2,6-Diacetyl­pyridine–resorcinol (1/1)

Quoc-Cuong Ton; Michael Bolte

doi:10.1107/S1600536812035131

. 2012 Aug 11;68(Pt 9):o2699. doi: 10.1107/S1600536812035131

2,6-Diacetylpyridine–resorcinol (1/1)

Quoc-Cuong Ton ^a, Michael Bolte ^b,^*

PMCID: PMC3435719 PMID: 22969590

Abstract

The title co-crystal, C₉H₉NO₂·C₆H₆O₂, is composed of one 2,6-diacetylpyridine molecule and one resorcinol molecule as the asymmetric unit. In the 2,6-diacetylpyridine molecule, the two carbonyl groups are antiperiplanar to the pyridine N atom. In the crystal, the 2,6-diacetylpyridine and resorcinol molecules are connected by two O—H⋯O hydrogen bonds, forming planar chains of alternating components running along [120].

Related literature

For background to 2,6-diacetylpyridine and resorcinol, see: Bacon & Lisher (1980 ▶); MacGillivray et al. (2000 ▶); Boldog et al. (2004 ▶); Matsumoto et al. (2006 ▶); Anwar et al. (2007 ▶); Friščić & MacGillivray (2009 ▶).

Experimental

Crystal data

C₉H₉NO₂·C₆H₆O₂
M _r = 273.28
Triclinic,
a = 7.346 (2) Å
b = 7.866 (2) Å
c = 12.342 (3) Å
α = 101.61 (3)°
β = 90.51 (3)°
γ = 98.72 (3)°
V = 689.9 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 173 K
0.30 × 0.30 × 0.23 mm

Data collection

Stoe IPDS II two-circle diffractometer
9113 measured reflections
2515 independent reflections
1605 reflections with I > 2σ(I)
R _int = 0.094

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.130
S = 0.93
2515 reflections
185 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2001 ▶); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2001 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 2008 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812035131/ng5287sup1.cif

e-68-o2699-sup1.cif^{(21.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812035131/ng5287Isup2.hkl

e-68-o2699-Isup2.hkl^{(123.5KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812035131/ng5287Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—HO3⋯O2	0.84	1.95	2.784 (2)	174
O4—HO4⋯O1ⁱ	0.84	1.96	2.802 (3)	177

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Symmetry code: (i) Inline graphic .

Acknowledgments

We thank Dr Guido Wagner for quantum-mechanical calculations of the relative stability of the 2,6-diacetylpyridine conformations and Professor Dr E. Egert for helpful discussions.

supplementary crystallographic information

Comment

The co-crystallization process between two components which possess either donor or acceptor hydrogen bond properties in order to obtain the AAA-DDD (A=Acceptor, D= Donor) hydrogen bond pattern containing two strong O—H···O hydrogen bonds and one weak C—H···O hydrogen bond (see Fig. 1, III) was the initial motivation of this research. Therefore, 2,6-diacetylpyridine, I, (CSD REFCODE: BARKAH) and resorcinol, II, (CSD REFCODE: RESORA03) have been chosen for this purpose. Compounds I and II can exist in three possible conformations (Anwar et al., 2007). Considering all possible hydrogen bonds between the two components, forming the complex as mentioned above is the most unfavourable constellation. The calculations of the three molecular conformations of 2,6-diacetylpyridine using quantum-mechanical calculations (Gaussian 03) predict that conformer Ia is the most stable, followed by Ib, and then Ic. The determination of the relative stability of resorcinol using quantum–mechanical density functional theory (DFT) said that conformer IIa is the most stable, followed by IIb, and then IIc. Two out of three conformers of resorcinol have been observed in neutron powder experiments (Bacon & Lisher, 1980). Beyond that all three conformations have been found in diverse multi-component-complexes (Boldog et al. 2004; MacGillivray et al. 2000; Friščić & MacGillivray, 2009; Matsumoto et al., 2006) where resorcinol showed these conformations. Another possibility of building a finite hydrogen bond network between the two components is highlighted as an example (V in Fig. 1), where different conformers are involved. The energy for the conversion of the relative stable conformers Ia and IIb to the least energetically favoured conformational states Ic and IIc is estimated to be approximately 60 kJ/mol. The co-crystal of the title compound (Fig. 2) in the constellation of Ia and IIb adopts a chain motif (IV in Fig. 1) (Fig. 3). The desired complex (III in Fig. 1) was not formed.

Experimental

The starting compounds 2,6-diacetylpyridine and resorcinol were purchased from Aldrich and Alfa Aesar which were used for co-crystallization experiments without purification. The starting compounds were dissolved in a 1:1 molecular ratio in ether and setlaid aside at room temperature. After several weeks adequate single crystals were obtained.