Crystal structures of [Ln(NO₃)₃(μ₂-bpydo)₂], where Ln = Ce, Pr or Nd, and bpydo = 4,4′-bi­pyridine N,N′-dioxide: layered coordination networks containing 4⁴ grids

The crystal structures of poly[bis­(μ₂-4,4′-bi­pyridine N,N′-dioxide-κ² O:O′)trinitratocerium(III)] and its isostructural praseodymium and neodymium analogues feature a 4⁴ grid-like layered structure with inter­digitation of layers promoted by C—H⋯O inter­actions between nitrate anions and 4,4′-bi­pyridine N,N′-dioxide ligands.

Abstract

Three isostructural coordination networks of Ce, Pr, and Nd nitrate with 4,4′-bi­pyridine N,N′-dioxide (bpydo) are reported, namely poly[[tris­(nitrato-κ² O,O′)cerium(III)]-bis­(μ₂-4,4′-bi­pyridine N,N′-dioxide-κ² N:N′)], [Ce(NO₃)₃(C₁₀H₈N₂O₂)₂], poly[[tris­(nitrato-κ² O,O′)praeseodymium(III)]-bis­(μ₂-4,4′-bi­pyridine N,N′-dioxide-κ² N:N′)], [Pr(NO₃)₃(C₁₀H₈N₂O₂)₂], and poly[[tris(nitrato-κ² O,O′)neodymium(III)]-bis­(μ₂-4,4′-bi­pyridine N,N′-dioxide-κ² N:N′], [Nd(NO₃)₃(C₁₀H₈N₂O₂)₂]. All three compounds are isostructural to the previously reported La analogue. The asymmetric unit of [Ln(NO₃)₃(μ₂-bpydo)₂] contains one lanthanide cation, two bpydo ligands, and three nitrate anions. Both bpydo ligands act as end-to-end μ₂-bridges and display nearly ideal cis and gauche conformations, respectively. The bpydo ligands link the ten-coordinate Ln ^III cations, forming inter­digitating 4⁴ grid-like layers extending parallel to (-101), where inter­digitation of layers is promoted by C—H⋯O inter­actions between nitrate anions and bpydo ligands. The inter­digitated layers are linked to sets of neighboring layers via further C—H⋯O and π–π inter­actions.

Chemical context  

The use of aromatic N,N′-dioxide ligands such as 4,4′-bi­pyridine N,N′-dioxide (bpydo) in the synthesis of lanthanide compounds comprising coordination networks has been of recent inter­est (Dillner et al., 2010a ▸,b ▸; Hill et al., 2004 ▸, 2005a ▸,b ▸; Long et al., 2000 ▸, 2002 ▸). The coordination modes of aromatic N,N′-dioxide ligands are flexible; they may act as terminal ligands, end-on or end-to-end μ₂-bridges, μ₃-bridges, or μ₄-bridges (Lu et al., 2002 ▸; Ma et al., 2001 ▸, 2003 ▸; Zhang et al., 2004a ▸,b ▸). When acting as end-to-end μ₂-bridges, these ligands can display cis, gauche, or trans conformations where the ideal conformations have M—O⋯O—M torsion angles of 0, 90 and 180°, respectively (Sun et al., 2004 ▸). Furthermore, aromatic N,N′-dioxide ligands are able to participate in a variety of hydrogen-bonding inter­actions (González Mantero et al., 2006 ▸). Structure prediction with these ligands can be difficult, not only due to their flexible bonding modes and various hydrogen-bonding inter­actions, but also due to the influences of solvent and anion (Hill et al., 2005a ▸).

Structural commentary  

Three isostructural coordination networks of Ce, Pr, and Nd nitrate with 4,4′-bi­pyridine N,N′-dioxide (bpydo), [Ln(NO₃)₃(μ₂-bpydo)₂] [Ln = Ce (I), Pr (II), and Nd (III)] are reported. All three compounds are isostructural to the previously reported La analogue (Hill et al., 2004 ▸).

The asymmetric unit of [Ln(NO₃)₃(μ₂-bpydo)₂] contains one lanthanide cation, two end-to-end bridging μ₂-bpydo ligands, and three chelating nitrate anions. All atoms in the asymmetric unit lie on general positions (Fig. 1 ▸). The Ln ^III atoms have a coordination sphere defined by six oxygen atoms from chelating nitrate anions and four oxygen atoms from bpydo ligands. The ten oxygen atoms in the LnO₁₀ coordination environment form a distorted bi-capped square prism (Fig. 2 ▸). One of the ligands bridges in a nearly perfect cis conformation with an Lnl—O3⋯O4—Ln1^iv torsion angle of approximately 5° and a dihedral angle between the rings of approximately 33°. The other ligand bridges in a nearly perfect gauche conformation with an Lnl—O2⋯O1—Ln1ⁱⁱⁱ torsion angle of approximately 92° and a dihedral angle between the rings of approximately 28° (see Table 1 ▸). The bpydo ligands link the Ln ^III atoms, forming 4⁴ grid-like layers that are parallel to (01) (Fig. 3 ▸). Each layer inter­digitates with a symmetry-equivalent second layer related by a twofold screw axis. The nitrate anions chelate to the metal cations on one side of the 4⁴ grid and are directed towards the square void of the symmetry-related inter­digitated 4⁴ grid (Fig. 4 ▸).

Figure 1.

Coordination sphere around the Ce^III cation in the structure of (I), with displacement ellipsoids drawn at the 50% probability level. Dashed lines represent C—H⋯O inter­actions between neighboring bpydo ligands within the coordination sphere. [Symmetry codes: (i) x − , −y + , z − ; (ii) x, y − 1, z.]

Figure 2.

LnO₁₀ coordination environment forming a distorted bicapped square prism. [Symmetry codes: (i) x − , −y + , z − ; (ii) x, y − 1, z.]

Table 1. Selected geometric parameters (Å, °) for (I)–(III).

Dihedral angles are reported between the mean planes defined by the indicated aromatic rings. Cg1 is the centroid of the N3/C11–C15 ring.

		(I)	(II)	(III)
Ln⋯Ln distances
	Ln1⋯Ln1iii	13.3398 (13)	13.3127 (9)	13.3035 (5)
	Ln1⋯Ln1iv	13.2996 (11)	13.2634 (8)	13.2558 (4)
Dihedral angles
	N1/C1–C5⋯N2/C6–C10	27.387 (58)	28.041 (62)	28.471 (109)
	N3/C11–C15⋯N4/C16–C20	22.560 (50)	22.552 (55)	22.677 (93)
Torsion angles
	Ln1—O2⋯O1—Ln1iii	92.53 (6)	91.80 (6)	91.75 (11)
	Ln1—O3⋯O4—Ln1iv	5.38 (7)	4.86 (8)	4.87 (14)
π–π inter­actions for Cg1⋯Cg1x
	Centroid–centroid distance	3.7535 (10)	3.7465 (10)	3.7344 (17)
	Inter­planar distance	3.2830 (6)	3.2790 (7)	3.2815 (11)
	Slippage	1.820	1.810	1.783
	Cg1—H15x distance	3.305	3.312	3.311

Symmetry codes: (iii) x, y + 1, z; (iv) x + , −y + , z + ; (x) −x + , −y + , −z + 2.

Figure 3.

Diagram showing the 4⁴ grid-like layers that lie parallel to (01) in (I). Dashed lines represent C—H⋯O inter­actions between neighboring bpydo ligands within the Ce^III coordination sphere.

Figure 4.

Diagram showing the C—H⋯O inter­actions between anions and ligands of inter­digitated layers in (I). Individual layers are represented in green and blue. Dashed red lines represent C—H⋯O inter­actions between the layers. [Symmetry codes: (iii) x, y + 1, z; (v) −x + , y + , −z + ; (xi) x + , −y + , z + .]

While a roughly linear decrease in cell volume for a series of isostructural lanthanide compounds due to the lanthanide contraction may be expected (see, for example, He et al., 2005 ▸; Ji et al., 2012 ▸), deviations from a linear trend as observed for compounds (I)–(III) are not unprecedented, and the gradual decrease in Ln—X bond lengths and bridged Ln⋯Ln distances provides evidence of the lanthanide contraction (see, for example, Jia et al., 2013 ▸; Li et al., 2004 ▸, 2015 ▸). Recent studies on several series of isostructural lanthanide compounds have shown that the lanthanide contraction can be observed by the quadratic decay of the Ln—O bond lengths with increasing atomic number (Quadrelli, 2002 ▸; Seitz et al., 2007 ▸; Xu et al., 2013 ▸). An examination of both the Ln—O_bpydo and Ln—O_nitrate distances for compounds (I)–(III) shows the expected gradual decrease in the Ln—O bond lengths from Ce (I) to Nd (III) due to the lanthanide contraction (Table 2 ▸). The gradual decrease in bpydo-bridged Ln⋯Ln distances within the layers is also consistent with the radius contraction from Ce to Nd (Table 1 ▸).

Table 2. Selected bond lengths (Å) in compounds (I)–(III).

	Compound	(I)	(II)	(III)
Ln—O bond lengths involving bpydo ligands
	Ln1—O1ii	2.5464 (11)	2.5360 (12)	2.526 (2)
	Ln1—O2	2.5192 (11)	2.5009 (12)	2.488 (2)
	Ln1—O3	2.4685 (11)	2.4558 (11)	2.451 (2)
	Ln1—O4i	2.4692 (11)	2.4554 (12)	2.448 (2)
	Average Ln—O distances	2.501	2.487	2.478
Ln—O bond lengths involving chelating nitrate anions
	Ln1—O5	2.5929 (13)	2.5750 (13)	2.555 (2)
	Ln1—O6	2.6573 (13)	2.6443 (14)	2.640 (2)
	Ln1—O8	2.6004 (12)	2.5832 (13)	2.573 (2)
	Ln1—O9	2.6428 (12)	2.6242 (13)	2.615 (2)
	Ln1—O11	2.6231 (12)	2.6036 (12)	2.585 (2)
	Ln1—O12	2.6333 (11)	2.6147 (12)	2.597 (2)
	Average Ln—O distances	2.625	2.608	2.594

Symmetry codes: (i) x − , −y + , z − ; (ii) x, y − 1, z.

Supra­molecular features  

Stabilizing C—H⋯O inter­actions (C5—H5⋯O4^vii, C10—H10⋯O3, C15—H15⋯O1ⁱⁱ, and C20—H20⋯O2^iv) are observed between neighboring bpydo ligands within the coordination sphere of the Ln ^III cation (see Tables 3 ▸–5 ▸ ▸ for symmetry codes; Fig. 1 ▸). The inter­digitation of layers is promoted by C—H⋯O inter­actions (C1—H1⋯O5^v, C4—H4⋯O13^vi, C9—H9⋯O10^v, C11—H11⋯O10^v, C14—H14⋯O7^ix, C16—H16⋯O13^v, and C17—H17⋯O12^v) between the ligands of one layer and nitrate anions of the other layer (Fig. 4 ▸). Further C—H⋯O inter­actions (C9—H9⋯O9^viii and C10—H10⋯O7^viii) and π–π inter­actions between Cg1 and the inversion-related Cg1^x link each set of inter­digitated layers to symmetry-equivalent sets of layers above and below it [symmetry code: (x) −x + , −y + , −z + 2; Fig. 5 ▸). π–π inter­actions between the neighboring rings are observed with a centroid-to-centroid distance of 3.7535 (10) Å and an inter­planar distance of 3.2830 (6) Å for (I); there is a slippage of 1.820 Å such that H15^x of the neighboring N-oxide ring lies nearly centered over the centroid of Cg1 at a distance of 3.305 Å [see Table 1 ▸ for distances in compounds (II) and (III)].

Table 3. Hydrogen-bond geometry (Å, °) for (I) .

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯O5v	0.95	2.59	3.342 (2)	136
C4—H4⋯O13vi	0.95	2.37	3.208 (2)	148
C5—H5⋯O4vii	0.95	2.38	3.1868 (19)	142
C9—H9⋯O9viii	0.95	2.62	3.206 (2)	121
C9—H9⋯O10v	0.95	2.59	3.475 (2)	156
C10—H10⋯O3	0.95	2.32	3.128 (2)	143
C10—H10⋯O7viii	0.95	2.58	3.264 (2)	129
C11—H11⋯O10v	0.95	2.49	3.237 (2)	135
C14—H14⋯O7ix	0.95	2.22	3.004 (2)	139
C15—H15⋯O1ii	0.95	2.32	3.1069 (19)	140
C16—H16⋯O13v	0.95	2.55	3.154 (2)	122
C17—H17⋯O12v	0.95	2.36	3.2837 (19)	164
C20—H20⋯O2iv	0.95	2.63	3.3265 (19)	130

Symmetry codes: (ii) ; (iv) ; (v) ; (vi) ; (vii) ; (viii) ; (ix) .

Table 4. Hydrogen-bond geometry (Å, °) for (II) .

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯O5v	0.95	2.59	3.331 (2)	135
C4—H4⋯O13vi	0.95	2.36	3.200 (2)	147
C5—H5⋯O4vii	0.95	2.37	3.168 (2)	141
C9—H9⋯O9viii	0.95	2.61	3.204 (2)	121
C9—H9⋯O10v	0.95	2.58	3.468 (2)	156
C10—H10⋯O3	0.95	2.31	3.115 (2)	143
C10—H10⋯O7viii	0.95	2.60	3.277 (3)	129
C11—H11⋯O10v	0.95	2.50	3.239 (2)	135
C14—H14⋯O7ix	0.95	2.22	3.002 (2)	139
C15—H15⋯O1ii	0.95	2.31	3.0924 (19)	140
C16—H16⋯O13v	0.95	2.56	3.154 (2)	121
C17—H17⋯O12v	0.95	2.36	3.288 (2)	164
C20—H20⋯O2iv	0.95	2.62	3.307 (2)	130

Symmetry codes: (ii) ; (iv) ; (v) ; (vi) ; (vii) ; (viii) ; (ix) .

Table 5. Hydrogen-bond geometry (Å, °) for (III) .

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯O5v	0.95	2.61	3.353 (4)	135
C4—H4⋯O13vi	0.95	2.37	3.206 (4)	147
C5—H5⋯O4vii	0.95	2.37	3.163 (4)	141
C9—H9⋯O9viii	0.95	2.63	3.216 (4)	121
C9—H9⋯O10v	0.95	2.58	3.464 (4)	156
C10—H10⋯O3	0.95	2.30	3.110 (4)	142
C10—H10⋯O7viii	0.95	2.61	3.289 (4)	129
C11—H11⋯O10v	0.95	2.50	3.243 (4)	135
C14—H14⋯O7ix	0.95	2.21	2.998 (4)	139
C15—H15⋯O1ii	0.95	2.31	3.091 (4)	139
C16—H16⋯O13v	0.95	2.56	3.159 (4)	121
C17—H17⋯O12v	0.95	2.37	3.295 (4)	165
C20—H20⋯O2iv	0.95	2.61	3.294 (4)	130

Symmetry codes: (ii) ; (iv) ; (v) ; (vi) ; (vii) ; (viii) ; (ix) .

Figure 5.

Diagram showing C—H⋯O inter­actions and π–π inter­actions that link each set of inter­digitated layers to similar sets of layers above and below it in (I). Individual layers are represented in green and blue. Dashed red lines represent C—H⋯O inter­actions, and dashed black lines represent π–π inter­actions.

Database survey  

A survey of the Cambridge Structural Database (CSD, November 2014; Groom & Allen, 2014 ▸) returned hits for 333 structures with 4,4′-bi­pyridine N,N′-dioxide. Sixty three structures are reported where bpydo coordinates to a lanthanide metal and acts a as bridging ligand in a coordination network. Of these structures, ten are reported with nitrate as the counter-ion. In [Tb(bpydo)₂(NO₃)₃], linear chains are observed (Long et al., 2002 ▸). A one-dimensional network composed of zigzag chains is observed for [Tb(bpydo)(CH₃OH)(NO₃)₃] (Long et al., 2002 ▸). In {[Ln(bpydo)_1.5(NO₃)₃]·CH₂Cl₂} with Ln = Eu (Dillner et al., 2010a ▸), Gd (Dillner et al., 2010b ▸), and Tb (Long et al., 2002 ▸), a one-dimensional network composed of ladder-like chains is observed. [La(bpydo)₂(NO₃)₃] is a two-dimensional network composed of sheets with 4⁴ topology and is isostructural to the Ce, Pr, and Nd structures reported herein (Hill et al., 2004 ▸). In {[Er₂(bpydo)₃(NO₃)₆]·2CH₃OH}, {[Tb(bpydo)_1.5(NO₃)₃]·CH₃OH·0.8H₂O}, and {[Tb(bpydo)_1.5(NO₃)₃]·0.4CCl₄·0.8CH₃OH}, two-dimensional networks composed of sheets with 4.8² topology are formed (Long et al., 2000 ▸, 2002 ▸). In {[Sm(bpydo)₂(NO₃)₃]·0.5H₂O}, a twofold inter­penetrating three-dimensional network is formed (Long et al., 2000 ▸).

Synthesis and crystallization  

4,4′-bi­pyridine N,N′-dioxide·H₂O was synthesized from 4,4′-bi­pyridine according to the method of Simpson et al. (1963 ▸). All other chemicals were obtained from commercial sources and used without further purification. For the Ce, Pr and Nd compounds, respectively, the appropriate Ln(NO₃)₃·6H₂O (0.113 mmol) was placed in the bottom of a test tube and covered with CH₂Cl₂ (5 ml). 4,4′-Bi­pyridine-N,N′-dioxide·H₂O (0.0376 g, 0.182 mmol) was dissolved in methanol (8 ml), and this solution was layered over the CH₂Cl₂ solution. The two solutions were allowed to slowly mix. Over a period of several weeks the Ln(NO₃)₃·6H₂O dissolved, and red block-like crystals of [Ce(μ₂-bpydo)₂(NO₃)₃], yellow block-like crystals of [Pr(μ₂-bpydo)₂(NO₃)₃], and yellow block-like crystals of [Nd(μ₂-bpydo)₂(NO₃)₃] were formed.

Refinement  

All aromatic H atoms were positioned geometrically and refined using a riding model with C—H = 0.95 Å and with U _iso(H) = 1.2U _eq(C). Crystal data, data collection and structure refinement details are summarized in Table 6 ▸.

Table 6. Experimental details.

	(I)	(II)	(III)
Crystal data
Chemical formula	[Ce(NO3)3(C10H8N2O2)2]	[Pr(NO3)3(C10H8N2O2)2]	[Nd(NO3)3(C10H8N2O2)2]
M r	702.52	703.31	706.64
Crystal system, space group	Monoclinic, C2/c	Monoclinic, C2/c	Monoclinic, C2/c
Temperature (K)	173	173	173
a, b, c (Å)	26.786 (3), 13.3398 (13), 13.7571 (13)	26.7416 (18), 13.3127 (9), 13.7586 (9)	26.7422 (10), 13.3035 (5), 13.7804 (5)
β (°)	105.837 (1)	105.981 (1)	106.065 (1)
V (Å3)	4729.1 (8)	4708.8 (5)	4711.1 (3)
Z	8	8	8
Radiation type	Mo Kα	Mo Kα	Mo Kα
μ (mm−1)	2.01	2.16	2.29
Crystal size (mm)	0.55 × 0.45 × 0.38	0.55 × 0.37 × 0.26	0.14 × 0.12 × 0.08
Data collection
Diffractometer	Bruker APEXII CCD	Bruker APEXII CCD	Bruker D8 Quest CMOS
Absorption correction	Multi-scan (SADABS; Bruker, 2009 ▸)	Multi-scan (SADABS; Bruker, 2009 ▸ ▸)	Multi-scan (SADABS; Bruker, 2009 ▸ ▸)
T min, T max	0.536, 0.746	0.579, 0.746	0.682, 0.747
No. of measured, independent and observed [I > 2σ(I)] reflections	15990, 7152, 6686	18363, 7241, 6782	47148, 8277, 5419
R int	0.018	0.020	0.115
(sin θ/λ)max (Å−1)	0.735	0.737	0.777
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.020, 0.050, 1.05	0.021, 0.052, 1.05	0.051, 0.067, 1.01
No. of reflections	7152	7241	8277
No. of parameters	370	370	370
H-atom treatment	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	1.10, −0.65	0.89, −1.06	1.49, −1.29

Computer programs: APEX2 and SAINT (Bruker, 2009 ▸, 2014 ▸), SHELXS97 (Sheldrick, 2008 ▸), SHELXL2014 (Sheldrick, 2015 ▸) and X-SEED (Barbour, 2001 ▸).

Supplementary Material

CCDC references: 1440109, 1440108, 1440107

Additional supporting information: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

(I) Poly[[tris(nitrato-κ²O,O')cerium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Crystal data

[Ce(NO3)3(C10H8N2O2)2]	F(000) = 2776
Mr = 702.52	Dx = 1.973 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 26.786 (3) Å	Cell parameters from 11055 reflections
b = 13.3398 (13) Å	θ = 2.5–31.5°
c = 13.7571 (13) Å	µ = 2.01 mm−1
β = 105.837 (1)°	T = 173 K
V = 4729.1 (8) Å3	Block, red
Z = 8	0.55 × 0.45 × 0.38 mm

(I) Poly[[tris(nitrato-κ²O,O')cerium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Data collection

Bruker APEXII CCD diffractometer	6686 reflections with I > 2σ(I)
phi and ω scans	Rint = 0.018
Absorption correction: multi-scan (SADABS; Bruker, 2009)	θmax = 31.5°, θmin = 1.6°
Tmin = 0.536, Tmax = 0.746	h = −37→37
15990 measured reflections	k = −11→19
7152 independent reflections	l = −20→19

(I) Poly[[tris(nitrato-κ²O,O')cerium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.020	H-atom parameters constrained
wR(F2) = 0.050	w = 1/[σ2(Fo2) + (0.0231P)2 + 5.9858P] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max = 0.002
7152 reflections	Δρmax = 1.10 e Å−3
370 parameters	Δρmin = −0.65 e Å−3

(I) Poly[[tris(nitrato-κ²O,O')cerium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

(I) Poly[[tris(nitrato-κ²O,O')cerium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Ce1	0.12666 (2)	0.27581 (2)	0.66455 (2)	0.00880 (3)
O1	0.14943 (4)	1.12935 (8)	0.78743 (9)	0.0138 (2)
O2	0.07510 (4)	0.41815 (8)	0.70896 (9)	0.0154 (2)
O3	0.18037 (4)	0.33380 (8)	0.83061 (8)	0.0131 (2)
O4	0.54328 (4)	0.28358 (8)	1.18738 (9)	0.0126 (2)
O5	0.19329 (6)	0.41286 (11)	0.65215 (10)	0.0288 (3)
O6	0.12041 (6)	0.42801 (10)	0.53717 (11)	0.0267 (3)
O7	0.18842 (7)	0.50937 (10)	0.52255 (12)	0.0365 (4)
O8	0.21266 (5)	0.18687 (11)	0.66189 (9)	0.0221 (3)
O9	0.16939 (5)	0.24235 (9)	0.51565 (9)	0.0157 (2)
O10	0.23607 (5)	0.14464 (9)	0.52773 (9)	0.0195 (2)
O11	0.05806 (5)	0.25187 (9)	0.48914 (9)	0.0162 (2)
O12	0.09542 (4)	0.11414 (8)	0.55499 (8)	0.0148 (2)
O13	0.03572 (5)	0.11024 (10)	0.41152 (9)	0.0217 (3)
N1	0.14037 (5)	1.03162 (9)	0.77682 (9)	0.0113 (2)
N2	0.08640 (5)	0.51564 (10)	0.71907 (10)	0.0134 (2)
N3	0.23131 (5)	0.32751 (10)	0.87085 (9)	0.0109 (2)
N4	0.49487 (5)	0.28718 (9)	1.12873 (10)	0.0111 (2)
N5	0.16766 (7)	0.45133 (11)	0.56933 (12)	0.0253 (3)
N6	0.20687 (5)	0.19053 (10)	0.56676 (10)	0.0145 (2)
N7	0.06262 (5)	0.15808 (10)	0.48319 (9)	0.0137 (2)
C1	0.18034 (6)	0.96562 (12)	0.79956 (12)	0.0142 (3)
H1	0.2150	0.9895	0.8219	0.017*
C2	0.17085 (6)	0.86374 (12)	0.79041 (12)	0.0144 (3)
H2	0.1991	0.8180	0.8075	0.017*
C3	0.12012 (6)	0.82731 (11)	0.75622 (11)	0.0121 (3)
C4	0.08022 (6)	0.89772 (12)	0.73462 (12)	0.0137 (3)
H4	0.0452	0.8759	0.7115	0.016*
C5	0.09092 (6)	0.99873 (12)	0.74644 (12)	0.0136 (3)
H5	0.0632	1.0457	0.7331	0.016*
C6	0.05307 (6)	0.58316 (12)	0.66253 (13)	0.0171 (3)
H6	0.0225	0.5606	0.6144	0.021*
C7	0.06325 (6)	0.68421 (12)	0.67436 (12)	0.0165 (3)
H7	0.0393	0.7310	0.6351	0.020*
C8	0.10854 (6)	0.71893 (11)	0.74362 (12)	0.0124 (3)
C9	0.14170 (6)	0.64712 (12)	0.80061 (12)	0.0162 (3)
H9	0.1727	0.6677	0.8485	0.019*
C10	0.12988 (6)	0.54644 (12)	0.78811 (13)	0.0172 (3)
H10	0.1525	0.4984	0.8284	0.021*
C11	0.25885 (6)	0.41124 (11)	0.90585 (11)	0.0128 (3)
H11	0.2421	0.4747	0.8972	0.015*
C12	0.31105 (6)	0.40468 (12)	0.95406 (11)	0.0131 (3)
H12	0.3300	0.4637	0.9793	0.016*
C13	0.33644 (6)	0.31212 (11)	0.96620 (11)	0.0117 (3)
C14	0.30687 (6)	0.22856 (11)	0.92576 (12)	0.0137 (3)
H14	0.3231	0.1647	0.9302	0.016*
C15	0.25463 (6)	0.23682 (11)	0.87958 (12)	0.0132 (3)
H15	0.2349	0.1788	0.8538	0.016*
C16	0.47610 (6)	0.37514 (11)	1.08504 (11)	0.0131 (3)
H16	0.4985	0.4315	1.0918	0.016*
C17	0.42495 (6)	0.38381 (12)	1.03088 (12)	0.0135 (3)
H17	0.4122	0.4460	1.0004	0.016*
C18	0.39170 (6)	0.30199 (11)	1.02043 (11)	0.0115 (3)
C19	0.41282 (6)	0.21126 (11)	1.06413 (12)	0.0125 (3)
H19	0.3915	0.1534	1.0567	0.015*
C20	0.46424 (6)	0.20521 (12)	1.11776 (12)	0.0129 (3)
H20	0.4782	0.1433	1.1471	0.015*

(I) Poly[[tris(nitrato-κ²O,O')cerium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Ce1	0.00749 (4)	0.00690 (4)	0.01083 (4)	−0.00080 (3)	0.00051 (3)	−0.00044 (2)
O1	0.0156 (5)	0.0062 (5)	0.0175 (5)	−0.0020 (4)	0.0008 (4)	−0.0001 (4)
O2	0.0164 (5)	0.0053 (5)	0.0237 (6)	−0.0017 (4)	0.0043 (4)	−0.0023 (4)
O3	0.0069 (4)	0.0139 (5)	0.0155 (5)	0.0001 (4)	−0.0021 (4)	−0.0013 (4)
O4	0.0063 (5)	0.0135 (5)	0.0158 (5)	0.0010 (4)	−0.0008 (4)	0.0013 (4)
O5	0.0369 (8)	0.0279 (7)	0.0231 (6)	−0.0185 (6)	0.0107 (6)	−0.0048 (5)
O6	0.0349 (7)	0.0180 (6)	0.0309 (7)	0.0042 (5)	0.0152 (6)	0.0061 (5)
O7	0.0665 (11)	0.0128 (6)	0.0464 (9)	−0.0089 (7)	0.0427 (8)	−0.0018 (6)
O8	0.0195 (6)	0.0320 (7)	0.0146 (5)	0.0088 (5)	0.0041 (4)	0.0025 (5)
O9	0.0138 (5)	0.0163 (5)	0.0164 (5)	0.0019 (4)	0.0030 (4)	0.0025 (4)
O10	0.0201 (6)	0.0183 (6)	0.0224 (6)	0.0039 (5)	0.0094 (5)	−0.0015 (5)
O11	0.0169 (5)	0.0131 (5)	0.0170 (5)	0.0016 (4)	0.0018 (4)	0.0001 (4)
O12	0.0154 (5)	0.0117 (5)	0.0151 (5)	0.0000 (4)	0.0006 (4)	−0.0010 (4)
O13	0.0184 (6)	0.0261 (6)	0.0167 (5)	−0.0039 (5)	−0.0016 (4)	−0.0090 (5)
N1	0.0129 (6)	0.0079 (5)	0.0118 (5)	−0.0016 (4)	0.0010 (4)	0.0003 (4)
N2	0.0141 (6)	0.0084 (6)	0.0170 (6)	−0.0003 (5)	0.0033 (5)	−0.0013 (5)
N3	0.0083 (5)	0.0115 (6)	0.0115 (5)	0.0001 (4)	0.0002 (4)	−0.0002 (4)
N4	0.0081 (5)	0.0116 (6)	0.0127 (6)	0.0007 (4)	0.0014 (4)	0.0008 (4)
N5	0.0444 (10)	0.0104 (6)	0.0298 (8)	−0.0066 (6)	0.0244 (7)	−0.0040 (6)
N6	0.0132 (6)	0.0139 (6)	0.0163 (6)	−0.0010 (5)	0.0041 (5)	−0.0004 (5)
N7	0.0119 (6)	0.0169 (6)	0.0117 (5)	−0.0021 (5)	0.0023 (4)	−0.0028 (5)
C1	0.0113 (6)	0.0125 (7)	0.0170 (7)	0.0000 (5)	0.0005 (5)	0.0002 (5)
C2	0.0129 (6)	0.0117 (7)	0.0172 (7)	0.0012 (5)	0.0017 (5)	−0.0002 (5)
C3	0.0147 (7)	0.0083 (6)	0.0117 (6)	−0.0010 (5)	0.0012 (5)	−0.0007 (5)
C4	0.0118 (6)	0.0112 (7)	0.0163 (7)	−0.0011 (5)	0.0010 (5)	0.0003 (5)
C5	0.0113 (6)	0.0112 (7)	0.0163 (7)	0.0002 (5)	0.0005 (5)	0.0007 (5)
C6	0.0155 (7)	0.0120 (7)	0.0196 (7)	−0.0009 (6)	−0.0025 (6)	0.0000 (6)
C7	0.0172 (7)	0.0103 (7)	0.0186 (7)	0.0005 (6)	−0.0010 (6)	0.0018 (6)
C8	0.0143 (7)	0.0084 (6)	0.0139 (7)	−0.0009 (5)	0.0029 (5)	−0.0007 (5)
C9	0.0145 (7)	0.0103 (7)	0.0201 (7)	0.0001 (5)	−0.0015 (6)	−0.0015 (6)
C10	0.0134 (7)	0.0105 (7)	0.0237 (8)	0.0010 (6)	−0.0018 (6)	0.0005 (6)
C11	0.0112 (6)	0.0095 (6)	0.0164 (7)	0.0001 (5)	0.0014 (5)	−0.0014 (5)
C12	0.0099 (6)	0.0111 (6)	0.0163 (7)	−0.0008 (5)	0.0002 (5)	−0.0029 (5)
C13	0.0096 (6)	0.0128 (7)	0.0114 (6)	0.0002 (5)	0.0006 (5)	0.0003 (5)
C14	0.0118 (7)	0.0101 (7)	0.0170 (7)	0.0008 (5)	0.0002 (5)	0.0005 (5)
C15	0.0122 (7)	0.0093 (6)	0.0159 (7)	0.0002 (5)	0.0004 (5)	−0.0004 (5)
C16	0.0108 (6)	0.0112 (6)	0.0158 (7)	−0.0002 (5)	0.0010 (5)	0.0028 (5)
C17	0.0115 (6)	0.0116 (6)	0.0161 (7)	0.0009 (5)	0.0017 (5)	0.0033 (5)
C18	0.0094 (6)	0.0124 (6)	0.0118 (6)	0.0007 (5)	0.0014 (5)	0.0009 (5)
C19	0.0114 (6)	0.0104 (6)	0.0145 (7)	−0.0006 (5)	0.0015 (5)	0.0009 (5)
C20	0.0121 (6)	0.0102 (6)	0.0151 (7)	0.0000 (5)	0.0017 (5)	0.0010 (5)

(I) Poly[[tris(nitrato-κ²O,O')cerium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Geometric parameters (Å, º)

Ce1—O3	2.4685 (11)	C1—H1	0.9500
Ce1—O4i	2.4692 (11)	C2—C3	1.398 (2)
Ce1—O2	2.5192 (11)	C2—H2	0.9500
Ce1—O1ii	2.5464 (11)	C3—C4	1.393 (2)
Ce1—O5	2.5929 (13)	C3—C8	1.479 (2)
Ce1—O8	2.6004 (12)	C4—C5	1.378 (2)
Ce1—O11	2.6231 (12)	C4—H4	0.9500
Ce1—O12	2.6333 (11)	C5—H5	0.9500
Ce1—O9	2.6428 (12)	C6—C7	1.376 (2)
Ce1—O6	2.6573 (13)	C6—H6	0.9500
O1—N1	1.3268 (16)	C7—C8	1.401 (2)
O1—Ce1iii	2.5464 (11)	C7—H7	0.9500
O2—N2	1.3339 (16)	C8—C9	1.393 (2)
O3—N3	1.3277 (15)	C9—C10	1.380 (2)
O4—N4	1.3281 (16)	C9—H9	0.9500
O4—Ce1iv	2.4694 (11)	C10—H10	0.9500
O5—N5	1.267 (2)	C11—C12	1.377 (2)
O6—N5	1.260 (2)	C11—H11	0.9500
O7—N5	1.2321 (19)	C12—C13	1.398 (2)
O8—N6	1.2761 (18)	C12—H12	0.9500
O9—N6	1.2629 (18)	C13—C14	1.393 (2)
O10—N6	1.2264 (17)	C13—C18	1.471 (2)
O11—N7	1.2619 (18)	C14—C15	1.374 (2)
O12—N7	1.2718 (17)	C14—H14	0.9500
O13—N7	1.2292 (17)	C15—H15	0.9500
N1—C5	1.3490 (19)	C16—C17	1.374 (2)
N1—C1	1.355 (2)	C16—H16	0.9500
N2—C10	1.350 (2)	C17—C18	1.391 (2)
N2—C6	1.354 (2)	C17—H17	0.9500
N3—C15	1.3517 (19)	C18—C19	1.400 (2)
N3—C11	1.3527 (19)	C19—C20	1.376 (2)
N4—C20	1.3504 (19)	C19—H19	0.9500
N4—C16	1.3512 (19)	C20—H20	0.9500
C1—C2	1.382 (2)
O3—Ce1—O4i	107.56 (4)	O7—N5—O5	120.87 (18)
O3—Ce1—O2	76.05 (4)	O6—N5—O5	117.48 (14)
O4i—Ce1—O2	68.67 (4)	O10—N6—O9	122.32 (13)
O3—Ce1—O1ii	69.67 (4)	O10—N6—O8	121.08 (14)
O4i—Ce1—O1ii	74.36 (4)	O9—N6—O8	116.59 (13)
O2—Ce1—O1ii	117.72 (4)	O13—N7—O11	121.39 (14)
O3—Ce1—O5	66.55 (4)	O13—N7—O12	120.88 (14)
O4i—Ce1—O5	153.81 (4)	O11—N7—O12	117.72 (12)
O2—Ce1—O5	85.25 (4)	N1—C1—C2	120.25 (14)
O1ii—Ce1—O5	122.70 (4)	N1—C1—H1	119.9
O3—Ce1—O8	82.02 (4)	C2—C1—H1	119.9
O4i—Ce1—O8	133.70 (4)	C1—C2—C3	120.67 (14)
O2—Ce1—O8	153.34 (4)	C1—C2—H2	119.7
O1ii—Ce1—O8	66.84 (4)	C3—C2—H2	119.7
O5—Ce1—O8	72.09 (5)	C4—C3—C2	117.13 (14)
O3—Ce1—O11	167.04 (4)	C4—C3—C8	120.68 (14)
O4i—Ce1—O11	69.34 (4)	C2—C3—C8	122.18 (14)
O2—Ce1—O11	91.27 (4)	C5—C4—C3	120.78 (14)
O1ii—Ce1—O11	119.87 (4)	C5—C4—H4	119.6
O5—Ce1—O11	110.32 (4)	C3—C4—H4	119.6
O8—Ce1—O11	109.41 (4)	N1—C5—C4	120.64 (14)
O3—Ce1—O12	143.16 (4)	N1—C5—H5	119.7
O4i—Ce1—O12	69.69 (4)	C4—C5—H5	119.7
O2—Ce1—O12	130.28 (4)	N2—C6—C7	120.35 (15)
O1ii—Ce1—O12	74.50 (4)	N2—C6—H6	119.8
O5—Ce1—O12	131.05 (4)	C7—C6—H6	119.8
O8—Ce1—O12	76.27 (4)	C6—C7—C8	120.73 (15)
O11—Ce1—O12	48.73 (4)	C6—C7—H7	119.6
O3—Ce1—O9	120.26 (4)	C8—C7—H7	119.6
O4i—Ce1—O9	129.97 (4)	C9—C8—C7	117.14 (14)
O2—Ce1—O9	134.21 (4)	C9—C8—C3	121.68 (14)
O1ii—Ce1—O9	108.00 (4)	C7—C8—C3	121.18 (14)
O5—Ce1—O9	67.46 (4)	C10—C9—C8	120.65 (15)
O8—Ce1—O9	48.65 (4)	C10—C9—H9	119.7
O11—Ce1—O9	67.00 (4)	C8—C9—H9	119.7
O12—Ce1—O9	63.59 (4)	N2—C10—C9	120.55 (14)
O3—Ce1—O6	106.67 (4)	N2—C10—H10	119.7
O4i—Ce1—O6	115.64 (4)	C9—C10—H10	119.7
O2—Ce1—O6	69.15 (4)	N3—C11—C12	120.16 (14)
O1ii—Ce1—O6	169.94 (4)	N3—C11—H11	119.9
O5—Ce1—O6	48.58 (5)	C12—C11—H11	119.9
O8—Ce1—O6	103.65 (4)	C11—C12—C13	120.71 (14)
O11—Ce1—O6	65.43 (4)	C11—C12—H12	119.6
O12—Ce1—O6	107.17 (4)	C13—C12—H12	119.6
O9—Ce1—O6	65.20 (4)	C14—C13—C12	117.02 (14)
N1—O1—Ce1iii	132.64 (9)	C14—C13—C18	120.87 (14)
N2—O2—Ce1	129.52 (9)	C12—C13—C18	122.11 (14)
N3—O3—Ce1	129.72 (9)	C15—C14—C13	121.13 (14)
N4—O4—Ce1iv	134.54 (9)	C15—C14—H14	119.4
N5—O5—Ce1	97.52 (10)	C13—C14—H14	119.4
N5—O6—Ce1	94.62 (10)	N3—C15—C14	120.03 (14)
N6—O8—Ce1	97.86 (9)	N3—C15—H15	120.0
N6—O9—Ce1	96.18 (9)	C14—C15—H15	120.0
N7—O11—Ce1	97.15 (8)	N4—C16—C17	120.61 (14)
N7—O12—Ce1	96.39 (8)	N4—C16—H16	119.7
O1—N1—C5	119.22 (13)	C17—C16—H16	119.7
O1—N1—C1	120.25 (13)	C16—C17—C18	120.36 (14)
C5—N1—C1	120.49 (13)	C16—C17—H17	119.8
O2—N2—C10	119.84 (13)	C18—C17—H17	119.8
O2—N2—C6	119.56 (13)	C17—C18—C19	117.49 (14)
C10—N2—C6	120.56 (14)	C17—C18—C13	120.50 (14)
O3—N3—C15	119.41 (13)	C19—C18—C13	122.01 (14)
O3—N3—C11	119.65 (12)	C20—C19—C18	120.59 (14)
C15—N3—C11	120.89 (13)	C20—C19—H19	119.7
O4—N4—C20	120.08 (12)	C18—C19—H19	119.7
O4—N4—C16	118.99 (12)	N4—C20—C19	120.07 (14)
C20—N4—C16	120.83 (13)	N4—C20—H20	120.0
O7—N5—O6	121.65 (18)	C19—C20—H20	120.0
Ce1—O3—O4—Ce1iv	5.38 (7)	Ce1—O2—O1—Ce1iii	92.53 (6)

Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) x, y−1, z; (iii) x, y+1, z; (iv) x+1/2, −y+1/2, z+1/2.

(I) Poly[[tris(nitrato-κ²O,O')cerium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···O5v	0.95	2.59	3.342 (2)	136
C4—H4···O13vi	0.95	2.37	3.208 (2)	148
C5—H5···O4vii	0.95	2.38	3.1868 (19)	142
C9—H9···O9viii	0.95	2.62	3.206 (2)	121
C9—H9···O10v	0.95	2.59	3.475 (2)	156
C10—H10···O3	0.95	2.32	3.128 (2)	143
C10—H10···O7viii	0.95	2.58	3.264 (2)	129
C11—H11···O10v	0.95	2.49	3.237 (2)	135
C14—H14···O7ix	0.95	2.22	3.004 (2)	139
C15—H15···O1ii	0.95	2.32	3.1069 (19)	140
C16—H16···O13v	0.95	2.55	3.154 (2)	122
C17—H17···O12v	0.95	2.36	3.2837 (19)	164
C20—H20···O2iv	0.95	2.63	3.3265 (19)	130

Symmetry codes: (ii) x, y−1, z; (iv) x+1/2, −y+1/2, z+1/2; (v) −x+1/2, y+1/2, −z+3/2; (vi) −x, −y+1, −z+1; (vii) x−1/2, −y+3/2, z−1/2; (viii) x, −y+1, z+1/2; (ix) −x+1/2, y−1/2, −z+3/2.

(II) Poly[[tris(nitrato-κ²O,O')praeseodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Crystal data

[Pr(NO3)3(C10H8N2O2)2]	F(000) = 2784
Mr = 703.31	Dx = 1.984 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 11450 reflections
a = 26.7416 (18) Å	θ = 2.5–31.3°
b = 13.3127 (9) Å	µ = 2.16 mm−1
c = 13.7586 (9) Å	T = 173 K
β = 105.981 (1)°	Block, yellow
V = 4708.8 (5) Å3	0.55 × 0.37 × 0.26 mm
Z = 8

(II) Poly[[tris(nitrato-κ²O,O')praeseodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Data collection

Bruker APEXII CCD diffractometer	7241 independent reflections
Radiation source: sealed tube	6782 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
phi and ω scans	θmax = 31.6°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −39→38
Tmin = 0.579, Tmax = 0.746	k = −18→18
18363 measured reflections	l = −19→15

(II) Poly[[tris(nitrato-κ²O,O')praeseodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.021	H-atom parameters constrained
wR(F2) = 0.052	w = 1/[σ2(Fo2) + (0.0248P)2 + 6.7123P] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max = 0.003
7241 reflections	Δρmax = 0.89 e Å−3
370 parameters	Δρmin = −1.06 e Å−3

(II) Poly[[tris(nitrato-κ²O,O')praeseodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

(II) Poly[[tris(nitrato-κ²O,O')praeseodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Pr1	0.12674 (2)	0.27553 (2)	0.66470 (2)	0.00790 (3)
O1	0.14910 (4)	1.12982 (8)	0.78780 (9)	0.0121 (2)
O2	0.07540 (5)	0.41686 (8)	0.70889 (10)	0.0138 (2)
O3	0.17985 (4)	0.33321 (9)	0.83058 (9)	0.0115 (2)
O4	0.54388 (4)	0.28390 (8)	1.18793 (9)	0.0111 (2)
O5	0.19376 (6)	0.41071 (11)	0.65327 (11)	0.0253 (3)
O6	0.12068 (6)	0.42773 (10)	0.53849 (11)	0.0236 (3)
O7	0.18928 (7)	0.50822 (10)	0.52428 (13)	0.0324 (4)
O8	0.21197 (5)	0.18554 (11)	0.66227 (10)	0.0196 (3)
O9	0.16890 (5)	0.24298 (10)	0.51644 (10)	0.0144 (2)
O10	0.23564 (5)	0.14508 (10)	0.52791 (10)	0.0181 (2)
O11	0.05832 (5)	0.25265 (10)	0.49034 (9)	0.0144 (2)
O12	0.09581 (4)	0.11451 (9)	0.55595 (9)	0.0135 (2)
O13	0.03605 (5)	0.11082 (10)	0.41182 (10)	0.0198 (3)
N1	0.14024 (5)	1.03189 (10)	0.77697 (10)	0.0100 (2)
N2	0.08667 (5)	0.51456 (10)	0.71901 (11)	0.0117 (2)
N3	0.23089 (5)	0.32704 (10)	0.87050 (10)	0.0096 (2)
N4	0.49530 (5)	0.28712 (10)	1.12884 (11)	0.0097 (2)
N5	0.16820 (7)	0.45013 (11)	0.57063 (13)	0.0219 (3)
N6	0.20645 (5)	0.19037 (11)	0.56710 (11)	0.0129 (3)
N7	0.06291 (5)	0.15870 (11)	0.48410 (10)	0.0124 (3)
C1	0.18032 (6)	0.96583 (12)	0.79944 (13)	0.0127 (3)
H1	0.2151	0.9899	0.8217	0.015*
C2	0.17102 (6)	0.86383 (12)	0.79021 (13)	0.0130 (3)
H2	0.1994	0.8182	0.8072	0.016*
C3	0.12013 (6)	0.82702 (12)	0.75610 (12)	0.0106 (3)
C4	0.07981 (6)	0.89758 (12)	0.73481 (13)	0.0126 (3)
H4	0.0447	0.8756	0.7120	0.015*
C5	0.09060 (6)	0.99871 (12)	0.74667 (12)	0.0120 (3)
H5	0.0628	1.0457	0.7334	0.014*
C6	0.05349 (6)	0.58208 (12)	0.66223 (13)	0.0152 (3)
H6	0.0230	0.5593	0.6138	0.018*
C7	0.06337 (6)	0.68346 (12)	0.67370 (13)	0.0145 (3)
H7	0.0394	0.7301	0.6340	0.017*
C8	0.10860 (6)	0.71840 (11)	0.74358 (13)	0.0109 (3)
C9	0.14177 (6)	0.64669 (12)	0.80127 (13)	0.0149 (3)
H9	0.1727	0.6674	0.8499	0.018*
C10	0.12999 (6)	0.54590 (12)	0.78830 (14)	0.0154 (3)
H10	0.1527	0.4979	0.8288	0.019*
C11	0.25850 (6)	0.41103 (12)	0.90557 (12)	0.0116 (3)
H11	0.2417	0.4746	0.8969	0.014*
C12	0.31102 (6)	0.40482 (12)	0.95382 (13)	0.0120 (3)
H12	0.3300	0.4640	0.9790	0.014*
C13	0.33636 (6)	0.31196 (12)	0.96590 (12)	0.0100 (3)
C14	0.30678 (6)	0.22808 (11)	0.92570 (13)	0.0122 (3)
H14	0.3231	0.1642	0.9302	0.015*
C15	0.25433 (6)	0.23623 (12)	0.87957 (13)	0.0116 (3)
H15	0.2346	0.1780	0.8540	0.014*
C16	0.47654 (6)	0.37537 (12)	1.08487 (12)	0.0117 (3)
H16	0.4990	0.4318	1.0914	0.014*
C17	0.42522 (6)	0.38374 (12)	1.03083 (13)	0.0120 (3)
H17	0.4124	0.4461	1.0005	0.014*
C18	0.39185 (6)	0.30165 (12)	1.02012 (12)	0.0102 (3)
C19	0.41298 (6)	0.21084 (12)	1.06397 (13)	0.0113 (3)
H19	0.3916	0.1528	1.0566	0.014*
C20	0.46461 (6)	0.20508 (12)	1.11778 (13)	0.0116 (3)
H20	0.4787	0.1431	1.1472	0.014*

(II) Poly[[tris(nitrato-κ²O,O')praeseodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Pr1	0.00728 (4)	0.00661 (4)	0.00934 (5)	−0.00065 (2)	0.00148 (3)	−0.00049 (3)
O1	0.0148 (5)	0.0056 (5)	0.0146 (5)	−0.0022 (4)	0.0018 (4)	−0.0004 (4)
O2	0.0154 (5)	0.0052 (5)	0.0209 (6)	−0.0015 (4)	0.0053 (5)	−0.0021 (4)
O3	0.0063 (4)	0.0124 (5)	0.0137 (5)	0.0004 (4)	−0.0007 (4)	−0.0013 (4)
O4	0.0065 (5)	0.0123 (5)	0.0129 (5)	0.0013 (4)	0.0001 (4)	0.0010 (4)
O5	0.0328 (7)	0.0242 (7)	0.0209 (7)	−0.0155 (6)	0.0106 (6)	−0.0031 (6)
O6	0.0300 (7)	0.0164 (6)	0.0278 (7)	0.0033 (5)	0.0139 (6)	0.0046 (5)
O7	0.0589 (10)	0.0118 (6)	0.0418 (9)	−0.0076 (6)	0.0397 (8)	−0.0016 (6)
O8	0.0178 (6)	0.0292 (7)	0.0122 (6)	0.0078 (5)	0.0046 (5)	0.0029 (5)
O9	0.0129 (5)	0.0150 (5)	0.0146 (6)	0.0029 (4)	0.0029 (4)	0.0024 (5)
O10	0.0188 (6)	0.0181 (6)	0.0205 (6)	0.0040 (5)	0.0105 (5)	−0.0012 (5)
O11	0.0149 (5)	0.0119 (5)	0.0152 (6)	0.0010 (4)	0.0020 (5)	−0.0003 (5)
O12	0.0145 (5)	0.0112 (5)	0.0130 (5)	0.0008 (4)	0.0009 (4)	−0.0001 (4)
O13	0.0181 (6)	0.0232 (7)	0.0154 (6)	−0.0038 (5)	0.0000 (5)	−0.0078 (5)
N1	0.0129 (6)	0.0075 (6)	0.0094 (6)	−0.0014 (4)	0.0024 (5)	0.0000 (5)
N2	0.0128 (6)	0.0068 (6)	0.0157 (6)	−0.0005 (4)	0.0043 (5)	−0.0013 (5)
N3	0.0079 (5)	0.0102 (6)	0.0102 (6)	0.0001 (4)	0.0016 (4)	0.0000 (5)
N4	0.0077 (5)	0.0109 (6)	0.0106 (6)	0.0006 (4)	0.0028 (5)	0.0003 (5)
N5	0.0391 (9)	0.0081 (6)	0.0260 (8)	−0.0043 (6)	0.0216 (7)	−0.0035 (6)
N6	0.0121 (6)	0.0125 (6)	0.0148 (7)	0.0002 (5)	0.0048 (5)	0.0000 (5)
N7	0.0112 (6)	0.0152 (6)	0.0108 (6)	−0.0018 (5)	0.0031 (5)	−0.0029 (5)
C1	0.0107 (6)	0.0121 (7)	0.0146 (7)	0.0003 (5)	0.0022 (6)	−0.0003 (6)
C2	0.0119 (7)	0.0112 (7)	0.0146 (7)	0.0012 (5)	0.0017 (6)	−0.0009 (6)
C3	0.0137 (7)	0.0072 (6)	0.0107 (7)	−0.0007 (5)	0.0031 (5)	0.0000 (5)
C4	0.0113 (6)	0.0105 (7)	0.0149 (7)	−0.0007 (5)	0.0018 (6)	0.0007 (6)
C5	0.0120 (6)	0.0094 (7)	0.0137 (7)	0.0001 (5)	0.0021 (6)	0.0006 (6)
C6	0.0141 (7)	0.0111 (7)	0.0176 (8)	−0.0016 (5)	−0.0005 (6)	0.0007 (6)
C7	0.0157 (7)	0.0101 (7)	0.0152 (8)	−0.0006 (5)	−0.0001 (6)	0.0009 (6)
C8	0.0132 (7)	0.0077 (7)	0.0120 (7)	−0.0002 (5)	0.0037 (6)	−0.0009 (5)
C9	0.0135 (7)	0.0100 (7)	0.0186 (8)	0.0001 (5)	−0.0001 (6)	−0.0010 (6)
C10	0.0132 (7)	0.0095 (7)	0.0205 (8)	0.0013 (5)	−0.0006 (6)	0.0006 (6)
C11	0.0111 (6)	0.0084 (6)	0.0143 (7)	0.0001 (5)	0.0018 (6)	−0.0010 (6)
C12	0.0100 (6)	0.0097 (7)	0.0152 (7)	−0.0013 (5)	0.0019 (5)	−0.0015 (6)
C13	0.0086 (6)	0.0111 (7)	0.0100 (7)	−0.0006 (5)	0.0019 (5)	0.0004 (5)
C14	0.0113 (7)	0.0088 (7)	0.0151 (7)	0.0003 (5)	0.0015 (6)	0.0003 (6)
C15	0.0113 (7)	0.0082 (6)	0.0141 (7)	0.0000 (5)	0.0011 (6)	−0.0001 (6)
C16	0.0100 (6)	0.0099 (7)	0.0148 (7)	−0.0002 (5)	0.0027 (5)	0.0027 (6)
C17	0.0102 (6)	0.0097 (7)	0.0153 (7)	0.0004 (5)	0.0023 (6)	0.0027 (6)
C18	0.0084 (6)	0.0112 (7)	0.0106 (7)	−0.0001 (5)	0.0020 (5)	0.0000 (6)
C19	0.0107 (6)	0.0103 (7)	0.0127 (7)	−0.0008 (5)	0.0029 (5)	0.0003 (6)
C20	0.0113 (6)	0.0101 (7)	0.0131 (7)	0.0005 (5)	0.0029 (6)	0.0011 (6)

(II) Poly[[tris(nitrato-κ²O,O')praeseodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Geometric parameters (Å, º)

Pr1—O4i	2.4554 (12)	C1—H1	0.9500
Pr1—O3	2.4558 (11)	C2—C3	1.400 (2)
Pr1—O2	2.5009 (12)	C2—H2	0.9500
Pr1—O1ii	2.5360 (12)	C3—C4	1.399 (2)
Pr1—O5	2.5750 (13)	C3—C8	1.479 (2)
Pr1—O8	2.5832 (13)	C4—C5	1.377 (2)
Pr1—O11	2.6036 (12)	C4—H4	0.9500
Pr1—O12	2.6147 (12)	C5—H5	0.9500
Pr1—O9	2.6242 (13)	C6—C7	1.376 (2)
Pr1—O6	2.6443 (14)	C6—H6	0.9500
O1—N1	1.3261 (17)	C7—C8	1.401 (2)
O1—Pr1iii	2.5360 (12)	C7—H7	0.9500
O2—N2	1.3337 (17)	C8—C9	1.393 (2)
O3—N3	1.3261 (16)	C9—C10	1.379 (2)
O4—N4	1.3300 (17)	C9—H9	0.9500
O4—Pr1iv	2.4554 (12)	C10—H10	0.9500
O5—N5	1.268 (2)	C11—C12	1.381 (2)
O6—N5	1.261 (2)	C11—H11	0.9500
O7—N5	1.233 (2)	C12—C13	1.397 (2)
O8—N6	1.2782 (19)	C12—H12	0.9500
O9—N6	1.2646 (18)	C13—C14	1.392 (2)
O10—N6	1.2229 (18)	C13—C18	1.472 (2)
O11—N7	1.2620 (18)	C14—C15	1.375 (2)
O12—N7	1.2722 (18)	C14—H14	0.9500
O13—N7	1.2319 (18)	C15—H15	0.9500
N1—C5	1.352 (2)	C16—C17	1.373 (2)
N1—C1	1.355 (2)	C16—H16	0.9500
N2—C10	1.348 (2)	C17—C18	1.393 (2)
N2—C6	1.351 (2)	C17—H17	0.9500
N3—C15	1.352 (2)	C18—C19	1.399 (2)
N3—C11	1.353 (2)	C19—C20	1.377 (2)
N4—C20	1.349 (2)	C19—H19	0.9500
N4—C16	1.353 (2)	C20—H20	0.9500
C1—C2	1.380 (2)
O4i—Pr1—O3	106.95 (4)	O4—N4—C16	118.73 (13)
O4i—Pr1—O2	68.60 (4)	C20—N4—C16	120.89 (14)
O3—Pr1—O2	75.79 (4)	O7—N5—O6	121.81 (18)
O4i—Pr1—O1ii	73.85 (4)	O7—N5—O5	120.86 (18)
O3—Pr1—O1ii	69.44 (4)	O6—N5—O5	117.33 (15)
O2—Pr1—O1ii	117.22 (4)	O7—N5—Pr1	168.42 (12)
O4i—Pr1—O5	154.35 (4)	O6—N5—Pr1	60.94 (9)
O3—Pr1—O5	66.68 (4)	O5—N5—Pr1	57.81 (8)
O2—Pr1—O5	85.82 (5)	O10—N6—O9	122.44 (15)
O1ii—Pr1—O5	122.36 (4)	O10—N6—O8	121.27 (14)
O4i—Pr1—O8	133.11 (4)	O9—N6—O8	116.28 (14)
O3—Pr1—O8	82.56 (4)	O13—N7—O11	121.44 (14)
O2—Pr1—O8	153.82 (4)	O13—N7—O12	120.85 (14)
O1ii—Pr1—O8	66.88 (4)	O11—N7—O12	117.70 (13)
O5—Pr1—O8	72.05 (5)	N1—C1—C2	120.45 (14)
O4i—Pr1—O11	69.62 (4)	N1—C1—H1	119.8
O3—Pr1—O11	166.61 (4)	C2—C1—H1	119.8
O2—Pr1—O11	91.05 (4)	C1—C2—C3	120.60 (15)
O1ii—Pr1—O11	120.17 (4)	C1—C2—H2	119.7
O5—Pr1—O11	110.48 (4)	C3—C2—H2	119.7
O8—Pr1—O11	109.43 (4)	C4—C3—C2	117.20 (14)
O4i—Pr1—O12	69.86 (4)	C4—C3—C8	120.55 (14)
O3—Pr1—O12	143.04 (4)	C2—C3—C8	122.25 (14)
O2—Pr1—O12	130.35 (4)	C5—C4—C3	120.50 (14)
O1ii—Pr1—O12	74.59 (4)	C5—C4—H4	119.8
O5—Pr1—O12	130.84 (4)	C3—C4—H4	119.8
O8—Pr1—O12	75.74 (4)	N1—C5—C4	120.79 (15)
O11—Pr1—O12	49.12 (4)	N1—C5—H5	119.6
O4i—Pr1—O9	130.11 (4)	C4—C5—H5	119.6
O3—Pr1—O9	120.78 (4)	N2—C6—C7	120.78 (15)
O2—Pr1—O9	134.05 (4)	N2—C6—H6	119.6
O1ii—Pr1—O9	108.67 (4)	C7—C6—H6	119.6
O5—Pr1—O9	67.21 (4)	C6—C7—C8	120.43 (15)
O8—Pr1—O9	49.00 (4)	C6—C7—H7	119.8
O11—Pr1—O9	66.91 (4)	C8—C7—H7	119.8
O12—Pr1—O9	63.63 (4)	C9—C8—C7	117.22 (14)
O4i—Pr1—O6	115.98 (4)	C9—C8—C3	121.62 (14)
O3—Pr1—O6	106.61 (4)	C7—C8—C3	121.16 (14)
O2—Pr1—O6	69.19 (4)	C10—C9—C8	120.43 (15)
O1ii—Pr1—O6	170.15 (4)	C10—C9—H9	119.8
O5—Pr1—O6	48.87 (5)	C8—C9—H9	119.8
O8—Pr1—O6	103.98 (4)	N2—C10—C9	120.93 (15)
O11—Pr1—O6	65.42 (4)	N2—C10—H10	119.5
O12—Pr1—O6	107.45 (4)	C9—C10—H10	119.5
O9—Pr1—O6	65.03 (4)	N3—C11—C12	120.32 (14)
O4i—Pr1—N5	139.09 (4)	N3—C11—H11	119.8
O3—Pr1—N5	88.34 (4)	C12—C11—H11	119.8
O2—Pr1—N5	79.39 (4)	C11—C12—C13	120.37 (14)
O1ii—Pr1—N5	146.01 (4)	C11—C12—H12	119.8
O5—Pr1—N5	24.63 (5)	C13—C12—H12	119.8
O8—Pr1—N5	85.53 (5)	C14—C13—C12	117.30 (14)
O11—Pr1—N5	86.73 (5)	C14—C13—C18	120.64 (14)
O12—Pr1—N5	118.82 (4)	C12—C13—C18	122.05 (14)
O9—Pr1—N5	60.42 (4)	C15—C14—C13	121.05 (15)
O6—Pr1—N5	24.63 (5)	C15—C14—H14	119.5
N1—O1—Pr1iii	132.45 (9)	C13—C14—H14	119.5
N2—O2—Pr1	129.47 (9)	N3—C15—C14	120.09 (14)
N3—O3—Pr1	129.16 (9)	N3—C15—H15	120.0
N4—O4—Pr1iv	134.06 (10)	C14—C15—H15	120.0
N5—O5—Pr1	97.56 (10)	N4—C16—C17	120.31 (14)
N5—O6—Pr1	94.43 (10)	N4—C16—H16	119.8
N6—O8—Pr1	97.84 (9)	C17—C16—H16	119.8
N6—O9—Pr1	96.25 (9)	C16—C17—C18	120.61 (15)
N7—O11—Pr1	97.00 (9)	C16—C17—H17	119.7
N7—O12—Pr1	96.18 (9)	C18—C17—H17	119.7
O1—N1—C5	119.07 (13)	C17—C18—C19	117.47 (14)
O1—N1—C1	120.46 (13)	C17—C18—C13	120.49 (14)
C5—N1—C1	120.42 (14)	C19—C18—C13	122.02 (14)
O2—N2—C10	120.08 (13)	C20—C19—C18	120.40 (15)
O2—N2—C6	119.67 (13)	C20—C19—H19	119.8
C10—N2—C6	120.20 (14)	C18—C19—H19	119.8
O3—N3—C15	119.46 (13)	N4—C20—C19	120.27 (15)
O3—N3—C11	119.65 (13)	N4—C20—H20	119.9
C15—N3—C11	120.82 (13)	C19—C20—H20	119.9
O4—N4—C20	120.28 (13)

Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) x, y−1, z; (iii) x, y+1, z; (iv) x+1/2, −y+1/2, z+1/2.

(II) Poly[[tris(nitrato-κ²O,O')praeseodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N')] . Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···O5v	0.95	2.59	3.331 (2)	135
C4—H4···O13vi	0.95	2.36	3.200 (2)	147
C5—H5···O4vii	0.95	2.37	3.168 (2)	141
C9—H9···O9viii	0.95	2.61	3.204 (2)	121
C9—H9···O10v	0.95	2.58	3.468 (2)	156
C10—H10···O3	0.95	2.31	3.115 (2)	143
C10—H10···O7viii	0.95	2.60	3.277 (3)	129
C11—H11···O10v	0.95	2.50	3.239 (2)	135
C14—H14···O7ix	0.95	2.22	3.002 (2)	139
C15—H15···O1ii	0.95	2.31	3.0924 (19)	140
C16—H16···O13v	0.95	2.56	3.154 (2)	121
C17—H17···O12v	0.95	2.36	3.288 (2)	164
C20—H20···O2iv	0.95	2.62	3.307 (2)	130

Symmetry codes: (ii) x, y−1, z; (iv) x+1/2, −y+1/2, z+1/2; (v) −x+1/2, y+1/2, −z+3/2; (vi) −x, −y+1, −z+1; (vii) x−1/2, −y+3/2, z−1/2; (viii) x, −y+1, z+1/2; (ix) −x+1/2, y−1/2, −z+3/2.

(III) Poly[[tris(nitrato-κ²O,O')neodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N'}] . Crystal data

[Nd(NO3)3(C10H8N2O2)2]	F(000) = 2792
Mr = 706.64	Dx = 1.993 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 26.7422 (10) Å	Cell parameters from 8852 reflections
b = 13.3035 (5) Å	θ = 2.5–31.4°
c = 13.7804 (5) Å	µ = 2.29 mm−1
β = 106.065 (1)°	T = 173 K
V = 4711.1 (3) Å3	Block, yellow
Z = 8	0.14 × 0.12 × 0.08 mm

(III) Poly[[tris(nitrato-κ²O,O')neodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N'}] . Data collection

Bruker D8 Quest CMOS diffractometer	8277 independent reflections
Radiation source: I-mu-S microsource X-ray tube	5419 reflections with I > 2σ(I)
Laterally graded multilayer (Goebel) mirror monochromator	Rint = 0.115
ω and phi scans	θmax = 33.5°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −38→39
Tmin = 0.682, Tmax = 0.747	k = −20→18
47148 measured reflections	l = −21→18

(III) Poly[[tris(nitrato-κ²O,O')neodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N'}] . Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.051	H-atom parameters constrained
wR(F2) = 0.067	w = 1/[σ2(Fo2) + (0.0161P)2 + 13.5513P] where P = (Fo2 + 2Fc2)/3
S = 1.01	(Δ/σ)max = 0.001
8277 reflections	Δρmax = 1.49 e Å−3
370 parameters	Δρmin = −1.29 e Å−3

(III) Poly[[tris(nitrato-κ²O,O')neodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N'}] . Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

(III) Poly[[tris(nitrato-κ²O,O')neodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N'}] . Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Nd1	0.12681 (2)	0.27502 (2)	0.66431 (2)	0.00728 (4)
O1	0.14904 (8)	1.13013 (15)	0.78718 (16)	0.0116 (5)
O2	0.07574 (8)	0.41599 (15)	0.70766 (16)	0.0130 (5)
O3	0.17968 (8)	0.33233 (15)	0.83003 (15)	0.0111 (4)
O4	0.54422 (8)	0.28373 (16)	1.18789 (15)	0.0104 (4)
O5	0.19319 (10)	0.40971 (18)	0.65362 (18)	0.0251 (6)
O6	0.12057 (10)	0.42656 (17)	0.53782 (19)	0.0236 (6)
O7	0.18928 (11)	0.50787 (17)	0.5251 (2)	0.0317 (7)
O8	0.21193 (9)	0.18587 (18)	0.66255 (16)	0.0190 (5)
O9	0.16865 (8)	0.24311 (15)	0.51655 (16)	0.0139 (5)
O10	0.23559 (9)	0.14500 (17)	0.52853 (17)	0.0187 (5)
O11	0.05854 (8)	0.25293 (15)	0.49154 (16)	0.0136 (5)
O12	0.09612 (8)	0.11469 (16)	0.55686 (16)	0.0120 (5)
O13	0.03619 (9)	0.11085 (17)	0.41220 (17)	0.0198 (5)
N1	0.14002 (10)	1.03179 (18)	0.77624 (18)	0.0092 (5)
N2	0.08697 (10)	0.51388 (19)	0.7183 (2)	0.0113 (6)
N3	0.23077 (10)	0.32610 (19)	0.87052 (18)	0.0094 (5)
N4	0.49563 (9)	0.28710 (19)	1.12926 (17)	0.0094 (5)
N5	0.16807 (13)	0.4492 (2)	0.5712 (2)	0.0228 (7)
N6	0.20618 (10)	0.19050 (19)	0.56738 (19)	0.0125 (6)
N7	0.06299 (10)	0.1590 (2)	0.48487 (19)	0.0124 (6)
C1	0.18004 (12)	0.9658 (2)	0.7982 (2)	0.0123 (6)
H1	0.2148	0.9899	0.8201	0.015*
C2	0.17080 (12)	0.8640 (2)	0.7892 (2)	0.0120 (6)
H2	0.1993	0.8185	0.8059	0.014*
C3	0.12022 (12)	0.8270 (2)	0.7557 (2)	0.0097 (6)
C4	0.07995 (12)	0.8974 (2)	0.7348 (2)	0.0117 (6)
H4	0.0449	0.8751	0.7123	0.014*
C5	0.09037 (12)	0.9987 (2)	0.7464 (2)	0.0121 (6)
H5	0.0625	1.0455	0.7334	0.015*
C6	0.05363 (13)	0.5813 (2)	0.6616 (2)	0.0144 (7)
H6	0.0230	0.5584	0.6133	0.017*
C7	0.06354 (12)	0.6827 (2)	0.6730 (2)	0.0137 (7)
H7	0.0396	0.7293	0.6329	0.016*
C8	0.10854 (11)	0.7181 (2)	0.7431 (2)	0.0099 (6)
C9	0.14192 (13)	0.6463 (2)	0.8007 (2)	0.0147 (7)
H9	0.1729	0.6671	0.8491	0.018*
C10	0.13017 (13)	0.5451 (2)	0.7879 (3)	0.0168 (7)
H10	0.1528	0.4970	0.8287	0.020*
C11	0.25859 (12)	0.4103 (2)	0.9057 (2)	0.0109 (6)
H11	0.2419	0.4740	0.8964	0.013*
C12	0.31067 (12)	0.4040 (2)	0.9544 (2)	0.0115 (6)
H12	0.3295	0.4633	0.9803	0.014*
C13	0.33621 (12)	0.3117 (2)	0.9664 (2)	0.0099 (6)
C14	0.30682 (11)	0.2278 (2)	0.9260 (2)	0.0111 (6)
H14	0.3232	0.1639	0.9307	0.013*
C15	0.25439 (12)	0.2359 (2)	0.8795 (2)	0.0117 (6)
H15	0.2348	0.1776	0.8536	0.014*
C16	0.47655 (12)	0.3749 (2)	1.0850 (2)	0.0118 (6)
H16	0.4989	0.4314	1.0915	0.014*
C17	0.42538 (12)	0.3837 (2)	1.0310 (2)	0.0115 (6)
H17	0.4126	0.4459	1.0002	0.014*
C18	0.39187 (12)	0.3015 (2)	1.0209 (2)	0.0101 (6)
C19	0.41335 (12)	0.2105 (2)	1.0646 (2)	0.0113 (6)
H19	0.3920	0.1522	1.0570	0.014*
C20	0.46497 (12)	0.2047 (2)	1.1181 (2)	0.0109 (6)
H20	0.4791	0.1426	1.1474	0.013*

(III) Poly[[tris(nitrato-κ²O,O')neodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N'}] . Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Nd1	0.00565 (7)	0.00592 (7)	0.00960 (7)	−0.00075 (8)	0.00098 (5)	−0.00046 (8)
O1	0.0140 (12)	0.0039 (10)	0.0155 (11)	−0.0026 (9)	0.0018 (9)	0.0000 (9)
O2	0.0142 (12)	0.0030 (10)	0.0215 (12)	−0.0035 (9)	0.0046 (10)	−0.0026 (9)
O3	0.0036 (10)	0.0125 (11)	0.0143 (11)	0.0003 (9)	−0.0023 (9)	−0.0010 (9)
O4	0.0050 (10)	0.0122 (11)	0.0121 (10)	0.0010 (9)	−0.0009 (8)	−0.0004 (9)
O5	0.0326 (16)	0.0244 (14)	0.0197 (13)	−0.0162 (12)	0.0095 (12)	−0.0016 (11)
O6	0.0301 (16)	0.0144 (12)	0.0295 (14)	0.0025 (11)	0.0136 (12)	0.0065 (11)
O7	0.060 (2)	0.0106 (12)	0.0401 (16)	−0.0062 (12)	0.0397 (16)	0.0002 (12)
O8	0.0165 (13)	0.0297 (14)	0.0104 (11)	0.0076 (11)	0.0032 (10)	0.0031 (10)
O9	0.0118 (11)	0.0138 (12)	0.0155 (11)	0.0024 (9)	0.0028 (9)	0.0025 (9)
O10	0.0190 (13)	0.0168 (12)	0.0236 (13)	0.0047 (10)	0.0115 (11)	−0.0020 (10)
O11	0.0140 (11)	0.0103 (12)	0.0153 (11)	0.0011 (8)	0.0021 (9)	0.0004 (8)
O12	0.0122 (12)	0.0097 (11)	0.0117 (11)	0.0000 (9)	−0.0007 (9)	−0.0002 (9)
O13	0.0160 (13)	0.0240 (13)	0.0159 (12)	−0.0041 (10)	−0.0014 (10)	−0.0109 (10)
N1	0.0105 (14)	0.0081 (13)	0.0081 (12)	−0.0017 (10)	0.0013 (11)	−0.0009 (10)
N2	0.0123 (14)	0.0068 (13)	0.0164 (14)	−0.0004 (11)	0.0064 (12)	−0.0015 (11)
N3	0.0085 (13)	0.0107 (13)	0.0076 (12)	0.0021 (11)	−0.0002 (10)	−0.0008 (10)
N4	0.0082 (12)	0.0122 (13)	0.0074 (11)	0.0004 (11)	0.0017 (10)	−0.0018 (10)
N5	0.040 (2)	0.0092 (14)	0.0285 (17)	−0.0060 (14)	0.0242 (16)	−0.0043 (13)
N6	0.0126 (14)	0.0106 (13)	0.0145 (13)	−0.0015 (11)	0.0042 (11)	−0.0008 (11)
N7	0.0104 (14)	0.0132 (14)	0.0144 (13)	−0.0016 (11)	0.0045 (11)	−0.0036 (11)
C1	0.0098 (16)	0.0119 (16)	0.0146 (15)	−0.0011 (13)	0.0021 (13)	−0.0001 (13)
C2	0.0117 (16)	0.0104 (15)	0.0131 (15)	0.0023 (13)	0.0022 (13)	−0.0014 (12)
C3	0.0124 (16)	0.0084 (15)	0.0081 (14)	0.0005 (13)	0.0023 (12)	0.0018 (12)
C4	0.0089 (16)	0.0103 (15)	0.0138 (15)	−0.0004 (12)	−0.0005 (13)	0.0022 (13)
C5	0.0103 (16)	0.0113 (16)	0.0149 (16)	0.0014 (13)	0.0037 (13)	0.0013 (13)
C6	0.0125 (17)	0.0115 (16)	0.0156 (16)	−0.0009 (13)	−0.0021 (13)	0.0002 (13)
C7	0.0120 (16)	0.0099 (15)	0.0156 (16)	0.0010 (13)	−0.0021 (13)	0.0007 (13)
C8	0.0111 (15)	0.0071 (14)	0.0123 (14)	0.0015 (13)	0.0044 (12)	−0.0008 (13)
C9	0.0114 (16)	0.0114 (16)	0.0186 (17)	0.0010 (13)	−0.0004 (14)	−0.0016 (13)
C10	0.0122 (17)	0.0132 (16)	0.0218 (18)	0.0042 (13)	−0.0007 (14)	−0.0001 (14)
C11	0.0112 (16)	0.0071 (15)	0.0138 (15)	−0.0001 (12)	0.0023 (13)	−0.0019 (12)
C12	0.0090 (16)	0.0102 (15)	0.0145 (15)	−0.0021 (12)	0.0019 (13)	−0.0029 (13)
C13	0.0100 (15)	0.0119 (15)	0.0082 (14)	−0.0005 (12)	0.0032 (12)	−0.0004 (12)
C14	0.0103 (14)	0.0093 (14)	0.0133 (14)	0.0008 (14)	0.0024 (12)	0.0004 (14)
C15	0.0136 (15)	0.0074 (14)	0.0129 (14)	−0.0027 (13)	0.0018 (12)	−0.0020 (13)
C16	0.0114 (16)	0.0095 (15)	0.0148 (15)	−0.0003 (12)	0.0039 (13)	0.0032 (13)
C17	0.0100 (16)	0.0099 (15)	0.0141 (15)	0.0021 (12)	0.0026 (13)	0.0012 (12)
C18	0.0096 (15)	0.0126 (16)	0.0094 (14)	0.0022 (12)	0.0049 (12)	0.0001 (12)
C19	0.0113 (15)	0.0098 (16)	0.0135 (14)	−0.0017 (12)	0.0044 (12)	−0.0007 (12)
C20	0.0135 (16)	0.0085 (16)	0.0113 (14)	−0.0001 (12)	0.0041 (13)	0.0002 (11)

(III) Poly[[tris(nitrato-κ²O,O')neodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N'}] . Geometric parameters (Å, º)

Nd1—O4i	2.448 (2)	C1—H1	0.9500
Nd1—O3	2.451 (2)	C2—C3	1.393 (4)
Nd1—O2	2.488 (2)	C2—H2	0.9500
Nd1—O1ii	2.526 (2)	C3—C4	1.396 (4)
Nd1—O5	2.555 (2)	C3—C8	1.482 (4)
Nd1—O8	2.573 (2)	C4—C5	1.376 (4)
Nd1—O11	2.585 (2)	C4—H4	0.9500
Nd1—O12	2.597 (2)	C5—H5	0.9500
Nd1—O9	2.615 (2)	C6—C7	1.377 (4)
Nd1—O6	2.640 (2)	C6—H6	0.9500
O1—N1	1.331 (3)	C7—C8	1.399 (4)
O1—Nd1iii	2.526 (2)	C7—H7	0.9500
O2—N2	1.335 (3)	C8—C9	1.396 (4)
O3—N3	1.328 (3)	C9—C10	1.383 (4)
O4—N4	1.328 (3)	C9—H9	0.9500
O4—Nd1iv	2.448 (2)	C10—H10	0.9500
O5—N5	1.263 (4)	C11—C12	1.371 (4)
O6—N5	1.262 (4)	C11—H11	0.9500
O7—N5	1.238 (3)	C12—C13	1.393 (4)
O8—N6	1.279 (3)	C12—H12	0.9500
O9—N6	1.264 (3)	C13—C14	1.389 (4)
O10—N6	1.227 (3)	C13—C18	1.476 (4)
O11—N7	1.261 (3)	C14—C15	1.375 (4)
O12—N7	1.277 (3)	C14—H14	0.9500
O13—N7	1.237 (3)	C15—H15	0.9500
N1—C5	1.351 (4)	C16—C17	1.370 (4)
N1—C1	1.352 (4)	C16—H16	0.9500
N2—C10	1.347 (4)	C17—C18	1.395 (4)
N2—C6	1.350 (4)	C17—H17	0.9500
N3—C15	1.346 (4)	C18—C19	1.403 (4)
N3—C11	1.358 (4)	C19—C20	1.376 (4)
N4—C16	1.351 (4)	C19—H19	0.9500
N4—C20	1.352 (4)	C20—H20	0.9500
C1—C2	1.375 (4)
O4i—Nd1—O3	106.54 (7)	O4—N4—C20	120.2 (2)
O4i—Nd1—O2	68.50 (7)	C16—N4—C20	120.6 (3)
O3—Nd1—O2	75.84 (7)	O7—N5—O6	121.4 (3)
O4i—Nd1—O1ii	73.79 (7)	O7—N5—O5	121.2 (3)
O3—Nd1—O1ii	69.19 (7)	O6—N5—O5	117.4 (3)
O2—Nd1—O1ii	117.21 (7)	O7—N5—Nd1	168.5 (2)
O4i—Nd1—O5	153.95 (8)	O6—N5—Nd1	61.29 (16)
O3—Nd1—O5	66.72 (7)	O5—N5—Nd1	57.42 (15)
O2—Nd1—O5	85.50 (8)	O10—N6—O9	122.5 (3)
O1ii—Nd1—O5	122.38 (8)	O10—N6—O8	120.9 (3)
O4i—Nd1—O8	133.41 (7)	O9—N6—O8	116.5 (2)
O3—Nd1—O8	82.44 (7)	O13—N7—O11	121.8 (3)
O2—Nd1—O8	153.59 (7)	O13—N7—O12	120.8 (3)
O1ii—Nd1—O8	67.03 (7)	O11—N7—O12	117.4 (2)
O5—Nd1—O8	72.07 (8)	N1—C1—C2	120.5 (3)
O4i—Nd1—O11	69.68 (7)	N1—C1—H1	119.7
O3—Nd1—O11	166.35 (6)	C2—C1—H1	119.7
O2—Nd1—O11	90.70 (7)	C1—C2—C3	120.8 (3)
O1ii—Nd1—O11	120.39 (6)	C1—C2—H2	119.6
O5—Nd1—O11	110.58 (7)	C3—C2—H2	119.6
O8—Nd1—O11	109.88 (7)	C2—C3—C4	117.0 (3)
O4i—Nd1—O12	70.06 (7)	C2—C3—C8	122.6 (3)
O3—Nd1—O12	142.80 (7)	C4—C3—C8	120.4 (3)
O2—Nd1—O12	130.40 (7)	C5—C4—C3	120.9 (3)
O1ii—Nd1—O12	74.57 (6)	C5—C4—H4	119.6
O5—Nd1—O12	131.16 (7)	C3—C4—H4	119.6
O8—Nd1—O12	75.92 (7)	N1—C5—C4	120.4 (3)
O11—Nd1—O12	49.47 (6)	N1—C5—H5	119.8
O4i—Nd1—O9	130.37 (7)	C4—C5—H5	119.8
O3—Nd1—O9	121.01 (7)	N2—C6—C7	120.6 (3)
O2—Nd1—O9	133.70 (7)	N2—C6—H6	119.7
O1ii—Nd1—O9	109.03 (7)	C7—C6—H6	119.7
O5—Nd1—O9	67.36 (7)	C6—C7—C8	120.7 (3)
O8—Nd1—O9	49.27 (7)	C6—C7—H7	119.7
O11—Nd1—O9	67.02 (7)	C8—C7—H7	119.7
O12—Nd1—O9	63.80 (7)	C9—C8—C7	117.1 (3)
O4i—Nd1—O6	115.92 (7)	C9—C8—C3	121.4 (3)
O3—Nd1—O6	107.00 (7)	C7—C8—C3	121.5 (3)
O2—Nd1—O6	69.17 (7)	C10—C9—C8	120.5 (3)
O1ii—Nd1—O6	170.26 (7)	C10—C9—H9	119.8
O5—Nd1—O6	49.03 (8)	C8—C9—H9	119.8
O8—Nd1—O6	103.89 (7)	N2—C10—C9	120.7 (3)
O11—Nd1—O6	65.12 (7)	N2—C10—H10	119.6
O12—Nd1—O6	107.37 (7)	C9—C10—H10	119.6
O9—Nd1—O6	64.68 (7)	N3—C11—C12	120.4 (3)
O4i—Nd1—N5	139.01 (8)	N3—C11—H11	119.8
O3—Nd1—N5	88.42 (8)	C12—C11—H11	119.8
O2—Nd1—N5	79.15 (7)	C11—C12—C13	120.7 (3)
O1ii—Nd1—N5	146.02 (8)	C11—C12—H12	119.7
O5—Nd1—N5	24.61 (8)	C13—C12—H12	119.7
O8—Nd1—N5	85.48 (8)	C14—C13—C12	117.2 (3)
O11—Nd1—N5	86.77 (8)	C14—C13—C18	120.6 (3)
O12—Nd1—N5	119.07 (7)	C12—C13—C18	122.2 (3)
O9—Nd1—N5	60.38 (7)	C15—C14—C13	121.0 (3)
O6—Nd1—N5	24.79 (8)	C15—C14—H14	119.5
N1—O1—Nd1iii	132.26 (17)	C13—C14—H14	119.5
N2—O2—Nd1	129.77 (17)	N3—C15—C14	120.3 (3)
N3—O3—Nd1	129.30 (16)	N3—C15—H15	119.8
N4—O4—Nd1iv	134.20 (16)	C14—C15—H15	119.8
N5—O5—Nd1	97.97 (19)	N4—C16—C17	120.9 (3)
N5—O6—Nd1	93.92 (19)	N4—C16—H16	119.5
N6—O8—Nd1	97.58 (17)	C17—C16—H16	119.5
N6—O9—Nd1	95.95 (16)	C16—C17—C18	120.3 (3)
N7—O11—Nd1	97.07 (17)	C16—C17—H17	119.8
N7—O12—Nd1	96.06 (16)	C18—C17—H17	119.8
O1—N1—C5	119.2 (2)	C17—C18—C19	117.3 (3)
O1—N1—C1	120.4 (2)	C17—C18—C13	120.5 (3)
C5—N1—C1	120.4 (3)	C19—C18—C13	122.2 (3)
O2—N2—C10	120.1 (3)	C20—C19—C18	120.6 (3)
O2—N2—C6	119.4 (3)	C20—C19—H19	119.7
C10—N2—C6	120.4 (3)	C18—C19—H19	119.7
O3—N3—C15	119.8 (2)	N4—C20—C19	120.2 (3)
O3—N3—C11	119.8 (2)	N4—C20—H20	119.9
C15—N3—C11	120.4 (3)	C19—C20—H20	119.9
O4—N4—C16	119.2 (2)
Nd1—O3—O4—Nd1iv	4.87 (14)	Nd1—O2—O1—Nd1iii	91.75 (11)

Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) x, y−1, z; (iii) x, y+1, z; (iv) x+1/2, −y+1/2, z+1/2.

(III) Poly[[tris(nitrato-κ²O,O')neodymium(III)]-bis(µ-4,4'-bipyridine N,N'-dioxide-κ²N:N'}] . Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···O5v	0.95	2.61	3.353 (4)	135
C4—H4···O13vi	0.95	2.37	3.206 (4)	147
C5—H5···O4vii	0.95	2.37	3.163 (4)	141
C9—H9···O9viii	0.95	2.63	3.216 (4)	121
C9—H9···O10v	0.95	2.58	3.464 (4)	156
C10—H10···O3	0.95	2.30	3.110 (4)	142
C10—H10···O7viii	0.95	2.61	3.289 (4)	129
C11—H11···O10v	0.95	2.50	3.243 (4)	135
C14—H14···O7ix	0.95	2.21	2.998 (4)	139
C15—H15···O1ii	0.95	2.31	3.091 (4)	139
C16—H16···O13v	0.95	2.56	3.159 (4)	121
C17—H17···O12v	0.95	2.37	3.295 (4)	165
C20—H20···O2iv	0.95	2.61	3.294 (4)	130

Symmetry codes: (ii) x, y−1, z; (iv) x+1/2, −y+1/2, z+1/2; (v) −x+1/2, y+1/2, −z+3/2; (vi) −x, −y+1, −z+1; (vii) x−1/2, −y+3/2, z−1/2; (viii) x, −y+1, z+1/2; (ix) −x+1/2, y−1/2, −z+3/2.