catena-Poly[[[triaqua­manganese(II)]-μ-4,4′-bipyridine-κ2 N:N′-[triaqua­manganese(II)]-μ-pyrimidine-4,6-dicarboxyl­ato-κ4 N 1,O 6:N 3,O 4] sulfate trihydrate]

Wenguo Wang; Elisa Barea; Fátima Linares

doi:10.1107/S1600536809053896

. 2009 Dec 19;66(Pt 1):m86–m87. doi: 10.1107/S1600536809053896

catena-Poly[[[triaquamanganese(II)]-μ-4,4′-bipyridine-κ² N:N′-[triaquamanganese(II)]-μ-pyrimidine-4,6-dicarboxylato-κ⁴ N ¹,O ⁶:N ³,O ⁴] sulfate trihydrate]

Wenguo Wang ^a, Elisa Barea ^a, Fátima Linares ^a,^*

PMCID: PMC2980029 PMID: 21579978

Abstract

The two independent Mn^II ions in the polymeric title compound, {[Mn₂(C₆H₂N₂O₄)(C₁₀H₈N₂)(H₂O)₆]SO₄·3H₂O}, exhibit distorted MnN₂O₄ octahedral coordination geometries, with the pyrimidine-4,6-dicarboxylate (pmdc) ligand acting in the bis-chelating μ-(κO,κN:κO′,κN′) bridging mode and the 4,4′-bipyridine (bpy) ligand in the μ-(κN:κN′) bridging mode. The remaining coordination sites are occupied by O atoms of water molecules. As a consequence, cationic chains of [Mn₂(μ-pmdc)(μ-4,4′-bpy)(H₂O)₆]²⁺ are generated, which extend approximately along the a axis. Sulfate counter-anions and three uncoordinated water molecules complete the structure, which is stabilized by multiple O—H⋯O hydrogen-bonding interactions between the structural units.

Related literature

For the preparation of the pyrimidine-4,6-dicarboxylato ligand (pmdc) we utilized the commercially available 4,6-dimethyl-pyrimidine, which can easily be oxidized to the corresponding dicarboxylic acid (H₂pmdc), originally prepared by Hunt et al. (1959 ▶). For pmdc coordination compounds, see: Beobide et al. (2008 ▶); Masciocchi et al. (2009 ▶).

Experimental

Crystal data

[Mn₂(C₆H₂N₂O₄)(C₁₀H₈N₂)(H₂O)₆]SO₄·3H₂O
M _r = 690.36
Monoclinic,
a = 18.745 (2) Å
b = 10.7639 (14) Å
c = 14.1585 (18) Å
β = 111.044 (2)°
V = 2666.2 (6) Å³
Z = 4
Mo Kα radiation
μ = 1.11 mm⁻¹
T = 298 K
0.32 × 0.27 × 0.21 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.693, T _max = 0.794
30075 measured reflections
6219 independent reflections
5467 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.115
S = 1.09
6219 reflections
403 parameters
14 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.62 e Å⁻³
Δρ_min = −0.36 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: XP in SHELXTL; software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809053896/wm2288sup1.cif

e-66-00m86-sup1.cif^{(24.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809053896/wm2288Isup2.hkl

e-66-00m86-Isup2.hkl^{(304.4KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Mn1—O12W	2.174 (2)
Mn1—O11W	2.180 (2)
Mn1—O1W	2.187 (2)
Mn1—O42	2.188 (2)
Mn1—N1Bⁱ	2.219 (2)
Mn1—N3	2.272 (2)
Mn2—O2W	2.154 (2)
Mn2—O21W	2.170 (2)
Mn2—O22W	2.201 (2)
Mn2—O62	2.2055 (19)
Mn2—N1B1	2.214 (2)
Mn2—N1	2.282 (2)

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Symmetry code: (i) Inline graphic .

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1AW⋯O4W	0.82 (1)	1.85 (1)	2.667 (5)	176 (4)
O1W—H1BW⋯O2Sⁱⁱ	0.82 (1)	2.11 (2)	2.891 (3)	159 (4)
O2W—H2BW⋯O62ⁱⁱⁱ	0.82 (1)	1.96 (1)	2.775 (3)	172 (4)
O2W—H2AW⋯O1Sⁱⁱ	0.82 (1)	1.87 (1)	2.681 (3)	172 (4)
O21W—H21A⋯O3S^iv	0.82 (1)	1.86 (1)	2.663 (3)	166 (4)
O21W—H21B⋯O5W	0.82 (1)	1.97 (1)	2.782 (4)	172 (4)
O11W—H11A⋯O42^v	0.82 (1)	1.95 (1)	2.760 (3)	167 (4)
O11W—H11B⋯O2S^iv	0.82 (1)	1.99 (1)	2.797 (3)	168 (4)
O5W—H5AW⋯O4Sⁱⁱ	0.82	2.12	2.927 (4)	168
O5W—H5BW⋯O61^vi	0.82	2.15	2.910 (3)	154
O4W—H4AW⋯O41^vii	0.82 (1)	1.89 (1)	2.702 (4)	170 (6)
O4W—H4BW⋯O4W^viii	0.82 (1)	2.48 (6)	2.908 (7)	114 (6)
O3W—H3BW⋯O3S^iv	0.82	1.93	2.746 (5)	178
O12W—H12A⋯O3W	0.82 (1)	1.85 (1)	2.656 (4)	167 (4)
O12W—H12B⋯O2Sⁱⁱ	0.82 (1)	2.04 (1)	2.840 (3)	166 (4)
O22W—H22A⋯O4S^iv	0.82 (1)	1.95 (1)	2.764 (3)	171 (3)
O22W—H22B⋯O61^ix	0.82 (1)	2.03 (1)	2.852 (3)	177 (3)

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Symmetry codes: (ii) Inline graphic ; (iii) ; (iv) ; (v) ; (vi) ; (vii) ; (viii) ; (ix) .

Acknowledgments

Financial support from Spanish MEC (CTQ2008–00037/PPQ and SB-2005–0115) is gratefully acknowledged. The authors thank Professor Jorge A. R. Navarro and Miguel Quirós (U. Granada), Professor Oscar Castillo (U. Vasque Country) and Professor Norberto Masciocchi (U. Insubria) for helpful discussions.

supplementary crystallographic information

Comment

In the structure of the title compound there are two independent manganese ions. Each metal ion exhibits a distorted octahedral coordination geometry built up of one oxygen atom and one nitrogen atom from the bis-chelating pyrimidine-4,6-dicarboxylato ligand (pmdc), one nitrogen atom from the 4,4'-bipyridine (bpy) ligand and three oxygen atoms belonging to three coordinated water molecules (Fig. 1). The bridging nature of the pmdc and bpy ligands yields 1_D polymeric chains (Fig. 2) extending approximately along the a axis. The pmdc ligands adopt a µ-(κO,κN:κO'',κN') coordination mode, and their N,O chelation results in the formation of two five-membered chelate rings for each metal ion.

The pmdc ligand combines the N,N'-coordination features of pyrimidine to the donor properties of the carboxylate group. Moreover, possessing two easily removable acidic hydrogen atoms, it can be coupled to the M(II) ions of the transition metal series, in search for homoleptic coordination compounds of [M(pmdc)] formulation. In this communication, we have employed 4,4'-bipyridine ligand in order to have a further connectivity.

The structur is in agreement with previous crystallographic studies carried out in our group revealing that the pmdc ligand typically displays a tetradentate µ-(κO,κN:κO',κN') coordination mode with the carboxylate groups almost coplanar with the pyrimidine ring.

Experimental

The ligand pyrimidine-4,6-dicarboxylic acid (H₂pmdc) was prepared from the oxidation of 4,6-dimethyl-pyrimidine (Hunt et al., 1959). The new metal complex [Mn₂(µ-4,4'bpy)(µ-pmdc)(H₂O)₆]SO₄3H₂O was obtained by reaction of an aqueous solution (30 ml) containing pyrimidine-4,6-dicarboxylato (168.3 mg) and MnSO₄(H₂O) (169.0 mg) at 353 K during 4 h. The resulting yellow suspension was cooled to room temperature and filtered. Subsequent diffusion of 4,4'_bipyridine (312.4 mg), dissolved in 10 ml of methanol, into this solution yielded pale yellow crystals suitable for X-ray diffraction after two weeks.