Hexaaqua-magnesium(II) bis-(pyridinium-2,6-dicarboxyl-ate).

In the title compound, [Mg(H(2)O)(6)](C(7)H(4)NO(4))(2), a single six-coordinate Mg(2+) cation (site symmetry 2/m) is bonded to six water mol-ecules in a distorted octa-hedral geometry. The crystal packing between the complex cation and the zwitterionic organic cation (m symmetry) is stabilized by inter-molecular O-H⋯O hydrogen bonds and weak inter-molecular C-H⋯O inter-actions.

Related literature

For background to proton-transfer compounds, see: Aghabozorg et al. (2008 ▶). For related structures, see: Aghabozorg et al. (2005 ▶); Grossel et al. (2006 ▶); Ptasiewicz-Bak & Leciejewicz (2003 ▶); Dale et al. (2003 ▶); Yang et al. (2005 ▶); Kariuki & Jones (1989 ▶)

Experimental

Crystal data

[Mg(H2O)6](C7H4NO4)2

M = 464.63

Monoclinic,

a = 13.432 (3) Å

b = 11.108 (2) Å

c = 6.5845 (13) Å

β = 92.79 (3)°

V = 981.3 (3) Å3

Z = 2

Mo Kα radiation

μ = 0.17 mm−1

T = 298 K

0.35 × 0.30 × 0.15 mm

Data collection

Stoe IPDS II diffractometer

Absorption correction: numerical (X-RED and X-SHAPE; Stoe & Cie, 2005 ▶) T min = 0.940, T max = 0.973

5499 measured reflections

1383 independent reflections

1178 reflections with I > 2σ(I)

R int = 0.031

Refinement

R[F 2 > 2σ(F 2)] = 0.038

wR(F 2) = 0.095

S = 1.12

1383 reflections

94 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.33 e Å−3

Δρmin = −0.18 e Å−3

Data collection: X-AREA (Stoe & Cie, 2005 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablocks I, glolbal. DOI: 10.1107/S1600536810046696/jj2069sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810046696/jj2069Isup2.hkl

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

[Mg(H2O)6](C7H4NO4)2	F(000) = 484.0
Mr = 464.63	Dx = 1.572 Mg m−3
Monoclinic, C2/m	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2y	Cell parameters from 1383 reflections
a = 13.432 (3) Å	θ = 2.4–29.1°
b = 11.108 (2) Å	µ = 0.17 mm−1
c = 6.5845 (13) Å	T = 298 K
β = 92.79 (3)°	Plate, colorless
V = 981.3 (3) Å3	0.35 × 0.30 × 0.15 mm
Z = 2

Stoe IPDS II diffractometer	1383 independent reflections
Radiation source: fine-focus sealed tube	1178 reflections with I > 2σ(I)
graphite	Rint = 0.031
Detector resolution: 0.15 pixels mm-1	θmax = 29.1°, θmin = 2.4°
rotation method scans	h = −17→18
Absorption correction: numerical (X-RED and X-SHAPE; Stoe & Cie, 2005)	k = −14→15
Tmin = 0.940, Tmax = 0.973	l = −9→8
5499 measured reflections

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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.095	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	w = 1/[σ2(Fo2) + (0.0414P)2 + 0.5177P] where P = (Fo2 + 2Fc2)/3
1383 reflections	(Δ/σ)max = 0.001
94 parameters	Δρmax = 0.33 e Å−3
0 restraints	Δρmin = −0.18 e Å−3

Experimental. shape of crystal determined optically

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	0.5000	0.0000	0.0000	0.0249 (2)
O1	0.40364 (11)	0.31353 (9)	0.27234 (16)	0.0499 (3)
O2	0.36594 (9)	0.18375 (8)	0.51657 (15)	0.0396 (3)
O3	0.5000	0.18182 (12)	0.0000	0.0360 (3)
O4	0.41819 (12)	0.0000	0.2566 (2)	0.0357 (3)
O5	0.36739 (11)	0.0000	−0.1931 (2)	0.0341 (3)
N1	0.37142 (12)	0.5000	0.4931 (2)	0.0257 (3)
C1	0.31770 (16)	0.5000	0.8796 (3)	0.0347 (4)
H1	0.2989	0.5000	1.0137	0.042*
C2	0.33156 (11)	0.39121 (12)	0.78070 (19)	0.0312 (3)
H2	0.3225	0.3186	0.8476	0.037*
C3	0.35898 (9)	0.39277 (10)	0.58164 (18)	0.0253 (3)
C4	0.37779 (11)	0.28571 (11)	0.4447 (2)	0.0310 (3)
H3	0.4708 (14)	0.2281 (19)	0.084 (3)	0.053 (5)*
H4	0.4046 (15)	0.0617 (19)	0.327 (3)	0.057 (6)*
H5	0.3664 (16)	0.0661 (19)	−0.270 (3)	0.065 (6)*
H1A	0.3899 (19)	0.5000	0.366 (4)	0.046 (7)*

	U11	U22	U33	U12	U13	U23
Mg1	0.0367 (5)	0.0173 (4)	0.0211 (4)	0.000	0.0062 (3)	0.000
O1	0.0892 (9)	0.0278 (5)	0.0351 (5)	0.0102 (5)	0.0267 (6)	−0.0011 (4)
O2	0.0626 (7)	0.0192 (4)	0.0374 (5)	0.0041 (4)	0.0054 (5)	0.0011 (4)
O3	0.0602 (10)	0.0177 (6)	0.0315 (7)	0.000	0.0172 (6)	0.000
O4	0.0566 (9)	0.0226 (6)	0.0296 (7)	0.000	0.0179 (6)	0.000
O5	0.0467 (8)	0.0295 (7)	0.0262 (6)	0.000	0.0034 (6)	0.000
N1	0.0353 (8)	0.0203 (7)	0.0220 (6)	0.000	0.0081 (6)	0.000
C1	0.0486 (12)	0.0344 (10)	0.0217 (8)	0.000	0.0080 (7)	0.000
C2	0.0422 (8)	0.0253 (6)	0.0265 (6)	0.0000 (5)	0.0059 (5)	0.0048 (5)
C3	0.0303 (6)	0.0192 (5)	0.0267 (5)	0.0018 (4)	0.0036 (4)	0.0007 (4)
C4	0.0410 (7)	0.0210 (6)	0.0312 (6)	0.0050 (5)	0.0048 (5)	−0.0027 (5)

Mg1—O3i	2.0197 (14)	O5—H5	0.89 (2)
Mg1—O3	2.0197 (14)	N1—C3ii	1.3401 (13)
Mg1—O4i	2.0601 (15)	N1—C3	1.3401 (13)
Mg1—O4	2.0601 (15)	N1—H1A	0.89 (3)
Mg1—O5i	2.1375 (16)	C1—C2	1.3897 (16)
Mg1—O5	2.1375 (16)	C1—C2ii	1.3897 (16)
O1—C4	1.2422 (17)	C1—H1	0.9300
O2—C4	1.2406 (16)	C2—C3	1.3788 (17)
O3—H3	0.862 (19)	C2—H2	0.9300
O4—H4	0.85 (2)	C3—C4	1.5208 (17)
O3i—Mg1—O3	180.0	Mg1—O5—H5	109.1 (13)
O3i—Mg1—O4i	90.0	C3ii—N1—C3	125.46 (15)
O3—Mg1—O4i	90.0	C3ii—N1—H1A	117.27 (8)
O3i—Mg1—O4	90.0	C3—N1—H1A	117.27 (8)
O3—Mg1—O4	90.0	C2—C1—C2ii	120.82 (17)
O4i—Mg1—O4	180.00 (8)	C2—C1—H1	119.6
O3i—Mg1—O5i	90.0	C2ii—C1—H1	119.6
O3—Mg1—O5i	90.0	C3—C2—C1	118.87 (12)
O4i—Mg1—O5i	91.46 (6)	C3—C2—H2	120.6
O4—Mg1—O5i	88.54 (6)	C1—C2—H2	120.6
O3i—Mg1—O5	90.0	N1—C3—C2	117.99 (12)
O3—Mg1—O5	90.0	N1—C3—C4	114.17 (11)
O4i—Mg1—O5	88.54 (6)	C2—C3—C4	127.84 (11)
O4—Mg1—O5	91.46 (6)	O2—C4—O1	128.49 (12)
O5i—Mg1—O5	180.00 (8)	O2—C4—C3	117.37 (12)
Mg1—O3—H3	126.6 (13)	O1—C4—C3	114.14 (11)
Mg1—O4—H4	125.5 (14)
C2ii—C1—C2—C3	−0.3 (3)	N1—C3—C4—O2	−178.85 (14)
C3ii—N1—C3—C2	−0.3 (3)	C2—C3—C4—O2	1.3 (2)
C3ii—N1—C3—C4	179.77 (12)	N1—C3—C4—O1	1.23 (19)
C1—C2—C3—N1	0.3 (2)	C2—C3—C4—O1	−178.66 (14)
C1—C2—C3—C4	−179.83 (15)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O1	0.862 (19)	1.834 (19)	2.6940 (14)	174.6 (19)
O4—H4···O2	0.85 (2)	1.93 (2)	2.7758 (14)	171 (2)
O5—H5···O2iii	0.89 (2)	1.92 (2)	2.7960 (14)	167.5 (19)
C1—H1···O5iv	0.93	2.58	3.308 (3)	136

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O1	0.862 (19)	1.834 (19)	2.6940 (14)	174.6 (19)
O4—H4⋯O2	0.85 (2)	1.93 (2)	2.7758 (14)	171 (2)
O5—H5⋯O2i	0.89 (2)	1.92 (2)	2.7960 (14)	167.5 (19)
C1—H1⋯O5ii	0.93	2.58	3.308 (3)	136

Symmetry codes: (i) ; (ii) .