Crystal structure of poly[μ-acetato-bis­[μ-2-oxo-2-(quinolin-8-yl)ethano­ato]tris­odium]

Rachel L Nicholls; Christopher M Pask; Bao Nguyen

doi:10.1107/S1600536814023423

. 2014 Oct 31;70(Pt 11):m385–m386. doi: 10.1107/S1600536814023423

Crystal structure of poly[μ-acetato-bis[μ-2-oxo-2-(quinolin-8-yl)ethanoato]trisodium]

Rachel L Nicholls ^a, Christopher M Pask ^a, Bao Nguyen ^a,^*

PMCID: PMC4257345 PMID: 25484788

Abstract

The title compound [Na₃(C₁₁H₆NO₃)₂(C₂H₃O₂)]_n, crystallized through diffusion of diethyl ether into methanol as needles. There are three crystallographically independent Na⁺ cations present, each exhibiting a distorted octahedral coordination geometry, two through coordination by five O atoms and one N atom, and one through coordination by six O atoms. A series of intermolecular O⋯Na and N⋯Na contacts leads to the formation of chains along the a-axis direction.

Keywords: crystal structure, keto acid, sodium, acetate

Related literature

The sodium salt of 2-oxo-2-(quinolin-8-yl)ethanoic acid was prepared as an authentic product during a catalytic process development within our group. Ethyl 2-oxo-2-(quinolin-8-yl)ethanoate was prepared by a literature procedure (Crespo-Peña et al., 2012 ▶) and then hydrolysed under basic conditions to yield the title compound. For sodium salts of keto-acids, see; Lis & Matuszewski (1984 ▶); Jain et al. (1969 ▶); Tavale et al. (1961 ▶, 1964 ▶); Rach et al. (1988 ▶). A similar Na⋯C=N(quinoline) interaction is observed in a previously published samarium Schiff base complex (Li et al., 2008 ▶).

Experimental

Crystal data

[Na₃(C₁₁H₆NO₃)₂(C₂H₃O₂)]
M _r = 528.35
Monoclinic,
a = 6.1101 (5) Å
b = 22.7075 (19) Å
c = 16.1587 (12) Å
β = 94.626 (7)°
V = 2234.6 (3) Å³
Z = 4
Cu Kα radiation
μ = 1.50 mm⁻¹
T = 120 K
0.19 × 0.04 × 0.03 mm

Data collection

Agilent SuperNova (Dual, Cu at zero, Atlas) diffractometer
Absorption correction: analytical [CrysAlis PRO (Agilent, 2014 ▶), based on expressions derived by Clark & Reid (1995 ▶)] T _min = 0.887, T _max = 0.971
7799 measured reflections
3943 independent reflections
2557 reflections with I > 2σ(I)
R _int = 0.059

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.130
S = 0.99
3943 reflections
335 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2014 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: OLEX2 (Dolomanov et al., 2009 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536814023423/pj2016sup1.cif

e-70-0m385-sup1.cif^{(59.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814023423/pj2016Isup2.hkl

e-70-0m385-Isup2.hkl^{(193.3KB, hkl)}

Click here for additional data file.^{(1.5MB, tif)}

. DOI: 10.1107/S1600536814023423/pj2016fig1.tif

The asymmetric unit of (1) showing the labelling scheme. Displacement ellipsoids are at the 50% probability level. Hydrogen atoms have been omitted for clarity.

Click here for additional data file.^{(3MB, tif)}

a . DOI: 10.1107/S1600536814023423/pj2016fig2.tif

Partial packing diagram of (1) showing the one-dimensional chain along the crystallographic a-axis. Displacement ellipsoids are at the 50% probability level.

Click here for additional data file.^{(2.4MB, tif)}

bc . DOI: 10.1107/S1600536814023423/pj2016fig3.tif

Partial packing diagram of (1) viewed on the bc plane. Displacement ellipsoids are at the 50% probability level.

CCDC reference: 1030741

Additional supporting information: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors wish to thank the University of Leeds for a University Research Scholarship (RLN) and funding.

supplementary crystallographic information

S1. Comment

The sodium salt (1) of 2-oxo-2-(quinolin-8-yl)ethanoic acid was prepared as an authentic product during a catalytic process development within our group. Ethyl 2-oxo-2-(quinolin-8-yl)ethanoate was prepared by a literature procedure (Crespo-Peña et al., 2012) and then hydrolysed under basic conditions to yield the title compound.

The asymmetric unit of 1 (Fig. 1) contains two crystallographically independent 2-oxo-2-(quinolin-8-yl)ethanoate anions, one acetate anion and three crystallographically independent sodium cations. Each sodium cation exhibits distorted octahedral geometry. One sodium cation (Na36) is coordinated by six oxygen atoms from the oxo-2'-quinolin-8'-yl-ethanoate and acetate ions. Na···O bond distances are in the range 2.290 (3) to 2.610 (3) Å. The other two sodium cations (Na35, Na37) are coordinated by five oxygen atoms (2.272 (3)-2.727 (3) Å) and what appears to be an η₂ interaction with a C=N of the quinoline ring (Na···N = 2.769 (3), 2.814 (3); Na···C = 3.035 (4), 3.073 (4)). A similar Na···C=N (quinoline) interaction is observed in a previously published samarium Schiff base complex (Li et al., 2008), although this is somewhat shorter than that observed in 1. Na···O bond lengths are comparable to previously published sodium salts of keto acids (Lis et al., 1984, Jain et al., 1969, Tavale et al., 1961, 1964, Rach et al., 1988).

These Na···O interactions lead to the formation of one-dimensional chains along the crystallographic a-axis (Fig. 2). The quinoline rings of the oxo(8-quinolyl)acetate groups and methyl groups of acetate ions appear to act as a hydrophobic sheath, encapsulating the Na···O core of the chains, keeping them separated in the solid state. (Fig. 3).

S2. Experimental

A solution of ethyl 2-oxo-2-(quinolin-8-yl)ethanoate (217 mg, 0.947 mmol) in methanol (3mL) was cooled to 0 °C and aqueous 2M NaOH (3 mL) added and stirred at room temperature for 90 min. The methanol was removed under vacuum and the remaining aqueous solution was washed at pH 9 with ethyl acetate (2 x 20 mL). The aqueous solution was acidified to pH 5 with 1M HCl and washed with ethyl acetate (2 x 20 mL). The remaining aqueous solution was reduced under vacuum to give a white solid (0.231 g) which was dissolved in methanol and filtered to remove NaCl. The product was recrystallised through diffusion of diethyl ether into a solution of the product in a minimum amount of methanol over three days to afford colourless needles.

S3. Refinement

No special refinement procedures were applied to this crystal structure. All hydrogen atoms were placed in calculated positions and refined isotropically using a riding model.