4,4′-Dichloro-2,2′-(piperazine-1,4-diyldimethyl­ene)diphenol

Koji Kubono; Yuki Tsuno; Keita Tani; Kunihiko Yokoi

doi:10.1107/S1600536808035769

. 2008 Nov 13;64(Pt 12):o2309. doi: 10.1107/S1600536808035769

4,4′-Dichloro-2,2′-(piperazine-1,4-diyldimethylene)diphenol

Koji Kubono ^a,^*, Yuki Tsuno ^a, Keita Tani ^a, Kunihiko Yokoi ^a

PMCID: PMC2959987 PMID: 21581286

Abstract

In the titile compound, C₁₈H₂₀Cl₂N₂O₂, the piperazine ring adopts a chair conformation. The molecule has a non-crystallographic inversion centre in the middle of the piperazine ring at approximate position (3/4, 1/8, 3/8). There are intramolecular O—H⋯N hydrogen bonds forming S(6) ring motifs. Intermolecular C—H⋯O hydrogen bonds generate antiparallel C(5) chain motifs propagating along the b axis, forming sheets parallel to the bc plane with a first-level graph-set S(6)C(5)R ₆ ⁶(26).

Related literature

For graph-set notations for hydrogen bonds, see: Bernstein et al. (1995 ▶). For the synthesis of a ligand with two piperazine arms, see: Bharathi et al. (2006 ▶). For the use of piperazine derivatives as buffers, see: Good et al. (1966 ▶). For the monoclinic and orthorhombic polymorphs of a tetrachloro-2,2′-(piperazine-1,4-diyldimethylene)diphenol, see: Kubono & Yokoi (2007 ▶). For the structure of 1,4-bis(2-hydroxy-5-methylbenzyl)piperazine, see: Kuppayee et al. (1999 ▶).

Experimental

Crystal data

C₁₈H₂₀Cl₂N₂O₂
M _r = 367.26
Orthorhombic,
a = 14.055 (4) Å
b = 21.214 (11) Å
c = 11.873 (3) Å
V = 3540 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.38 mm⁻¹
T = 298.1 K
0.18 × 0.13 × 0.13 mm

Data collection

Rigaku AFC-7R diffractometer
Absorption correction: none
5928 measured reflections
4066 independent reflections
2735 reflections with F ² > 2σ(F ²)
R _int = 0.039
3 standard reflections every 150 reflections intensity decay: 0.7%

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.105
S = 1.00
2739 reflections
237 parameters
All H-atom parameters refined
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.45 e Å⁻³

Data collection: WinAFC (Rigaku/MSC, 2006 ▶); cell refinement: WinAFC; data reduction: CrystalStructure (Rigaku/MSC, 2006 ▶); program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808035769/si2120sup1.cif

e-64-o2309-sup1.cif^{(19.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808035769/si2120Isup2.hkl

e-64-o2309-Isup2.hkl^{(149.9KB, hkl)}

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
O1—H1⋯N1	0.85	1.88	2.649 (3)	150
O2—H20⋯N2	0.85	1.87	2.647 (3)	151
C7—H6⋯O2ⁱ	0.95	2.59	3.230 (3)	125
C12—H15⋯O1ⁱⁱ	0.95	2.56	3.300 (3)	134

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This study was supported financially in part by Grants-in-Aid (Nos. 19550040 and 20550075) from the Ministry of Education, Culture, Sports, Science, and Technology, Japan.

supplementary crystallographic information

Comment

Piprazine derivatives are widly utilized as buffers, e.g., 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) (Good et al., 1966), and can act as complexing reagents with metal ions (Bharathi et al., 2006).

The molecular structure of the title compound (Fig. 1) (I), consists of two chlorophenol arms and a piperazine ring, which adopt a chair conformation. The molecule has a pseudo-inversion centre in the middle of the piperazine ring at position (3/4, 1/8, 3/8). It is interesting to note that in the polymorh structures of dichlorophenol derivatives (Kubono & Yokoi, 2007) the molecules occupy crystallographic inversion centres (Z' = 1/2). The bond lengths and angles in (I) are normal and comparable with those in the monoclinic and orthorhombic polymorph structures (Kubono & Yokoi, 2007) and in the p-cresol derivative (Kuppayee et al., 1999). Intramolecular O—H···N hydrogen bonds in (I) have similar geometric parameters and higher level graph set notations as was observed in the polymorph structures. The torsion angles C1—C6—C7—N1 and N2—C12—C13—C18 are -34.8 (3) and 37.5 (3) °, respectively. The dihedral angles between the mean planes of two benzene rings are 4.68 (12) °.

In the crystal structure of (I), there are two intermolecular C—H···O hydrogen bonds (Table 1). Atom C7 in the molecule at (x, y, z) acts as hydrogen bond donor to atom O2 in the molecule at (x, 1/2 - y, z - 1/2), so forming a C(5) (Bernstein et al., 1995) chain running parallel to the [010] direction and generated by the c-glide plane at y = 1/4. In addition, atom C12 in the molecule at (x, y, z) acts as hydrogen bond donor to atom O1 atom in the molecule at (3/2 - x, -y, 1/2 + z), so forming a C(5) chain running parallel to the [010] direction and generated by the 2₁ screw axis along (3/4, 0, z). The molecules are linked by the combination of the two S(6) rings and the two antiparalle C(5) chains into a sheet parallel to b,c-plane with a first level graph set S(6)C(5)R₆⁶(26) (Fig. 2).

Experimental

A mixture of 4-chlorophenol (25.0 g, 194 mmol), piperazine (8.34 g, 97.2 mmol) and paraformaldehyde (5.82 g, 194 mmol) in methanol (80 ml) was refluxed for 6 h. The mixture was cooled to room temperature, then the solvent was evaporated under vacuum. The product was recrystallized from CHCl₃—MeOH to give prismatic crystals of (I) [yeild 13.8 g (38.7%); m.p. 515.0–515.4 K]. Analysis calculated for C₁₈H₂₀Cl₄N₂O₂: C 58.86, H 5.49, N 7.63%; found: C 58.50, H 5.44, N 7.55%. ¹H-NMR(CDCl₃, p.p.m., 400 MHz): 2.68 (brs, 8H, CH₂), 3.69 (s, 4H, CH₂), 6.75 (d, J = 2.4 Hz, 2H, ArH), 6.96 (s, 2H, ArH), 7.13 (d, J = 2.4 Hz, 2H, ArH), 10.6 (brs, 2H, OH).