Tetra­kis[2-(benzyl­amino­carbonyl)phenox­ymeth­yl]methane

Xue-Qin Song

doi:10.1107/S1600536808028286

. 2008 Sep 13;64(Pt 10):o1911. doi: 10.1107/S1600536808028286

Tetrakis[2-(benzylaminocarbonyl)phenoxymethyl]methane

Xue-Qin Song ^a,^*

PMCID: PMC2959481 PMID: 21201120

Abstract

The title compound, C₆₁H₅₆N₄O₈, is arranged with all four salicylamide arms disposed in a circular fashion. Each arm has a similar conformation and they are extended so that their terminal groups can fold back. The four carbonyl O atoms are located on the outside of the molecule. The structure is stabilized by intra- and intermolecular N—H⋯O hydrogen-bonding interactions.

Related literature

For details of the advantages of salicylamide ligands, see: Zhang et al. (2002 ▶); Tang et al. (2005 ▶). Salicylamide-derived ligands are excellent complexing agents for lanthanide ions because of their attractive sensitization of lanthanide luminescence as well as the construction of novel metal–organic frameworks, see: Song, Dou et al. (2007 ▶); Song, Liu et al. (2007 ▶); Song et al. (2008 ▶). For bond-length data, see: Allen et al. (1987 ▶). For related literature, see: Farber & Conley (1974 ▶); Jiri et al. (1994 ▶).

Experimental

Crystal data

C₆₁H₅₆N₄O₈
M _r = 973.10
Triclinic,
a = 13.0505 (4) Å
b = 13.6943 (4) Å
c = 14.3577 (4) Å
α = 92.519 (1)°
β = 102.677 (1)°
γ = 92.737 (1)°
V = 2496.66 (13) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 153 (2) K
0.39 × 0.36 × 0.10 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: none
20607 measured reflections
9277 independent reflections
7923 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.119
S = 0.98
9277 reflections
659 parameters
H-atom parameters constrained
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 2004 ▶); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808028286/at2625sup1.cif

e-64-o1911-sup1.cif^{(38.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808028286/at2625Isup2.hkl

e-64-o1911-Isup2.hkl^{(453.7KB, 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
N1—H1⋯O1	0.88	2.12	2.7705 (16)	130
N2—H2⋯O3	0.88	1.96	2.6731 (14)	137
N3—H3⋯O5	0.88	2.27	2.7399 (14)	113
N4—H8⋯O7	0.88	2.16	2.7341 (16)	122
N4—H8⋯O4ⁱ	0.88	2.54	3.1841 (17)	131

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

In the last decade, synthetic studies on salicylamide delived ligands have been carried out because of their attractive sensitization of lanthanide luminescence as well as construction of novel metal–organic frameworks (Zhang et al., 2002; Tang et al., 2005) we are systematically studying the structure and the photophysical properties of complexing salicylamide ligands of capable of sensitizing Eu(III) and Tb(III) emission recently. So far, some intriguing supramolecular complexes based on salicylamide derivatives have been reported (Song, Dou et al., 2007; Song, Liu et al., 2007; Song et al., 2008). However, the tetrapodal ligand featuring salicylamide pendant arms, which is analogues of the ligands studies above, is still unprecedented. In view of this, we report here the synthesis and crystal structure of the title compound (I) which is a part of our studies.

The molecular structure of the title compound (I) is shown in Fig. 1. All bond lengths and angles in (I) are generally within normal ranges (Allen et al., 1987). Four benzylsalicylamide arms are linked together by the quarternary carbon atom at the tetrahedry position and are severely twisted with a ca 65° dihedral angle between phenyl rings. The amide hydrogen atoms (H1, H2, H3 and H4) are hydrogen bonded to the ether oxygen atoms (O1, O3, O5 and O7) to provide four hydrogen bonded six-membered rings. It is no doubt to note that the robust intramolecular hydrogen bond have a template effect and participate in the stabilization of the complete structure (Table 1). Interestingly, the title compound was arranged with all four salicylamide arms in a circular fashion and each salicylamide arm had a similar conformation and the arm is so long that their terminal groups can "fold back". Four oxygen atoms of the carbonyl groups of the compound, namely, O2, O4, O6 and, O8, are located in the outer part of the whole molecule.

Experimental

The title compound was synthesized by the following method. To a solution of pentaerythritol benzenesulfonate (2.32 g, 3.3 mmol) (Farber et al.,1974) in dry DMF was added K₂CO₃ (0.69 g, 5 mmol) and the mixture stirred and heated for 10 min, N-benzylsalicylamide (3.40 g, 15 mmol) (Jiri et al.,1994) in 50 ml DMF was added dropwise in 30 min and the resulting solution stirred and heated to reflux for 12 h. After cooling down, inorganic salts was separated by filtration and the solvent was removed from the filtrate under reduced pressure. The crude product was purified by chromatography on silica, gradient elution from petroleum to 10:1 petroleum–ethyl acetate to give a white powder. Colourless single crystals were grown from methanol and ethyl acetate mixed solution (v:v =1:5) with slow evaporation at room temperature. The crystals were isolated, washed three times with ethyl acetate and dried in vacuum desiccator using anhydrous CaCl₂ (yield 87.4%). Analysis found (%): C 75.59, H 5.59, N 5.18; calculated for C₆₁H₅₆N₄O₈: C 75.29, H 5.61, N 5.20.