Aggregates of complexes [Sc(H2O)4(NCS) 2]+ and [Sc(H2O)2(NCS) 4]- with 18-crown-6

Article abstract of DOI:10.1134/S1070328407040057

The compounds [Sc(H₂O)₄(NCS)₂][Sc(H ₂O)₂(NCS)₄] ?2(18C6) (I) and [Sc(H ₂O)₄(NCS)₂][Sc(H₂O) ₂(NCS)₄] ? 3(18C6) ? H₂

Full text of DOI:10.1134/S1070328407040057

ISSN 1070-3284, Russian Journal of Coordination Chemistry, 2007, Vol. 33, No. 4, pp. 265–271. © Pleiades Publishing, Ltd., 2007.
Original Russian Text © A.B. Ilyukhin, S.P. Petrosyants, 2007, published in Koordinatsionnaya Khimiya, 2007, Vol. 33, No. 4, pp. 275–281.
+
Aggregates of Complexes [Sc(H O) (NCS) ]
2
4
2
−
and [Sc(H O) (NCS) ] with 18-Crown-6
2
2
4
A. B. Ilyukhin and S. P. Petrosyants
Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia
Received May 31, 2006
Abstract—The
compounds
[Sc(H O) (NCS) ][Sc(H O) (NCS) ]
·2(18C6)
(I)
and
2
4
2
2
2
4
[
Sc(H O) (NCS) ][Sc(H O) (NCS) ] · 3(18C6) · H O (II) were synthesized and studied by X-ray diffraction
2
4
2
2
2
4
2
analysis. It was found that the cations in the structures of compounds I and II form sandwiches
–
[
Sc(H O) (NCS) ] · 2(18C6). In the case of I, the sandwiches are united by the [Sc(H O) (NCS) ] anions into
2 4 2 2 2 4
chains, while in compound II, the sandwiches and infinite chains of [Sc(H O) (NCS) ] · 18C6 · H O are bonded
2
2
4
2
by van der Waals contacts only.
DOI: 10.1134/S1070328407040057
In the previous publication [1], we showed that For C H N O S Sc
2
3
0
60
6
18
6
+
complexes [M(18C6)] (M = Na, K) in solvatosystems
anal. calcd, (%):
Found (%):
C, 33.48; H, 5.58; N, 7.81; S, 15.85.
C, 34.81; H, 6.98; N, 6.28; S, 14.14.
3
-
of different composition stabilize the [Sc(NCS)6]
anions.
In view of the data [1], the conditions of the synthe-
sis of supramolecular aggregates of scandium thiocyan-
–1
The IR spectrum (cm ): ν(H O) 3380, 3140; ν(CN)
2
2
042, δ(H O) 1628, ν (COC) 1099, ν(CS) 834, δ(NCS)
2
as
ate Sc(H O) (NCS) with 18C6 were chosen.
2
3
3
489.
Synthesis of [Sc(H O) (NCS) ][Sc(H O) (NCS) ] ·
2
4
2
2
2
4
3
(18C6) · H O (II). A specimen of Sc (SO ) · 5H O
2 2 4 3 2
EXPERIMENTAL
(
0.31 g, 1.30 mmol Sc) was dissolved in 2 ml of ç é
2
and mixed with a solution of Ba(NCS) · 3H O (0.60 g,
The commercial grade KNCS, Ba(NCS) · 3H O,
2
2
2
2
1
.95 mmol) in 10 ml of ç é and stored for ~2 h; the
2
Sc (SO ) · 5H O, 18C6 (1,4,7,10,13,16-hexaoxocy-
clooctadecane), diethyl ether, and absolute EtOH were
used as received.
2
4 3
2
precipitate formed was filtered off. Then, 15 ml of
diethyl ether was added to the filtrate, and the ether
extract was added to a solution of 18C6 (0.34 g,
1
.27 mmol) in the ether–EtOH (1 : 1) mixture to give
The analysis for C, H, N, and S was performed using
standard procedures on a Carlo Erba analyzer.
rose-colored solution. The orange crystals precipitated
from the solution obtained were washed with diethyl ether.
The IR spectra were recorded on a Nexus spectrom-
eter (Nicolet Instrument Incorp., USA) at 400–
For C H N O S Sc
2
4
2
86
6
25
6
–
1
4
000 cm (Nujol mulls, KBr cells).
anal. calcd, (%): C, 37.17; H, 6.34; N, 6.19; S, 14.15.
Found (%): C, 37.93; H, 6.16; N, 4.45; S, 13.55.
Synthesis of [Sc(H O) (NCS) ][Sc(H O) (NCS) ] ·
2
4
2
2
2
4
2
(18C6) (I). A solution of scandium chloride obtained
–1
by extraction from a solid phase (Sc O + HCl) with
The IR spectrum (cm ): ν(H O) 3429, 3150; ν(CN)
2
2
3
ethanol (20 ml) and containing 0.22 mmol of Sc was 2051, δ(H O) 1637, ν (COC) 1107, ν(CS) 839, δ(NCS)
2
as
added to KNCS specimen (0.076 g, 0.78 mmol). The 489.
mixture was stirred and left overnight. The precipitated
KCl was filtered off; the filtrate was mixed with a solu-
tion of 18C6 (0.064 g, 0.24 mmol) in 1 ml of EtOH. The
red-violet crystals, formed after isothermic concentra-
tion of the obtained solution, were filtered off, washed
The X-ray diffraction analysis of compounds I and
II was performed on an Enraf Nonius CAD-4 diffracto-
meter. The main crystallographic parameters and the
results of refinement of structures I and II are given in
Table 1. The structures were solved by combination of
with EtOH and dried in a vacuum desiccator over silica the direct method and Fourier synthesis (SHELXS-97
gel. The yield was 0.04 g (33.5% (Sc)). [2] and SHELXL-97 [3]).
2
65

2
66
ILYUKHIN, PETROSYANTS
Table 1. The main crystallographic parameters and summary
of data collection for [Sc(H O) (NCS) ][Sc(H O) (NCS) ] ·
In this work, we performed the synthesis analogous
2
4
2
2
2
4
to the synthesis of [[K(18C6)] [Sc(NCS) ]Cl · 3.33H O
4
6
2
2
3
(18C6) (I) and [Sc(H O) (NCS) ][Sc(H O) (NCS) ] ·
2 4 2 2 2 4
in THF [1], but with the use of absolute EtOH with the
(18C6) · H O (II)
2
content of H O < 0.2% (according to Fischer). Note that
2
–
3+
in solution with a molar ratio NCS : Sc ≈ 1 : 3.6, at
minimum content of water, crystals of compound I pre-
Value
Parameter
I
II
+
cipitated containing the [Sc(H O) (NCS) ] cation and
2
4
2
–
[
Sc(H O) (NCS) ] anion, which were formed as a
Temperature, K
Radiation
Crystal system
Space group
a, Å
296
MoKα
295
CuKα
Monoclinic
C2/c
46.420(5)
18.636(11)
40.214(7)
128.914(14)
27069(17)
16
2 2 4
result of disproportionation of the molecular complex
Sc(H O) (NCS) . Trihalide (pseudohalide) complexes
2
3
3
Rhombic
Pbnm
11.981(2)
15.850(2)
27.079(6)
of Group III elements (Al, Ga, In) with molecular
ligands (Py, Bipy, DMSO, CH CN, THF, iso-PrOH,
3
etc.) in solid phase often undergo disproportionation to
the ionic dimmers, which was confirmed by the X-ray
diffraction analysis and by the other methods [4]. How-
ever, in the case with scandium, we established that sol-
vatosystems containing the Cl ion but having different
b, Å
c, Å
β, deg
3
V, Å
5142.3(16)
4
31.389
0.575
–
3+
composition (with a molar ratio Cl : Sc from 3 to 20)
only gave the molecular complex Sc(H O) Cl in the
Z
3
2
3
3
ρ(calcd.), g/cm
µ, mm
1.332
4.096
H-bonded aggregates with 18C6 or DA18C6, whereas
no disproportionation was observed [5]. The formation
of ionic dimers from the molecular complexes depends
on many factors, but the key role is played by the steric
parameters, donor capabilities of competing ligands,
and configuration lability (the change in coordination
–
1
Crystal size, mm
θ, deg
Number of reflections
0.2 × 0.2 × 0.13 0.35 × 0.3 × 0.2
1.50–22.47
3435
2.45–50.00
22312
Number of indepen-
dent reflections
3435
13885
3
+
number, etc.). It is most likely that for the Sc ion,
Number of refined
reflections
GOOF (F )
295
1469
which does not show a tendency of decreasing its coor-
–
dination number, the Cl ion is not suitable (in terms of
2
its “rigidity”) to give complexes with the number of
0.974
0.962
–
ions Cl > 3, whereas a more rigid thiocyanate ion in
R , wR (I > 2σ(I))
0.0597, 0.0927 0.0584, 0.0991
1
2
combination with a rigid ligand ç é favors dispropor-
2
R , wR (for all reflec- 0.2949, 0.1486 0.3296, 0.1426
1
2
tionation of Sc(H O) (NCS) .
tions)
2
3
3
Compound I was synthesized using KNCS; how-
ever, minimization of the possibility of the complex
+
In the structure of compound II, one sulfur atom [K(18C6)] formation made it possible to prevent the
3
–
(
S(10)) is disordered over two positions. The hydrogen appearance of the forms containing [Sc(NCS) ] ,
6
atoms of crown ether molecules in compounds I and II which was observed in [1].
were localized from geometrical considerations; the
hydrogen atoms of water molecules were localized
from the Fourier difference syntheses. The structures
were refined by anisotropic least-squares method. The
aliphatic hydrogen atoms were refined in the rider
model with thermal parameters that were 20% as high
as those for the hydrogen atoms bonded to them; the
hydrogen atoms of water molecules were fixed.
In the synthesis of compound II, the starting Sc thiocy-
anate was obtained in an aqueous solution, from which it
passed to the ether [6]. In the absence of the alkali metal
cations in water–organic solutions, aggregates of 18C6
+
with ionic complexes [Sc(H O) (NCS) ]
and
2
4
2
–
[
Sc(H O) (NCS) ] are formed, but compound II contains
2 2 4
water molecule of crystallization, i.e., 2[Sc(H O) (NCS) ] ·
2
3
3
3
(18C6) · H O. Note that the starting reagents 18C6 and
2
The structural data were deposited with the Cam- Sc(H O) (NCS) are readily soluble in diethyl ether, while
2
3
3
bridge Structural Database (CCDC 609048 and 609049 compound II is almost insoluble in this solvent, for which
for I and II, respectively).
reason the synthesis was performed in the ether–ethanol
mixture.
The structure of I consists of the cations
RESULTS AND DISCUSSION
The formation of supramolecular aggregates of
+
–
[
1
Sc(H O) (NCS) ] , anions [Sc(H O) (NCS) ] and
2 4 2 2 2 4
8C6 molecules. The cation occupies partial position on
3
-
hexathiocyanate anion Sc(NCS) , with 18C6 was
6
the m plane, while the anion has symmetry 1. The values
discovered in solvatosystems (organic solvent–water)
of the bond lengths (Table 2) and bond angles are stan-
−
3+
at a molar ratio NCS : Sc ≈ 1 : 3 and explained by the dard as in analogous compounds. The cation forms eight
+
presence of the [å(18C6)] complexes (M = Na, K) hydrogen bonds (HB) (Table 3, Fig. 1a) with two ether
formed as a result of incomplete precipitation of MCl molecules, while the anion unites sandwiches into chains
from water–organic medium [1].
through four HB. With such an arrangement of HBs, ten
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

AGGREGATES OF COMPLEXES
267
Table 2. Bond lengths in polyhedra of Sc atoms in structures Table 3. Geometrical parameters of hydrogen bonds in I
I and II
and II
Distance, Å
D–H H···A D···A
The
DHA an-
gle, deg
Bond
d, Å
D–H···A*
I
I
Sc(1)–O(1)
Sc(1)–N(1)
Sc(1)–N(2)
Sc(2)–O(2)
Sc(2)–O(3)
Sc(2)–O(4)
Sc(2)–N(3)
Sc(2)–N(4)
2.130(6) × 2
2.129(10) × 2
2.116(10) × 2
2.091(5) × 2
2.133(9)
O(1)–H(1)···O(5)
O(1)–H(2)···O(8)
O(2)–H(3)···O(9)
O(2)–H(4)···O(7)
O(3)–H(5)···O(6)
O(4)–H(6)···O(10)
0.91 1.82 2.709(9)
1.03 1.74 2.737(10)
0.92 1.85 2.718(9)
0.86 1.88 2.623(8)
0.78 2.11 2.768(8)
1.02 1.68 2.682(9)
II
167
162
156
145
144
165
2.099(9)
O(1)–H(1)···O(20)
O(1)–H(2)···O(32)
O(2)–H(3)···O(35)
O(2)–H(3)···O(36)
O(2)–H(4)···O(33)
O(2)–H(4)···O(34)
O(3)–H(5)···O(19)
O(3)–H(6)···O(23)
O(3)–H(6)···O(24)
O(4)–H(7)···O(22)
O(4)–H(8)···O(36)
O(5)–H(9)···O(25)
O(5)–H(10)···O(29)
O(6)–H(11)···O(26)
O(6)–H(11)···O(27)
O(6)–H(12)···O(28)
O(7)–H(13)···O(17)
O(7)–H(14)···O(15)
O(8)–H(15)···O(13)
O(8)–H(15)···O(18)
O(8)–H(16)···O(14)
O(8)–H(16)···O(15)
O(9)–H(17)···O(37)
O(9)–H(17)···O(39)
O(9)–H(18)···O(38)
0.95 1.78 2.708(9)
1.00 1.73 2.665(9)
1.08 1.93 2.794(9)
1.08 2.26 3.096(10)
0.84 2.38 3.013(9)
0.84 2.02 2.762(9)
1.17 1.75 2.892(9)
0.90 2.01 2.871(9)
0.90 2.23 2.742(9)
1.12 1.65 2.696(10)
0.98 1.82 2.704(9)
0.84 1.97 2.760(9)
0.91 1.91 2.717(9)
1.02 1.83 2.838(10)
1.02 2.30 2.759(9)
1.01 1.96 2.949(9)
1.16 1.55 2.697(10)
0.86 1.97 2.743(9)
0.87 2.05 2.741(9)
0.87 2.15 2.843(10)
1.06 2.16 2.950(9)
1.06 2.23 3.204(9)
1.08 1.69 2.728(9)
1.08 2.45 3.029(9)
1.06 1.78 2.704(9)
0.76 1.79 2.536(8)
1.01 1.75 2.720(8)
0.88 1.72 2.586(8)
0.97 1.81 2.776(9)
1.01 2.07 2.839(10)
1.01 2.14 3.032(10)
1.11 2.21 2.951(10)
1.11 2.29 3.125(10)
0.91 2.04 2.832(10)
164
154
135
133
133
148
164
160
116
153
149
155
146
169
106
166
170
150
137
137
129
151
158
112
143
167
160
166
175
131
145
122
130
144
2.126(15)
2.090(13)
II
Sc(1)–O(1)
Sc(1)–O(2)
Sc(1)–O(3)
Sc(1)–O(4)
Sc(1)–N(1)
Sc(1)–N(2)
Sc(2)–O(5)
Sc(2)–O(6)
Sc(2)–N(3)
Sc(3)–O(7)
Sc(3)–O(8)
Sc(3)–N(4)
Sc(4)–O(9)
2.110(6)
2.107(5)
2.094(5)
2.129(6)
2.141(9)
#
#
1
1
2.179(10)
2.109(6) × 2
2.107(6) × 2
2.098(10) × 2
2.128(6) × 2
2.081(5) × 2
2.104(9) × 2
2.080(6)
#
#
2
2
Sc(4)–O(10)
Sc(4)–N(5)
Sc(4)–N(6)
Sc(4)–N(7)
Sc(4)–N(8)
Sc(5)–O(11)
Sc(5)–O(12)
Sc(5)–N(9)
Sc(5)–N(10)
Sc(5)–N(11)
Sc(5)–N(12)
2.096(7)
O(10)–H(19)···O(50)
O(10)–H(20)···O(46)
O(11)–H(21)···O(49)
O(11)–H(22)···O(44)
O(12)–H(23)···O(42)
O(12)–H(23)···O(40)
O(12)–H(24)···O(41)
O(12)–H(24)···O(40)
O(49)–H(25)···O(45)
2.128(10)
2.135(9)
#
3
2.112(9)
2.128(8)
#
#
#
3
3
3
2.070(7)
2.146(6)
O(49)–H(26)···O(43)# 0.87 2.06 2.850(11)
3
151
130
168
168
2.174(8)
#3
O(49)–H(26)···O(44)
O(50)–H(27)···O(48)
O(50)–H(28)···O(47)
0.87 2.42 3.057(9)
0.91 1.90 2.797(10)
0.94 1.89 2.821(10)
2.166(10)
2.191(9)
#
3
*
Symmetry transformations: #1–x + 1, y, –z + 3/2; #2–x + 1/2, −y +
3/2, –z + 1; –x + 1/2, –y + 1/2, –z + 1; the coordinates of
#
3
+
2.190(10)
atoms A are x, y, z.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

2
68
ILYUKHIN, PETROSYANTS
S(4)
S(3)
O(7)
O(2)
O(3)
Sc(2)
O(8)
O(1)
O(9)
O(6)
O(4)
O(10)
Sc(1)
O(5)
S(1)
S(2)
(‡)
O(8)
O(5)
O(6)
O(10)
O(7)
(b)
O(9)
Fig. 1. (a) The structure of a chain and (b) crown ether conformation in structure I.
z
0
y
x
Fig. 2. Projection of structure I along the z axis.
atoms (the O(5,8) atoms and the adjacent ethylene frag- within 60°–68°. Thus, in structure I, all the H atoms of
ments) from eighteen 18C6 atoms lie in one plane within water molecules and all the O atoms of crown ether are
an accuracy of ±0.07 Å (Fig. 1b). Ten torsion angles involved in HBs. The chains are arranged in staggered
CCOC lie in an interval 165°–179°, two torsion angles order and are bonded only by van der Waals contacts
are equal to 72° and 77°, whereas the OCCO angles vary (Fig. 2).
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

AGGREGATES OF COMPLEXES
269
S(3)
O(20)
O(19)
S(1)
O(32)
O(33)
O(29)
O(28)
O(1)
O(21)
O(23)
O(31)
O(5A)
O(2)
O(3)
O(27)
O(34)
O(35)
O(24)
O(6)
O(30)
Sc(1)
O(4)
Sc(2)
O(6A)
O(5)
O(22)
O(25)
O(36)
O(26)
O(29A)
S(2)
S(3A)
S(4A)
O(7A)
O(18)
O(17)
O(8)
O(13)
O(8A) Sc(3)
S(4)
O(7)
O(14)
O(16)
O(17A)
O(15)
+
Fig. 3. The structure of the [Sc(H O) (NCS) ] · 2(18C6) cations in compound II.
2
4
2
The structure of II is formed by the O(31–36) is analogous to that found in the fragments
+
–
[
Sc(H O) (NCS) ]
cations,
[Sc(H O) (NCS) ]
Sc(2, 3) (12 torsion angles CCOC lie within 165°–
2
4
2
2
2
4
anions, the 18C6 molecules, and crystallization water 180°, six angles OCCO lie in a range of 62°–66°). In
the second molecule O(19–24), one torsion angle
CCOC decreases to 155° (the remaining 11 angles lie in
an interval 160°–179°), two OCCO angles are equal to
molecules. To bind an additional (as compared to com-
pound I) molecule of crown ether, the cations and
anions move apart. Compound II contains three crys-
tallographically independent cations, two of which
occupy partial positions on twofold axes. As in the
structure of I, all the three cations form sandwiches, but
in the structure of II, they are isolated, i.e., 12 O atoms
of diethyl ether are due to eight H atoms of the com-
plex. The crown ether molecules and the complex cat-
ions are arranged in such a way that the HBs are formed
by five O atoms of each molecule (Table 3, Fig. 3). In
the fragments Sc(2, 3) (the Sc atoms lying on axes 2),
3
6
9° and 41° (the remaining four angles vary within
2°–66°). The analysis of the thermal vibrations of the
atoms in this molecule reveals at least four disordered
atoms, but we could not record this disordering cor-
rectly.
Two crystallographically independent anions, four
independent ether molecules, and two molecules of
water of crystallization give two independent chains
(Fig. 4). All the ether molecules in these chains have
crown ethers have common conformations: 12 torsion crystallographic symmetry 1 . In every chain, two inde-
angles CCOC lie within 162°–179°, six torsion angles pendent ether molecules perform different structural
OCCO vary within 62°–72°. A fragment Sc(1) has a functions. The molecules O(46–48) in the chain Sc(4)
general position, the conformation of crown ether and O(43–45) in the chain Sc(5) form HBs (Table 3,
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

2
70
ILYUKHIN, PETROSYANTS
S(5)
S(7)
O(48)
O(38)
O(39)
O(37)
O(47)
O(50)
O(10)
Sc(4)
O(46A)
O(10B)
O(47A)
O(9)
O(39A)
Sc(4A) O(9A)
O(46)
Sc(4B)
O(37A)
O(38A)
S(8)
O(48A)
S(6)
S(9)
O(44A)
O(43A)
O(42)
O(41)
O(49)
S(101)
Sc(5)
O(11B)
O(40A)
O(12A)
O(45A)
Sc(5B)
Sc(5A)
O(11)
O(12)
O(41A)
O(42A)
O(43)
O(40)
O(45)
S(12)
O(44)
S(11)
Fig. 4. The structure of the [Sc(H O) (NCS) ](18C6) · H O chains in compound II.
2
2
4
2
x
z
0
y
Fig. 5. Projection of the structure of II along the y axis.
Fig. 4) with both coordinated and crystallization water ether molecules (O(37–39) in the chain Sc(4) and
molecules. The acceptor potentialities of the ether are O(40–42) in the chain Sc(5)). In order to realize their
fully realized—every O atom participates in HB with acceptor capabilities in HBs, the crown ether molecules
one H atom, and the crown ether molecules have stan- are rearranged in such a way that one crystallographi-
dard conformation—the torsion angles CCOC lie in a cally independent H atom in every chain participates in
range 166°–179°, the OCCO angles vary within 63°– mono-, while another one participates in bifurcated
72°. Only four H atoms fall to each of the remaining HB. Note that the molecules of these ethers have differ-
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

AGGREGATES OF COMPLEXES
271
The IR spectra of compounds I and II revealed the
peculiarities of their compositions and structural
motifs. Shown in Fig. 6 are the absorption bands corre-
sponding to the stretching vibrations ν(CN) and
‡
δ(ç é)
for
compounds
I,
II,
and
2
[
ä(18C6)] [Sc(NCS) ]Cl · 3.33H O (III), which was
4
6
2
isolated form THF solution [1]. For compound III, con-
3
–
taining only octahedral [Sc(NCS) ] anions, the half-
6
–
1
width of the absorption band ν(CN) is about ~90 cm
(
Fig. 6a), whereas in the IR spectrum of compound I,
–
1
the half-width of the same band increases to 220 cm
(
Fig. 6b), and in the case of compound II (Fig. 6c), a
pronounced structurization of the band is observed. The
analogous tendency can be noted also for the band
νas(COC). In the IR spectrum of II, this band is also
structurized (and has almost triplet profile).
b
Such a difference in the IR spectra of compounds I
and II correlates with the number of crystallographi-
cally independent thiocyanate ions: compound I con-
tains four independent ligands, while compound II has
1
2 independent ligands.
As shown in [1], the presence in compounds under
c
study of the alkali metal atoms, which coordinated the
crown ether molecules resulted in the formation of
3–
complexes [Sc(NCS) ] . The choice of the synthesis
6
conditions such that the crown ether molecules enter
the crystal structure as individual molecules (as accep-
tors of the H atoms in HB), also leads to the formation
in the structure of the donors of the H atoms in HB, i.e.,
the cationic and anionic aqua complexes of Sc.
ACKNOWLEDGMENTS
This work was supported by the Russian Foundation
for Basic Research (project no. 06-03-32460) and the
RAS Presidium program “The development of methods
for the synthesis of chemical compounds and design of
novel materials” (project no. FP31).
2
500
2000
1500
ν, cm–1
Fig. 6. The IR spectra of compound (a) III, (b) II, and (c) I.
ent conformation. In a molecule with the atoms
O(37−39) (the chain Sc(4)), 10 torsion angles CCOC
lie within 150°–178°, two angles are equal to 86° each,
while the values of the OCCO angles vary in an interval
REFERENCES
1
2
. Petrosyants, S.P. and Ilyukhin, A.B., Koord. Khim.,
007, vol. 33, no. 3, p. 163.
. Sheldrick, G.M., SHELXS-97. Program for the Solution
of Crystal Structures, Göttingen (Germany), Univ. of
Göttingen, 1997.
. Sheldrick, G.M., SHELXL-97. Program for the Refine-
ment of Crystal Structures, Göttingen (Germany), Univ.
of Göttingen, 1997.
2
4
5°–63°. In a molecule with the atoms O(40–42) (the
chain Sc(5)), eight torsion angles CCOC vary within
1
52°–172°, four angles are equal to 78°–79°, while the
3
OCCO angles lie in an interval 60°–69°.
In the structure of II, the anionic chains are parallel
to the y axis. One can conventionally distinguish the
cationic and anionic layers (Fig. 5). The mean-square
planes of crown ether molecules in the cationic sand-
wiches and anionic chains are mutually perpendicular.
The neighboring chains, sandwiches and chains and the
adjacent sandwiches are bonded only by van der Waals
contacts.
4. Petrosyants, S.P., Doctoral (Chem.) Dissertation, Mos-
cow: Inst. of General and Inorg. Chem., 1992. 298 p.
5. Petrosyants, S.P. and Ilyukhin, A.B., Zh. Neorg. Khim.,
2003, vol. 48, no. 9, p. 1463 [Russ. J. Inorg. Chem.
(Engl. Transl.), vol. 48, no. 9, p. 1327].
6. Olszanski, D.J. and Melson, G.A., Inorg. Chim. Acta,
1978, vol. 26, no. 2, p. 263.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007