catena-Poly[[[tetra­aqua­praseo­dym­ium(III)]-di-μ-nicotinato-κ2 O:N;κ2 O:N-disilver(I)-di-μ-nicotinato-κ2 N:O;κ2 N:O] perchlorate monohydrate]

Biao Guan; Chao-Hua Zhang; Wen-Dong Song

doi:10.1107/S1600536809001718

. 2009 Jan 17;65(Pt 2):m208–m209. doi: 10.1107/S1600536809001718

catena-Poly[[[tetraaquapraseodymium(III)]-di-μ-nicotinato-κ² O:N;κ² O:N-disilver(I)-di-μ-nicotinato-κ² N:O;κ² N:O] perchlorate monohydrate]

Biao Guan ^a, Chao-Hua Zhang ^b, Wen-Dong Song ^c,^*

PMCID: PMC2968334 PMID: 21581805

Abstract

In the title compound, {[Ag₂Pr(C₆H₄NO₂)₄(H₂O)₄]ClO₄·H₂O}_n, the Pr^III atom, lying on a twofold rotation axis, has a distorted square-antiprismatic coordination geometry, defined by four O atoms from four nicotinate (nic) ligands and four water molecules. The Ag^I atom is coordinated in an almost linear fashion by two pyridyl N atoms from two nicotinate ligands. The linear coordination is augmented by weak interactions with three O atoms from one perchlorate anion, one uncoordinated water molecule and one carboxylate group. Two Pr atoms link two {Ag(nic)₂}⁺ units into a ring, which is further extended into an infinite zigzag chain by sharing the Pr atoms. These chains are further connected into a three-dimensional network via weak Ag⋯O interactions, O—H⋯O hydrogen bonds, Ag⋯Ag interactions [3.357 (2) Å] and π–π interactions between the pyridyl rings [centroid–centroid distance = 3.685 (4) Å].

Related literature

For general background, see: Cheng et al. (2007a ▶,b ▶); Luo et al. (2006 ▶, 2007 ▶).

Experimental

Crystal data

[Ag₂Pr(C₆H₄NO₂)₄(H₂O)₄]ClO₄·H₂O
M _r = 1034.59
Orthorhombic,
a = 35.396 (3) Å
b = 12.3733 (10) Å
c = 15.2324 (13) Å
V = 6671.2 (10) Å³
Z = 8
Mo Kα radiation
μ = 2.76 mm⁻¹
T = 273 (2) K
0.30 × 0.25 × 0.22 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.453, T _max = 0.552
16336 measured reflections
3065 independent reflections
2478 reflections with I > 2σ(I)
R _int = 0.049

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.097
S = 1.06
3065 reflections
227 parameters
27 restraints
H-atom parameters constrained
Δρ_max = 1.56 e Å⁻³
Δρ_min = −0.87 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); 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: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809001718/hy2177sup1.cif

e-65-0m208-sup1.cif^{(17.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809001718/hy2177Isup2.hkl

e-65-0m208-Isup2.hkl^{(150.7KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Pr1—O3ⁱ	2.390 (14)
Pr1—O1W	2.477 (14)
Pr1—O2W	2.495 (14)
Pr1—O1	2.504 (13)
Ag1—N2	2.165 (18)
Ag1—N1	2.175 (18)
Ag1—O4ⁱⁱ	2.777 (16)
Ag1—O5	2.81 (3)
Ag1—O3W	2.90 (2)

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

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1W⋯O2ⁱⁱⁱ	0.88	1.79	2.67 (2)	179
O1W—H2W⋯O4^iv	0.97	1.68	2.63 (2)	163
O2W—H3W⋯O2^v	1.00	1.77	2.77 (2)	176
O2W—H4W⋯O2^vi	0.83	1.95	2.76 (2)	162
O3W—H5W⋯O1W^vii	0.82	2.15	2.91 (2)	157

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Symmetry codes: (iii) Inline graphic ; (iv) ; (v) ; (vi) ; (vii) .

Acknowledgments

The authors acknowledge Guangdong Ocean University for supporting this work.

supplementary crystallographic information

Comment

Nicotinic acid is a multifunctional bridging ligand possessing of O and N donors, which can thus be utilized to construct lanthanide–transition heterometallic complexes, via carboxylate O atoms binding to lanthanides and N atoms binding to transition metal ions such as Ag^I or Cu^I (Cheng et al., 2007a,b; Luo et al., 2006, 2007). On the basis of above considerations, we chose nicotinic acid, Pr^III and Ag^I metal ions as building blocks. A new one-dimensional 4 d–4f coordination polymer was obtained from the hydrothermal treatment of Pr₆O₁₁, AgNO₃, perchloric acid and nicotinic acid in water.

In the title compound (Fig. 1), the Pr^III atom, lying on a twofold rotation axis, has a distorted square-antiprismatic coordination geometry, defined by four O atoms from four nicotinate (nic) ligands and four water molecules. The perchlorate anion lies on a mirror plane and the uncoordinated water molecule lies on a twofold rotation axis. The Ag^I atom is coordinated in an almost linear fashion by two pyridyl N atoms from two nic ligands. The linear coordination are augmented by weak Ag···O interactions with one O atom from the ClO₄^- anion, one O atom from the uncoordinated water molecule and one carboxylate O atom from the nic ligand (Table 1). The Ag atom also exhibits an argentophilic interaction, with an Ag···Ag distance of 3.357 (1) Å. The pyridyl rings of the nic ligands coordinating to the Ag atom are almost coplanar and have a dihedral angle of 1.74 (2)°. Two Pr atoms link two Ag(nic)₂⁺ units into a ring, which are further extended into an infinite zigzag chain by sharing the common Pr atoms (Fig. 2). These chains are further connected into a three-dimensional network via the weak Ag···O interactions, O—H···O hydrogen bonds (Table 2), weak Ag···Ag interactions and π–π interactions occurring between the pyridyl rings of neighboring nic ligands [centroid–centroid distance = 3.685 (4) Å].

Experimental

A mixture of Pr₆O₁₁ (0.170 g, 0.5 mmol), AgNO₃ (0.169 g, 1 mmol), nicotinic acid (0.123 g, 1 mmol), HClO₄ (0.12 ml) and H₂O (10 ml) was placed in a 23 ml Teflon-lined reactor, which was heated to 433 K for 3 d and then cooled to room temperature at a rate of 10 K h^-1. The pale-purple plate crystals obtained were washed with water and dried in air (yield 46% based on Pr).