Bis(μ-4-carb­oxy-2-sulfonato­benzoato)bis­[aqua­(2,2′-bipyrid­yl)­manganese(II)]

In the title compound, [Mn₂(C₈H₄O₇S)₂(C₁₀H₈N₂)₂(H₂O)₂], pairs of hexa­coordinated manganese(II) centres are bridged by 2-sulfonatoterephthalate(2−) anions to form cyclic centrosymmetric dimers, which are linked into sheets by O—H...O hydrogen bonds.

S1. Comment

The rational design and synthesis of metal-organic frameworks have recently received extensive attention owing to their potential applications in catalysis, chemical separation and gas storage (Chae et al., 2004; Eddaoudi et al., 2002; Rosi et al.,2003; Rowsell et al., 2004; Seo et al., 2000; Jesse & Yaghi, 2005). Multidentate O/N-donor ligands containing rigid frameworks, such as polycarboxylates, polybipyridines or their derivatives, and mixed polycarboxylate and polybipyridine ligands, have been employed to construct metal coordination frameworks (Rosi et al., 2005; Zhang et al., 2003; Wen et al., 2007; Sun et al., 2001, 2003). Among such ligands, rod-like multidentate bridging ligands, such as terephthalate (tp), are known to form one-, two- and three-dimensional coordination networks.

The coordination chemistry of the deprotonated forms of H₂tp with up to four potential O-atom donors, which can adopt different coordination modes in different chemical environments, has been widely investigated. Terephthalate anions can act as bridging ligands, forming short bridges by use of just one carboxylate unit or long bridges by use of both carboxylate groups. 2-Sulfoterephthalic acid (STP) has been little explored (Horike, Matsuda, Tanaka, Matsubara et al., 2006; Horike, Matsuda, Tanaka, Mizuno et al., 2006). However, the sulfonate group shows interesting functional properties owing to flexible coordination modes caused by weak interactions between metal centres and the sulfonate group (Cote & Shimizu, 2003). By introduction of a soft sulfonate group into rigid multicarboxylate ligands, coordination complexes with diverse structural frameworks can be expected. We report here the synthesis and crystal structure of the title compound, (I), which exemplifies this type of coordination.

The asymmetric unit of (I) consists of one Mn^II ion, one 2,2'-bipyridine molecule, one HSTP²⁻ anion and one water molecule (Fig. 1). The six-coordinate metal centre is located on a general position, and the [N₂O₄] chromophore about the Mn centre involves the two pyridine N atoms from a 2,2'-bipyridine molecule and two cis carboxylate O atoms from two symmetry-related STP ligands at the equatorial sites; the axial positions are occupied by a water molecule and a sulfonate O atom. The Mn—N distances (Table 1) are in agreement with values observed previously (Ma et al., 2004). The Mn—O distances are similar to those documented elsewhere (Chen et al., 2003). The C—O distances are consistent with the location of the H atoms deduced from difference maps, which indicate that the STP ligand carries a charge of −2, so satisfying the charge-balance requirement. The angles subtended at Mn by cis pairs of ligating atoms cover the range 80.75 (10)–108.28 (9)°, and angles of subtended by the trans pairs are in the range 156.51 (8) to 167.23 (9)°, indicating that the Mn(N₂O₄) unit is distorted from regular octahedral geometry.

The two symmetry-related STP ligands in (I) act as bridging ligands, forming long bridges that link metal centres to generate a dimeric unit containing a 16-membered ring. Although some examples of H-shaped dimeric units or pseudo-honeycomb coordination nets constructed by the tp or 5-sulfoisophthalate ligands have been reported (Cano et al., 1997; Chen et al., 2003; Kulynych & Shimizu, 2002), the pattern found here for (I) has not been reported previously. The sulfonate groups of 2-sulfoterephthalate adopt a µ₁ mode coordinated to metal centers, similar to that of the Cu derivative (Kulynych & Shimizu, 2002) but different from that of the Cd derivative (Horike, Matsuda, Tanaka, Matsubara et al., 2006; Horike, Matsuda, Tanaka, Mizuno et al., 2006). The sulfonate O atom and cis carboxylate O atom coordinated to the metal center form a seven-membered chelate ring. The carboxylate group acts as a bismonodentate ligand toward two metal centres. The whole STP ligand adopts a µ₂ mode bridging two metal centers. The dihedral angle between the mean plane of the benzene ring and the plane of the carboxylate group is 57.0°, while the protonated carboxylate group and the aromatic ring are coplanar. The rings of the 2,2'-bipyridine ligand are also twisted by 10.55°. Three types of hydrogen bonds are observed (Table 2), and these link the dimers into sheets parallel to (001) (Fig. 2).

Related literature

For related literature, see: Kulynych & Shimizu (2002); Cano et al. (1997); Chae et al. (2004); Chen et al. (2003); Cote & Shimizu (2003); Eddaoudi et al. (2002); Horike et al. (2006a, 2006b); Jesse & Yaghi (2005); Ma et al. (2004); Rosi et al. (2003, 2005); Rowsell et al. (2004); Seo et al. (2000); Sun et al. (2001, 2003); Wen et al. (2007); Zhang et al. (2003).

S2. Experimental

A mixture of STP (0.025 g, 0.1 mmol), MnCl₂(0.013 g, 0.1 mmol), 2,2'-bipyridine (0.016 g, 0.1 mmol) and water (7 ml) was stirred for about 30 min. The pH of the resulting solution was adjusted to 7.0 using aqueous sodium hydroxide solution (0.1 mol dm⁻³), and then sealed in a Teflon-lined stainless steel autoclave and heated to 393 K for 3 d. The autoclave was then allowed to cool to ambient temperature. Compound (I) was obtained as yellow block crystals, recovered by vacuum filtration and dried in air (yield ca 82%).

S3. Refinement

The C-bound H atoms were positioned geometrically (C—H = 0.93 Å) and refined as riding, with U_iso(H) values of 1.2U_eq(C). The O-bound H atoms were located in difference maps and refined as riding in their as-found relative positions with U_iso(H) set at 1.2U_eq(O_aqua) or 1.5U_eq(O_OH), giving O—H distances of 0.82–0.83 Å.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2000); cell refinement: CrysAlis RED (Oxford Diffraction, 2000); data reduction: CrysAlis RED (Oxford Diffraction, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL (Bruker, 1997).

Figures

	Fig. 1. The molecular structure of (I), showing 30% probability displacement ellipsoids. All H atoms have been omitted for clarity.
	Fig. 2. The extended structure of (I), viewed down [001], with hydrogen bonds shown as dashed lines. C-bound H atoms have been omitted for clarity.

Bis(µ-4-carboxy-2-sulfonatobenzoato)bis[aqua(2,2'-bipyridyl)manganese(II)]

Crystal data

[Mn2(C8H4O7S)2(C10H8N2)2(H2O)2]	Z = 1
Mr = 946.62	F(000) = 482
Triclinic, P1	Dx = 1.754 Mg m^−3
Hall symbol: -P1	Cu Kα radiation, λ = 1.54178 Å
a = 7.317 (7) Å	Cell parameters from 7219 reflections
b = 9.604 (3) Å	θ = 12–18°
c = 12.799 (5) Å	µ = 7.58 mm^−1
α = 88.47 (3)°	T = 293 K
β = 86.06 (5)°	Block, yellow
γ = 87.74 (5)°	0.30 × 0.25 × 0.20 mm
V = 896.4 (10) Å^3

Data collection

Manufacturer? Model? 4-circle diffractometer	3189 independent reflections
Radiation source: Enhance (Cu) X-ray Source	2685 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
scintillation counter scans	θmax = 67.5°, θmin = 3.5°
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2000)	h = −7→8
Tmin = 0.163, Tmax = 0.220	k = −11→11
7219 measured reflections	l = −13→15

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.038	H-atom parameters constrained
wR(F^2) = 0.105	w = 1/[σ^2(Fo^2) + (0.0662P)^2 + 0.0716P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max = 0.001
3189 reflections	Δρmax = 0.40 e Å^−3
273 parameters	Δρmin = −0.36 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0096 (8)

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
Mn1	0.35301 (6)	0.37188 (4)	0.73148 (3)	0.02815 (17)
S1	0.73354 (9)	0.18304 (6)	0.75083 (4)	0.02792 (19)
O1	0.5524 (3)	0.43997 (19)	0.61665 (14)	0.0357 (4)
O2	0.7981 (3)	0.47575 (19)	0.51285 (15)	0.0349 (4)
O3	0.7646 (4)	−0.2693 (2)	0.54026 (16)	0.0465 (6)
H3A	0.7647	−0.3499	0.5206	0.070*
O4	0.7466 (3)	−0.2198 (2)	0.37026 (15)	0.0402 (5)
O5	0.5427 (3)	0.2084 (2)	0.78411 (15)	0.0382 (5)
O6	0.8338 (3)	0.3073 (2)	0.75568 (15)	0.0416 (5)
O7	0.8095 (3)	0.0634 (2)	0.80357 (15)	0.0423 (5)
O8	0.0978 (3)	0.4927 (2)	0.69620 (15)	0.0377 (5)
H81	0.0150	0.4407	0.7164	0.045*
H82	0.1059	0.5185	0.6339	0.045*
N1	0.4045 (3)	0.5604 (2)	0.82531 (17)	0.0325 (5)
N2	0.2270 (3)	0.3340 (3)	0.89299 (17)	0.0330 (5)
C1	0.4819 (4)	0.6756 (3)	0.7863 (2)	0.0397 (7)
H1	0.5402	0.6737	0.7194	0.048*
C2	0.4790 (5)	0.7972 (3)	0.8409 (3)	0.0478 (8)
H2	0.5317	0.8765	0.8107	0.057*
C3	0.3981 (5)	0.7996 (4)	0.9397 (3)	0.0503 (8)
H3	0.3948	0.8808	0.9779	0.060*
C4	0.3210 (5)	0.6810 (3)	0.9827 (2)	0.0432 (7)
H4	0.2678	0.6800	1.0508	0.052*
C5	0.3244 (4)	0.5631 (3)	0.9226 (2)	0.0321 (6)
C6	0.2394 (4)	0.4340 (3)	0.9632 (2)	0.0319 (6)
C7	0.1778 (4)	0.4143 (4)	1.0670 (2)	0.0416 (7)
H7	0.1825	0.4859	1.1142	0.050*
C8	0.1101 (5)	0.2889 (4)	1.0995 (2)	0.0496 (8)
H8	0.0700	0.2736	1.1693	0.059*
C9	0.1017 (5)	0.1861 (4)	1.0285 (3)	0.0486 (8)
H9	0.0581	0.0994	1.0494	0.058*
C10	0.1590 (4)	0.2131 (3)	0.9256 (2)	0.0412 (7)
H10	0.1497	0.1439	0.8769	0.049*
C11	0.7180 (4)	0.2445 (3)	0.53918 (19)	0.0274 (5)
C12	0.7361 (4)	0.1419 (3)	0.61668 (19)	0.0268 (5)
C13	0.7541 (4)	0.0030 (3)	0.5913 (2)	0.0287 (5)
H13	0.7683	−0.0648	0.6437	0.034*
C14	0.7511 (4)	−0.0356 (3)	0.4876 (2)	0.0285 (6)
C15	0.7398 (4)	0.0655 (3)	0.4099 (2)	0.0348 (6)
H15	0.7408	0.0402	0.3402	0.042*
C16	0.7269 (4)	0.2043 (3)	0.4354 (2)	0.0352 (6)
H16	0.7241	0.2721	0.3823	0.042*
C17	0.6853 (4)	0.3976 (3)	0.55979 (18)	0.0278 (6)
C18	0.7551 (4)	−0.1853 (3)	0.4612 (2)	0.0315 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mn1	0.0375 (3)	0.0253 (3)	0.0218 (2)	−0.00349 (18)	0.00001 (17)	−0.00709 (16)
S1	0.0393 (4)	0.0244 (3)	0.0205 (3)	−0.0019 (3)	−0.0035 (2)	−0.0032 (2)
O1	0.0459 (12)	0.0264 (10)	0.0332 (10)	−0.0006 (8)	0.0090 (9)	−0.0020 (8)
O2	0.0464 (11)	0.0213 (9)	0.0361 (10)	−0.0045 (8)	0.0067 (8)	−0.0038 (7)
O3	0.0838 (17)	0.0183 (10)	0.0377 (10)	−0.0018 (10)	−0.0047 (11)	−0.0049 (8)
O4	0.0588 (13)	0.0289 (10)	0.0341 (10)	−0.0053 (9)	−0.0057 (9)	−0.0128 (8)
O5	0.0443 (12)	0.0408 (12)	0.0285 (9)	−0.0005 (9)	0.0027 (8)	−0.0002 (8)
O6	0.0567 (13)	0.0380 (12)	0.0316 (10)	−0.0143 (10)	−0.0025 (9)	−0.0123 (8)
O7	0.0606 (13)	0.0380 (12)	0.0289 (10)	0.0046 (10)	−0.0113 (9)	0.0013 (8)
O8	0.0436 (11)	0.0368 (11)	0.0327 (9)	−0.0035 (9)	−0.0007 (8)	−0.0031 (8)
N1	0.0381 (12)	0.0326 (12)	0.0275 (11)	−0.0030 (10)	−0.0050 (9)	−0.0064 (9)
N2	0.0371 (12)	0.0353 (13)	0.0269 (10)	−0.0013 (10)	−0.0016 (9)	−0.0057 (9)
C1	0.0446 (17)	0.0385 (16)	0.0369 (14)	−0.0056 (13)	−0.0067 (13)	−0.0048 (12)
C2	0.057 (2)	0.0337 (17)	0.0546 (19)	−0.0087 (15)	−0.0125 (16)	−0.0049 (14)
C3	0.060 (2)	0.0381 (18)	0.0547 (19)	0.0009 (15)	−0.0132 (16)	−0.0208 (15)
C4	0.0492 (18)	0.0450 (18)	0.0364 (15)	0.0020 (14)	−0.0053 (13)	−0.0162 (13)
C5	0.0338 (14)	0.0358 (15)	0.0275 (13)	0.0044 (12)	−0.0076 (11)	−0.0108 (11)
C6	0.0313 (13)	0.0375 (15)	0.0270 (12)	0.0057 (11)	−0.0055 (10)	−0.0063 (11)
C7	0.0444 (17)	0.0526 (19)	0.0276 (13)	0.0026 (14)	−0.0028 (12)	−0.0063 (12)
C8	0.0492 (18)	0.068 (2)	0.0312 (14)	−0.0022 (16)	−0.0010 (13)	0.0045 (15)
C9	0.0478 (18)	0.053 (2)	0.0451 (17)	−0.0092 (15)	−0.0024 (14)	0.0127 (15)
C10	0.0463 (17)	0.0391 (17)	0.0386 (15)	−0.0062 (14)	−0.0041 (13)	−0.0022 (12)
C11	0.0355 (14)	0.0205 (13)	0.0263 (12)	−0.0029 (10)	−0.0002 (10)	−0.0035 (9)
C12	0.0333 (13)	0.0230 (12)	0.0244 (12)	−0.0037 (10)	−0.0008 (10)	−0.0042 (9)
C13	0.0387 (14)	0.0218 (12)	0.0259 (12)	−0.0020 (11)	−0.0027 (10)	−0.0018 (9)
C14	0.0367 (14)	0.0219 (13)	0.0275 (12)	−0.0030 (11)	−0.0035 (10)	−0.0066 (10)
C15	0.0517 (17)	0.0300 (14)	0.0235 (12)	−0.0024 (12)	−0.0045 (11)	−0.0071 (10)
C16	0.0561 (18)	0.0238 (13)	0.0258 (12)	−0.0017 (12)	−0.0042 (12)	−0.0003 (10)
C17	0.0418 (15)	0.0216 (13)	0.0202 (11)	−0.0026 (11)	−0.0026 (10)	−0.0010 (9)
C18	0.0379 (15)	0.0240 (13)	0.0331 (14)	−0.0035 (11)	−0.0016 (11)	−0.0084 (11)

Geometric parameters (Å, º)

Mn1—O1	2.108 (2)	C2—H2	0.9300
Mn1—O4^i	2.163 (2)	C3—C4	1.376 (5)
Mn1—O5	2.179 (3)	C3—H3	0.9300
Mn1—O8	2.226 (3)	C4—C5	1.384 (4)
Mn1—N2	2.232 (3)	C4—H4	0.9300
Mn1—N1	2.257 (2)	C5—C6	1.475 (4)
S1—O7	1.430 (2)	C6—C7	1.385 (4)
S1—O6	1.430 (2)	C7—C8	1.364 (5)
S1—O5	1.445 (3)	C7—H7	0.9300
S1—C12	1.771 (3)	C8—C9	1.365 (5)
O1—C17	1.237 (4)	C8—H8	0.9300
O2—C17	1.250 (3)	C9—C10	1.376 (5)
O3—C18	1.281 (3)	C9—H9	0.9300
O3—H3A	0.8200	C10—H10	0.9300
O4—C18	1.225 (3)	C11—C12	1.389 (4)
O4—Mn1^i	2.163 (2)	C11—C16	1.390 (4)
O8—H81	0.8239	C11—C17	1.507 (4)
O8—H82	0.8280	C12—C13	1.380 (4)
N1—C1	1.332 (4)	C13—C14	1.390 (4)
N1—C5	1.340 (4)	C13—H13	0.9300
N2—C10	1.327 (4)	C14—C15	1.376 (4)
N2—C6	1.342 (4)	C14—C18	1.484 (4)
C1—C2	1.376 (5)	C15—C16	1.379 (4)
C1—H1	0.9300	C15—H15	0.9300
C2—C3	1.359 (5)	C16—H16	0.9300
O1—Mn1—O4^i	92.90 (9)	C3—C4—H4	120.7
O1—Mn1—O5	90.57 (9)	C5—C4—H4	120.7
O4^i—Mn1—O5	87.09 (9)	N1—C5—C4	121.9 (3)
O1—Mn1—O8	104.73 (9)	N1—C5—C6	116.8 (2)
O4^i—Mn1—O8	84.08 (9)	C4—C5—C6	121.3 (3)
O5—Mn1—O8	162.66 (8)	N2—C6—C7	121.2 (3)
O1—Mn1—N2	156.51 (8)	N2—C6—C5	115.8 (2)
O4^i—Mn1—N2	108.28 (9)	C7—C6—C5	123.0 (3)
O5—Mn1—N2	80.75 (10)	C8—C7—C6	119.4 (3)
O8—Mn1—N2	87.89 (10)	C8—C7—H7	120.3
O1—Mn1—N1	88.62 (9)	C6—C7—H7	120.3
O4^i—Mn1—N1	167.23 (9)	C7—C8—C9	119.3 (3)
O5—Mn1—N1	105.59 (9)	C7—C8—H8	120.4
O8—Mn1—N1	83.27 (9)	C9—C8—H8	120.4
N2—Mn1—N1	73.02 (9)	C8—C9—C10	118.9 (3)
O7—S1—O6	115.26 (14)	C8—C9—H9	120.6
O7—S1—O5	111.48 (14)	C10—C9—H9	120.6
O6—S1—O5	110.89 (14)	N2—C10—C9	122.5 (3)
O7—S1—C12	106.60 (13)	N2—C10—H10	118.7
O6—S1—C12	106.44 (12)	C9—C10—H10	118.7
O5—S1—C12	105.46 (13)	C12—C11—C16	118.3 (2)
C17—O1—Mn1	142.07 (18)	C12—C11—C17	124.4 (2)
C18—O3—H3A	109.5	C16—C11—C17	117.2 (2)
C18—O4—Mn1^i	145.31 (19)	C13—C12—C11	120.7 (2)
S1—O5—Mn1	128.78 (12)	C13—C12—S1	117.59 (19)
Mn1—O8—H81	104.0	C11—C12—S1	121.7 (2)
Mn1—O8—H82	108.8	C12—C13—C14	120.1 (2)
H81—O8—H82	118.6	C12—C13—H13	120.0
C1—N1—C5	118.3 (3)	C14—C13—H13	120.0
C1—N1—Mn1	124.84 (19)	C15—C14—C13	119.7 (2)
C5—N1—Mn1	115.97 (19)	C15—C14—C18	120.2 (2)
C10—N2—C6	118.7 (3)	C13—C14—C18	120.1 (2)
C10—N2—Mn1	123.3 (2)	C14—C15—C16	119.9 (2)
C6—N2—Mn1	117.60 (19)	C14—C15—H15	120.0
N1—C1—C2	122.7 (3)	C16—C15—H15	120.0
N1—C1—H1	118.7	C15—C16—C11	121.1 (2)
C2—C1—H1	118.7	C15—C16—H16	119.4
C3—C2—C1	118.9 (3)	C11—C16—H16	119.4
C3—C2—H2	120.5	O1—C17—O2	123.8 (3)
C1—C2—H2	120.5	O1—C17—C11	121.2 (2)
C2—C3—C4	119.5 (3)	O2—C17—C11	115.0 (2)
C2—C3—H3	120.3	O4—C18—O3	125.4 (3)
C4—C3—H3	120.3	O4—C18—C14	120.3 (2)
C3—C4—C5	118.7 (3)	O3—C18—C14	114.4 (2)

Symmetry code: (i) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3A···O2^ii	0.82	1.69	2.483 (4)	163
O8—H81···O6^iii	0.82	1.91	2.735 (4)	175
O8—H82···O2^iv	0.83	1.96	2.743 (4)	158

Symmetry codes: (ii) x, y−1, z; (iii) x−1, y, z; (iv) −x+1, −y+1, −z+1.