Disodium tricopper(II) tetra­kis[selenate(IV)] tetra­hydrate

Liu, W.; Zhang, L.; Hu, K.; Cao, L.; Su, G.; Zhao, J.

doi:10.1107/S160053680803434X

inorganic compounds

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ISSN: 2056-9890

Volume 64| Part 11| November 2008| Page i78

doi:10.1107/S160053680803434X

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Disodium tricopper(II) tetrakis[selenate(IV)] tetrahydrate

Wei Liu,^a ^* Lan Zhang,^a Kai Hu,^b Lixin Cao,^a Ge Su ^a and Jingtai Zhao ^c

^aInstitute of Materials Science and Engineering, The Ocean University of China, Qingdao 266100, People's Republic of China, ^bDepartment of Computer Science, Dezhou University, Shandong 253023, People's Republic of China, and ^cState Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050, People's Republic of China
^*Correspondence e-mail: weiliu@ouc.edu.cn

(Received 9 September 2008; accepted 21 October 2008; online 25 October 2008)

The title compound, Na₂Cu₃(SeO₃)₄(H₂O)₄, has been prepared under hydrothermal conditions. The crystal structure contains a three-dimensional anionic framework made up from distorted [CuO₄(H₂O)₂] octahedra ( $[\overline{1}]$ symmetry), [CuO₄(H₂O)] square pyramids and trigonal-pyramidal SeO₃ units sharing common corners. The connectivity among these units leads to four- and eight-membered polyhedral rings, which by edge-sharing interconnect into walls. A rhombus-like 16-membered polyhedral ring channel system with a longest length of approximately 14.0 Å and a shortest length of 5.3 Å is enclosed by such walls along the a axis. The water molecules attached to the Cu atoms, as well as the electron lone pairs of the Se^IV atoms, protrude into these channels. The seven-coordinated Na⁺ counter-cations occupy the remaining free space of the 16-membered polyhedral ring channels. An intricate network of O—H⋯O hydrogen bonds further consolidates the three-dimensional structure.

Related literature

For the structures of other hydrous copper(II) selenates(IV) or selenates(VI), see: Asai & Kiriyama (1973 ), Giester (1991 ); Iskhakova & Kozlova (1995 ).

Experimental

Crystal data

Na₂Cu₃(SeO₃)₄(H₂O)₄
M_r = 816.50
Monoclinic, P 2₁ /c
a = 5.2218 (5) Å
b = 8.9863 (6) Å
c = 15.7960 (11) Å
β = 92.071 (4)°
V = 740.74 (10) Å³
Z = 2
Mo Kα radiation
μ = 14.24 mm⁻¹
T = 296 (2) K
0.15 × 0.10 × 0.10 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ) T_min = 0.204, T_max = 0.250
6010 measured reflections
2142 independent reflections
2065 reflections with I > 2σ(I)
R_int = 0.027

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.068
S = 1.12
2142 reflections
115 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.77 e Å⁻³
Δρ_min = −1.02 e Å⁻³

Table 1
Selected bond lengths (Å)

Se1—O7	1.698 (3)
Se1—O2	1.705 (3)
Se1—O4	1.709 (3)
Se2—O8	1.673 (3)
Se2—O1	1.708 (3)
Se2—O3	1.717 (3)
Cu1—O4	1.968 (3)
Cu1—O6	1.990 (3)
Cu1—O8ⁱ	2.475 (3)
Cu2—O1ⁱⁱ	1.947 (3)
Cu2—O3	1.962 (3)
Cu2—O2	1.968 (3)
Cu2—O7ⁱⁱⁱ	1.980 (3)
Cu2—O5	2.268 (3)
Symmetry codes: (i) $[-x-1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (ii) x+1, y, z; (iii) x-1, y, z.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—H1⋯O4^iv	0.80 (8)	2.00 (8)	2.786 (4)	168 (7)
O5—H2⋯O3^v	0.87 (8)	1.88 (8)	2.746 (4)	174 (7)
O6—H3⋯O8^vi	0.87 (8)	1.91 (8)	2.758 (5)	163 (7)
O6—H4⋯O1ⁱ	0.89 (8)	1.76 (8)	2.641 (4)	169 (8)
Symmetry codes: (i) $[-x-1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iv) -x, -y+1, -z; (v) $[-x-1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (vi) $[-x, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ) and DIAMOND (Crystal Impact, 2004 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680803434X/wm2197sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053680803434X/wm2197Isup2.hkl

checkCIF report

Comment top

Studies of hydrous copper selenites and selenates with three-dimensional frameworks have been reported previously, e.g. by Asai & Kiriyama (1973), Giester (1991) and Iskhakova & Kozlova (1995). Among the corresponding structures various polyhedral ring channel systems are established. The current article presents the result of the single-crystal X-ray analysis of a new sodium copper selenite, Na₂Cu₃(SeO₃)₄(H₂O)₄, (I), with a 16-membered polydedral ring channel system.

In the asymmetric unit of (I) there are two crystallographically distinct copper atoms. The six-coordinated Cu1 site is a typical Jahn-Teller ion with a distorted, tetragonally elongated octahedral [Cu1O₄(H₂O)₂] coordination, whereas Cu2 is surrounded by five O-atoms, leading to a distorted square-pyramidal [Cu2O₄(H₂O)] environment. The two independent selenium atoms are coordinated by three oxygen atoms, forming the characteristic trigonal-pyramidal SeO₃^2- anion (Fig. 1).

The square-pyramidal [Cu2O₄(H₂O)] units share its basal O atoms with four neighboring SeO₃ units leading to chains of corner-shared four-membered polyhedral rings running along [100]. The [Cu1O₄(H₂O)₂] units are located between such parallel chains and bridge them via Cu—O—Se bonds into an open framework. The water molecules attached to Cu1 and Cu2 as well as the electron lone-pairs of the selenium(IV) atoms protrude into the free space of this network (Fig. 2).

The basic features of the structure could also be described as the assemblage of linear chains of Cu and Se centres leading to 4-membered and 8-membered rings that interconnect by edge-sharing into two similar wavy layer packings extending along [011] and [011], respectively. Such layers intersect at the Cu(1) sites, eventually forming a rhombus-like 16-membered ring channel system extending along the a axis with the biggest length of approximately 14.0 Å and the smallest length of 5.3 Å (Fig.3).

The Na⁺ counter cations are coordinated by seven oxygen atoms and occupy the central space of the 16-membered ring polyhedral channels to keep the structural stability and satisfy the charge balance. An intricate network of O—H···O hydrogen bonds further consolidates the three-dimensional structure (Table 2).

Related literature top

For the structures of other hydrous copper(II) selenates(IV) or selenates(VI), see: Asai & Kiriyama (1973), Giester (1991); Iskhakova & Kozlova (1995).

Experimental top

The title compound was synthesized under hydrothermal conditions. A mixture of Na₂SeO₃ and CuSO₄^.5H₂O in a molar ratio of 1:1 was placed in a Teflon-lined stainless steel autoclave and heated to 443 K for 5 d, cooled at 2 K/h to 373 K, and finally cooled to room temperature. Light blue crystals with a rod-like habit were obtained. Cu, Se and Na contents were analyzed using ICP-AES (Varian Vista, radial observation): Obs./calc. mass%: Cu, 23.33/23.91; Se, 38.70/39.23; Na, 5.63/5.42.

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Crystal Impact, 2004); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The coordination environment of copper and selenium atoms with anisotropic thermal ellipsoids drawn at the 60% probability level. H atoms are draw as small spheres of arbitrary radius. [Symmetry codes: (i) -x, -y, -z; (ii) -x - 1, y - 1/2, -z + 1/2; (iii) x + 1, y, z; (iv) x - 1, y, z).]
	Fig. 2. The 16-membered polyhedral ring channels of (I), filled with Na⁺ counter cations.
	Fig. 3. Schematic representation of the formation of the anionic framework structure of (I). (a): The wavy layer built from an edge-sharing linear chain by corner-sharing 4-membered rings and ladders by edge-sharing 8-membered rings; (b): The wavy layers intersecting each other with an approximate angle of 110° to the entire three-dimensional open-framework. (Black spheres: Cu atoms; white spheres: Se atoms).

disodium tricopper(II) tetrakis[selenate(IV)] tetrahydrate top

Crystal data top

Na₂Cu₃(SeO₃)₄(H₂O)₄	F(000) = 762
M_r = 816.50	D_x = 3.661 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 986 reflections
a = 5.2218 (5) Å	θ = 2.6–22.8°
b = 8.9863 (6) Å	µ = 14.24 mm⁻¹
c = 15.7960 (11) Å	T = 296 K
β = 92.071 (4)°	Rod, light blue
V = 740.74 (10) Å³	0.15 × 0.10 × 0.10 mm
Z = 2

Data collection top

Bruker SMART CCD diffractometer	2142 independent reflections
Radiation source: fine-focus sealed tube	2065 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.027
ω scans	θ_max = 30.0°, θ_min = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −7→7
T_min = 0.204, T_max = 0.250	k = −12→12
6010 measured reflections	l = −21→22

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.068	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	w = 1/[σ²(F_o²) + (0.0202P)² + 3.7977P] where P = (F_o² + 2F_c²)/3
2142 reflections	(Δ/σ)_max = 0.001
115 parameters	Δρ_max = 0.77 e Å⁻³
0 restraints	Δρ_min = −1.02 e Å⁻³

Crystal data top

Na₂Cu₃(SeO₃)₄(H₂O)₄	V = 740.74 (10) Å³
M_r = 816.50	Z = 2
Monoclinic, P2₁/c	Mo Kα radiation
a = 5.2218 (5) Å	µ = 14.24 mm⁻¹
b = 8.9863 (6) Å	T = 296 K
c = 15.7960 (11) Å	0.15 × 0.10 × 0.10 mm
β = 92.071 (4)°

Data collection top

Bruker SMART CCD diffractometer	2142 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	2065 reflections with I > 2σ(I)
T_min = 0.204, T_max = 0.250	R_int = 0.027
6010 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	0 restraints
wR(F²) = 0.068	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	Δρ_max = 0.77 e Å⁻³
2142 reflections	Δρ_min = −1.02 e Å⁻³
115 parameters

Special details top

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

Refinement. Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > σ(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	U_iso*/U_eq
Se1	0.20254 (7)	0.28287 (4)	0.09687 (2)	0.01090 (10)
Se2	−0.79415 (7)	0.53958 (5)	0.27304 (2)	0.01476 (11)
Cu1	0.0000	0.0000	0.0000	0.01381 (14)
Cu2	−0.29891 (8)	0.42910 (6)	0.17116 (3)	0.01266 (11)
O1	−1.0733 (5)	0.4403 (4)	0.27181 (18)	0.0207 (6)
O2	−0.0088 (5)	0.4276 (3)	0.09497 (18)	0.0153 (5)
O3	−0.5831 (5)	0.4016 (3)	0.24757 (18)	0.0165 (5)
O4	0.1289 (6)	0.2058 (3)	0.00011 (18)	0.0166 (5)
O5	−0.3653 (7)	0.6725 (4)	0.1392 (2)	0.0209 (6)
O6	0.2781 (6)	−0.0756 (4)	0.07804 (19)	0.0199 (6)
O7	0.4702 (5)	0.3793 (3)	0.07309 (17)	0.0149 (5)
O8	−0.7371 (6)	0.5600 (4)	0.3773 (2)	0.0272 (7)
Na1	0.7415 (3)	0.3619 (2)	−0.04070 (11)	0.0226 (4)
H1	−0.277 (15)	0.707 (9)	0.104 (5)	0.050*
H2	−0.372 (14)	0.748 (9)	0.174 (5)	0.050*
H4	0.226 (15)	−0.063 (9)	0.131 (5)	0.050*
H3	0.437 (15)	−0.049 (9)	0.088 (5)	0.050*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Se1	0.01040 (17)	0.01286 (18)	0.00949 (17)	−0.00189 (12)	0.00133 (12)	−0.00064 (12)
Se2	0.01172 (18)	0.0176 (2)	0.01500 (18)	0.00083 (13)	0.00180 (13)	−0.00071 (14)
Cu1	0.0139 (3)	0.0124 (3)	0.0149 (3)	−0.0023 (2)	−0.0030 (2)	−0.0004 (2)
Cu2	0.0085 (2)	0.0195 (2)	0.0101 (2)	0.00022 (17)	0.00143 (15)	−0.00087 (17)
O1	0.0097 (12)	0.0415 (19)	0.0110 (12)	−0.0042 (12)	0.0007 (10)	−0.0034 (12)
O2	0.0107 (12)	0.0208 (14)	0.0146 (12)	0.0036 (10)	0.0042 (10)	0.0019 (11)
O3	0.0137 (12)	0.0207 (14)	0.0152 (12)	0.0002 (11)	0.0044 (10)	0.0009 (11)
O4	0.0211 (14)	0.0166 (13)	0.0121 (12)	−0.0080 (11)	0.0015 (10)	−0.0022 (10)
O5	0.0298 (16)	0.0117 (14)	0.0215 (15)	−0.0011 (12)	0.0048 (13)	−0.0013 (11)
O6	0.0177 (14)	0.0280 (17)	0.0138 (13)	0.0011 (12)	−0.0030 (11)	−0.0043 (12)
O7	0.0099 (11)	0.0215 (14)	0.0135 (12)	−0.0054 (10)	0.0010 (9)	−0.0021 (11)
O8	0.0190 (14)	0.045 (2)	0.0176 (14)	−0.0028 (14)	0.0012 (12)	−0.0149 (14)
Na1	0.0193 (8)	0.0307 (10)	0.0177 (8)	0.0015 (7)	0.0015 (6)	0.0005 (7)

Geometric parameters (Å, º) top

Se1—O7	1.698 (3)	Cu2—O1ⁱⁱⁱ	1.947 (3)
Se1—O2	1.705 (3)	Cu2—O3	1.962 (3)
Se1—O4	1.709 (3)	Cu2—O2	1.968 (3)
Se2—O8	1.673 (3)	Cu2—O7^iv	1.980 (3)
Se2—O1	1.708 (3)	Cu2—O5	2.268 (3)
Se2—O3	1.717 (3)	Na1—O7	2.333 (4)
Cu1—O4	1.968 (3)	Na1—O5^v	2.482 (4)
Cu1—O4ⁱ	1.968 (3)	Na1—O2^vi	2.519 (4)
Cu1—O6	1.990 (3)	Na1—O4ⁱⁱⁱ	2.526 (4)
Cu1—O6ⁱ	1.990 (3)	Na1—O2ⁱⁱⁱ	2.537 (3)
Cu1—O8ⁱⁱ	2.475 (3)	Na1—O7^vi	2.618 (4)
Cu1—O8ⁱⁱ	2.475 (3)	Na1—O6^vii	2.641 (4)

O7—Se1—O2	98.30 (14)	Cu2—O5—H2	129 (5)
O7—Se1—O4	99.75 (13)	Na1^v—O5—H2	116 (5)
O2—Se1—O4	99.71 (14)	H1—O5—H2	100 (7)
O8—Se2—O1	100.95 (16)	Cu1—O6—Na1^vii	99.94 (13)
O8—Se2—O3	102.54 (16)	Cu1—O6—H4	107 (5)
O1—Se2—O3	100.08 (15)	Na1^vii—O6—H4	109 (5)
O4—Cu1—O4ⁱ	180.00 (6)	Cu1—O6—H3	133 (5)
O4—Cu1—O6	94.50 (13)	Na1^vii—O6—H3	110 (5)
O4ⁱ—Cu1—O6	85.50 (13)	H4—O6—H3	97 (7)
O4—Cu1—O6ⁱ	85.50 (13)	Se1—O7—Cu2ⁱⁱⁱ	115.16 (15)
O4ⁱ—Cu1—O6ⁱ	94.50 (13)	Se1—O7—Na1	131.60 (16)
O6—Cu1—O6ⁱ	180.00 (14)	Cu2ⁱⁱⁱ—O7—Na1	104.37 (12)
O1ⁱⁱⁱ—Cu2—O3	87.30 (12)	Se1—O7—Na1^vi	98.71 (13)
O1ⁱⁱⁱ—Cu2—O2	92.48 (12)	Cu2ⁱⁱⁱ—O7—Na1^vi	101.13 (12)
O3—Cu2—O2	172.34 (13)	Na1—O7—Na1^vi	99.95 (12)
O1ⁱⁱⁱ—Cu2—O7^iv	169.80 (14)	O7—Na1—O5^v	90.14 (12)
O3—Cu2—O7^iv	90.00 (12)	O7—Na1—O2^vi	124.83 (13)
O2—Cu2—O7^iv	88.88 (11)	O5^v—Na1—O2^vi	108.41 (12)
O1ⁱⁱⁱ—Cu2—O5	102.39 (14)	O7—Na1—O4ⁱⁱⁱ	110.09 (12)
O3—Cu2—O5	98.36 (13)	O5^v—Na1—O4ⁱⁱⁱ	134.38 (13)
O2—Cu2—O5	89.17 (12)	O2^vi—Na1—O4ⁱⁱⁱ	93.18 (11)
O7^iv—Cu2—O5	87.73 (12)	O7—Na1—O2ⁱⁱⁱ	69.01 (10)
Se2—O1—Cu2^iv	121.82 (17)	O5^v—Na1—O2ⁱⁱⁱ	158.39 (13)
Se1—O2—Cu2	120.42 (16)	O2^vi—Na1—O2ⁱⁱⁱ	80.72 (11)
Se1—O2—Na1^vi	102.26 (13)	O4ⁱⁱⁱ—Na1—O2ⁱⁱⁱ	62.06 (10)
Cu2—O2—Na1^vi	130.61 (15)	O7—Na1—O7^vi	80.06 (12)
Se1—O2—Na1^iv	98.62 (14)	O5^v—Na1—O7^vi	70.66 (11)
Cu2—O2—Na1^iv	97.75 (12)	O2^vi—Na1—O7^vi	60.11 (10)
Na1^vi—O2—Na1^iv	99.28 (11)	O4ⁱⁱⁱ—Na1—O7^vi	150.69 (12)
Se2—O3—Cu2	124.02 (17)	O2ⁱⁱⁱ—Na1—O7^vi	99.14 (11)
Se1—O4—Cu1	116.58 (15)	O7—Na1—O6^vii	102.55 (12)
Se1—O4—Na1^iv	98.94 (14)	O5^v—Na1—O6^vii	73.44 (11)
Cu1—O4—Na1^iv	104.54 (13)	O2^vi—Na1—O6^vii	132.30 (12)
Cu2—O5—Na1^v	97.49 (13)	O4ⁱⁱⁱ—Na1—O6^vii	62.63 (11)
Cu2—O5—H1	116 (6)	O2ⁱⁱⁱ—Na1—O6^vii	115.47 (12)
Na1^v—O5—H1	94 (5)	O7^vi—Na1—O6^vii	144.02 (11)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O5—H1···O4^v	0.80 (8)	2.00 (8)	2.786 (4)	168 (7)
O5—H2···O3^viii	0.87 (8)	1.88 (8)	2.746 (4)	174 (7)
O6—H3···O8^ix	0.87 (8)	1.91 (8)	2.758 (5)	163 (7)
O6—H4···O1ⁱⁱ	0.89 (8)	1.76 (8)	2.641 (4)	169 (8)

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

Experimental details

Crystal data
Chemical formula	Na₂Cu₃(SeO₃)₄(H₂O)₄
M_r	816.50
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	5.2218 (5), 8.9863 (6), 15.7960 (11)
β (°)	92.071 (4)
V (Å³)	740.74 (10)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	14.24
Crystal size (mm)	0.15 × 0.10 × 0.10

Data collection
Diffractometer	Bruker SMART CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2004)
T_min, T_max	0.204, 0.250
No. of measured, independent and observed [I > 2σ(I)] reflections	6010, 2142, 2065
R_int	0.027
(sin θ/λ)_max (Å⁻¹)	0.703

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.068, 1.12
No. of reflections	2142
No. of parameters	115
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.77, −1.02

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Crystal Impact, 2004), WinGX (Farrugia, 1999).

Selected bond lengths (Å) top

Se1—O7	1.698 (3)	Cu1—O6	1.990 (3)
Se1—O2	1.705 (3)	Cu1—O8ⁱ	2.475 (3)
Se1—O4	1.709 (3)	Cu2—O1ⁱⁱ	1.947 (3)
Se2—O8	1.673 (3)	Cu2—O3	1.962 (3)
Se2—O1	1.708 (3)	Cu2—O2	1.968 (3)
Se2—O3	1.717 (3)	Cu2—O7ⁱⁱⁱ	1.980 (3)
Cu1—O4	1.968 (3)	Cu2—O5	2.268 (3)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O5—H1···O4^iv	0.80 (8)	2.00 (8)	2.786 (4)	168 (7)
O5—H2···O3^v	0.87 (8)	1.88 (8)	2.746 (4)	174 (7)
O6—H3···O8^vi	0.87 (8)	1.91 (8)	2.758 (5)	163 (7)
O6—H4···O1ⁱ	0.89 (8)	1.76 (8)	2.641 (4)	169 (8)

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

Acknowledgements

This work was supported by the opening project of the State Key Laboratory of High Performance Ceramics and Superfine Microstructure (grant No. SKL200706SIC).

References

Asai, T. & Kiriyama, R. (1973). Bull. Chem. Soc. Jpn, 46, 2395–2401. CrossRef CAS Web of Science Google Scholar
Bruker (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Crystal Impact (2004). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Giester, G. (1991). Monatsh. Chem. 122, 229–234. CrossRef CAS Web of Science Google Scholar
Iskhakova, L. D. & Kozlova, N. P. (1995). Kristallografiya, 40, 635–638. CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2004). SADABS. University of Göttingen, Germany. Google Scholar