Poly[hexa-aqua-bis-(μ(4)-pyrimidine-4,6-dicarboxyl-ato)tetra-lithium].

The asymmetric unit of the title compound, [Li(4)(C(6)H(2)N(2)O(4))(2)(H(2)O)(6)](n), comprises two Li(+) ions bridged by a completely deprotonated pyrimidine-3,6-dicarboxyl-ate ligand and coordinated by two water mol-ecules; the asymmetric units related by an inversion operation create a structural unit which forms part of a two-dimensional polymeric structure parallel to (10-1). One of the Li(+) ions shows a distorted tetra-hedral arrangement involving two symmetry-related coordinating water mol-ecules and two carboxyl-ate O atoms. The other Li(+) ion is in distorted trigonal-bipyramidal geometry defined by N and O atoms of the ligands and a water mol-ecule. Water O atoms are proton donors to carboxyl-ate O atoms forming hydrogen bonds.

Related literature

For the crystal structures of pyrimidine-3,6-dicarb­oxy­lic acid dihydrate and two K+ complexes with pyrimidine-3,6-dicarboxyl­ate and aqua ligands, see: Beobide et al. (2007 ▶). For the structures of Li+ complexes with a pyrimidine-2-carboxyl­ato ligand, see: Starosta & Leciejewicz (2011 ▶) and with a pyrimidine-4-carboxyl­ate ligand, see: Starosta & Leciejewicz (2012 ▶).

Experimental

Crystal data

[Li4(C6H2N2O4)2(H2O)6]

M = 234.02

Monoclinic,

a = 6.7014 (13) Å

b = 11.755 (2) Å

c = 12.251 (3) Å

β = 98.38 (3)°

V = 954.8 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.15 mm−1

T = 293 K

0.48 × 0.20 × 0.13 mm

Data collection

Kuma KM-4 four-cricle diffractometer

Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2008 ▶) T min = 0.960, T max = 0.988

3009 measured reflections

2792 independent reflections

2094 reflections with I > 2σ(I)

R int = 0.023

3 standard reflections every 200 reflections intensity decay: 0.4%

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.126

S = 0.95

2792 reflections

178 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.47 e Å−3

Δρmin = −0.41 e Å−3

Data collection: KM-4 Software (Kuma, 1996 ▶); cell refinement: KM-4 Software; data reduction: DATAPROC (Kuma, 2001 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812038755/kp2437sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812038755/kp2437Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

[Li4(C6H2N2O4)2(H2O)6]	F(000) = 480
Mr = 234.02	Dx = 1.628 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 25 reflections
a = 6.7014 (13) Å	θ = 6–15°
b = 11.755 (2) Å	µ = 0.15 mm−1
c = 12.251 (3) Å	T = 293 K
β = 98.38 (3)°	Blocks, colourless
V = 954.8 (3) Å3	0.48 × 0.20 × 0.13 mm
Z = 4

Kuma KM-4 four-cricle diffractometer	2094 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.023
Graphite monochromator	θmax = 30.1°, θmin = 2.4°
profile data from ω/2θ scans	h = −9→0
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2008)	k = 0→16
Tmin = 0.960, Tmax = 0.988	l = −17→17
3009 measured reflections	3 standard reflections every 200 reflections
2792 independent reflections	intensity decay: 0.4%

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.126	H atoms treated by a mixture of independent and constrained refinement
S = 0.95	w = 1/[σ2(Fo2) + (0.0949P)2 + 0.1908P] where P = (Fo2 + 2Fc2)/3
2792 reflections	(Δ/σ)max = 0.001
178 parameters	Δρmax = 0.47 e Å−3
0 restraints	Δρmin = −0.41 e Å−3

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.

	x	y	z	Uiso*/Ueq
O2	0.24613 (17)	1.10050 (8)	0.59876 (7)	0.0279 (2)
O3	0.44978 (14)	0.61780 (7)	0.39479 (7)	0.0225 (2)
O4	0.34896 (15)	0.65464 (8)	0.55698 (7)	0.0244 (2)
N3	0.26576 (17)	0.80458 (9)	0.30736 (8)	0.0208 (2)
O1	0.16917 (19)	1.18808 (8)	0.43666 (8)	0.0321 (2)
C8	0.37372 (17)	0.67999 (9)	0.46084 (9)	0.0174 (2)
N1	0.18480 (16)	1.00000 (8)	0.32426 (8)	0.0205 (2)
C7	0.21347 (17)	1.10298 (9)	0.49612 (9)	0.0181 (2)
O6	0.82841 (18)	0.51649 (10)	0.29471 (8)	0.0315 (2)
C4	0.30347 (16)	0.79650 (9)	0.41748 (9)	0.0162 (2)
C6	0.22823 (16)	0.99180 (9)	0.43410 (9)	0.0157 (2)
O7	0.85977 (18)	0.58692 (9)	0.52784 (9)	0.0345 (3)
C5	0.28409 (18)	0.88905 (9)	0.48558 (9)	0.0172 (2)
H5	0.3074	0.8825	0.5620	0.021*
C2	0.2031 (2)	0.90580 (10)	0.26635 (9)	0.0235 (3)
H2	0.1691	0.9109	0.1902	0.028*
Li1	0.0920 (4)	1.16918 (19)	0.27116 (17)	0.0257 (5)
Li2	0.6732 (4)	0.51046 (19)	0.4213 (2)	0.0259 (4)
H71	0.951 (5)	0.556 (2)	0.574 (2)	0.070 (8)*
H72	0.848 (4)	0.668 (2)	0.530 (2)	0.056 (7)*
H62	0.789 (4)	0.481 (2)	0.229 (2)	0.058 (7)*
H61	0.832 (4)	0.589 (2)	0.279 (2)	0.055 (7)*
O5	−0.19709 (17)	1.23656 (9)	0.26248 (8)	0.0291 (2)
H51	−0.223 (4)	1.284 (2)	0.207 (2)	0.066 (7)*
H52	−0.239 (4)	1.268 (2)	0.317 (2)	0.055 (6)*

	U11	U22	U33	U12	U13	U23
O2	0.0469 (6)	0.0212 (4)	0.0151 (4)	0.0015 (4)	0.0028 (4)	−0.0020 (3)
O3	0.0321 (5)	0.0169 (4)	0.0189 (4)	0.0065 (3)	0.0052 (3)	−0.0018 (3)
O4	0.0391 (5)	0.0177 (4)	0.0176 (4)	0.0048 (3)	0.0080 (3)	0.0036 (3)
N3	0.0309 (5)	0.0173 (4)	0.0140 (4)	0.0046 (4)	0.0021 (4)	−0.0008 (3)
O1	0.0598 (7)	0.0139 (4)	0.0214 (4)	0.0058 (4)	0.0022 (4)	0.0013 (3)
C8	0.0217 (5)	0.0126 (4)	0.0174 (5)	0.0013 (4)	0.0013 (4)	0.0006 (4)
N1	0.0310 (5)	0.0162 (4)	0.0143 (4)	0.0049 (4)	0.0029 (4)	0.0017 (3)
C7	0.0229 (5)	0.0142 (5)	0.0175 (5)	0.0005 (4)	0.0037 (4)	−0.0018 (4)
O6	0.0486 (6)	0.0248 (5)	0.0221 (5)	0.0005 (4)	0.0090 (4)	−0.0011 (4)
C4	0.0205 (5)	0.0134 (4)	0.0149 (5)	0.0018 (4)	0.0031 (4)	0.0011 (3)
C6	0.0200 (5)	0.0134 (5)	0.0142 (5)	0.0007 (4)	0.0040 (4)	−0.0001 (4)
O7	0.0406 (6)	0.0243 (5)	0.0359 (6)	0.0057 (4)	−0.0034 (4)	−0.0093 (4)
C5	0.0249 (5)	0.0147 (5)	0.0123 (4)	0.0024 (4)	0.0035 (4)	0.0007 (4)
C2	0.0374 (7)	0.0195 (5)	0.0128 (5)	0.0065 (5)	0.0013 (4)	0.0002 (4)
Li1	0.0381 (12)	0.0196 (10)	0.0195 (10)	−0.0007 (8)	0.0042 (9)	0.0028 (8)
Li2	0.0334 (11)	0.0186 (10)	0.0261 (10)	0.0034 (8)	0.0053 (8)	0.0000 (8)
O5	0.0445 (6)	0.0217 (4)	0.0228 (4)	0.0065 (4)	0.0102 (4)	0.0028 (4)

O2—C7	1.2449 (14)	C8—Li2ii	2.707 (3)
O3—C8	1.2527 (14)	N1—C2	1.3305 (15)
Li1—O5	2.081 (3)	N1—C6	1.3382 (14)
Li1—O3i	2.100 (2)	C7—C6	1.5222 (15)
Li1—N3i	2.153 (2)	O6—H62	0.91 (3)
Li1—O1	2.030 (2)	O6—H61	0.88 (3)
Li1—N1	2.156 (2)	C4—C5	1.3886 (15)
Li2—O4ii	1.967 (2)	C6—C5	1.3885 (15)
Li2—O7	1.898 (3)	O7—H71	0.85 (3)
Li2—O6	1.990 (3)	O7—H72	0.96 (3)
Li2—O3	1.949 (2)	C5—H5	0.9300
O3—Li1iii	2.100 (2)	C2—H2	0.9300
O4—C8	1.2492 (14)	Li1—Li2i	3.313 (3)
O4—Li2ii	1.968 (2)	Li2—C8ii	2.707 (3)
N3—C2	1.3352 (15)	Li2—Li2ii	3.237 (5)
N3—C4	1.3393 (14)	Li2—Li1iii	3.313 (3)
N3—Li1iii	2.153 (2)	O5—H51	0.87 (3)
O1—C7	1.2476 (14)	O5—H52	0.85 (3)
C8—C4	1.5187 (15)
C8—O3—Li2	130.20 (11)	O1—Li1—O3i	167.65 (14)
C8—O3—Li1iii	116.62 (10)	O5—Li1—O3i	93.91 (10)
Li2—O3—Li1iii	109.76 (11)	O1—Li1—N1	77.25 (8)
C8—O4—Li2ii	112.72 (10)	O5—Li1—N1	126.29 (12)
C2—N3—C4	116.43 (10)	O3i—Li1—N1	91.07 (10)
C2—N3—Li1iii	128.76 (10)	O1—Li1—N3i	107.48 (11)
C4—N3—Li1iii	111.52 (9)	O5—Li1—N3i	99.51 (10)
C7—O1—Li1	119.98 (10)	O3i—Li1—N3i	77.60 (8)
O4—C8—O3	126.32 (11)	N1—Li1—N3i	133.62 (12)
O4—C8—C4	117.91 (10)	O1—Li1—Li2i	143.55 (11)
O3—C8—C4	115.77 (10)	O5—Li1—Li2i	77.24 (9)
O4—C8—Li2ii	42.09 (7)	O3i—Li1—Li2i	33.61 (6)
O3—C8—Li2ii	87.24 (8)	N1—Li1—Li2i	78.26 (8)
C4—C8—Li2ii	151.42 (9)	N3i—Li1—Li2i	108.96 (9)
C2—N1—C6	116.92 (10)	O7—Li2—O3	102.77 (12)
C2—N1—Li1	130.69 (10)	O7—Li2—O4ii	115.41 (13)
C6—N1—Li1	112.39 (9)	O3—Li2—O4ii	126.15 (14)
O1—C7—O2	126.90 (11)	O7—Li2—O6	98.77 (12)
O1—C7—C6	115.10 (10)	O3—Li2—O6	108.87 (12)
O2—C7—C6	118.00 (10)	O4ii—Li2—O6	101.48 (11)
Li2—O6—H62	124.0 (15)	O7—Li2—C8ii	98.08 (10)
Li2—O6—H61	104.1 (16)	O3—Li2—C8ii	118.56 (11)
H62—O6—H61	105 (2)	O4ii—Li2—C8ii	25.19 (5)
N3—C4—C5	121.96 (10)	O6—Li2—C8ii	124.03 (11)
N3—C4—C8	114.82 (9)	O7—Li2—Li2ii	94.80 (12)
C5—C4—C8	123.20 (10)	O3—Li2—Li2ii	63.13 (9)
N1—C6—C5	121.62 (10)	O4ii—Li2—Li2ii	76.67 (10)
N1—C6—C7	114.81 (9)	O6—Li2—Li2ii	165.63 (16)
C5—C6—C7	123.56 (10)	C8ii—Li2—Li2ii	58.00 (7)
Li2—O7—H71	126.2 (19)	O7—Li2—Li1iii	117.02 (11)
Li2—O7—H72	116.1 (14)	O3—Li2—Li1iii	36.62 (6)
H71—O7—H72	118 (2)	O4ii—Li2—Li1iii	127.50 (11)
C4—C5—C6	116.82 (10)	O6—Li2—Li1iii	73.31 (8)
C4—C5—H5	121.6	C8ii—Li2—Li1iii	138.88 (10)
C6—C5—H5	121.6	Li2ii—Li2—Li1iii	96.31 (11)
N1—C2—N3	126.12 (10)	Li1—O5—H51	111.2 (18)
N1—C2—H2	116.9	Li1—O5—H52	122.7 (17)
N3—C2—H2	116.9	H51—O5—H52	106 (2)
O1—Li1—O5	96.27 (11)

D—H···A	D—H	H···A	D···A	D—H···A
O7—H71···O6iv	0.85 (3)	2.19 (3)	3.0409 (18)	175 (2)
O7—H72···O1v	0.96 (3)	1.75 (3)	2.6920 (15)	168 (2)
O6—H62···O2vi	0.91 (3)	1.85 (3)	2.7518 (15)	172 (2)
O6—H61···O5iii	0.88 (3)	1.98 (3)	2.7889 (16)	151 (2)
O5—H51···O2vii	0.87 (3)	1.89 (3)	2.7594 (14)	172 (3)
O5—H52···O4viii	0.85 (3)	2.02 (3)	2.8670 (14)	178 (2)

Table 1

Selected bond lengths (Å)

Li1—O5	2.081 (3)
Li1—O3i	2.100 (2)
Li1—N3i	2.153 (2)
Li1—O1	2.030 (2)
Li1—N1	2.156 (2)
Li2—O4ii	1.967 (2)
Li2—O7	1.898 (3)
Li2—O6	1.990 (3)
Li2—O3	1.949 (2)

Symmetry codes: (i) ; (ii) .

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H71⋯O6iii	0.85 (3)	2.19 (3)	3.0409 (18)	175 (2)
O7—H72⋯O1iv	0.96 (3)	1.75 (3)	2.6920 (15)	168 (2)
O6—H62⋯O2v	0.91 (3)	1.85 (3)	2.7518 (15)	172 (2)
O6—H61⋯O5vi	0.88 (3)	1.98 (3)	2.7889 (16)	151 (2)
O5—H51⋯O2vii	0.87 (3)	1.89 (3)	2.7594 (14)	172 (3)
O5—H52⋯O4viii	0.85 (3)	2.02 (3)	2.8670 (14)	178 (2)

Symmetry codes: (iii) ; (iv) ; (v) ; (vi) ; (vii) ; (viii) .