{1,8-Bis[2-(2-oxidobenzyl­idene­amino)phen­oxy]-3,6-dioxaocta­ne}nitrato­praseodymium(III) trichloro­methane solvate

Wei-Sheng Liu; Hui-Juan Wang; Xiao-Liang Tang; Zhi-Peng Zang; Da-Qi Wang

doi:10.1107/S1600536808021259

. 2008 Jul 31;64(Pt 8):m1087. doi: 10.1107/S1600536808021259

{1,8-Bis[2-(2-oxidobenzylideneamino)phenoxy]-3,6-dioxaoctane}nitratopraseodymium(III) trichloromethane solvate

Wei-Sheng Liu ^a,^b,^*, Hui-Juan Wang ^a, Xiao-Liang Tang ^a, Zhi-Peng Zang ^a, Da-Qi Wang ^c

PMCID: PMC2961995 PMID: 21203065

Abstract

In the title compound, [Pr(C₃₂H₃₀N₂O₆)(NO₃)]·CHCl₃, the Pr^III ion is ten-coordinated by eight O atoms and two N atoms from the acyclic crown-type Schiff base ligand and the bidentate nitrate group. The coordination polyhedron around Pr^III is a distorted bicapped square antiprism. The chloroform solvent molecule is not involved either in coordination to the Pr^III center or in hydrogen bonding to the complex. The Pr—O(phenolate) bonds are significantly shorter than the Pr—O(ether) and Pr—O(nitrate) bonds, which suggests that the Pr—O(phenolate) bond is stronger than these other bonds. In the crystal structure, the acyclic crown-type Schiff base ligand wraps around the Pr^III centre, forming a pseudo-ring.

Related literature

For general backgound, see: Wen et al. (2001 ▶); Liu et al. (2004 ▶). For related structures, see: Yu et al. (2006 ▶); Ding et al. (2007 ▶). For related literature, see: Si et al. (1994 ▶).

Experimental

Crystal data

[Pr(C₃₂H₃₀N₂O₆)(NO₃)]·CHCl₃
M _r = 860.87
Monoclinic,
a = 11.3454 (14) Å
b = 20.150 (2) Å
c = 15.4676 (17) Å
β = 100.585 (2)°
V = 3475.9 (7) Å³
Z = 4
Mo Kα radiation
μ = 1.69 mm⁻¹
T = 298 (2) K
0.48 × 0.43 × 0.21 mm

Data collection

Bruker SMART 1000 CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.498, T _max = 0.718
17233 measured reflections
6118 independent reflections
4284 reflections with I > 2σ(I)
R _int = 0.043

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.083
S = 1.03
6118 reflections
442 parameters
H-atom parameters constrained
Δρ_max = 1.44 e Å⁻³
Δρ_min = −0.55 e Å⁻³

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); data reduction: SAINT; 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: publCIF (Westrip, 2008 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808021259/wn2255sup1.cif

e-64-m1087-sup1.cif^{(26.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808021259/wn2255Isup2.hkl

e-64-m1087-Isup2.hkl^{(299.5KB, hkl)}

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

Table 1. Selected geometric parameters (Å, °).

Pr1—O6	2.269 (3)
Pr1—O5	2.278 (3)
Pr1—N1	2.646 (3)
Pr1—O8	2.649 (3)
Pr1—O7	2.649 (3)
Pr1—N2	2.670 (4)
Pr1—O1	2.708 (3)
Pr1—O2	2.710 (3)
Pr1—O3	2.787 (3)
Pr1—O4	2.801 (3)

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O6—Pr1—N1	79.26 (11)
O6—Pr1—O7	76.36 (11)
O8—Pr1—O7	47.81 (10)
O5—Pr1—N2	77.19 (11)
N1—Pr1—N2	79.07 (10)
O7—Pr1—N2	92.76 (10)
N1—Pr1—O1	59.47 (9)
O1—Pr1—O2	60.33 (8)
O2—Pr1—O3	60.76 (9)
O5—Pr1—O4	73.42 (9)
N2—Pr1—O4	56.72 (9)
O3—Pr1—O4	60.53 (8)

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Acknowledgments

The authors acknowledge the National Natural Science Foundation of China (grant Nos. 20771048, 20431010, 20621091 and J0630962) for financial support.

supplementary crystallographic information

Comment

Open chain polyethers offer many advantages over traditional crown ethers (Liu et al.,2004). They are excellent reagents for activating ion-selective electrodes and extracts of rare earth ions (Wen et al., 2001). In recent years the structures and properties of complexes with the zinc(II) ion, rare earth ions, and non-cyclic crown-type Schiff bases have been reported (Ding et al., 2007; Yu et al., 2006). To further understand the ability of these compounds to complex rare earth ions, we have prepared a non-cyclic crown-type Schiff base,1,8-bis[2-(2-hydroxyphenylideneimino)phenoxy]-3,6-dioxaoctane (H₂L), as a ligand and investigated the reaction of H₂L with Pr(NO₃)₃.6H₂O. As part of a series of studies, we report here the crystal structure of the title compound. The structure of the complex is illustrated in Fig.1. Selected bond lengths and angles are given in Table 1. The Pr^III ion is coordinated by ten donor atoms, eight of which belong to the non-cyclic crown-type Schiff base ligand and the remaining two to the bidentate nitrate group. The coordination polyhedron around Pr^III is a distorted bicapped square antiprism (Fig. 2). The chloroform solvent molecule is not involved either in coordination to the Pr^III center or in hydrogen bonding to the complex. The Pr—O (phenolate) bonds are stronger than the other Pr—O bonds. In the crystal structure, the non-cyclic crown-type Schiff base ligand wraps around the Pr^III centre, forming a pseudo-ring.

Experimental

H₂L was synthesized using a literature method (Si et al.,1994). The title compound Pr(NO₃)(C₃₂H₃₀O₆N₂)(CHCl₃) was synthesized as follows: NaOH (8.0 mg, 0.2 mmol) was added to 10 ml of ethyl acetate solution containing H₂L (54.0 mg, 0.1 mmol). The mixture was stirred for 10 min at room temperature to obtain a yellow solution. 5 ml of ethyl acetate solution containing Pr(NO₃)₃.6H₂O (43.4 mg, 0.1 mmol) was then added to the mixture and a yellow precipitate formed. The precipitate was collected and washed three times with ethyl acetate. Further drying in a vacuum afforded a yellow powder. Yellow single crystals of the title compound were grown from a mixed methanol/chloroform solution (v:v 1:2) by slow evaporation at room temperature.