catena-Poly[[tetra­kis(hexa­methyl­phos­pho­ramide-κO)bis­(nitrato-κ2 O,O′)neodymium(III)] [silver(I)-di-μ2-sulfido-tungsten(VI)-di-μ2-sulfido]]

Guodong Tang; Jinfang Zhang; Chi Zhang

doi:10.1107/S1600536808001256

. 2008 Feb 15;64(Pt 3):m478. doi: 10.1107/S1600536808001256

catena-Poly[[tetrakis(hexamethylphosphoramide-κO)bis(nitrato-κ² O,O′)neodymium(III)] [silver(I)-di-μ₂-sulfido-tungsten(VI)-di-μ₂-sulfido]]

Guodong Tang ^a,^b, Jinfang Zhang ^a, Chi Zhang ^a,^*

PMCID: PMC2960880 PMID: 21201866

Abstract

In the title compound, {[Nd(NO₃)₂(C₆H₁₈N₃OP)₄][AgWS₄]}_n, the central Nd atom of the monovalent cation is coordinated by eight O atoms from two nitrate and four hexamethylphosphoramide ligands. The monovalent anion, {[WS₄Ag]⁻}_n, forms a polymeric chain in a distorted linear configuration with W—Ag—W and Ag—W—Ag angles of 163.81 (3) and 154.786 (12)°, respectively. Thirteen C and three N atoms are disordered equally over two positions. One C atom is disordered over two positions with site occupancy factors of 0.6 and 0.4.

Related literature

For related structures, see: Lang et al. (1993 ▶); Huang et al. (1996 ▶, 1997 ▶); Zhang, Qian et al. (2007 ▶); Zhang, Cao et al. (2007 ▶). For a review of polymeric Mo(W)/S/Ag(Cu) clusters, see: Niu et al. (2004 ▶, and references therein). For third-order non-linear optical properties, see: Zhang, Song et al. (2007 ▶).

Experimental

Crystal data

[Nd(NO₃)₂(C₆H₁₈N₃OP)₄][AgWS₄]
M _r = 1405.07
Monoclinic,
a = 15.8250 (19) Å
b = 29.873 (4) Å
c = 11.4345 (13) Å
β = 90.689 (3)°
V = 5405.2 (12) Å³
Z = 4
Mo Kα radiation
μ = 3.76 mm⁻¹
T = 153 (2) K
0.2 × 0.15 × 0.1 mm

Data collection

Rigaku Mercury diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.132, T _max = 0.329 (expected range = 0.275–0.687)
46733 measured reflections
9877 independent reflections
9086 reflections with I > 2σ(I)
R _int = 0.045

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.108
S = 1.14
9877 reflections
506 parameters
28 restraints
H-atom parameters constrained
Δρ_max = 1.42 e Å⁻³
Δρ_min = −1.36 e Å⁻³

Data collection: CrystalClear (Rigaku Corporation, 2000 ▶); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku/MSC, 2002 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXL97; software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808001256/pv2063sup1.cif

e-64-0m478-sup1.cif^{(41.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808001256/pv2063Isup2.hkl

e-64-0m478-Isup2.hkl^{(483.1KB, hkl)}

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

Acknowledgments

This work is supported by the National Natural Science Foundation of China (No. 50472048), the Program for New Century Excellent Talents in Universities (NCET-05-0499), and the Graduate Innovation Laboratory Center of Nanjing University of Science and Tecnology

supplementary crystallographic information

Comment

One-dimensional Mo(W)/S/Ag anionic polymers have attracted much attention for their configurational isomerism (Niu et al., 2004, and references therein) and potential applications, especially in third-order nonlinear optical (NLO) materials. (Zhang, Song et al., 2007). Different solvent-coordinated rare-earth cations proved effective to obtain various configurations of anionic chains (Niu et al., 2004, and references therein). The title compound, {[Nd(hmp)₄(NO₃)₂][WS₄Ag]}_n (hmp = hexamethylphosphoramide) with a wave-like anionic chain was prepared by following such route using Nd(III)-hmp complex as counterion.

In possession of two nitrate ligands, the cation in the title compound is univalent (Fig. 1), which leads to an anionic chain with a univalent repeat unit, unlike other solvent-coordinated rare-earth cations, in the literature (Niu et al., 2004, and references therein), which are trivalent and induce trivalent repeat units. For example, [Nd(dmf)₈]³⁺ induces an anionic chain with a trivalent repeat unit [W₄S₁₆Ag₅]^3- (Huang et al., 1996).

As illustrated in Fig. 2, the anionic chain in the title compound has a distorted linear configuration with W—Ag—W and Ag—W—Ag angles of 163.81 (3) and 154.786 (12) °, respectively, unlike those in {(γ-MePyH)[WS₄Ag]}_n (Lang et al. 1993) and {[NH₃C(CH₂OH)₃][WS₄Ag](2DMF)}_n (Huang et al., 1997), showing an ideal linear chain and a nearly linear chain, respectively. This observation suggests that cations with bigger bulk lead to more distorted anionic chains.

Similar angles for W—Ag—W and Ag—W—Ag are found in two distorted linear chains in {[Eu(hmp)₄(NO₃)₂][WS₄Ag]}_n (Zhang, Qian et al., 2007) and {[Y(hmp)₄(NO₃)₂][WS₄Ag]}_n (Zhang, Cao et al., 2007), implying that different rare earth cations with the same coordination environments will result in the same anionic structures.

Experimental

Ag₂S (0.25 g, 1 mmol) was added to a solution of (NH₄)₂WS₄ (0.70 g, 2 mmol in 30 ml h mp) with thorough stirring for 10 h. The solution underwent an additional stir for one minute after Nd(NO₃)₃6H₂O (0.44 g, 1 mmol) was added. After filtration the orange-red filtrate was carefully laid on the surface with 30 ml i-PrOH. Orange-red block crystals were obtained after ten days. Yield: 1.129 g in pure form, 40.2% (based on W).