Na+·C2H3N2O3− | F(000) = 128 |
Mr = 126.05 | Dx = 1.897 Mg m−3 |
Monoclinic, P21/m | Mo Kα radiation, λ = 0.71073 Å |
a = 4.9640 (15) Å | Cell parameters from 355 reflections |
b = 6.346 (2) Å | θ = 2.6–25.0° |
c = 7.336 (2) Å | µ = 0.25 mm−1 |
β = 107.25 (2)° | T = 150 K |
V = 220.70 (11) Å3 | Plate, orange |
Z = 2 | 0.42 × 0.12 × 0.03 mm |
Data collection top
Kappa-CCD diffractometer | 406 independent reflections |
Radiation source: fine-focus sealed X-ray tube | 308 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.091 |
ϕ scans, and ω scans with κ offsets | θmax = 25.0°, θmin = 4.3° |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | h = 0→5 |
Tmin = 0.902, Tmax = 0.993 | k = 0→7 |
1075 measured reflections | l = −8→8 |
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)] = 0.059 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.162 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0449P)2 + 0.064P] where P = (Fo2 + 2Fc2)/3 |
406 reflections | (Δ/σ)max < 0.001 |
52 parameters | Δρmax = 0.48 e Å−3 |
0 restraints | Δρmin = −0.42 e Å−3 |
Crystal data top
Na+·C2H3N2O3− | V = 220.70 (11) Å3 |
Mr = 126.05 | Z = 2 |
Monoclinic, P21/m | Mo Kα radiation |
a = 4.9640 (15) Å | µ = 0.25 mm−1 |
b = 6.346 (2) Å | T = 150 K |
c = 7.336 (2) Å | 0.42 × 0.12 × 0.03 mm |
β = 107.25 (2)° | |
Data collection top
Kappa-CCD diffractometer | 406 independent reflections |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | 308 reflections with I > 2σ(I) |
Tmin = 0.902, Tmax = 0.993 | Rint = 0.091 |
1075 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.059 | 0 restraints |
wR(F2) = 0.162 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.48 e Å−3 |
406 reflections | Δρmin = −0.42 e Å−3 |
52 parameters | |
Special details top
Experimental. The program DENZO-SMN (Otwinowski & Minor, 1997) uses a scaling algorithm
[Fox, G·C. & Holmes, K·C. (1966). Acta Cryst. 20, 886–891]which
effectively corrects for absorption effects. High redundancy data were used in
the scaling program hence the 'multi-scan' code word was used. No transmission
coefficients are available from the program (only scale factors for each
frame). The scale factors in the experimental table are calculated from the
'size' command in the SHELXL97 input file. |
Geometry. Mean-plane data from the final SHELXL97 refinement run:- |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Na1 | 0.5000 | 0.5000 | 0.5000 | 0.0350 (7) | |
O1 | 1.0402 (7) | 0.7500 | −0.2181 (6) | 0.0440 (11) | |
O2 | 0.6608 (6) | 0.7500 | 0.3103 (5) | 0.0355 (10) | |
O3 | 1.1278 (6) | 0.7500 | 0.4454 (4) | 0.0346 (10) | |
N1 | 0.7565 (8) | 0.7500 | −0.2246 (6) | 0.0378 (11) | |
N2 | 0.9105 (8) | 0.7500 | 0.2873 (6) | 0.0324 (10) | |
C1 | 0.7297 (10) | 0.7500 | −0.0538 (8) | 0.0382 (13) | |
C2 | 0.9554 (10) | 0.7500 | 0.1189 (7) | 0.0351 (12) | |
H1 | 1.030 (14) | 0.7500 | −0.371 (10) | 0.063 (19)* | |
H1A | 0.5434 | 0.7500 | −0.0435 | 0.046* | |
H2 | 1.1439 | 0.7500 | 0.1129 | 0.042* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Na1 | 0.0250 (11) | 0.0413 (14) | 0.0412 (13) | 0.0003 (7) | 0.0135 (9) | 0.0001 (8) |
O1 | 0.0268 (18) | 0.060 (3) | 0.047 (3) | 0.000 | 0.0132 (17) | 0.000 |
O2 | 0.0209 (16) | 0.047 (2) | 0.043 (2) | 0.000 | 0.0155 (14) | 0.000 |
O3 | 0.0201 (16) | 0.047 (2) | 0.037 (2) | 0.000 | 0.0087 (14) | 0.000 |
N1 | 0.024 (2) | 0.045 (3) | 0.044 (3) | 0.000 | 0.0092 (17) | 0.000 |
N2 | 0.0222 (19) | 0.037 (3) | 0.039 (2) | 0.000 | 0.0111 (17) | 0.000 |
C1 | 0.029 (2) | 0.044 (3) | 0.043 (3) | 0.000 | 0.015 (2) | 0.000 |
C2 | 0.030 (2) | 0.039 (3) | 0.042 (3) | 0.000 | 0.019 (2) | 0.000 |
Geometric parameters (Å, º) top
O1—N1 | 1.395 (5) | O1—H1 | 1.11 (7) |
N1—C1 | 1.299 (6) | O2—Na1iii | 2.398 (2) |
C1—C2 | 1.421 (7) | O3—Na1iv | 2.377 (2) |
Na1—O2 | 2.398 (2) | O3—Na1v | 2.377 (2) |
Na1—O3i | 2.377 (2) | N1—Na1vi | 2.587 (3) |
C2—N2 | 1.319 (6) | N1—Na1vii | 2.587 (3) |
N2—O2 | 1.300 (5) | C1—H1A | 0.9500 |
N2—O3 | 1.329 (5) | C2—H2 | 0.9500 |
Na1—N1ii | 2.587 (3) | | |
| | | |
O2—Na1—N1ii | 82.87 (10) | N1x—Na1—Na1iii | 127.82 (6) |
O2—Na1—O3i | 80.59 (9) | N1ii—Na1—Na1iii | 52.18 (6) |
O3i—Na1—N1ii | 84.27 (9) | Na1xi—Na1—Na1iii | 180 |
O3viii—Na1—O3i | 180 | N1—O1—H1 | 103 (4) |
O3viii—Na1—O2 | 99.41 (9) | N2—O2—Na1 | 124.74 (16) |
O3viii—Na1—O2ix | 80.59 (9) | N2—O2—Na1iii | 124.74 (16) |
O3i—Na1—O2ix | 99.41 (9) | Na1—O2—Na1iii | 82.86 (10) |
O2—Na1—O2ix | 180 | N2—O3—Na1iv | 122.41 (16) |
O3viii—Na1—N1x | 84.27 (9) | N2—O3—Na1v | 122.41 (16) |
O3i—Na1—N1x | 95.73 (9) | Na1iv—O3—Na1v | 83.72 (9) |
O2—Na1—N1x | 97.13 (10) | C1—N1—O1 | 111.0 (4) |
O2ix—Na1—N1x | 82.87 (10) | C1—N1—Na1vi | 125.87 (19) |
O3viii—Na1—N1ii | 95.73 (9) | O1—N1—Na1vi | 106.6 (2) |
O2ix—Na1—N1ii | 97.13 (10) | C1—N1—Na1vii | 125.87 (19) |
N1x—Na1—N1ii | 180 | O1—N1—Na1vii | 106.6 (2) |
O3viii—Na1—Na1xi | 48.14 (5) | Na1vi—N1—Na1vii | 75.65 (12) |
O3i—Na1—Na1xi | 131.86 (5) | O2—N2—C2 | 123.6 (4) |
O2—Na1—Na1xi | 131.43 (5) | O2—N2—O3 | 116.4 (3) |
O2ix—Na1—Na1xi | 48.57 (5) | C2—N2—O3 | 119.9 (4) |
N1x—Na1—Na1xi | 52.18 (6) | N1—C1—C2 | 125.5 (4) |
N1ii—Na1—Na1xi | 127.82 (6) | N1—C1—H1A | 117.2 |
O3viii—Na1—Na1iii | 131.86 (5) | C2—C1—H1A | 117.2 |
O3i—Na1—Na1iii | 48.14 (5) | N2—C2—C1 | 121.9 (4) |
O2—Na1—Na1iii | 48.57 (5) | N2—C2—H2 | 119.1 |
O2ix—Na1—Na1iii | 131.43 (5) | C1—C2—H2 | 119.1 |
| | | |
O3viii—Na1—O2—N2 | −11.4 (3) | Na1—O2—N2—O3 | −53.63 (18) |
O3i—Na1—O2—N2 | 168.6 (3) | Na1iii—O2—N2—O3 | 53.63 (18) |
N1x—Na1—O2—N2 | −96.7 (3) | Na1iv—O3—N2—O2 | −127.77 (15) |
N1ii—Na1—O2—N2 | 83.3 (3) | Na1v—O3—N2—O2 | 127.77 (15) |
Na1xi—Na1—O2—N2 | −52.3 (3) | Na1iv—O3—N2—C2 | 52.23 (15) |
Na1iii—Na1—O2—N2 | 127.7 (3) | Na1v—O3—N2—C2 | −52.23 (15) |
O3viii—Na1—O2—Na1iii | −139.10 (8) | O1—N1—C1—C2 | 0.0 |
O3i—Na1—O2—Na1iii | 40.90 (8) | Na1vi—N1—C1—C2 | 130.82 (19) |
N1x—Na1—O2—Na1iii | 135.55 (9) | Na1vii—N1—C1—C2 | −130.82 (19) |
N1ii—Na1—O2—Na1iii | −44.45 (9) | O2—N2—C2—C1 | 0.0 |
Na1—O2—N2—C2 | 126.37 (18) | O3—N2—C2—C1 | 180 |
Na1iii—O2—N2—C2 | −126.37 (18) | N1—C1—C2—N2 | 180 |
Symmetry codes: (i) x−1, y, z; (ii) x, y, z+1; (iii) −x+1, y+1/2, −z+1; (iv) −x+2, y+1/2, −z+1; (v) x+1, y, z; (vi) x, y, z−1; (vii) −x+1, y+1/2, −z; (viii) −x+2, −y+1, −z+1; (ix) −x+1, −y+1, −z+1; (x) −x+1, −y+1, −z; (xi) −x+1, y−1/2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O3vi | 1.11 (7) | 1.56 (7) | 2.630 (5) | 160 (6) |
C1—H1A···O1i | 0.95 | 2.45 | 3.274 (7) | 146 |
C2—H2···O2v | 0.95 | 2.55 | 3.364 (6) | 145 |
Symmetry codes: (i) x−1, y, z; (v) x+1, y, z; (vi) x, y, z−1. |
Experimental details
Crystal data |
Chemical formula | Na+·C2H3N2O3− |
Mr | 126.05 |
Crystal system, space group | Monoclinic, P21/m |
Temperature (K) | 150 |
a, b, c (Å) | 4.9640 (15), 6.346 (2), 7.336 (2) |
β (°) | 107.25 (2) |
V (Å3) | 220.70 (11) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.25 |
Crystal size (mm) | 0.42 × 0.12 × 0.03 |
|
Data collection |
Diffractometer | Kappa-CCD diffractometer |
Absorption correction | Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.902, 0.993 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1075, 406, 308 |
Rint | 0.091 |
(sin θ/λ)max (Å−1) | 0.595 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.059, 0.162, 1.07 |
No. of reflections | 406 |
No. of parameters | 52 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.48, −0.42 |
Selected geometric parameters (Å, º) topO1—N1 | 1.395 (5) | C2—N2 | 1.319 (6) |
N1—C1 | 1.299 (6) | N2—O2 | 1.300 (5) |
C1—C2 | 1.421 (7) | N2—O3 | 1.329 (5) |
Na1—O2 | 2.398 (2) | Na1—N1ii | 2.587 (3) |
Na1—O3i | 2.377 (2) | | |
| | | |
O2—Na1—N1ii | 82.87 (10) | O3i—Na1—N1ii | 84.27 (9) |
O2—Na1—O3i | 80.59 (9) | | |
Symmetry codes: (i) x−1, y, z; (ii) x, y, z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O3iii | 1.11 (7) | 1.56 (7) | 2.630 (5) | 160 (6) |
C1—H1A···O1i | 0.95 | 2.45 | 3.274 (7) | 146 |
C2—H2···O2iv | 0.95 | 2.55 | 3.364 (6) | 145 |
Symmetry codes: (i) x−1, y, z; (iii) x, y, z−1; (iv) x+1, y, z. |
We report here the structure of sodium 2-nitroethanaloximate, Na[O2NCHCHNOH], (I), an unexpected coupling product derived from nitromethane, which was isolated serendipitously following attempted crystallization from aqueous nitromethane of an organic salt of sodium. \sch
Both ions of (I) (Fig. 1) lie in special positions in space group P21/m, with Z' = 0.5. The Na lies at a centre of inversion, selected as that at (1/2, 1/2, 1/2), and the atoms of the anion all lie on a mirror plane, selected as that at y = 0.75. The overall structure thus consists of layers of anions at y = (n/2 + 1/4) (n = zero or integer) linked by Na at y = (1/2, n/2, 1/2) (n = zero or integer). Each Na is six coordinate and approximately octahedral (Table 1, Fig. 1). The coordinating atoms (4O + 2 N) around the Na at (1/2, 1/2, 1/2) lie in the anions at (x, 3/4, z), (-1 + x, 3/4, z), (1 - x, -.25, 1 - z), and (2 - x, 1/4, 1 - z) (O donors), and at (x, 3/4, 1 + z) and (1 - x, 1/4, -z) (N donors). Similarly each anion is coordinated to six different Na centres: in the reference anions, N1 is coordinated to Na at (1/2, 1/2, -0.5) and (1/2, 1, -0.5); O2 to Na at (1/2, 1/2, 1/2,) and (1/2, 1, 1/2); and O3 to Na at (1.5, 1/2, 1/2) and (1.5, 1, 1/2). These metal-ligand interactions thus generate a chain of confacial NaN2O4 octahedra running parallel to [010] (Fig. 1), propagation of which by translation links all the ions into a single layered-framework structure.
In addition, the anions within each layer are linked into a continuous sheet by hydrogen bonds (Table 2, Fig. 2). Oxime O1 at (x, y, z) acts as hydrogen-bond donor to nitro O3 at (x, y, -1 + z), so generating by translation a C(7) chain parallel to [001]. Adjacent [001] chains are linked by C—H···O hydrogen bonds: C1 and C2 at (x, y, z) act as hydrogen-bond donors to O1 and O2 at (-1 + x, y, z) and (1 + x, y, z) respectively (Table 2). In this manner, the [001] chains are linked into (010) sheets built from R22(10) and R44(14) rings (Fig. 2). The combination of the (010) anion layers and the [010] metal-ligand chains generates the overall layer structure.
In the strictly planar anion, O1 is cis to C2: the bond distances (Table 1) within the anion are highly unusual in comparison with typical values for these bond types (Allen et al., 1987), and they are consistent with extensive delocalization of the negative charge. The N—O bonds in the nitro group are both very long [mean distance, 1.218 Å (Allen et al., 1987)], while the N2—C2 and C2—C1 bonds are both rather short (mean distances, 1.468 and 1.455 Å, respectively); although the N—O distance in the oxime unit is unexceptional, the N1—C1 distance is somewhat long for its type (mean value 1.281 Å; upper quartile value 1.288 Å). These observations, taken together, can most simply be interpreted in terms of a dominant contribution from form (IIa) with a lesser involvement of form (IIb). The Na—O distances (Table 1) are significantly shorter than the Na—N distance. The fact that N1, O2 and O3 all act as bridging atoms between pairs of Na is consistent with the involvement of both (IIa) and (IIb): in form (IIa), N1 carries only a single lone pair and hence would not be expected to act as a bridging atom, whereas in (IIb) it carries two lone pairs.
A plausible mechanism for the formation of the anion in (I) (Scheme) involves nucleophilic addition of the conjugate anion of nitromethane to a neutral molecule in the enolized aci form, followed by loss of water and a proton shift.