catena-Poly[[[tetra­aqua­erbium(III)]-μ-oxalato-κ4O1,O2:O1′,O2′] [bromidobis(pyrazine-2-carboxyl­ato-κ2N1,O)cuprate(II)] tetra­hydrate]

Yang, H.-F.; Xu, S.-H.

doi:10.1107/S1600536810025274

metal-organic compounds

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ISSN: 2056-9890

Volume 66| Part 8| August 2010| Pages m874-m875

https://doi.org/10.1107/S1600536810025274

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catena-Poly[[[tetraaquaerbium(III)]-μ-oxalato-κ⁴O¹,O²:O^1′,O^2′] [bromidobis(pyrazine-2-carboxylato-κ²N¹,O)cuprate(II)] tetrahydrate]

Hui-Fu Yang ^a and Shi-Hai Xu ^a ^*

^aDepartment of Chemistry, Jinan University, Guangzhou 510632, People's Republic of China
^*Correspondence e-mail: xuhs09@126.com

(Received 10 June 2010; accepted 28 June 2010; online 3 July 2010)

In the title heterometallic complex, {[Er(C₂O₄)(H₂O)₄][CuBr(C₅H₃N₂O₂)₂]·4H₂O}_n, the Er^III atom is eight-coordinated by four O atoms from two centrosymmetric oxalate ligands and four water molecules, displaying a bicapped trigonal-prismatic geometry. The oxalate ligands bridge the Er atoms into a polymeric cationic chain along [110]. The Cu^II atom is five-coordinated in a square-pyramidal geometry by two pyrazine-2-carboxylate ligands and a Br atom, forming a discrete anion. The polymeric cations, complex anions and uncoordinated water molecules are self-assembled into a three-dimensional supramolecular network through O—H⋯N, O—H⋯O and O—H⋯Br hydrogen bonds.

Related literature

For general background to the topologies and potential applications of transition metal–lanthanide complexes, see: Barbour (2006 ); Kong et al. (2008 ); Rao et al. (2004 ); Zhang et al. (2005 ); Zhao et al. (2003 ). For general background to transition metal–lanthanide complexes with organic ligands containing mixed-donor atoms, see: Costes et al. (2004 ); Deng et al. (1996 ); He et al. (2005 ); Liang et al. (2001 ); Mahata et al. (2005 ); Ma, Liu et al. (2009 ); Zhang et al. (2004 ). For heterometallic complexes constructed from pyrazine-2-carboxylic acid, see: Deng et al. (2008 ); Feng & Wen (2009 ). For general background to in situ reactions, see: Li et al. (2006 ); Ma, Zeng et al. (2009 ).

Experimental

Crystal data

[Er(C₂O₄)(H₂O)₄][CuBr(C₅H₃N₂O₂)₂]·4H₂O
M_r = 789.05
Triclinic, $[P \overline 1]$
a = 8.6678 (3) Å
b = 10.2623 (4) Å
c = 13.8748 (2) Å
α = 96.872 (1)°
β = 99.419 (1)°
γ = 99.748 (1)°
V = 1186.10 (6) Å³
Z = 2
Mo Kα radiation
μ = 6.18 mm⁻¹
T = 295 K
0.26 × 0.25 × 0.19 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.232, T_max = 0.324
14850 measured reflections
5260 independent reflections
4480 reflections with I > 2σ(I)
R_int = 0.023

Refinement

R[F² > 2σ(F²)] = 0.027
wR(F²) = 0.072
S = 1.01
5260 reflections
316 parameters
24 restraints
H-atom parameters constrained
Δρ_max = 1.59 e Å⁻³
Δρ_min = −0.88 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1W⋯O5Wⁱ	0.82	1.92	2.712 (3)	163
O1W—H2W⋯N2ⁱⁱ	0.82	2.01	2.823 (4)	168
O2W—H3W⋯O4ⁱⁱⁱ	0.82	2.04	2.825 (3)	159
O2W—H4W⋯O7W^iv	0.82	1.97	2.788 (4)	174
O3W—H5W⋯O2^v	0.82	1.97	2.781 (3)	167
O3W—H6W⋯O5W^vi	0.82	1.89	2.710 (4)	176
O4W—H7W⋯O7W^vi	0.82	1.94	2.758 (3)	178
O4W—H8W⋯N4	0.82	2.08	2.886 (4)	169
O5W—H9W⋯O8W	0.82	1.92	2.670 (4)	152
O5W—H10W⋯O6W^vii	0.82	2.03	2.835 (4)	168
O6W—H11W⋯Br1^viii	0.82	2.59	3.299 (3)	146
O6W—H12W⋯O3^ix	0.82	2.57	3.238 (4)	139
O6W—H12W⋯O4^ix	0.82	2.07	2.866 (4)	164
O7W—H13W⋯O5	0.82	2.04	2.826 (3)	161
O7W—H14W⋯O6W	0.82	1.94	2.746 (4)	167
O8W—H15W⋯O1^viii	0.82	2.58	3.351 (4)	157
O8W—H15W⋯O2^viii	0.82	2.23	2.951 (4)	147
O8W—H16W⋯Br1^vi	0.82	2.53	3.337 (3)	170
Symmetry codes: (i) x, y+1, z; (ii) x-1, y, z+1; (iii) -x+1, -y+2, -z+1; (iv) x-1, y, z; (v) -x+1, -y+1, -z; (vi) -x+1, -y+1, -z+1; (vii) x, y-1, z; (viii) x, y, z+1; (ix) -x+2, -y+2, -z+1.

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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810025274/hy2323sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810025274/hy2323Isup2.hkl

checkCIF report

Comment top

The design and construction of transition–lanthanide metal complexes has gained great recognition over the last decade because of their intriguing network topolopies and potential applications, and due to their magnetic properties, their capacity for gas storage, as luminescent materials, and so on (Barbour, 2006; Kong et al., 2008; Rao et al., 2004; Zhang et al., 2005; Zhao et al., 2003). So far, numerous heterometallic complexes have been obtained by allowing the assembly of mixed metal ions and organic ligands containing mixed-donor atoms similar to the established methods used in traditional transition metal chemistry, such as pyridinecarboxylate, pyrazinecarboxylate, carbonyl, CN group, amino acids and so on (Costes et al., 2004; Deng et al., 1996; He et al., 2005; Liang et al., 2001; Mahata et al., 2005; Ma, Liu et al., 2009; Zhang et al., 2004). Pyrazine-2-carboxylic acid (2-Hpzc) is a multifunctional bridging ligand possessing of O and N donors, which can thus be chosen to construct heterometallic complexes, as is reported in literature (Deng et al., 2008; Feng & Wen, 2009). In this paper, we describe the synthesis and structure of a heterometallic hybrid compound obtained by the reaction of 2-Hpzc with Er₂O₃ and CuBr₂ via a hydrothermal method. Since no oxalate was directly introduced into the starting reaction mixture, we suppose that the oxalate ligand was synthesized in situ reactions.

Firstly, the decarboxylation reaction of the 2-Hpzc occured under high temperatures, forming CO₂. Then, the oxalate anion was formed via the in situ reductive coupling of CO₂. Actually, such in situ reactions have been reported in literature [Li et al., 2006; Ma, Zeng et al., 2009]. As depicted in Fig. 1, the title compound is composed of an [Er(C₂O₄)(H₂O)₄]⁺ cation, a [Cu(2-pzc)₂Br]^- anion and four uncoordinated water molecules. The Er^III atom lies in the region of z close to 0.5 and the Cu^II atom in the region of z close to 0. The Er^III center is eight-coordinated by four carboxylate O atoms from two oxalate ligands and four water molecules, displaying a bicapped trigonal-prismatic geometry. The coordination geometry around the Cu^II center can be described as square-pyramidal, defined by two O and two N atoms from two 2-pzc ligands and one Br atom. The oxalate ligands bridge the Er atoms into a polymeric cationic chain along [1 1 0], with Er···Er separations of 6.176 (2) and 6.088 (3) Å. The Cu atoms form a simple dimer by a Cu···O contact [3.127 (2) Å], with a Cu···Cu separation of 5.321 (2) Å. The linear coordination polymers, discrete dimers and uncoordinated water molecules are further self-assembled into a three-dimensional supramolecular network structure via intermolecular O—H···O, O—H···N and O—H···Br hydrogen bonds involving the carboxylate O atoms of the 2-pzc ligands, the O atoms from coordinated and uncoordinated water molecules and Br atom (Fig. 2, Table 1).

Related literature top

For general background to the topologies and potential applications of transitionmetal–lanthanide complexes, see: Barbour (2006); Kong et al. (2008); Rao et al. (2004); Zhang et al. (2005); Zhao et al. (2003). For general background to transition metal–lanthanide complexes with organic ligands containing mixed-donor atoms, see: Costes et al. (2004); Deng et al. (1996); He et al. (2005); Liang et al. (2001); Mahata et al. (2005); Ma, Liu et al. (2009); Zhang et al. (2004). For heterometallic complexes constructed from pyrazine-2-carboxylic acid, see: Deng et al. (2008); Feng & Wen (2009). For general background to in situ reactions, see: Li et al. (2006); Ma, Zeng et al. (2009).

Experimental top

A mixture of copper bromide (0.5 mmol, 0.112 g), 2-Hpzc (0.5 mmol, 0.062 g), erbium oxide (0.52 mmol, 0.096 g), HNO₃ (1 ml) and H₂O (10 ml) was stirred for 30 min in air and then sealed in a 23 ml Teflon-lined reactor and kept under autogenous pressure at 423 K for 72 h. The mixture was cooled to room temperature at a rate of 10 K h^-1. The purple block crystals were obtained in a yield of 42% based on Er.

Structure description top

For general background to the topologies and potential applications of transitionmetal–lanthanide complexes, see: Barbour (2006); Kong et al. (2008); Rao et al. (2004); Zhang et al. (2005); Zhao et al. (2003). For general background to transition metal–lanthanide complexes with organic ligands containing mixed-donor atoms, see: Costes et al. (2004); Deng et al. (1996); He et al. (2005); Liang et al. (2001); Mahata et al. (2005); Ma, Liu et al. (2009); Zhang et al. (2004). For heterometallic complexes constructed from pyrazine-2-carboxylic acid, see: Deng et al. (2008); Feng & Wen (2009). For general background to in situ reactions, see: Li et al. (2006); Ma, Zeng et al. (2009).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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 (Sheldrick, 2008).

Figures top

	Fig. 1. The structure of the title compound, showing the 30% probability displacement ellipsoids. H atoms have been omitted for clarity. [Symmetry codes: (i) 2-x, -y, 1-z; (ii) 1-x, -y, 1-z.]
	Fig. 2. A packing view of the title compound, showing the intermolecular hydrogen bonds (dashed lines).

catena-Poly[[[tetraaquaerbium(III)]-µ-oxalato- κ⁴O¹,O²:O^1',O^2'] [bromidobis(pyrazine-2-carboxylato-κ²N¹,O)cuprate(II)] tetrahydrate] top

Crystal data top

[Er(C₂O₄)(H₂O)₄][CuBr(C₅H₃N₂O₂)₂]·4H₂O	Z = 2
M_r = 789.05	F(000) = 764
Triclinic, P1	D_x = 2.209 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.6678 (3) Å	Cell parameters from 5837 reflections
b = 10.2623 (4) Å	θ = 2.8–27.9°
c = 13.8748 (2) Å	µ = 6.18 mm⁻¹
α = 96.872 (1)°	T = 295 K
β = 99.419 (1)°	Block, purple
γ = 99.748 (1)°	0.26 × 0.25 × 0.19 mm
V = 1186.10 (6) Å³

Data collection top

Bruker APEXII CCD diffractometer	5260 independent reflections
Radiation source: fine-focus sealed tube	4480 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.023
φ and ω scan	θ_max = 27.5°, θ_min = 1.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→11
T_min = 0.232, T_max = 0.324	k = −13→13
14850 measured reflections	l = −18→17

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.027	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.072	H-atom parameters constrained
S = 1.01	w = 1/[σ²(F_o²) + (0.0399P)² + 0.5356P] where P = (F_o² + 2F_c²)/3
5260 reflections	(Δ/σ)_max = 0.001
316 parameters	Δρ_max = 1.59 e Å⁻³
24 restraints	Δρ_min = −0.88 e Å⁻³

Crystal data top

[Er(C₂O₄)(H₂O)₄][CuBr(C₅H₃N₂O₂)₂]·4H₂O	γ = 99.748 (1)°
M_r = 789.05	V = 1186.10 (6) Å³
Triclinic, P1	Z = 2
a = 8.6678 (3) Å	Mo Kα radiation
b = 10.2623 (4) Å	µ = 6.18 mm⁻¹
c = 13.8748 (2) Å	T = 295 K
α = 96.872 (1)°	0.26 × 0.25 × 0.19 mm
β = 99.419 (1)°

Data collection top

Bruker APEXII CCD diffractometer	5260 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	4480 reflections with I > 2σ(I)
T_min = 0.232, T_max = 0.324	R_int = 0.023
14850 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.027	24 restraints
wR(F²) = 0.072	H-atom parameters constrained
S = 1.01	Δρ_max = 1.59 e Å⁻³
5260 reflections	Δρ_min = −0.88 e Å⁻³
316 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Er1	0.242464 (16)	0.750762 (12)	0.496898 (10)	0.02163 (6)
Br1	0.63182 (5)	0.80237 (4)	−0.05645 (3)	0.04494 (11)
Cu1	0.86112 (6)	0.70254 (4)	0.05289 (3)	0.03103 (11)
O1	0.8075 (3)	0.5245 (2)	−0.02710 (18)	0.0358 (6)
O2	0.8561 (4)	0.4105 (3)	−0.1609 (2)	0.0546 (8)
O3	0.9505 (3)	0.8638 (2)	0.14745 (18)	0.0371 (6)
O4	0.9256 (4)	0.9694 (3)	0.29159 (19)	0.0465 (7)
O5	0.5154 (3)	0.8333 (2)	0.49529 (17)	0.0275 (5)
O6	0.7024 (3)	1.0134 (2)	0.49841 (18)	0.0288 (5)
O7	0.0196 (3)	0.5961 (2)	0.40579 (16)	0.0305 (6)
O8	−0.1564 (3)	0.4115 (2)	0.40878 (17)	0.0310 (6)
N1	1.0142 (3)	0.7379 (3)	−0.03731 (19)	0.0270 (6)
N2	1.1892 (4)	0.7526 (3)	−0.1867 (2)	0.0360 (7)
N3	0.7441 (4)	0.6513 (3)	0.1585 (2)	0.0289 (6)
N4	0.5947 (4)	0.6246 (3)	0.3185 (2)	0.0413 (8)
C1	0.8766 (5)	0.5131 (3)	−0.1011 (2)	0.0320 (8)
C2	0.9942 (4)	0.6345 (3)	−0.1109 (2)	0.0271 (7)
C3	1.0800 (4)	0.6438 (4)	−0.1856 (3)	0.0326 (8)
H3	1.0617	0.5725	−0.2369	0.039*
C4	1.2098 (5)	0.8521 (4)	−0.1124 (3)	0.0358 (9)
H4	1.2867	0.9281	−0.1101	0.043*
C5	1.1210 (4)	0.8469 (3)	−0.0382 (3)	0.0317 (8)
H5	1.1361	0.9199	0.0113	0.038*
C6	0.8932 (4)	0.8711 (3)	0.2268 (3)	0.0310 (8)
C7	0.7757 (4)	0.7492 (3)	0.2364 (2)	0.0282 (7)
C8	0.6999 (5)	0.7350 (4)	0.3157 (3)	0.0353 (8)
H8	0.7226	0.8043	0.3687	0.042*
C9	0.5669 (5)	0.5284 (4)	0.2412 (3)	0.0433 (10)
H9	0.4962	0.4495	0.2417	0.052*
C10	0.6391 (5)	0.5408 (4)	0.1601 (3)	0.0384 (9)
H10	0.6144	0.4720	0.1067	0.046*
C11	0.5638 (4)	0.9558 (3)	0.4983 (2)	0.0228 (7)
C12	−0.0399 (4)	0.5024 (3)	0.4461 (2)	0.0241 (7)
O1W	0.3563 (3)	0.8151 (3)	0.66122 (17)	0.0430 (7)
H1W	0.4129	0.8882	0.6845	0.064*
H2W	0.3144	0.7877	0.7057	0.064*
O2W	0.0271 (3)	0.8392 (2)	0.5368 (2)	0.0409 (7)
H3W	0.0474	0.9082	0.5768	0.061*
H4W	−0.0580	0.7965	0.5443	0.061*
O3W	0.2166 (3)	0.7760 (2)	0.33238 (17)	0.0375 (6)
H5W	0.1866	0.7138	0.2865	0.056*
H6W	0.2701	0.8366	0.3118	0.056*
O4W	0.3673 (3)	0.5775 (2)	0.4469 (2)	0.0384 (6)
H7W	0.3347	0.4964	0.4398	0.058*
H8W	0.4410	0.5907	0.4168	0.058*
O5W	0.5945 (3)	0.0292 (3)	0.7338 (2)	0.0478 (7)
H9W	0.5749	0.0653	0.7851	0.072*
H10W	0.6603	−0.0171	0.7494	0.072*
O6W	0.8142 (4)	0.8544 (3)	0.7569 (2)	0.0604 (9)
H12W	0.8929	0.9105	0.7552	0.091*
H11W	0.8110	0.8507	0.8152	0.091*
O7W	0.7480 (3)	0.6941 (2)	0.5762 (2)	0.0387 (6)
H13W	0.6919	0.7345	0.5421	0.058*
H14W	0.7622	0.7313	0.6336	0.058*
O8W	0.5890 (4)	0.2199 (3)	0.8812 (2)	0.0631 (9)
H15W	0.6508	0.2917	0.8877	0.095*
H16W	0.5431	0.2229	0.9284	0.095*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Er1	0.02294 (10)	0.01592 (8)	0.02381 (9)	−0.00464 (6)	0.00914 (6)	−0.00033 (6)
Br1	0.0424 (2)	0.0477 (2)	0.0447 (2)	0.00720 (19)	0.00907 (19)	0.00745 (19)
Cu1	0.0406 (3)	0.0249 (2)	0.0266 (2)	−0.00133 (19)	0.0166 (2)	−0.00292 (17)
O1	0.0452 (16)	0.0277 (12)	0.0329 (13)	−0.0031 (11)	0.0188 (12)	−0.0028 (10)
O2	0.081 (2)	0.0332 (14)	0.0424 (16)	−0.0094 (15)	0.0276 (16)	−0.0142 (12)
O3	0.0457 (16)	0.0303 (13)	0.0318 (14)	−0.0056 (12)	0.0169 (12)	−0.0033 (11)
O4	0.0581 (19)	0.0359 (14)	0.0379 (15)	−0.0042 (13)	0.0151 (14)	−0.0137 (12)
O5	0.0262 (12)	0.0159 (10)	0.0394 (14)	−0.0024 (9)	0.0106 (11)	0.0025 (10)
O6	0.0252 (13)	0.0185 (10)	0.0421 (14)	−0.0032 (10)	0.0138 (11)	0.0019 (10)
O7	0.0358 (14)	0.0237 (11)	0.0257 (12)	−0.0112 (10)	0.0053 (11)	0.0037 (10)
O8	0.0319 (13)	0.0282 (12)	0.0262 (12)	−0.0127 (10)	0.0053 (11)	0.0038 (10)
N1	0.0311 (16)	0.0243 (14)	0.0237 (14)	0.0014 (12)	0.0066 (12)	−0.0002 (11)
N2	0.0399 (18)	0.0391 (17)	0.0304 (16)	0.0028 (15)	0.0147 (14)	0.0063 (13)
N3	0.0342 (16)	0.0237 (14)	0.0293 (15)	0.0023 (12)	0.0133 (13)	−0.0002 (12)
N4	0.048 (2)	0.0419 (18)	0.0375 (18)	0.0063 (16)	0.0211 (16)	0.0071 (15)
C1	0.044 (2)	0.0243 (16)	0.0255 (17)	0.0000 (16)	0.0110 (16)	−0.0007 (14)
C2	0.0344 (19)	0.0274 (16)	0.0204 (16)	0.0061 (15)	0.0082 (14)	0.0024 (13)
C3	0.039 (2)	0.0337 (18)	0.0246 (17)	0.0051 (17)	0.0110 (16)	−0.0001 (15)
C4	0.035 (2)	0.0352 (19)	0.036 (2)	−0.0019 (17)	0.0102 (17)	0.0057 (16)
C5	0.0326 (19)	0.0286 (17)	0.0312 (19)	0.0014 (15)	0.0071 (16)	−0.0004 (14)
C6	0.0318 (19)	0.0271 (17)	0.0326 (19)	0.0021 (15)	0.0093 (16)	−0.0005 (15)
C7	0.0325 (19)	0.0268 (17)	0.0258 (17)	0.0069 (15)	0.0082 (15)	0.0009 (14)
C8	0.045 (2)	0.0345 (19)	0.0285 (19)	0.0096 (17)	0.0132 (17)	0.0025 (15)
C9	0.047 (2)	0.034 (2)	0.052 (2)	0.0019 (18)	0.025 (2)	0.0071 (18)
C10	0.044 (2)	0.0285 (18)	0.041 (2)	0.0000 (17)	0.0159 (18)	−0.0013 (16)
C11	0.0250 (17)	0.0201 (15)	0.0221 (16)	−0.0002 (14)	0.0081 (14)	−0.0002 (12)
C12	0.0269 (18)	0.0205 (15)	0.0227 (17)	−0.0021 (14)	0.0106 (14)	−0.0033 (13)
O1W	0.0475 (17)	0.0427 (15)	0.0261 (13)	−0.0250 (13)	0.0108 (12)	−0.0022 (11)
O2W	0.0306 (14)	0.0292 (13)	0.0579 (17)	−0.0072 (11)	0.0199 (13)	−0.0102 (12)
O3W	0.0540 (17)	0.0287 (12)	0.0239 (12)	−0.0092 (12)	0.0094 (12)	0.0016 (10)
O4W	0.0421 (15)	0.0188 (11)	0.0575 (17)	0.0002 (11)	0.0276 (13)	0.0015 (11)
O5W	0.0489 (18)	0.0379 (15)	0.0496 (17)	−0.0084 (13)	0.0054 (14)	0.0076 (13)
O6W	0.060 (2)	0.061 (2)	0.0511 (19)	−0.0132 (17)	0.0087 (16)	0.0095 (16)
O7W	0.0362 (15)	0.0275 (12)	0.0513 (16)	0.0036 (11)	0.0088 (13)	0.0043 (12)
O8W	0.061 (2)	0.059 (2)	0.067 (2)	−0.0046 (17)	0.0265 (18)	0.0014 (17)

Geometric parameters (Å, º) top

Er1—O1W	2.300 (2)	C1—C2	1.504 (5)
Er1—O3W	2.307 (2)	C2—C3	1.375 (5)
Er1—O2W	2.326 (2)	C3—H3	0.9300
Er1—O4W	2.327 (2)	C4—C5	1.384 (5)
Er1—O8ⁱ	2.337 (2)	C4—H4	0.9300
Er1—O7	2.352 (2)	C5—H5	0.9300
Er1—O6ⁱⁱ	2.377 (2)	C6—C7	1.508 (5)
Er1—O5	2.379 (2)	C7—C8	1.382 (5)
Br1—Cu1	2.7158 (7)	C8—H8	0.9300
Cu1—O3	1.943 (2)	C9—C10	1.383 (5)
Cu1—O1	1.961 (2)	C9—H9	0.9300
Cu1—N3	1.985 (3)	C10—H10	0.9300
Cu1—N1	1.987 (3)	C11—C11ⁱⁱ	1.547 (6)
O1—C1	1.274 (4)	C12—C12ⁱ	1.553 (6)
O2—C1	1.228 (4)	O1W—H1W	0.8200
O3—C6	1.278 (4)	O1W—H2W	0.8200
O4—C6	1.229 (4)	O2W—H3W	0.8200
O5—C11	1.250 (4)	O2W—H4W	0.8200
O6—C11	1.245 (4)	O3W—H5W	0.8200
O6—Er1ⁱⁱ	2.377 (2)	O3W—H6W	0.8200
O7—C12	1.248 (4)	O4W—H7W	0.8200
O8—C12	1.246 (4)	O4W—H8W	0.8200
O8—Er1ⁱ	2.337 (2)	O5W—H9W	0.8200
N1—C5	1.328 (4)	O5W—H10W	0.8200
N1—C2	1.349 (4)	O6W—H12W	0.8200
N2—C4	1.329 (5)	O6W—H11W	0.8200
N2—C3	1.340 (5)	O7W—H13W	0.8200
N3—C10	1.334 (5)	O7W—H14W	0.8200
N3—C7	1.342 (4)	O8W—H15W	0.8200
N4—C9	1.328 (5)	O8W—H16W	0.8200
N4—C8	1.337 (5)

O1W—Er1—O3W	152.60 (9)	O2—C1—O1	124.3 (3)
O1W—Er1—O2W	85.77 (10)	O2—C1—C2	119.9 (3)
O3W—Er1—O2W	100.11 (10)	O1—C1—C2	115.8 (3)
O1W—Er1—O4W	103.65 (10)	N1—C2—C3	120.4 (3)
O3W—Er1—O4W	82.75 (9)	N1—C2—C1	114.4 (3)
O2W—Er1—O4W	153.97 (9)	C3—C2—C1	125.1 (3)
O1W—Er1—O8ⁱ	68.99 (8)	N2—C3—C2	121.9 (3)
O3W—Er1—O8ⁱ	138.02 (8)	N2—C3—H3	119.1
O2W—Er1—O8ⁱ	83.33 (9)	C2—C3—H3	119.1
O4W—Er1—O8ⁱ	77.78 (9)	N2—C4—C5	122.4 (3)
O1W—Er1—O7	136.09 (9)	N2—C4—H4	118.8
O3W—Er1—O7	70.96 (8)	C5—C4—H4	118.8
O2W—Er1—O7	76.34 (8)	N1—C5—C4	120.3 (3)
O4W—Er1—O7	80.30 (9)	N1—C5—H5	119.9
O8ⁱ—Er1—O7	69.32 (8)	C4—C5—H5	119.9
O1W—Er1—O6ⁱⁱ	80.45 (9)	O4—C6—O3	124.5 (3)
O3W—Er1—O6ⁱⁱ	76.48 (8)	O4—C6—C7	120.2 (3)
O2W—Er1—O6ⁱⁱ	70.57 (8)	O3—C6—C7	115.3 (3)
O4W—Er1—O6ⁱⁱ	134.44 (9)	N3—C7—C8	120.3 (3)
O8ⁱ—Er1—O6ⁱⁱ	141.07 (8)	N3—C7—C6	114.6 (3)
O7—Er1—O6ⁱⁱ	127.85 (8)	C8—C7—C6	125.1 (3)
O1W—Er1—O5	75.95 (9)	N4—C8—C7	121.9 (3)
O3W—Er1—O5	81.80 (9)	N4—C8—H8	119.1
O2W—Er1—O5	136.79 (8)	C7—C8—H8	119.1
O4W—Er1—O5	69.22 (8)	N4—C9—C10	122.5 (4)
O8ⁱ—Er1—O5	123.61 (8)	N4—C9—H9	118.7
O7—Er1—O5	141.32 (8)	C10—C9—H9	118.7
O6ⁱⁱ—Er1—O5	67.99 (7)	N3—C10—C9	120.0 (3)
O3—Cu1—O1	167.79 (12)	N3—C10—H10	120.0
O3—Cu1—N3	83.39 (11)	C9—C10—H10	120.0
O1—Cu1—N3	95.48 (11)	O6—C11—O5	127.1 (3)
O3—Cu1—N1	95.47 (11)	O6—C11—C11ⁱⁱ	117.2 (3)
O1—Cu1—N1	83.09 (10)	O5—C11—C11ⁱⁱ	115.8 (4)
N3—Cu1—N1	167.97 (12)	O7—C12—O8	127.0 (3)
O3—Cu1—Br1	97.11 (8)	O7—C12—C12ⁱ	116.8 (3)
O1—Cu1—Br1	95.08 (8)	O8—C12—C12ⁱ	116.3 (4)
N3—Cu1—Br1	98.49 (9)	Er1—O1W—H1W	124.5
N1—Cu1—Br1	93.53 (8)	Er1—O1W—H2W	122.6
C1—O1—Cu1	114.6 (2)	H1W—O1W—H2W	106.9
C6—O3—Cu1	115.0 (2)	Er1—O2W—H3W	116.9
C11—O5—Er1	119.8 (2)	Er1—O2W—H4W	126.3
C11—O6—Er1ⁱⁱ	119.3 (2)	H3W—O2W—H4W	107.1
C12—O7—Er1	118.4 (2)	Er1—O3W—H5W	124.0
C12—O8—Er1ⁱ	119.3 (2)	Er1—O3W—H6W	123.9
C5—N1—C2	118.2 (3)	H5W—O3W—H6W	107.0
C5—N1—Cu1	130.1 (2)	Er1—O4W—H7W	129.1
C2—N1—Cu1	111.5 (2)	Er1—O4W—H8W	120.7
C4—N2—C3	116.7 (3)	H7W—O4W—H8W	107.7
C10—N3—C7	118.4 (3)	H9W—O5W—H10W	107.1
C10—N3—Cu1	129.9 (2)	H12W—O6W—H11W	107.2
C7—N3—Cu1	111.6 (2)	H13W—O7W—H14W	107.4
C9—N4—C8	116.8 (3)	H15W—O8W—H16W	106.9

O3—Cu1—O1—C1	−89.6 (6)	C5—N1—C2—C3	−1.5 (5)
N3—Cu1—O1—C1	−173.7 (3)	Cu1—N1—C2—C3	174.7 (3)
N1—Cu1—O1—C1	−5.7 (3)	C5—N1—C2—C1	177.2 (3)
Br1—Cu1—O1—C1	87.2 (3)	Cu1—N1—C2—C1	−6.6 (4)
O1—Cu1—O3—C6	−89.5 (6)	O2—C1—C2—N1	−175.8 (3)
N3—Cu1—O3—C6	−4.1 (3)	O1—C1—C2—N1	2.1 (5)
N1—Cu1—O3—C6	−172.1 (3)	O2—C1—C2—C3	2.8 (6)
Br1—Cu1—O3—C6	93.7 (2)	O1—C1—C2—C3	−179.3 (3)
O1W—Er1—O5—C11	−84.7 (2)	C4—N2—C3—C2	−0.6 (5)
O3W—Er1—O5—C11	79.2 (2)	N1—C2—C3—N2	2.2 (5)
O2W—Er1—O5—C11	−16.8 (3)	C1—C2—C3—N2	−176.3 (3)
O4W—Er1—O5—C11	164.5 (3)	C3—N2—C4—C5	−1.7 (5)
O8ⁱ—Er1—O5—C11	−137.1 (2)	C2—N1—C5—C4	−0.7 (5)
O7—Er1—O5—C11	124.2 (2)	Cu1—N1—C5—C4	−176.1 (3)
O6ⁱⁱ—Er1—O5—C11	0.6 (2)	N2—C4—C5—N1	2.4 (6)
O1W—Er1—O7—C12	−19.6 (3)	Cu1—O3—C6—O4	−174.1 (3)
O3W—Er1—O7—C12	165.7 (3)	Cu1—O3—C6—C7	4.4 (4)
O2W—Er1—O7—C12	−88.3 (2)	C10—N3—C7—C8	−0.4 (5)
O4W—Er1—O7—C12	80.1 (2)	Cu1—N3—C7—C8	177.0 (3)
O8ⁱ—Er1—O7—C12	−0.4 (2)	C10—N3—C7—C6	−178.8 (3)
O6ⁱⁱ—Er1—O7—C12	−139.9 (2)	Cu1—N3—C7—C6	−1.4 (4)
O5—Er1—O7—C12	118.0 (2)	O4—C6—C7—N3	176.7 (3)
O3—Cu1—N1—C5	−9.8 (3)	O3—C6—C7—N3	−1.9 (5)
O1—Cu1—N1—C5	−177.6 (3)	O4—C6—C7—C8	−1.7 (6)
N3—Cu1—N1—C5	−93.8 (6)	O3—C6—C7—C8	179.8 (3)
Br1—Cu1—N1—C5	87.7 (3)	C9—N4—C8—C7	0.3 (6)
O3—Cu1—N1—C2	174.5 (2)	N3—C7—C8—N4	0.6 (6)
O1—Cu1—N1—C2	6.7 (2)	C6—C7—C8—N4	178.9 (3)
N3—Cu1—N1—C2	90.5 (6)	C8—N4—C9—C10	−1.4 (6)
Br1—Cu1—N1—C2	−88.0 (2)	C7—N3—C10—C9	−0.7 (5)
O3—Cu1—N3—C10	179.9 (3)	Cu1—N3—C10—C9	−177.5 (3)
O1—Cu1—N3—C10	−12.3 (3)	N4—C9—C10—N3	1.7 (6)
N1—Cu1—N3—C10	−94.9 (6)	Er1ⁱⁱ—O6—C11—O5	179.5 (3)
Br1—Cu1—N3—C10	83.7 (3)	Er1ⁱⁱ—O6—C11—C11ⁱⁱ	−0.3 (5)
O3—Cu1—N3—C7	2.9 (2)	Er1—O5—C11—O6	179.6 (3)
O1—Cu1—N3—C7	170.6 (2)	Er1—O5—C11—C11ⁱⁱ	−0.6 (4)
N1—Cu1—N3—C7	88.1 (6)	Er1—O7—C12—O8	−179.4 (3)
Br1—Cu1—N3—C7	−93.4 (2)	Er1—O7—C12—C12ⁱ	0.2 (5)
Cu1—O1—C1—O2	−178.5 (3)	Er1ⁱ—O8—C12—O7	−179.6 (3)
Cu1—O1—C1—C2	3.6 (4)	Er1ⁱ—O8—C12—C12ⁱ	0.8 (5)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W···O5Wⁱⁱⁱ	0.82	1.92	2.712 (3)	163
O1W—H2W···N2^iv	0.82	2.01	2.823 (4)	168
O2W—H3W···O4ⁱⁱ	0.82	2.04	2.825 (3)	159
O2W—H4W···O7W^v	0.82	1.97	2.788 (4)	174
O3W—H5W···O2^vi	0.82	1.97	2.781 (3)	167
O3W—H6W···O5W^vii	0.82	1.89	2.710 (4)	176
O4W—H7W···O7W^vii	0.82	1.94	2.758 (3)	178
O4W—H8W···N4	0.82	2.08	2.886 (4)	169
O5W—H9W···O8W	0.82	1.92	2.670 (4)	152
O5W—H10W···O6W^viii	0.82	2.03	2.835 (4)	168
O6W—H11W···Br1^ix	0.82	2.59	3.299 (3)	146
O6W—H12W···O3^x	0.82	2.57	3.238 (4)	139
O6W—H12W···O4^x	0.82	2.07	2.866 (4)	164
O7W—H13W···O5	0.82	2.04	2.826 (3)	161
O7W—H14W···O6W	0.82	1.94	2.746 (4)	167
O8W—H15W···O1^ix	0.82	2.58	3.351 (4)	157
O8W—H15W···O2^ix	0.82	2.23	2.951 (4)	147
O8W—H16W···Br1^vii	0.82	2.53	3.337 (3)	170

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

Experimental details

Crystal data
Chemical formula	[Er(C₂O₄)(H₂O)₄][CuBr(C₅H₃N₂O₂)₂]·4H₂O
M_r	789.05
Crystal system, space group	Triclinic, P1
Temperature (K)	295
a, b, c (Å)	8.6678 (3), 10.2623 (4), 13.8748 (2)
α, β, γ (°)	96.872 (1), 99.419 (1), 99.748 (1)
V (Å³)	1186.10 (6)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	6.18
Crystal size (mm)	0.26 × 0.25 × 0.19

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.232, 0.324
No. of measured, independent and observed [I > 2σ(I)] reflections	14850, 5260, 4480
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.027, 0.072, 1.01
No. of reflections	5260
No. of parameters	316
No. of restraints	24
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.59, −0.88

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W···O5Wⁱ	0.82	1.92	2.712 (3)	163
O1W—H2W···N2ⁱⁱ	0.82	2.01	2.823 (4)	168
O2W—H3W···O4ⁱⁱⁱ	0.82	2.04	2.825 (3)	159
O2W—H4W···O7W^iv	0.82	1.97	2.788 (4)	174
O3W—H5W···O2^v	0.82	1.97	2.781 (3)	167
O3W—H6W···O5W^vi	0.82	1.89	2.710 (4)	176
O4W—H7W···O7W^vi	0.82	1.94	2.758 (3)	178
O4W—H8W···N4	0.82	2.08	2.886 (4)	169
O5W—H9W···O8W	0.82	1.92	2.670 (4)	152
O5W—H10W···O6W^vii	0.82	2.03	2.835 (4)	168
O6W—H11W···Br1^viii	0.82	2.59	3.299 (3)	146
O6W—H12W···O3^ix	0.82	2.57	3.238 (4)	139
O6W—H12W···O4^ix	0.82	2.07	2.866 (4)	164
O7W—H13W···O5	0.82	2.04	2.826 (3)	161
O7W—H14W···O6W	0.82	1.94	2.746 (4)	167
O8W—H15W···O1^viii	0.82	2.58	3.351 (4)	157
O8W—H15W···O2^viii	0.82	2.23	2.951 (4)	147
O8W—H16W···Br1^vi	0.82	2.53	3.337 (3)	170

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

Acknowledgements

The authors acknowledge the National Natural Science Foundation of China (grant No. 20772048) for supporting this work.

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