Bis(μ-pyridine-2,4-dicarboxyl-ato)-κN,O:O;κO:N,O-bis-[triaqua-magnesium(II)].

In the title centrosymmetric Mg(II) complex, [Mg(2)(C(7)H(3)NO(4))(2)(H(2)O)(6)], each Mg cation is N,O-chelated by a pyridine-2,4-dicarboxyl-ate dianion and is coordinated by three water mol-ecules. A carboxyl-ate O atom from the neighboring pyridine-2,4-dicarboxyl-ate dianion bridges the Mg cation to complete the MgNO(5) distorted octa-hedral coordination geometry. The dinuclear complex mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonding, forming a three-dimensional supra-molecular structure.

Related literature

For the applications of Mg complexes, see: Davies et al. (2007 ▶); Dinca & Long (2005 ▶).

Experimental

Crystal data

[Mg2(C7H3NO4)2(H2O)6]

M = 486.92

Orthorhombic,

a = 7.9221 (8) Å

b = 12.0951 (12) Å

c = 20.2989 (18) Å

V = 1945.0 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.21 mm−1

T = 293 K

0.25 × 0.18 × 0.15 mm

Data collection

Bruker SMART CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.951, T max = 0.970

8884 measured reflections

1719 independent reflections

1289 reflections with I > 2σ(I)

R int = 0.042

Refinement

R[F 2 > 2σ(F 2)] = 0.040

wR(F 2) = 0.100

S = 1.06

1719 reflections

145 parameters

H-atom parameters constrained

Δρmax = 0.36 e Å−3

Δρmin = −0.30 e Å−3

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); data reduction: SAIn class="Chemical">NT; 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 datablocks I, global. DOI: 10.1107/S1600536810030722/xu5007sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810030722/xu5007Isup2.hkl

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

[Mg2(C7H3NO4)2(H2O)6]	F(000) = 1008
Mr = 486.92	Dx = 1.663 Mg m−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 2705 reflections
a = 7.9221 (8) Å	θ = 3.2–26.8°
b = 12.0951 (12) Å	µ = 0.21 mm−1
c = 20.2989 (18) Å	T = 293 K
V = 1945.0 (3) Å3	Block, colorless
Z = 4	0.25 × 0.18 × 0.15 mm

Bruker SMART CCD area-detector diffractometer	1719 independent reflections
Radiation source: fine-focus sealed tube	1289 reflections with I > 2σ(I)
graphite	Rint = 0.042
φ and ω scans	θmax = 25.0°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −5→9
Tmin = 0.951, Tmax = 0.970	k = −14→14
8884 measured reflections	l = −24→23

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.100	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0376P)2 + 1.7679P] where P = (Fo2 + 2Fc2)/3
1719 reflections	(Δ/σ)max < 0.001
145 parameters	Δρmax = 0.36 e Å−3
0 restraints	Δρmin = −0.30 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
Mg1	0.07954 (11)	0.60169 (7)	0.04323 (3)	0.0240 (2)
O1	−0.0075 (2)	0.43818 (14)	0.05141 (7)	0.0272 (4)
O2	−0.0923 (4)	0.30663 (19)	0.12021 (10)	0.0760 (9)
O3	−0.0102 (4)	0.3649 (2)	0.35781 (9)	0.0875 (11)
H6A	0.1178	0.8068	0.0765	0.105*
H5B	−0.1892	0.7246	0.0848	0.105*
H5A	−0.2377	0.6193	0.0826	0.105*
H7A	0.3503	0.5401	−0.0194	0.105*
H7B	0.4054	0.5600	0.0457	0.105*
H6B	0.2174	0.8016	0.0211	0.105*
O4	0.1026 (2)	0.51899 (15)	0.39638 (8)	0.0364 (5)
O5	−0.1604 (2)	0.66298 (14)	0.06670 (8)	0.0323 (5)
O6	0.1539 (3)	0.76106 (16)	0.04659 (9)	0.0491 (6)
O7	0.3209 (2)	0.56088 (17)	0.01937 (8)	0.0430 (5)
N1	0.1126 (3)	0.56101 (17)	0.14911 (9)	0.0257 (5)
C1	−0.0232 (4)	0.3941 (2)	0.10852 (11)	0.0325 (6)
C2	0.0461 (3)	0.4620 (2)	0.16485 (11)	0.0261 (6)
C3	0.0314 (3)	0.4258 (2)	0.22895 (11)	0.0302 (6)
H3	−0.0135	0.3564	0.2378	0.036*
C4	0.0838 (3)	0.4934 (2)	0.28011 (11)	0.0281 (6)
C5	0.0576 (4)	0.4556 (2)	0.35037 (12)	0.0361 (7)
C6	0.1530 (4)	0.5952 (2)	0.26430 (11)	0.0318 (6)
H6	0.1902	0.6426	0.2973	0.038*
C7	0.1660 (4)	0.6255 (2)	0.19836 (11)	0.0325 (6)
H7	0.2139	0.6935	0.1881	0.039*

	U11	U22	U33	U12	U13	U23
Mg1	0.0328 (5)	0.0234 (5)	0.0157 (4)	−0.0004 (4)	0.0015 (3)	−0.0008 (3)
O1	0.0415 (11)	0.0250 (10)	0.0151 (8)	0.0001 (8)	−0.0028 (8)	0.0000 (7)
O2	0.151 (3)	0.0485 (15)	0.0289 (11)	−0.0543 (16)	−0.0205 (13)	0.0080 (10)
O3	0.176 (3)	0.0627 (17)	0.0241 (11)	−0.0682 (19)	0.0088 (14)	0.0028 (10)
O4	0.0497 (12)	0.0419 (12)	0.0176 (8)	−0.0064 (9)	−0.0043 (8)	−0.0016 (8)
O5	0.0379 (11)	0.0271 (10)	0.0320 (9)	0.0057 (8)	0.0049 (8)	−0.0031 (8)
O6	0.0683 (15)	0.0308 (11)	0.0482 (12)	−0.0158 (10)	0.0282 (11)	−0.0089 (9)
O7	0.0339 (11)	0.0693 (15)	0.0260 (9)	0.0104 (10)	−0.0014 (8)	−0.0103 (9)
N1	0.0348 (13)	0.0239 (12)	0.0185 (10)	−0.0021 (9)	−0.0003 (9)	0.0002 (8)
C1	0.0538 (18)	0.0229 (14)	0.0208 (13)	−0.0060 (13)	−0.0040 (12)	−0.0003 (11)
C2	0.0327 (15)	0.0238 (14)	0.0220 (12)	−0.0006 (11)	−0.0008 (11)	0.0010 (10)
C3	0.0445 (17)	0.0256 (14)	0.0205 (12)	−0.0074 (12)	−0.0023 (12)	0.0028 (10)
C4	0.0349 (15)	0.0301 (15)	0.0194 (12)	−0.0011 (12)	−0.0010 (11)	0.0007 (10)
C5	0.0526 (19)	0.0362 (17)	0.0193 (13)	−0.0074 (14)	−0.0014 (12)	0.0027 (12)
C6	0.0449 (16)	0.0308 (15)	0.0196 (12)	−0.0068 (13)	−0.0052 (12)	−0.0026 (10)
C7	0.0466 (17)	0.0275 (15)	0.0236 (13)	−0.0102 (13)	−0.0025 (12)	0.0009 (11)

Mg1—N1	2.2202 (19)	O7—H7A	0.8581
Mg1—O1	2.1011 (19)	O7—H7B	0.8563
Mg1—O1i	2.0613 (16)	N1—C7	1.336 (3)
Mg1—O5	2.0953 (19)	N1—C2	1.347 (3)
Mg1—O6	2.017 (2)	C1—C2	1.511 (3)
Mg1—O7	2.033 (2)	C2—C3	1.378 (3)
O1—C1	1.282 (3)	C3—C4	1.385 (3)
O2—C1	1.215 (3)	C3—H3	0.9300
O3—C5	1.231 (3)	C4—C6	1.385 (4)
O4—C5	1.260 (3)	C4—C5	1.512 (3)
O5—H5B	0.8616	C6—C7	1.392 (3)
O5—H5A	0.8701	C6—H6	0.9300
O6—H6A	0.8688	C7—H7	0.9300
O6—H6B	0.8725
O6—Mg1—O7	88.02 (9)	H6A—O6—H6B	104.2
O6—Mg1—O1i	109.63 (8)	Mg1—O7—H7A	123.0
O7—Mg1—O1i	88.93 (7)	Mg1—O7—H7B	126.1
O6—Mg1—O5	85.36 (8)	H7A—O7—H7B	110.8
O7—Mg1—O5	173.33 (9)	C7—N1—C2	117.7 (2)
O1i—Mg1—O5	92.50 (7)	C7—N1—Mg1	129.22 (17)
O6—Mg1—O1	173.16 (8)	C2—N1—Mg1	112.37 (15)
O7—Mg1—O1	95.68 (8)	O2—C1—O1	125.6 (2)
O1i—Mg1—O1	76.26 (7)	O2—C1—C2	119.3 (2)
O5—Mg1—O1	90.98 (8)	O1—C1—C2	115.0 (2)
O6—Mg1—N1	98.32 (8)	N1—C2—C3	122.7 (2)
O7—Mg1—N1	93.77 (8)	N1—C2—C1	116.5 (2)
O1i—Mg1—N1	152.00 (8)	C3—C2—C1	120.7 (2)
O5—Mg1—N1	88.02 (8)	C2—C3—C4	119.7 (2)
O1—Mg1—N1	75.74 (7)	C2—C3—H3	120.2
O6—Mg1—Mg1i	148.06 (7)	C4—C3—H3	120.2
O7—Mg1—Mg1i	92.97 (6)	C6—C4—C3	118.0 (2)
O1i—Mg1—Mg1i	38.56 (5)	C6—C4—C5	122.8 (2)
O5—Mg1—Mg1i	92.20 (6)	C3—C4—C5	119.2 (2)
O1—Mg1—Mg1i	37.70 (4)	O3—C5—O4	125.1 (2)
N1—Mg1—Mg1i	113.44 (7)	O3—C5—C4	116.5 (2)
C1—O1—Mg1i	135.94 (16)	O4—C5—C4	118.4 (2)
C1—O1—Mg1	119.66 (15)	C4—C6—C7	119.1 (2)
Mg1i—O1—Mg1	103.74 (7)	C4—C6—H6	120.5
Mg1—O5—H5B	130.0	C7—C6—H6	120.5
Mg1—O5—H5A	120.5	N1—C7—C6	122.9 (2)
H5B—O5—H5A	100.5	N1—C7—H7	118.6
Mg1—O6—H6A	122.4	C6—C7—H7	118.6
Mg1—O6—H6B	133.3

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5A···O4ii	0.87	1.80	2.668 (3)	172.
O5—H5B···O2iii	0.86	2.12	2.834 (3)	140.
O6—H6A···O3iv	0.87	1.73	2.576 (3)	163.
O6—H6B···O5v	0.87	2.07	2.880 (2)	154.
O7—H7A···O4vi	0.86	1.89	2.745 (2)	174.
O7—H7B···O4vii	0.86	2.02	2.857 (3)	166.

Table 1

Selected bond lengths (Å)

Mg1—N1	2.2202 (19)
Mg1—O1	2.1011 (19)
Mg1—O1i	2.0613 (16)
Mg1—O5	2.0953 (19)
Mg1—O6	2.017 (2)
Mg1—O7	2.033 (2)

Symmetry code: (i) .

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—H5A⋯O4ii	0.87	1.80	2.668 (3)	172
O5—H5B⋯O2iii	0.86	2.12	2.834 (3)	140
O6—H6A⋯O3iv	0.87	1.73	2.576 (3)	163
O6—H6B⋯O5v	0.87	2.07	2.880 (2)	154
O7—H7A⋯O4vi	0.86	1.89	2.745 (2)	174
O7—H7B⋯O4vii	0.86	2.02	2.857 (3)	166

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