Retracted: A novel heterocyclic compound: catena-poly[[[diaquasodium(I)]-di-μ-aqua] hemi(1,5-dihydr­oxy-4,8,9-trioxa-2,6-diaza­bicyclo­[3.3.1]nona-2,6-diene-3,7-diolate)]

In the title compound, {[Na(H₂O)₄]₂(C₄H₂N₂O₇)}_n, the 1,5-dihydr­oxy-4,8,9-trioxa-2,6-diaza­bicyclo­[3.3.1]nona-2,6-diene-3,7-diolate anion lies across a twofold axis in the space group C2/c; there are two independent Na sites, one on a twofold axis and the other on a centre of inversion. Hydrogen bonds link the {[Na(H₂O)₄]⁺}_n chains and diolate anions into a three-dimensional framework.

S1. Comment

The synthesis of organic compounds from common inorganic materials has long attracted attention because of its potential significance in pharmacology, agriculture and chemical industry (Gleix, 1954; Achille et al., 1998). To our knowledge, however, there have been no reports of the formation of heterobicyclic compounds from a metal carbonate with ammonia in a single-step process. Recently, we have synthesized from sodium carbonate and aqueous ammonia by a hydrothermal method the novel heterocyclic title compound, (I), whose structure is reported here.

The title compound crystallizes in the centrosymmetric space group C2/c with two independent Na sites, one on a twofold axis and one on an inversion centre, and a C₄H₂N₂O₇^- anion located across a twofold axis (Fig. 1). Both Na sites are six-coordinated by O atoms from water molecules, forming distorted octahedra with Na—O distances in the range 2.395 (3)–2.458 (3) Å, which are comparable to those observed in Na₂CO₃·H₂O (Harper, 1968) and in Na₂CO₃·7H₂O (Betzel et al., 1982). Neighbouring sodium octahedra share edges via two water molecules, forming infinite chains parallel to [001] (Fig. 1). Similar arrangements of hydrated sodium ions are found in Na₂C₄O₄·3H₂O (Ranganathan & Kulkarni, 2002) and in NaHC₄O₄·H₂O (Petrova et al., 2006).

The C₄H₂N₂O₇^2- anion contains a novel heterocyclic skeleton. All the bond length are in their normal ranges. The C—O single-bond lengths (C1—O1, C1—O2, C2—O3, C2—O4 and C2—O1A; symmetry code A is defined in Fig. 1) are between 1.366 (5) and 1.495 (4) Å, while the C1═N1 and C2—N1 bond lengths are 1.384 (4) Å and 1.507 (4) Å, respectively. The O2—C1—O1, O2—C1—N1 and O1—C1—N1 angles are close to 120°, while the O3—C2—O4 and O1A—C2—N1 angles are 111.8 (3) and 108.3 (3)°. In the C₄H₂N₂O₇^2- anion, atoms N1, O1, N1A and O1A constitute an equatorial plane with a mean deviation from the mean plane of 0.0781 Å. Atoms O3, O4 and C2 are displaced above the plane at distances of 1.7111, 1.6691 and 0.8775 Å, and atoms O2 and C1 atoms are below the plane at distances of 0.9588 and 0.3207 Å, respectively.

All the H atoms of hydroxyl and water molecules contribute to the formation of a hydrogen-bond network (Table 1), and O—H···O and O—H···N hydrogen bonds link the C₄H₂N₂O₇^2- anions and the {[Na(H₂O)₄]⁺}_n chains into a three-dimensional framework (Fig. 2).

Related literature

For related literature, see: Achille et al. (1998); Betzel et al. (1982); Gleix (1954); Harper (1968); Petrova et al. (2006); Ranganathan & Kulkarni (2002).

S2. Experimental

Anhydrous sodium carbonate (0.318 g) and 18% aqueous ammonia (0.6 ml) in a molar ratio of 3:5 were dissolved in water (5 ml) with stirring at room temperature for 10 min. The solution was then transferred into a 15 ml teflon-lined bomb and heated at 413 K for 4 days. Colourless crystals were obtained in 42% yield after cooling to room temperature. Analysis found: C 12.6, H 4.8, N 7.4%; calculated for C₄H₁₈N₂Na₂O₁₅: C 12.6, H 4.8, N 7.4% [found and calc. are identical; please confirm]. IR (KBr, cm^-1): 3442 (s), 1795 (w), 1254 (m), 1106 (m), 873 (w), 816 (w).

S3. Refinement

All H atoms were located in difference maps and then treated as riding atoms (O—H = 0.81–0.85 Å). The U_iso(H) values were refined freely. The highest residual peak is located 0.98 Å from O2, 1.77 Å from N1 and 1.98 Å from C1. Please check changes to text.

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The crystal structure of (I), showing 35% probability displacement ellipsoids. [Symmetry codes: (A) -x + 1, y, -z + 3/2; (B) -x, y, -z + 3/2; (C) -x, -y, -z + 1; (D) x, -y, 1/2 + z.] Please check use of symmetry codes in cation.
	Fig. 2. The crystal packing of (I), viewed along the b axis. Hydrogen bonds are shown as dashed lines.

bis(tetraaquasodium) 1,5-dihydroxy-4,8,9-trioxa-2,6-diazabicyclo[3.3.1]nona-2,6-diene-3,7-diolate

Crystal data

[Na(H2O)4]2(C4H2N2O7)	F(000) = 792
Mr = 380.18	Dx = 1.680 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 986 reflections
a = 11.935 (7) Å	θ = 2.8–24.3°
b = 10.709 (6) Å	µ = 0.22 mm^−1
c = 12.277 (7) Å	T = 298 K
β = 106.634 (8)°	Block, colourless
V = 1503.5 (16) Å^3	0.33 × 0.25 × 0.18 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	1333 independent reflections
Radiation source: fine-focus sealed tube	1146 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
ϕ and ω scans	θmax = 25.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 1998)	h = −14→14
Tmin = 0.932, Tmax = 0.962	k = −12→12
3719 measured reflections	l = −14→11

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.066	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.225	Only H-atom displacement parameters refined
S = 1.08	w = 1/[σ^2(Fo^2) + (0.1475P)^2 + 3.8784P] where P = (Fo^2 + 2Fc^2)/3
1333 reflections	(Δ/σ)max < 0.001
116 parameters	Δρmax = 0.96 e Å^−3
27 restraints	Δρmin = −0.81 e Å^−3

Special details

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 of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) 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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.4017 (3)	0.0430 (3)	0.6078 (3)	0.0314 (8)
C2	0.5853 (3)	0.1549 (3)	0.7149 (3)	0.0298 (8)
N1	0.51954 (19)	0.0657 (2)	0.62411 (19)	0.0144 (6)
Na1	0.0000	0.15330 (19)	0.7500	0.0353 (6)
Na2	0.0000	0.0000	0.5000	0.0325 (6)
O1	0.34573 (19)	0.0802 (2)	0.68557 (18)	0.0257 (6)
O2	0.3384 (2)	−0.0165 (2)	0.5113 (2)	0.0346 (7)
O3	0.5000	0.2326 (3)	0.7500	0.0226 (7)
O4	0.6607 (2)	0.2288 (2)	0.66778 (19)	0.0306 (7)
H4	0.7285	0.2297	0.7094	0.039 (11)*
O5	0.1230 (2)	−0.0005 (2)	0.6959 (2)	0.0336 (7)
H5A	0.1235	−0.0775	0.7027	0.072 (14)*
H5B	0.1928	0.0221	0.7004	0.050 (10)*
O6	−0.1230 (2)	0.1540 (2)	0.5516 (2)	0.0343 (7)
H6A	−0.1866	0.1251	0.5500	0.078 (13)*
H6B	−0.1284	0.1962	0.4921	0.058 (10)*
O7	0.1173 (2)	0.2949 (3)	0.6725 (2)	0.0409 (7)
H7A	0.1081	0.2719	0.6039	0.062 (9)*
H7B	0.1112	0.3733	0.6718	0.058 (10)*
O8	0.1194 (2)	0.1646 (2)	0.4620 (2)	0.0384 (7)
H8A	0.0843	0.1939	0.3999	0.051 (9)*
H8B	0.1829	0.1333	0.4614	0.050 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0281 (18)	0.0358 (18)	0.0320 (19)	−0.0002 (14)	0.0113 (15)	0.0006 (14)
C2	0.0271 (18)	0.0343 (18)	0.0273 (18)	−0.0025 (13)	0.0069 (14)	−0.0024 (13)
N1	0.0084 (12)	0.0230 (12)	0.0135 (12)	−0.0037 (9)	0.0057 (9)	−0.0065 (9)
Na1	0.0346 (12)	0.0408 (12)	0.0334 (12)	0.000	0.0142 (9)	0.000
Na2	0.0313 (12)	0.0366 (12)	0.0297 (12)	−0.0011 (8)	0.0088 (9)	−0.0013 (8)
O1	0.0198 (12)	0.0356 (13)	0.0233 (12)	−0.0032 (9)	0.0088 (9)	−0.0059 (9)
O2	0.0240 (14)	0.0506 (16)	0.0299 (14)	−0.0110 (10)	0.0088 (11)	−0.0162 (11)
O3	0.0241 (17)	0.0226 (16)	0.0214 (15)	0.000	0.0068 (12)	0.000
O4	0.0237 (13)	0.0419 (14)	0.0253 (12)	−0.0070 (10)	0.0057 (10)	0.0070 (10)
O5	0.0276 (15)	0.0332 (15)	0.0401 (16)	−0.0010 (10)	0.0100 (12)	0.0000 (10)
O6	0.0272 (13)	0.0416 (15)	0.0336 (14)	−0.0013 (10)	0.0077 (11)	0.0047 (11)
O7	0.0394 (16)	0.0392 (15)	0.0406 (16)	0.0007 (11)	0.0056 (12)	0.0053 (11)
O8	0.0329 (15)	0.0460 (16)	0.0343 (14)	0.0045 (11)	0.0066 (11)	0.0113 (12)

Geometric parameters (Å, º)

C1—O2	1.366 (5)	Na2—O8^iii	2.395 (3)
C1—O1	1.373 (4)	Na2—O6^iii	2.410 (3)
C1—N1	1.384 (4)	Na2—O6	2.410 (3)
C2—O4	1.438 (4)	Na2—O5	2.433 (3)
C2—O3	1.472 (4)	Na2—O5^iii	2.433 (3)
C2—O1^i	1.495 (4)	O4—H4	0.82
C2—N1	1.507 (4)	O5—H5A	0.83
Na1—O5	2.422 (3)	O5—H5B	0.85
Na1—O5^ii	2.422 (3)	O6—H6A	0.81
Na1—O7	2.435 (3)	O6—H6B	0.85
Na1—O7^ii	2.435 (3)	O7—H7A	0.85
Na1—O6^ii	2.458 (3)	O7—H7B	0.84
Na1—O6	2.458 (3)	O8—H8A	0.82
Na2—O8	2.395 (3)	O8—H8B	0.83
O2—C1—O1	118.7 (3)	O6—Na2—O5^iii	91.02 (9)
O2—C1—N1	119.7 (3)	O5—Na2—O5^iii	180.0
O1—C1—N1	121.7 (3)	O8—Na2—Na1^iii	91.46 (8)
O4—C2—O3	111.8 (3)	O8^iii—Na2—Na1^iii	88.54 (8)
O4—C2—O1^i	111.2 (2)	O6^iii—Na2—Na1^iii	44.91 (6)
O3—C2—O1^i	109.1 (2)	O6—Na2—Na1^iii	135.09 (6)
O4—C2—N1	107.8 (2)	O5—Na2—Na1^iii	135.93 (6)
O3—C2—N1	108.5 (2)	O5^iii—Na2—Na1^iii	44.07 (6)
O1^i—C2—N1	108.3 (3)	O8—Na2—H5A	102.3
C1—N1—C2	120.8 (2)	O8^iii—Na2—H5A	77.7
O5—Na1—O5^ii	94.31 (14)	O6^iii—Na2—H5A	79.3
O5—Na1—O7	81.67 (10)	O6—Na2—H5A	100.7
O5^ii—Na1—O7	172.80 (10)	O5—Na2—H5A	18.2
O5—Na1—O7^ii	172.80 (10)	O5^iii—Na2—H5A	161.8
O5^ii—Na1—O7^ii	81.67 (10)	Na1^iii—Na2—H5A	122.9
O7—Na1—O7^ii	102.94 (16)	O8—Na2—H6B	76.9
O5—Na1—O6^ii	92.10 (9)	O8^iii—Na2—H6B	103.1
O5^ii—Na1—O6^ii	88.12 (9)	O6^iii—Na2—H6B	160.9
O7—Na1—O6^ii	97.95 (10)	O6—Na2—H6B	19.1
O7^ii—Na1—O6^ii	81.84 (9)	O5—Na2—H6B	102.8
O5—Na1—O6	88.12 (9)	O5^iii—Na2—H6B	77.2
O5^ii—Na1—O6	92.10 (9)	Na1^iii—Na2—H6B	120.0
O7—Na1—O6	81.84 (9)	H5A—Na2—H6B	117.1
O7^ii—Na1—O6	97.95 (10)	C1—O1—C2^i	117.5 (3)
O6^ii—Na1—O6	179.67 (14)	C2—O3—C2^i	111.2 (3)
O5—Na1—Na2^ii	94.24 (8)	C2—O4—H4	111.9
O5^ii—Na1—Na2^ii	44.32 (7)	Na1—O5—Na2	91.61 (9)
O7—Na1—Na2^ii	141.59 (6)	Na1—O5—H5A	129.5
O7^ii—Na1—Na2^ii	78.70 (8)	Na2—O5—H5A	95.0
O6^ii—Na1—Na2^ii	43.80 (6)	Na1—O5—H5B	116.5
O6—Na1—Na2^ii	136.42 (8)	Na2—O5—H5B	111.4
O8—Na2—O8^iii	180.00 (13)	H5A—O5—H5B	107.3
O8—Na2—O6^iii	90.64 (10)	Na2—O6—Na1	91.28 (9)
O8^iii—Na2—O6^iii	89.36 (10)	Na2—O6—H6A	111.6
O8—Na2—O6	89.36 (10)	Na1—O6—H6A	108.1
O8^iii—Na2—O6	90.64 (10)	Na2—O6—H6B	92.3
O6^iii—Na2—O6	180.00 (11)	Na1—O6—H6B	137.2
O8—Na2—O5	88.27 (9)	H6A—O6—H6B	110.0
O8^iii—Na2—O5	91.73 (9)	Na1—O7—H7A	106.2
O6^iii—Na2—O5	91.02 (9)	Na1—O7—H7B	124.5
O6—Na2—O5	88.98 (9)	H7A—O7—H7B	107.0
O8—Na2—O5^iii	91.73 (9)	Na2—O8—H8A	106.8
O8^iii—Na2—O5^iii	88.27 (9)	Na2—O8—H8B	107.4
O6^iii—Na2—O5^iii	88.98 (9)	H8A—O8—H8B	111.7
O2—C1—N1—C2	166.3 (3)	O8—Na2—O5—Na1	89.70 (11)
O1—C1—N1—C2	−12.9 (5)	O8^iii—Na2—O5—Na1	−90.30 (11)
O4—C2—N1—C1	−138.1 (3)	O6—Na2—O5—Na1	0.31 (9)
O3—C2—N1—C1	−16.8 (4)	O6^iii—Na2—O5—Na1	−179.69 (9)
O1^i—C2—N1—C1	101.5 (3)	Na1^iii—Na2—O5—Na1	180.0
O2—C1—O1—C2^i	−174.8 (3)	O8—Na2—O6—Na1	−88.58 (10)
N1—C1—O1—C2^i	4.4 (5)	O8^iii—Na2—O6—Na1	91.42 (10)
O4—C2—O3—C2^i	173.2 (3)	O5—Na2—O6—Na1	−0.31 (9)
O1^i—C2—O3—C2^i	−63.34 (19)	O5^iii—Na2—O6—Na1	179.69 (9)
N1—C2—O3—C2^i	54.45 (18)	Na1^iii—Na2—O6—Na1	180.0
O5^ii—Na1—O5—Na2	91.66 (9)	O5^ii—Na1—O6—Na2	−93.94 (11)
O7—Na1—O5—Na2	−82.33 (10)	O5—Na1—O6—Na2	0.31 (9)
O6^ii—Na1—O5—Na2	179.94 (9)	O7^ii—Na1—O6—Na2	−175.81 (10)
O6—Na1—O5—Na2	−0.30 (9)	O7—Na1—O6—Na2	82.15 (11)
Na2^ii—Na1—O5—Na2	136.11 (7)	Na2^ii—Na1—O6—Na2	−93.88 (12)

Symmetry codes: (i) −x+1, y, −z+3/2; (ii) −x, y, −z+3/2; (iii) −x, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4···O7^i	0.82	2.11	2.897 (4)	160
O5—H5A···O4^iv	0.83	2.19	2.970 (4)	157
O5—H5B···O1	0.85	1.99	2.833 (4)	171
O6—H6A···O2^iii	0.81	2.10	2.869 (4)	157
O6—H6B···O4^v	0.85	2.05	2.888 (4)	169
O7—H7A···O8	0.85	2.12	2.943 (4)	161
O7—H7B···N1^vi	0.84	2.33	3.118 (4)	157
O8—H8A···O3^v	0.82	1.99	2.810 (3)	179
O8—H8B···O2	0.83	2.40	3.171 (4)	155

Symmetry codes: (i) −x+1, y, −z+3/2; (iii) −x, −y, −z+1; (iv) x−1/2, y−1/2, z; (v) −x+1/2, −y+1/2, −z+1; (vi) x−1/2, y+1/2, z.