Poly[diaqua-μ₂-oxalato-di-μ₂-pyrimidine-2-carboxyl­ato-dimanganese(II)]

In the title compound, [Mn₂(C₂O₄)(C₅H₃N₂O₂)₂(H₂O)₂]_n, the Mn^II atom exhibits a distorted octa­hedral coordination geometry, with the centrosymmetric oxalate anion and the monoanionic pyrimidine-2-carboxyl­ate ligands generating a two-dimensional honeycomb network with a (6,3)-topology.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.025
• wR factor = 0.063
• Data-to-parameter ratio = 11.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.93
PLAT369_ALERT_2_C Long   C(sp2)-C(sp2) Bond  C6     -   C7     ...       1.53 Ang.
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          2
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.11 Ratio

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.931
            Tmax scaled      0.720 Tmin scaled      0.665

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The title compound constitutes a new member of a series of honeycomb type compounds previously reported by us (Rodríguez-Diéguez, Cano et al., 2007).

The asymmetric unit of the title compound is illustrated in Fig. 1. The Mn(II) atom exhibits a distorted octahedral coordination geometry built by one pyrimidine-2-carboxylato ligand, half of an oxalic acid ligand and one water molecule. The compound can be described by Mn(pyrimidine-2-carboxylato) chains linked by oxalate ligands to obtain a bidimensional coordination polymer. Each Mn(II) is connected to three Mn atoms through two pyrimidine-2-carboxylato ligands and one oxalate ligand, generating a two-dimensional honeycomb network with a (6,3) topology (Fig. 2). The shortest perpendicular distance between symmetry related pyrimidine rings is ca 3.41 Å.

Related literature

For the preparation of 2-cyanopyrimidine, see: Rodríguez-Diéguez, Salinas-Castillo et al. (2007). For related literature, see: Rodríguez-Diéguez, Cano et al. (2007).

S2. Experimental

The multitopic bridging ligand 2-carboxy-pyrimidine (H-pymca) was prepared by basic hydrolysis of 2-cyanopyrimidine with KOH and further neutralization with 2 N HCl. The title compound was obtained by the reaction of a mixture of two solutions. The first contained pyrimidine-2-carboxylato (17.1 mg) and MnCl₂.4(H₂O) (8.67 mg) in water/MeOH (10 ml). The second was formed by addition of MnCl₂.4(H₂O) (8.67 mg) to a solution of sodium oxalate (9.23 mg) in water (10 ml). These two solutions were then mixed and stirred for 2 h to give a pale-yellow solution. After standing at room temperature for several days prismatic yellow crystals appeared.

S3. Refinement

The water H atoms were located in a difference Fourier map and refined as riding atoms with O—H = 0.77 and 0.80 Å and U_iso(H) = 1.2U_eq(O). The pyrimidine H atoms were positioned geometrically and treated as riding atoms with C—H = 0.93 Å, and U_iso(H) = 1.2U_eq(C).

Computing details

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

Figures

	Fig. 1. The molecular structure of the asymmetric unit of [Mn2(pymca)2(ox)(H2O)2]n, showing the atom labels. Thermal ellipsoids are drawn at the 50% probability level. H atoms are represented as spheres of arbitrary radii.
	Fig. 2. A view down the a axis of the crystal structure of [Mn2(pymca)2(ox)(H2O)2]n, showing the environment of the manganese atoms and the bidimensional (6,3) net topology. The H atoms have been omitted for clarity.

Poly[diaqua-µ₂-oxalato-di-µ₂-pyrimidine-2-carboxylato-dimanganese(II)]

Crystal data

[Mn2(C2O4)(C5H3N2O2)2(H2O)2]	F(000) = 480
Mr = 480.12	Dx = 1.988 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3384 reflections
a = 7.5447 (7) Å	θ = 2.8–28.9°
b = 11.1944 (11) Å	µ = 1.64 mm^−1
c = 9.7259 (10) Å	T = 150 K
β = 102.422 (1)°	Prismatic, yellow
V = 802.20 (14) Å^3	0.22 × 0.21 × 0.20 mm
Z = 2

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1495 independent reflections
Radiation source: fine-focus sealed tube	1389 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
ϕ and ω scans	θmax = 25.5°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −9→9
Tmin = 0.714, Tmax = 0.774	k = −13→13
5847 measured reflections	l = −11→11

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.025	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.062	H-atom parameters constrained
S = 1.11	w = 1/[σ^2(Fo^2) + (0.0274P)^2 + 0.6516P] where P = (Fo^2 + 2Fc^2)/3
1495 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 0.41 e Å^−3
0 restraints	Δρmin = −0.21 e Å^−3

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	0.22294 (4)	0.67224 (3)	0.51301 (3)	0.01810 (12)
N1	0.2376 (2)	0.87496 (16)	0.49706 (17)	0.0170 (4)
C2	0.1555 (3)	0.94939 (19)	0.3937 (2)	0.0224 (5)
H2	0.0850	0.9174	0.3117	0.027*
C3	0.1735 (3)	1.07187 (19)	0.4065 (2)	0.0230 (5)
H3	0.1164	1.1230	0.3353	0.028*
C4	0.2805 (3)	1.1150 (2)	0.5301 (2)	0.0229 (5)
H4	0.2929	1.1972	0.5428	0.027*
N5	0.3670 (2)	1.04205 (16)	0.63259 (18)	0.0196 (4)
C6	0.3405 (3)	0.92559 (18)	0.6111 (2)	0.0166 (4)
C7	0.4354 (3)	0.83993 (18)	0.7255 (2)	0.0182 (4)
O8	0.3827 (2)	0.73395 (13)	0.71406 (16)	0.0251 (4)
O9	0.5576 (2)	0.88282 (13)	0.81900 (15)	0.0224 (3)
O1B	0.4755 (2)	0.64691 (13)	0.43885 (16)	0.0230 (3)
O2B	0.30121 (19)	0.48353 (13)	0.56335 (16)	0.0217 (3)
C3B	0.5504 (3)	0.54766 (18)	0.4641 (2)	0.0185 (4)
O1W	−0.0119 (2)	0.64879 (13)	0.60530 (15)	0.0219 (3)
H2WB	−0.0848	0.6091	0.5523	0.026*
H1WA	0.0167	0.6192	0.6778	0.026*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mn1	0.01820 (19)	0.01263 (18)	0.01991 (19)	0.00050 (12)	−0.00384 (13)	−0.00014 (12)
N1	0.0170 (9)	0.0150 (9)	0.0171 (9)	0.0001 (7)	−0.0008 (7)	−0.0001 (6)
C2	0.0235 (11)	0.0219 (11)	0.0194 (10)	−0.0003 (9)	−0.0009 (9)	0.0000 (9)
C3	0.0250 (11)	0.0198 (11)	0.0229 (11)	0.0005 (9)	0.0024 (9)	0.0033 (9)
C4	0.0259 (11)	0.0165 (11)	0.0257 (11)	−0.0010 (9)	0.0044 (9)	0.0013 (9)
N5	0.0219 (9)	0.0166 (9)	0.0187 (9)	−0.0014 (7)	0.0007 (7)	−0.0005 (7)
C6	0.0162 (10)	0.0162 (10)	0.0170 (10)	0.0002 (8)	0.0026 (8)	−0.0002 (8)
C7	0.0185 (10)	0.0184 (11)	0.0167 (10)	0.0026 (8)	0.0016 (8)	−0.0003 (8)
O8	0.0297 (9)	0.0157 (8)	0.0241 (8)	−0.0014 (6)	−0.0074 (7)	0.0027 (6)
O9	0.0222 (8)	0.0211 (8)	0.0195 (8)	−0.0023 (6)	−0.0054 (6)	0.0001 (6)
O1B	0.0223 (8)	0.0136 (7)	0.0316 (8)	0.0020 (6)	0.0028 (7)	0.0050 (6)
O2B	0.0188 (7)	0.0163 (7)	0.0282 (8)	0.0010 (6)	0.0009 (6)	0.0016 (6)
C3B	0.0172 (10)	0.0151 (10)	0.0191 (10)	−0.0009 (8)	−0.0055 (8)	−0.0017 (8)
O1W	0.0235 (8)	0.0196 (8)	0.0193 (7)	−0.0002 (6)	−0.0028 (6)	0.0028 (6)

Geometric parameters (Å, º)

Mn1—O9^i	2.1175 (14)	C4—H4	0.9300
Mn1—O1W	2.1677 (15)	N5—C6	1.329 (3)
Mn1—O8	2.1771 (15)	C6—C7	1.526 (3)
Mn1—O1B	2.1958 (16)	C7—O9	1.244 (3)
Mn1—O2B	2.2196 (15)	C7—O8	1.248 (3)
Mn1—N1	2.2790 (18)	O9—Mn1^ii	2.1175 (14)
N1—C6	1.336 (3)	O1B—C3B	1.247 (2)
N1—C2	1.349 (3)	O2B—C3B^iii	1.255 (3)
C2—C3	1.381 (3)	C3B—O2B^iii	1.255 (3)
C2—H2	0.9300	C3B—C3B^iii	1.560 (4)
C3—C4	1.383 (3)	O1W—H2WB	0.8027
C3—H3	0.9300	O1W—H1WA	0.7669
C4—N5	1.344 (3)
O9^i—Mn1—O1W	87.50 (6)	C2—C3—H3	121.5
O9^i—Mn1—O8	177.38 (6)	C4—C3—H3	121.5
O1W—Mn1—O8	90.61 (6)	N5—C4—C3	122.1 (2)
O9^i—Mn1—O1B	93.21 (6)	N5—C4—H4	118.9
O1W—Mn1—O1B	164.73 (6)	C3—C4—H4	118.9
O8—Mn1—O1B	89.08 (6)	C6—N5—C4	116.55 (18)
O9^i—Mn1—O2B	89.85 (6)	N5—C6—N1	126.02 (19)
O1W—Mn1—O2B	89.76 (6)	N5—C6—C7	118.09 (18)
O8—Mn1—O2B	91.96 (5)	N1—C6—C7	115.90 (18)
O1B—Mn1—O2B	74.99 (5)	O9—C7—O8	127.13 (19)
O9^i—Mn1—N1	104.89 (6)	O9—C7—C6	116.64 (18)
O1W—Mn1—N1	101.81 (6)	O8—C7—C6	116.22 (18)
O8—Mn1—N1	73.72 (6)	C7—O8—Mn1	119.06 (13)
O1B—Mn1—N1	92.76 (6)	C7—O9—Mn1^ii	137.83 (14)
O2B—Mn1—N1	161.49 (6)	C3B—O1B—Mn1	116.05 (14)
C6—N1—C2	116.64 (18)	C3B^iii—O2B—Mn1	115.15 (13)
C6—N1—Mn1	113.21 (13)	O1B—C3B—O2B^iii	126.4 (2)
C2—N1—Mn1	130.12 (14)	O1B—C3B—C3B^iii	117.0 (2)
N1—C2—C3	121.7 (2)	O2B^iii—C3B—C3B^iii	116.6 (2)
N1—C2—H2	119.2	Mn1—O1W—H2WB	108.0
C3—C2—H2	119.2	Mn1—O1W—H1WA	109.9
C2—C3—C4	117.0 (2)	H2WB—O1W—H1WA	111.7

Symmetry codes: (i) x−1/2, −y+3/2, z−1/2; (ii) x+1/2, −y+3/2, z+1/2; (iii) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H2WB···O2B^iv	0.80	2.05	2.847 (2)	170
O1W—H1WA···N5^v	0.77	2.05	2.815 (2)	171

Symmetry codes: (iv) −x, −y+1, −z+1; (v) −x+1/2, y−1/2, −z+3/2.