Strontium nickel and barium nickel selenites: Synthesis and X-ray diffraction parameters

Article abstract of DOI:10.1134/S003602361001002X

A new strontium nickel selenite, Sr₂Ni(SeO₃) ₃, was prepared and structurally characterized. The compound crystallizes in triclinic system (space group P1?, a = 7.2860(10) ?, b = 7.581(2) ?, c = 8.722(2) ?, α = 103.02(2)°, β = 105.580(10)°, γ = 95.260(10)°, Z = 2) and is isostructural to cobalt and copper analogues. The structure of Sr₂Ni(SeO ₃)₃ is a three-dimensional framework built of eight-vertex polyhedra [SrO₈] and distorted octahedra [NiO₆] sharing edges and vertices. The framework channels accommodate selenium atoms bonded to the framework oxygen atoms. The selenite groups SeO₃ are pyramidal, which is indicative of high stereochemical activity of the Se(IV) lone pair. The possibility of replacement of some Ni atoms by Cu in Sr₂Ni(SeO ₃)₃ was studied. The search for analogous barium phases did not reveal such compounds, but BaM(SeO₃)₂ phases were found, where M = Co, Ni, or Cu. The unit cell parameters of the new selenite BaM(SeO₃)₂ were determined: space group Pnma, a = 14.989(5) ?, b = 5.439(2) ?, c = 7.161(3) ?, Z = 4.

Full text of DOI:10.1134/S003602361001002X

ISSN 0036ꢀ0236, Russian Journal of Inorganic Chemistry, 2010, Vol. 55, No. 1, pp. 6–12. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © P.S. Berdonosov, K.A. Batunin, A.V. Olenev, V.A. Dolgikh, 2010, published in Zhurnal Neorganicheskoi Khimii, 2010, Vol. 55, No. 1, pp. 9–15.
SYNTHESIS AND PROPERTIES
OF INORGANIC COMPOUNDS
Strontium Nickel and Barium Nickel Selenites:
Synthesis and XꢀRay Diffraction Parameters
P. S. Berdonosov*, K. A. Batunin, A. V. Olenev, and V. A. Dolgikh
Moscow State University, Moscow, 119991 Russia
*
eꢀmail: psberd@inorg.chem. msu.ru
Received July 17, 2008
Abstract—A new strontium nickel selenite, Sr Ni(SeO ) , was prepared and structurally characterized. The
2
3 3
compound crystallizes in triclinic system (space group P1,
= 103.02(2)°, = 105.580(10)°, = 95.260(10)°, = 2) and is isostructural to cobalt and copper anaꢀ
logues. The structure of Sr Ni(SeO ) is a threeꢀdimensional framework built of eightꢀvertex polyhedra
a = 7.2860(10) Å, b = 7.581(2) Å, c = 8.722(2) Å,
α
β
γ
Z
2
3 3
[
SrO ] and distorted octahedra [NiO ] sharing edges and vertices. The framework channels accommodate seleꢀ
8
6
nium atoms bonded to the framework oxygen atoms. The selenite groups SeO are pyramidal, which is indicaꢀ
3
tive of high stereochemical activity of the Se(IV) lone pair. The possibility of replacement of some Ni atoms by
Cu in Sr Ni(SeO ) was studied. The search for analogous barium phases did not reveal such compounds, but
2
3 3
BaM(SeO ) phases were found, where M = Co, Ni, or Cu. The unit cell parameters of the new selenite
3
2
BaM(SeO ) were determined: space group Pnma, a = 14.989(5) Å, b = 5.439(2) Å, c = 7.161(3) Å, Z = 4.
3
2
DOI: 10.1134/S003602361001002X
Elucidation of relationships between the composiꢀ edge, no data on such compounds are available from
tion, structure, and physical properties of phases is an the literature.
important task of modern chemistry. In particular, the
lack of a symmetry center in the crystal structure is an
EXPERIMENTAL
Synthesis
obligatory condition for nonlinearꢀoptical and piezoꢀ
electric properties in solids. Meanwhile, the probabilꢀ
ity of formation of acentric structures is postulated to
increase upon the introduction of ions with lone pairs,
New strontium and nickel selenite derivatives were
3+
4+
4+
such as Bi , Te , Se , etc., into compounds [1]. sought by spontaneous crystallization from a 2SrSeO3 ·
According to published data [2], selenite ions should NiCl2 stoichiometric mixture. Strontium selenite was
have a pyramidal structure SeO3E where the lone pair preliminarily prepared by as reported elsewhere [5].
(
E) of the Se(IV) atom functions as one ligand; hence, Selenium dioxide was from selenous acid known from
4+
the Se coordination environment is asymmetric, and [7], the product being purified by sublimation in dried
this may lead to a noncentrosymmetric crystal strucꢀ air and nitrogen dioxide streams. Anhydrous nickel
ture as a whole. In view of this postulate, selenites have chloride was prepared by direct chlorination of nickel
been vigorously studied in recent years (e.g., [3–6]) as metal (carbonylic nickel powder UTꢀ2) in a tubular furꢀ
new potential piezoelectrics and crystals suitable for nace in a dried chlorine stream at 1023 K. A mixture of
second optical harmonics generation.
the aboveꢀindicated composition (weighing ~1 g) was
placed in a quartz ampoule, which was evacuated
One more factor favorable for the formation of an
–2
(residual pressure of about 10 Torr) and sealed off.
acentric crystal structure is the presence of
d metals
The sample thus prepared was heated in a muffle furꢀ
nace in the following schedule: heating to 1023 K in 6 h,
maintenance at this temperature for 6 h, and cooling to
inducing structure distortion due to the Jahn–Teller
effect.
6
63 K over 180 h (2 K/min).
Based on these views, we carry out systematic analꢀ
ysis of various selenite derivatives of alkalineꢀearth and
The final product was a powder with a slight
d
metals.
amount of small crystals.
This paper describes the structure of a new nickel
The results of singleꢀcrystal Xꢀray diffraction
selenite Sr Ni(SeO ) and the results of the search for experiment gave composition Sr Ni(SeO ) , undeꢀ
2
3 3
2
3 3
similar barium transitionꢀmetal phases. To our knowlꢀ scribed in the literature.
6

STRONTIUM NICKEL AND BARIUM NICKEL SELENITES
7
Table 1. Unit cell parameters of the samples with the composition Sr Ni Cu (SeO ) , space group P1
2
1 –
x
x
3 3
x
a
, Å
b
, Å
c, Å
α
, deg
β, deg
γ, deg
V
, Å3
0
7.286(1)
7.263(2)
7.269(2)
7.264(1)
7.581(2)
7.563(2)
7.592(2)
7.615(1)
8.722(2)
8.682(3)
8.714(3)
8.697(1)
103.02(2)
102.85(3)
103.02(2)
102.85(1)
105.58(1)
105.46(3)
105.55(2)
105.48(1)
95.26(1)
95.49(3)
95.42(3)
95.55(1)
446.1(1)
442.0(2)
445.1(1)
445.75(7)
0.1
0.2
0.3
The possibility of replacement of some nickel Sr Ni1 ⎯ Cu (SeO3)3. This gave powders in which no
2
x
x
atoms in the new strontium nickel selenite by other
ions was examined by attempted synthesis of mixed
compounds Sr Ni Cu (SeO3)3. Copper was chosen
crystals were detected. The products were examined by
powder Xꢀray diffraction, which showed the absence
2
1 –
x
x
of phases isostructural to Sr Ni(SeO )
.
2
3 3
because the unit cell parameters of Sr Ni(SeO ) we
2
3 3
found are similar to those known for Sr Cu(SeO ) [8].
2
3 3
Table 2. Crystal data for Sr Ni(SeO )
3 3
The initial samples were prepared using selenium
dioxide and strontium selenite characterized above.
Chemically pure grade nickel oxide and high purity
grade copper(II) oxide (OsCh 9ꢀ2) were used.
2
Composition
System
Sr Ni(SeO )
2
3 3
Triclinic
The mixture was prepared according to the equation
Space group
Unit cell parameters
P1
2
SrSeO + (1 –
x
)NiO +
x
3 3
xCuO + SeO2
Sr Ni Cu (SeO ) ( = 0.1, 0.2, 0.3).
3
=
2
1 –
x
x
To this end, stoichiometric amounts of the compoꢀ
nents were weighed in a dry box, thoroughly mixed,
and ground together in an agate mortar. The mixtures
thus obtained were annealed in evacuated quartz tubes
in a furnace in the following schedule: heating to
a
, Å
, Å
, Å
, deg
, deg
, deg
, Å3
7.2860(10)
7.581(2)
8.722(2)
103.02(2)
105.58(1)
95.26(1)
446.1(2)
2
b
c
α
3
00
°
С
over 12 h, maintenance at this temperature for
in 6 h, maintenance at this temꢀ
1
2 h, heating to 600°С
β
perature for 120 h, and cooling to room temperature
together with the furnace. The samples thus obtained
were studied by powder Xꢀray diffraction (FR 552
γ
V
Guinier–deWolf camera (EnrafꢀNonius), Cu
K radiꢀ
α
1
Z
ation, germanium as the internal standard). The Xꢀray
diffraction patterns of the final products were indexed
with the assumption of triclinic system. The unit cell
ρ
, g/cm3
4.577
calcd
μ
, mm–1
26.266
parameters for different
Table 1.
x values are summarized in
Reflections: collected/independent 2773/2600
(int) = 0.019]
[R
The search for Ba M(SeO ) selenites was carried
2
3 3
out for M = Co, Ni, and Cu. The synthesis was based GOOF on F2
1.076
on the reaction
R
1 (F0 > 4
σ
(
F0))
0.0365
2BaSeO + MO + SeO = Ba M(SeO ) .
3 2 2 3 3
wR2 (F0 > 4
σ
(
F0))
0.1040
The starting compounds used were SeO2, NiO,
and CuO characterized above, BaSeO3 prepared by a
known procedure [4], and chemically pure grade
commercially available CoO. The reaction mixtures
were prepared and annealed as described for
Extinction coefficient
0.0337(17)
1.753/–1.989
419618
Δρmax/Δρ , e/Å3
min
ICSD number
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 55 No. 1 2010

8
BERDONOSOV et al.
10 ) and isotropic thermal paꢀ
Refinement of Sr Ni(SeO ) Structure
2 3 3
–4
Table 3. Atom coordinates (
rameters for Sr Ni(SeO )
×
2
3 3
For singleꢀcrystal Xꢀray diffraction, a crystal taken
from the reaction mixture was mounted on the gonioꢀ
metric head of a Nonius CADꢀ4 diffractometer (graphite
U
×
eq,
Atom
x
y
z
Å2
10
–3
monochromator,
ture, /2 scan mode). The triclinic unit cell parameters
were refined over 24 reflections in the angle range 16.0° <
θ < 17.9 . Absorption corrections were applied by aziꢀ
multhal scanning of 10 reflections with values close to
0°. The structure was solved by a direct method
SHELXSꢀ97 [9]) in assuming centrosymmetrical space
group 1. During the solution, the positions of stronꢀ
tium, nickel, selenium, and some of oxygen atoms were
located. The rest of the oxygen positions were found by
alternation of leastꢀsquares refinement and difference
Fourier syntheses (SHELXLꢀ97 [9]). The final anisotroꢀ
pic refinement gave R1 = 0.036. The key data collection
and crystal structure refinement data are presented in
Table 2, the positional and thermal parameters of atoms
are in Table 3, and selected interatomic distances are in
Table 4. XꢀRay experiment details are available from
Fachinformationszentrum Karlsruhe, 76344 Eggenꢀ
steinꢀLeopoldsgafen, Germany (Fax (+49)7247ꢀ808ꢀ
λ
(MoK ) = 0.71073 Å, room temperaꢀ
α
Sr(1)
Sr(2)
Se(1)
Se(2)
Se(3)
Ni
2558(1)
1292(1)
9146(1)
4823(1)
1102(1)
3066(1)
10(1)
11(1)
8(1)
ω θ
°
4031(1) 12113(1)
1393(1) 9168(1)
2654(1) 13626(1)
5443(1)
χ
9
(
–2966(1)
–883(1)
–2524(1)
–4025(5)
–1820(5)
–1460(6)
–1518(5)
3557(5)
9(1)
9(1)
P
4062(1)
1360(6)
–70(5)
6639(1)
6977(5)
8789(6)
9(1)
O(1)
O(2)
O(3)
O(4)
O(5)
O(6)
O(7)
O(8)
O(9)
12(1)
13(1)
19(1)
13(1)
15(1)
14(1)
12(1)
18(1)
16(1)
257(6) 12977(6)
3578(5) 9465(6)
4323(6) 11899(6)
3266(6) 13593(6)
1130(5)
6
66; eꢀmail: crisdata@fizꢀkarlsruhe.de, http://www.fizꢀ
2746(6)
6660(6)
3713(6)
5888(5)
5805(6)
7527(6)
–882(5)
4235(5)
karlsruhe.de/request_for_deposited_data.html)
CSD 419618.
for
3291(5)
RESULTS AND DISCUSSION
It follows from the Xꢀray diffraction experiment
that the single crystals obtained correspond to the new
strontium nickel selenite Sr Ni(SeO ) isostructural to
Table 4. Interatomic distances (
d
) Sr Ni(SeO )
2
3 3
Bond
d
, Å
Bond
d, Å
2
3 3
cobalt and copper analogs [8, 10]. The crystal strucꢀ
Sr(1)–O(9)
Sr(1)–O(5)
Sr(1)–O(2)
Sr(1)–O(3)
Sr(1)–O(4)
Sr(1)–O(2)
Sr(1)–O(7)
Sr(1)–O(4)
Sr(2)–O(9)
Sr(2)–O(3)
Sr(2)–O(6)
Sr(2)–O(8)
Sr(2)–O(1)
Sr(2)–O(2)
Sr(2)–O(1)
Sr(2)–O(7)
2.499(4)
2.571(4)
2.611(4)
2.619(4)
2.638(4)
2.685(4)
2.716(4)
2.811(4)
2.514(4)
2.563(4)
2.574(4)
2.596(4)
2.676(4)
2.676(4)
2.682(4)
2.968(4)
Sr(2)–O(5)
Se(1)–O(9)
Se(1)–O(8)
Se(1)–O(5)
Se(2)–O(2)
Se(2)–O(1)
Se(2)–O(4)
Se(3)–O(3)
Se(3)–O(6)
Se(3)–O(7)
Ni–O(8)
3.285(5)
1.675(4)
1.687(4)
1.689(4)
1.692(4)
1.703(4)
1.704(4)
1.675(4)
1.698(4)
1.710(4)
2.022(4)
2.046(4)
2.050(4)
2.074(4)
2.124(4)
2.223(4)
ture of Sr Ni(SeO ) (Fig. 1) contains two crystalloꢀ
2
3 3
graphically independent strontium atoms each having
a coordination environment of eight oxygen atoms
(
Table 4), which form irregular eightꢀvertex polyhedra
SrO8 (Fig. 2). These polyhedra share faces or vertices
thus being connected into layers parallel to the bc
plane. The nickel atom has a distorted octahedral
coordination (Table 4). The NiO6 octahedra share
edges and vertices with the strontium polyhedra of difꢀ
ferent layers to form a threeꢀdimensional framework
with endꢀtoꢀend channels (Fig. 3). These channels
accommodate the selenium atoms (Fig. 3) each
bonded to three oxygen atoms at typical Se–O disꢀ
tances of 1.67–1.71 Å. Thus, the selenium atoms
occupy pyramid apices, the triangular bases of the pyrꢀ
amids being each formed by three oxygen atoms. The
corners of these bases also belong to strontium and
nickel polyhedra. Presumably, selenium lone pairs
reside in framework voids.
Ni–O(6)
Ni–O(5)
Ni–O(7)
Our experiments showed that the nickel atoms in the
structure can be replaced by copper up to at least 30%.
Figure 4 shows the variation of the triclinic unit cell
Ni–O(1)
Ni–O(4)
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 55 No. 1 2010

STRONTIUM NICKEL AND BARIUM NICKEL SELENITES
9
Sr
Ni
Se
b
c
O
Fig. 1. Structure of Sr Ni(SeO ) projected onto the bc plane.
2
3 3
Sr(1)
Sr(2)
Fig. 2. Sr(1) and Sr(2) polyhedra in the Sr Ni(SeO ) structure.
2
3 3
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 55 No. 1 2010

10
BERDONOSOV et al.
Table 5. Results of indexing for a BaNi(SeO ) sample
3
2
2θexp, deg
dexp, Å
Q*
I/I**
h
k
l
Qcalcd
ΔQ
exp
0
1
2
2
7.119
0.262
0.518
5.1754
4.3792
4.3252
4.0888
3.7426
373.35
521.45
534.55
598.15
713.93
10
50
10
50
10
2
2
0
3
2
4
0
1
4
2
1
3
4
2
5
0
4
5
2
6
1
4
2
3
4
6
1
7
2
7
6
3
5
7
4
4
8
6
7
0
8
6
1
1
2
8
2
3
7
3
1
7
9
0
1
1
0
1
0
0
0
0
0
1
0
1
1
0
2
0
1
2
0
0
1
0
2
2
0
2
0
2
0
0
2
2
1
1
2
0
2
0
3
0
2
2
3
2
0
1
3
2
1
3
0
1
1
0
1
1
1
0
2
2
1
2
2
2
1
2
1
0
2
1
1
1
3
2
3
1
0
1
2
0
2
1
2
2
1
1
3
2
0
0
2
0
1
1
3
1
3
2
4
1
1
4
2
3
0
373.04
516.10
533.05
595.59
711.10
712.17
779.97
824.48
907.17
0.31
5.34
1.50
2.56
2.83
1.75
3.69
1.97
–2.32
0.55
1.10
0.33
1.89
2.33
1.00
4.39
1.82
0.20
3.33
0.21
–1.85
–7.35
–3.39
1.06
0.39
5.40
–1.27
–5.57
2.47
21.718
23.755
24.906
25.588
26.796
27.595
30.469
30.699
31.570
32.230
32.362
32.964
34.644
36.422
37.358
38.123
3.5722
3.4785
3.3244
3.2299
2.9315
2.9100
2.8317
2.7752
2.7642
2.7150
2.5872
2.4648
2.4052
2.3586
783.66
826.45
904.84
10
50
10
10
70
10
100
50
50
70
10
50
10
50
958.57
958.01
1163.64
1180.90
1247.11
1298.41
1308.76
1356.63
1493.96
1646.03
1728.61
1797.59
1162.54
1180.57
1245.23
1296.08
1307.76
1352.24
1492.14
1645.82
1725.28
1797.38
1799.45
1830.21
1932.98
1947.83
2064.41
1797.38
2176.72
2181.03
2310.26
2376.02
2382.36
2532.81
2660.00
2714.08
2805.17
2844.39
2848.69
2954.63
2961.00
3042.54
3043.69
3149.62
3151.69
3282.05
3285.22
3628.66
3635.99
3638.13
3728.26
3858.54
3867.03
3935.97
3943.44
38.402
39.556
39.762
40.977
2.3422
2.2765
2.2652
2.2007
2.3552
2.1440
1822.85
1929.59
1948.89
2064.80
1802.79
2175.46
10
50
50
10
50
10
3
4
8.181
2.112
43.486
2.0794
2.0510
2312.72
2377.22
10
10
44.119
1.19
–5.15
–3.56
–2.70
–4.52
–5.99
–0.85
–5.16
0.98
45.585
46.792
47.277
48.102
48.505
1.9884
1.9399
1.9211
1.8901
1.8753
2529.25
2657.30
2709.57
2799.18
2843.53
10
50
10
50
50
49.514
50.328
1.8394
1.8116
1.7831
1.7462
1.6594
2955.61
3047.02
3145.20
3279.53
3631.60
10
10
10
10
10
–5.39
4.48
3.34
51.189
–4.42
–6.49
–2.51
–5.69
2.93
–4.39
–6.53
–3.88
1.25
5
2.353
5.319
5
5
5
6.083
7.182
1.6386
1.6096
3724.38
3859.79
10
10
–7.23
5.18
–2.29
57.841
1.5929
3941.15
10
1
4
Notes: * Q = ꢀꢀꢀ × 10 .
2
d
*
* The intensity was estimated visually against a 100ꢀpoint scale.
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 55 No. 1 2010

STRONTIUM NICKEL AND BARIUM NICKEL SELENITES
11
Sr
Ni
b
Se
O
c
Fig. 3. Framework of the strontium and nickel polyhedra in the Sr Ni(SeO ) structure.
2
3 3
parameters of the Sr Ni Cu (SeO ) phases, which can der Xꢀray diffraction patterns of the cobalt and copper
2
1 –
x
x
3 3
be fitted by linear dependences. This is indicative of the products [11, 12]; thus, we assumed the existence of
formation of solid solutions in the indicated concentraꢀ previously unknown selenite BaNi(SeO3)2. To verify
tion range of the Sr Ni(SeO ) –Sr Cu(SeO ) system
2
3 3
2
3 3
this assumption, we carried out additional annealing
of a stoichiometric mixture of BaSeO3, NiO, and SeO2
under aboveꢀdescribed conditions according to the
reaction
(
strontium copper selenite also corresponds to space
group 1; = 7.229 = 7.710 = 8.656
02.68 = 105.31 = 96.12 [8]).
No barium compounds with the desired stoichiomꢀ
P
a
Å,
b
Å,
c
Å,
α
=
1
°,
β
°,
γ
°
BaSeO + NiO + SeO = BaNi(SeO ) .
3 2
3
2
etry are formed under our experimental conditions.
Analysis of the Xꢀray diffraction patterns of the final
barium samples showed that after annealing, the reacꢀ
tion mixtures of the asꢀbatch composition
Ba M(SeO ) with M = Co, Cu are mixtures of known
The Xꢀray diffraction pattern of the sample was
completely indexed by the homology method with the
assumption of orthorhombic system (space group
Pnma) (Table 5) with the parameters
= 5.439(2) Å, = 7.161(3) Å ( (30) = 17.3,
selenite BaSeO3. The Xꢀray diffraction pattern of the 12.7, = 4), indicating the singleꢀphase composition
a
= 14.989(5) Å,
2
3 3
selenites BaM(SeO3)2 (M = Co or Cu) and barium
b
c
F
M(20) =
Z
final nickelꢀcontaining product is similar to the powꢀ of the sample.
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 55 No. 1 2010

12
BERDONOSOV et al.
ACKNOWLEDGMENTS
9
8
8
8
8
8
7
7
7
7
7
.0
.8
.6
.4
.2
.0
.8
.6
.4
.2
.0
c
This work was supported by the Russian Foundaꢀ
tion for Basic Research, project nos. 06ꢀ03ꢀ32134 and
0
8ꢀ03ꢀ0058.
b
a
REFERENCES
1
. P. Sh. Halasyamani and K. R. Poeppelmeier, Chem.
Mater. 10, 2753 (1998).
. J. Galy, G. Meunier, S. Andersson, and A. Astrom,
J. Solid State Chem. 13, 142 (1975).
. C. N. R. Rao, J. N. Behera, and M. Dan, Chem. Soc.
Rev. 35, 375 (2006).
. H.ꢀL. Jiang and J.ꢀG. Mao, J. Solid State Chem. 181
345 (2008).
2
3
4
0
0.05 0.10 0.15 0.20 0.25 0.30 0.35
Content Cu,
x
108
106
104
102
100
β
,
α
5. O. A. Dityatiev, P. Lighfoot, PS. Berdonosov, and
V. A. Dolgikh, Acta Crystallogr., Sect. E 63, i149
(2007).
9
8
6
7
8
9
. M. Wildner and G. Giester, Neues Jahrb. Mineral. Abh.
184, 29 (2007).
. Yu. V. Karyakin and I. I. Angelov, Pure Chemicals
(Khimiya, Moscow, 1974) [in Russian].
9
9
6
4
γ
0
0.05 0.10 0.15 0.20 0.25 0.30 0.35
Content Cu,
x
. H. Effenberger, Acta Crystallogr., Sect. C 44, 800
(1988).
. G. M. Sheldrick, Acta Crystallogr., Sect. A 64, 112
2008).
(
Fig. 4. Triclinic unit cell parameters of the Sr Ni1 –
Cu (SeO ) phase vs. copper content.
2
x
1
0. M. Wildner, J. Alloys Compds 217, 209 (1995).
x
3 3
1
1. G. Giester and M. Wildner, J. Alloys Compds 239, 99
(1996).
Thus, in the family of alkalineꢀearth and
selenites, the following trend is observed: compounds
with the compositions of SrM(SeO3)2 (M= Mn [13],
d
ꢀmetal
1
2. H. Effenberger, J. Solid State Chem. 70, 303 (1987).
13. M. G. Johnston and W. T. A. Harrison, Acta Crystalꢀ
logr., Sect. E 58, i49 (2002).
Cu [12], Zn [14]) and Sr M(SeO ) (M = Co [10], Ni
2
3 3
14. M. G. Johnston and W. T. A. Harrison, Inorg. Chem.
(
this work), Cu [15]) are both possible for strontium,
40, 6518 (2001).
whereas for barium, the compound BaM(SeO3) is
2
15. H. Effenberger, Acta Crystallogr., Sect. C 44, 800
preferred. In all probability, this is due to the proꢀ
(1988).
2+
2+
nounced difference between the Sr and Ba ion
radii (1.26 and 1.42 Å, respectively [16]).
1
6. R. D. Shannon, Acta Crystallogr., Sect. A 32, 751
(1976).
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 55 No. 1 2010