Poly[(μ₆-6-oxidopyridinium-2-carboxyl­ato)caesium]

Abstract

The asymmetric unit of the polymeric title salt, [Cs(C₆H₄NO₃)]_n, comprises a Cs⁺ cation and a 6-oxidopyridinium-2-carboxyl­ate anion. The Cs⁺ cation is six-coordinated by O atoms derived from two oxido and four carboxyl­ate O atoms; each O atom in the anion bridges two Cs⁺ cations. In the crystal, inter­molecular N—H⋯O hydrogen bonding is present and contributes to the stability of the three-dimensional network generated by the bridging O atoms.

Related literature

For general background to pyridine carb­oxy­lic complexes, see: Kang (2011 ▶); Lee & Kang (2010 ▶); Hong et al. (2008 ▶). For the Cs—O bond lengths in caesium aryl­oxide complexes, see: Ungaro et al. (1994 ▶); Clark et al. (1998 ▶); Weinert et al. (2003 ▶).

Experimental

Crystal data

• [Cs(C₆H₄NO₃)]

• M _r = 271.01

• Monoclinic,

• a = 8.1746 (3) Å

• b = 7.5513 (2) Å

• c = 12.3843 (4) Å

• β = 91.889 (1)°

• V = 764.05 (4) ų

• Z = 4

• Mo Kα radiation

• μ = 4.8 mm⁻¹

• T = 296 K

• 0.10 × 0.07 × 0.06 mm

Data collection

• Bruker SMART CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2002 ▶) T _min = 0.654, T _max = 0.745

• 6897 measured reflections

• 1822 independent reflections

• 1592 reflections with I > 2σ(I)

• R _int = 0.072

Refinement

• R[F ² > 2σ(F ²)] = 0.028

• wR(F ²) = 0.072

• S = 1.00

• 1822 reflections

• 104 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 1.19 e Å⁻³

• Δρ_min = −1.14 e Å⁻³

Data collection: SMART (Bruker, 2002 ▶); cell refinement: SAINT (Bruker, 2002 ▶); data reduction: SAINT; 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 ▶) and DIAMOND (Brandenburg, 2010 ▶)’; software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

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

Table 1. Selected bond lengths (Å).

Cs1—O9i	2.938 (2)
Cs1—O10ii	2.991 (3)
Cs1—O9	3.070 (3)
Cs1—O10iii	3.105 (3)
Cs1—O11iv	3.147 (2)
Cs1—O11v	3.317 (2)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2⋯O11vi	0.78 (3)	2.15 (3)	2.915 (4)	168 (3)

Symmetry code: (vi) .

supplementary crystallographic information

Comment

During studies of lanthanide complexes of picolinic acid and their derivatives due to their interesting photoluminescent properties (Kang, 2011; Lee & Kang, 2010; Hong et al., 2008), the title compound was obtained as a side-product.

The asymmetric unit of the title compound, [Cs(C₆H₄NO₃)]_n, comprises a Cs⁺ cation and a carboxylatooxidopyridinium anion. The Cs⁺ cation is coordinated to the two oxide O atoms and four carboxylate-O atoms (Fig. 1). The Cs—O bond distances lie within the range 2.938 (2) - 3.317 (2) Å (Table 1). The observed Cs—O distances are a little longer than those observed in caesium picrate complexes and caesium phenoxide complexes (Ungaro et al., 1994: Clark et al., 1998; Weinert et al., 2003). The dihedral angle between the pyridine ring and the carboxylate group is 6.95 (19) °. In the crystal structure, the Cs atoms are linked by O atoms of the anionic ligands to form a three-dimensional network (Fig. 2) with additional stability provided by intermolecular N—H···O hydrogen bonding (Table 2).

Experimental

Europium trichloride solution was prepared by dissolving EuCl₃ 6H₂O (0.37 g, 1.0 mmol; Aldrich) in absolute ethanol (20 ml) at room temperature with stirring. The ligand solution was prepared by dissolving 6-hydroxypicolinic acid (0.56 g, 4.0 mmol; Aldrich) in absolute ethanol (30 ml) at room temperature. The pH of the ligand solution was adjusted to about 6 with 2 N CsOH solution. The Eu solution was added drop wise and slowly to the ligand solution. The reaction mixture was stirred for 2 h at room temperature. Colourless crystals of (I) were obtained at room temperature over a period of a few weeks. The complex was recrystallized from distilled water.

Refinement

The N—H atom was located in a difference Fourier map and refined freely. The remaining H atoms were positioned geometrically and refined using a riding model with C—H = 0.93 Å, and with U_iso(H) = 1.2U_eq (C). The maximum and minimum residual electron density peaks of 1.19 and -1.14 e Å^-3, respectively, were located 0.83 Å and 0.71 Å from the Cs1 atom, respectively.

Figures

Fig. 1.

Molecular structure of (l), showing the atom-numbering scheme and 20% probability ellipsoids. [Symmetry code: (i) -x + 1, y + 1/2, -z + 1/2; (ii) -x + 1, y - 1/2, -z + 1/2; (iii) x, -y + 1/2, z - 1/2; (iv) x + 1, -y + 1/2, z - 1/2; (v) -x, y - 1/2, -z + 1/2].

Fig. 2.

The three-dimensional framework of (I).

Crystal data

[Cs(C6H4NO3)]	F(000) = 504
Mr = 271.01	Dx = 2.356 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3429 reflections
a = 8.1746 (3) Å	θ = 2.5–28.3°
b = 7.5513 (2) Å	µ = 4.8 mm−1
c = 12.3843 (4) Å	T = 296 K
β = 91.889 (1)°	Block, colourless
V = 764.05 (4) Å3	0.1 × 0.07 × 0.06 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	1592 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.072
Absorption correction: multi-scan (SADABS; Bruker, 2002)	θmax = 28.3°, θmin = 2.5°
Tmin = 0.654, Tmax = 0.745	h = −3→10
6897 measured reflections	k = −10→7
1822 independent reflections	l = −15→15

Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.028	w = 1/[σ2(Fo2) + (0.0401P)2] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.072	(Δ/σ)max = 0.001
S = 1.00	Δρmax = 1.19 e Å−3
1822 reflections	Δρmin = −1.14 e Å−3
104 parameters

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cs1	0.51201 (2)	0.14792 (3)	0.127051 (18)	0.04196 (11)
N2	0.0320 (3)	0.2743 (4)	0.4216 (2)	0.0304 (5)
H2	0.088 (4)	0.348 (4)	0.446 (3)	0.028 (9)*
C3	0.1062 (3)	0.1326 (4)	0.3746 (3)	0.0291 (6)
C4	0.0159 (4)	−0.0019 (5)	0.3335 (3)	0.0402 (8)
H4	0.0655	−0.0992	0.3023	0.048*
C5	−0.1567 (4)	0.0085 (5)	0.3391 (3)	0.0474 (9)
H5	−0.221	−0.0826	0.3102	0.057*
C6	−0.2296 (4)	0.1484 (5)	0.3857 (3)	0.0444 (9)
H6	−0.343	0.152	0.3888	0.053*
C7	−0.1347 (3)	0.2903 (5)	0.4302 (3)	0.0334 (7)
C8	0.2926 (3)	0.1403 (4)	0.3700 (3)	0.0298 (6)
O9	0.3603 (3)	0.0066 (3)	0.3335 (2)	0.0487 (6)
O10	0.3588 (2)	0.2803 (4)	0.3984 (2)	0.0536 (7)
O11	−0.1942 (2)	0.4235 (3)	0.4750 (2)	0.0498 (7)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cs1	0.03869 (13)	0.03507 (16)	0.05252 (19)	−0.00018 (7)	0.00759 (9)	−0.00010 (9)
N2	0.0203 (10)	0.0308 (14)	0.0402 (16)	−0.0019 (10)	0.0026 (9)	−0.0062 (12)
C3	0.0234 (12)	0.0316 (16)	0.0324 (17)	0.0012 (10)	0.0034 (10)	0.0006 (12)
C4	0.0313 (14)	0.0409 (19)	0.049 (2)	−0.0026 (12)	0.0044 (12)	−0.0145 (16)
C5	0.0316 (15)	0.049 (2)	0.061 (3)	−0.0137 (14)	−0.0003 (14)	−0.0201 (18)
C6	0.0216 (13)	0.056 (2)	0.055 (2)	−0.0055 (12)	0.0003 (13)	−0.0125 (17)
C7	0.0209 (11)	0.0393 (17)	0.0401 (19)	0.0013 (11)	0.0030 (10)	−0.0036 (15)
C8	0.0226 (12)	0.0325 (17)	0.0346 (18)	0.0020 (10)	0.0045 (10)	0.0017 (12)
O9	0.0321 (11)	0.0421 (14)	0.0725 (19)	0.0074 (10)	0.0112 (10)	−0.0090 (13)
O10	0.0235 (9)	0.0383 (14)	0.099 (2)	−0.0025 (9)	0.0070 (11)	−0.0189 (15)
O11	0.0244 (10)	0.0483 (15)	0.0772 (19)	0.0022 (10)	0.0070 (10)	−0.0231 (14)

Geometric parameters (Å, °)

Cs1—O9i	2.938 (2)	C5—C6	1.352 (5)
Cs1—O10ii	2.991 (3)	C5—H5	0.93
Cs1—O9	3.070 (3)	C6—C7	1.423 (4)
Cs1—O10iii	3.105 (3)	C6—H6	0.93
Cs1—O11iv	3.147 (2)	C7—O11	1.254 (4)
Cs1—O11v	3.317 (2)	C8—O10	1.234 (4)
N2—C3	1.370 (4)	C8—O9	1.244 (4)
N2—C7	1.376 (3)	O9—Cs1ii	2.938 (2)
N2—H2	0.78 (3)	O10—Cs1i	2.991 (3)
C3—C4	1.345 (4)	O10—Cs1vi	3.105 (3)
C3—C8	1.527 (4)	O11—Cs1vii	3.147 (2)
C4—C5	1.418 (4)	O11—Cs1viii	3.317 (2)
C4—H4	0.93
O9i—Cs1—O10ii	138.47 (6)	C3—N2—C7	123.8 (3)
O9i—Cs1—O9	109.46 (5)	C3—N2—H2	118 (3)
O10ii—Cs1—O9	85.35 (7)	C7—N2—H2	119 (3)
O9i—Cs1—O10iii	96.96 (7)	C4—C3—N2	120.3 (3)
O10ii—Cs1—O10iii	101.48 (6)	C4—C3—C8	123.4 (3)
O9—Cs1—O10iii	131.16 (6)	N2—C3—C8	116.3 (2)
O9i—Cs1—O11iv	89.05 (7)	C3—C4—C5	118.3 (3)
O10ii—Cs1—O11iv	59.91 (6)	C3—C4—H4	120.8
O9—Cs1—O11iv	140.90 (6)	C5—C4—H4	120.8
O10iii—Cs1—O11iv	77.13 (6)	C6—C5—C4	121.1 (3)
O9i—Cs1—O11v	143.52 (6)	C6—C5—H5	119.4
O10ii—Cs1—O11v	76.13 (6)	C4—C5—H5	119.4
O9—Cs1—O11v	78.86 (6)	C5—C6—C7	120.8 (3)
O10iii—Cs1—O11v	56.95 (6)	C5—C6—H6	119.6
O11iv—Cs1—O11v	106.75 (4)	C7—C6—H6	119.6
O9i—Cs1—O10	74.53 (6)	O11—C7—N2	120.3 (3)
O10ii—Cs1—O10	118.05 (6)	O11—C7—C6	124.1 (3)
O9—Cs1—O10	36.14 (6)	N2—C7—C6	115.6 (3)
O10iii—Cs1—O10	129.22 (5)	O10—C8—O9	127.1 (3)
O11iv—Cs1—O10	149.72 (6)	O10—C8—C3	116.8 (3)
O11v—Cs1—O10	101.34 (6)	O9—C8—C3	116.0 (3)
O9i—Cs1—C7iv	74.04 (7)	Cs1ii—O9—Cs1	107.94 (7)
O10ii—Cs1—C7iv	76.81 (7)	Cs1i—O10—Cs1vi	78.52 (6)
O9—Cs1—C7iv	153.81 (6)	Cs1i—O10—Cs1	91.33 (7)
O10iii—Cs1—C7iv	72.02 (6)	Cs1vi—O10—Cs1	136.48 (6)
O11iv—Cs1—C7iv	16.91 (7)	Cs1vii—O11—Cs1viii	73.25 (4)
O11v—Cs1—C7iv	114.40 (7)

Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) x, −y+1/2, z−1/2; (iv) x+1, −y+1/2, z−1/2; (v) −x, y−1/2, −z+1/2; (vi) x, −y+1/2, z+1/2; (vii) x−1, −y+1/2, z+1/2; (viii) −x, y+1/2, −z+1/2.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O11ix	0.78 (3)	2.15 (3)	2.915 (4)	168 (3)

Symmetry codes: (ix) −x, −y+1, −z+1.