Four- and five-coordinate metal atoms in a supramolecular polymeric assembly of silver(I) with (4-methyl-2-quinolylthio)acetate

Article abstract of DOI:10.1134/S0036023616110097

The coordination compound [Ag₂L₂(H₂O)₂] · ₂H₂O (I), L = C₁₂H₁₀NO₂S has been synthesized by the reaction of AgNO₃ with 4-methyl-2-quinolylthioacetic acid (HL) preliminarily neutralized with an equimolar amount of NBu₄OH. Its crystal structure has been determined, and luminescence properties have been studied. Crystals of I are monoclinic, space group C2/_c, _a = 31.239(6) ?, _b = 12.056(2) ?, _c = 16.846(3) ?, β = 122.17(3)°, V = 5370.4(2) ?³, ρ_calc = 1.861 g/cm³, Z = 16. The structure is formed by two crystallographically nonequivalent silver atoms Ag(1) and Ag(2) and two tridentate bridging ligands L coordinated through the S, N, and O atoms. These atoms, together with water molecules, form the coordination environments of the metal atoms with CN = 5 and 4, respectively. The Ag⁺ ions and the tridentate ligands form infinite [Ag₄L₄]_n bands extended in the [001] direction. The presence of outer-sphere water molecules involved in O–H···O hydrogen bonding is responsible for the formation of a supramolecular framework structure. The photoluminescence spectrum of compound I shows two bands at ~450 and ~485 nm corresponding to the blue spectral range.

Full text of DOI:10.1134/S0036023616110097

ISSN 0036-0236, Russian Journal of Inorganic Chemistry, 2016, Vol. 61, No. 11, pp. 1397–1402. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © Yu.V. Kokunov, Yu.E. Gorbunova, V.V. Kovalev, L.D. Popov, S.A. Borodkin, G.A. Razgonyaeva, S.A. Kozyukhin, 2016, published in Zhurnal Neorganicheskoi
Khimii, 2016, Vol. 61, No. 11, pp. 1450–1455.
COORDINATION
COMPOUNDS
Four- and Five-Coordinate Metal Atoms
in a Supramolecular Polymeric Assembly of Silver(I)
with (4-Methyl-2-quinolylthio)acetate
a
a
a,
b,
Yu. V. Kokunov , Yu. E. Gorbunova , V. V. Kovalev *, L. D. Popov **,
b
a
a
S. A. Borodkin , G. A. Razgonyaeva , and S. A. Kozyukhin
Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
a
Leninskii pr. 31, Moscow, 119991 Russia
b
Southern Federal University, pr. Stachki 194/2, Rostov-on-Don, 344090 Russia
*e-mail: kovavlad@igic.ras.ru
*
*e-mail: ldpopov@mail.ru
Received May 15, 2016
Abstract—The coordination compound [Ag L (H O) ] ⋅ 2H O (I), L = C H NO S has been synthesized by
2
2
2
2
2
12 10
2
the reaction of AgNO with 4-methyl-2-quinolylthioacetic acid (HL) preliminarily neutralized with an equi-
3
molar amount of NBu OH. Its crystal structure has been determined, and luminescence properties have been
4
studied. Crystals of I are monoclinic, space group C2/c, a = 31.239(6) Å, b = 12.056(2) Å, c = 16.846(3) Å,
3
3
β = 122.17(3)°, V = 5370.4(2) Å , ρ = 1.861 g/cm , Z = 16. The structure is formed by two crystallograph-
calc
ically nonequivalent silver atoms Ag(1) and Ag(2) and two tridentate bridging ligands L coordinated through
the S, N, and O atoms. These atoms, together with water molecules, form the coordination environments of
+
the metal atoms with CN = 5 and 4, respectively. The Ag ions and the tridentate ligands form infinite [Ag L ]
4
4 n
bands extended in the [001] direction. The presence of outer-sphere water molecules involved in O–H⋅⋅⋅O hydro-
gen bonding is responsible for the formation of a supramolecular framework structure. The photoluminescence
spectrum of compound I shows two bands at ~450 and ~485 nm corresponding to the blue spectral range.
DOI: 10.1134/S0036023616110097
The development of the chemistry of coordination boxylate oxygen atoms and the silver atom and the
polymers calls for studying different factors that have an diazolyl nitrogen atom of the neighboring anion. There
+
effect on structure formation, such as coordination prop- are numerous examples of square coordination of Ag
erties of metals, the polyfunctionality of ligands, and ions [6]. Five-coordinate Ag(I) complexes are very rare
their steric properties. Carboxylic acids are widely used
for synthesis of various metal complexes [1, 2]. Carbox-
ylates are of interest not only as objects for basic research
but also as candidates for use as secondary blocks in syn-
thesis of coordination polymers as well as precursors of
nanocomposite and hybrid materials [3, 4].
+
[
6]. The coordination sphere of Ag is mainly com-
posed of halide ions and O- and N-containing ligands.
Known examples of coordination of S-containing
organic ligands are few in number [7, 8]. It has been
shown in [9] that weak silver–ligand interactions and
crystal lattice forces (energy) have a large effect on the
The introduction of donor atoms (N or S) into a car- structure of the resulting compounds.
boxylic acid chain can afford coordination polymers of
In this paper, we report the synthesis, crystal struc-
ture, and photoluminescence spectra of the silver
higher dimensions (2D, 3D) and unusual structural
compositions. Previously [5], we have shown that in the
coordination polymer of silver oxodiazolylacrylate,
pairs of centrosymmetric silver atoms are bound by
bidentate bridging oxygen atoms of the carboxylate
group of two anions to form dimeric blocks with the
coordination polymer [Ag L (H O) ] ⋅ 2H O (I).
2
2
2
2
2
EXPERIMENTAL
Synthesis of HL (4-methyl-2-quinolylthioacetic acid)
+
Ag–Ag distance of 2.854(1) Å. Each of the Ag ions has
a distorted tetrahedral environment formed by two car- was carried out as described in [10] by the scheme:
CH3
CH3
N
O
NaOH
+
S
ClCH C OH
2
O
N
H
S CH C OH
2
1397

1398
KOKUNOV et al.
Table 1. Crystallographic data and experimental details for structure I
FW
367.17
Color, shape
Crystal size, mm
Symmetry system, space group
Colorless, prism
0.20 × 0.11 × 0.09
Monoclinic, C2/c
Unit cell parameters:
a, Å
b, Å
c, Å
β, deg
V, Å3
Z
31.239(6)
12.056(2)
16.846(3)
122.17(3)
5
370.4(2)
16
.861
ρcalc, g/cm3
1
μMo, mm–1
1.665
F(000)
3008
Т, K
293(2)
Radiation, (λ, Å)
Scan mode
MoK (0.71073), graphite monochromator
α
ω
θ range, deg
2.08–27.96
Index ranges
–41 ≤ h ≤ 35, –1 ≤ k ≤ 15, –1 ≤ l ≤ 22
7757/6465 [R(int) = 0.0610]
100%
Total number of reflections/unique
Completeness to θ = 27.96°
Number of reflections with I ≥ 2σ(I)
Correction for absorption
2463
Semiempirical from equivalents
0.3251/0.5430
Transmission (Тmin/Тmax
)
Data/discarded/parameters
3290/0/334
GOOF on F2
R [I ≥ 2σ(I)]
R (all data)
0
.867
R1 = 0.0427, wR2 = 0.1081
R1 = 0.2095, wR2 = 0.1683
Residual electron density (max/min), e/Å3
1.392/–0.979
A mixture of 0.8 g (20 mmol) NaOH in 4 mL of of the BuN OH solution was added, and the reaction
4
water, 0.875 g (5 mmol) 4-methyl-2-thioxo-1H-quino- mixture was heated for 0.5 h at ~40–45°C. The result-
line, and 0.59 g (6.25 mmol) of chloroacetic acid was
heated in a water bath for 2 h. Then, the mixture was
cooled, diluted with 20 mL of water, filtered, and acid-
ified with hydrochloric acid to pH 5. The precipitate
was filtered off and washed with water. Yield, 97%
ing transparent solution was introduced, with stirring,
into a solution of 0.17 g (1 mmol) of silver nitrate in
5
mL of MeCN, which was accompanied by the for-
mation of an amorphous and nonsettleable light yel-
low reaction product with a brown admixture of silver
(
1.13 g, mp 115–116°C).
oxide. To the resulting suspension, an NH OH solu-
4
–1
IR, ν, cm : 2600–3200 (ОН); 1714 (С=О); 1598, tion was added until the major portion of the amor-
1553 (С=N and С=С).
phous phase was dissolved and its residue coagulated.
Then, the liquid phase was decanted and filtered, and
the filtrate was kept in the dark at room temperature
for slow evaporation of the solvent. The deposited light
yellow prismatic crystals was separated from the solu-
1
H NMR (DMSO-d ), δ, ppm: 2.80 (s, 3H, CH ),
6
3
5
(
.03 (s, 2H, CH ), 6.51 (s, 1H, CH arom.), 7.38–8.27
m, 4H, arom.).
2
Synthesis of I. Reagent grade AgNO , 1 M tion, washed with a small amount of acetonitrile, and
3
BuN OH solution in methanol, and 4-methyl-2-qui- dried in air. For C12
H
14AgNO
S (I) anal. calcd. (%):
nolylthioacetic acid were used. To a suspension of 0.23 g N, 3.73; C, 38.40; H, 3.73; S, 8.53. Found (%): N,
0.98 mmol) of the acid in 10 mL of acetonitrile, 1 mL 4.42; C, 39.18; H, 4.35; S, 7.89.
4
4
(
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY
Vol. 61
No. 11
2016

FOUR- AND FIVE-COORDINATE METAL ATOMS
C(6A)
1399
C(7A)
C(8A)
C(5A)
C(4A)
C(9A)
C(10A)
C(3A)
C(2A)
N(1A)
C(1A)
C(24A)
C(11A)
C(20A)
O(5B)
C(19A)
C(18A)
C(16A)
O(5C)
S(2A)
C(23A)
C(22A)
Ag(2A)
C(17A)
C(12A)
C(21A)
N(2A)
C(15A)
C(20) C(24)
O(3A)
C(23)
O(6A)
C(16)
S(1A)
C(13A)
Ag(1A)
C(18) C(19)
O(2)
O(1A)
C(14)
C(14A)
C(21)
O(4A)
C(15)
C(22)
C(17)
O(1)
N(2)
O(2A)
S(1)
Ag(1)
C(13)
C(8)
C(6)
C(3)
O(4)
C(7)
C(5) C(4)
C(11)
C(12)
C(9)
C(2)
Ag(2)
N(1)
C(1)
C(10)
O(5)
S(2)
O(6)
O(3)
O(5A)
Fig. 1. A fragment of structure I: the coordination environments of the Ag(1) and Ag(2) atoms.
When kept in air, the crystals are stable for 2 weeks;
Complete crystal data were deposited with the
on further storage, they gradually lose transparency, Cambridge Structural Database (no. 1475753;
while retaining their shape.
http://www.ccdc.cam.ac.uk/deposit/).
Photoluminescence spectra were recorded at room
X-ray crystallography. Experimental reflection
intensities from a crystal of I were collected on an
Enraf-Nonius CAD-4 automated diffractometer. The
structure was solved by direct methods and refined by
least-squares calculations in the full-matrix anisotro-
pic approximation for all non-hydrogen atoms
temperature on a Perkin Elmer LS-55 spectrometer
(
λ = 200−800 nm, λ = 200−900 nm, instrumental
ex
em
resolution 0.5 nm, slit width d = 10–12 nm, a solid
state attachment was used).
RESULTS AND DISCUSSION
Structure I is built by two crystallographically non-
(
SHELXL-97) [11]. Hydrogen atoms were placed in
geometrically calculated positions and refined using a
riding model. The water protons were located from a equivalent silver atoms, two independent tridentate
difference Fourier synthesis. Unit cell parameters and bridging (due to the S, N, and O atoms) ligands L, and
selected experimental details are presented in Table 1. two independent Н
O molecules. The ligand donor
2
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 61 No. 11 2016

1400
KOKUNOV et al.
S(2A)
Ag(2B)
S(1A)
Ag(1A)
O(2)
C(14)
O(1)
S(1)
N(2)
Ag(1)
O(4)
C(13)
O(3)
O(6)
Ag(2)
S(2)
C(11)
N(1) C(1)
O(5)
C(2)
C(12)
O(1w)
O(2w)
Fig. 2. Character of bonding of the independent [Ag L ] unit into infinite bands running in the [001] direction.
4
4
atoms and water molecules form the coordination [AgO C ], which is presumably responsible for a
2
2
+
environment of the Ag ions (Fig. 1). In the distorted noticeable distortion of the Ag(1) coordination poly-
trigonal-bipyramidal polyhedron of Ag(1), the axial hedron. The second crystallographically nonequiva-
vertices are occupied by the sulfur atoms of two inde- lent silver atom Ag(2) (Fig. 1) has an irregular tetrago-
pendent ligands L (Ag(1)–S(1A), 2.770(3) Å; Ag(1)– nal coordination environment formed by the S(1),
S(2), 2.780(2) Å; angle S(1A)Ag(1)S(2), 162.15(6)°). N(1), water O(3), and carboxylate O(5A) atoms
The equatorial plane is formed by the N(2) atom, the (Ag(2)–S(1), 2.915(2) Å; Ag(2)–N(1), 2.216(6) Å;
Ag(2)–O(3), 2.312(7) Å; Ag(2)–O(5A), 2.314(7) Å;
N(1)Ag(2)O(3), 147.4(2)°; N(1)Ag(2)O(5A),
O(4) atom of the water molecule, and the O(2A) atom
of the carboxylate moiety of ligand L (Ag(1)–N(2),
1
21.3(3)°; O(5A)Ag(2)S(1), 124.0(2)°; the other
2
.327(6) Å; Ag(1)–O(4), 2.484(6) Å; Ag(1)–O(2A),
angles, in the range 85.2(2)°–90.2(3)°).
2
.425(6) Å; N(2)Ag(1)O(2A), 115.0(2)°; N(2)Ag(1)O(4),
+
1
50.8(2)°; O(2A)Ag(1)O(4), 94.2(2)°). This coordina-
The interaction of Ag with the ligands containing
+
tion mode of the donor atoms to the Ag ion leads to three donor sites leads to the formation of infinite
the formation of the five-membered chelate ring [Ag
L ] bands extended in the [001] direction. The
4 4 n
Table 2. Hydrogen bond geometry in structure I
A–H⋅⋅⋅B bond
A⋅⋅⋅B, Å
A–H, Å
H⋅⋅⋅B, Å
AHB angle, deg
B atom position
O(1w)–H(1)⋅⋅⋅O(2w)
O(1w)–H(2)⋅⋅⋅O(6)
O(2w)–H(3)⋅⋅⋅O(5)
O(2w)–H(4)⋅⋅⋅O(1w)
O(2w)–H(4)⋅⋅⋅O(3)
O(3)–H(5)⋅⋅⋅O(2w)
O(3)–H(6)⋅⋅⋅O(4)
O(4)–H(7)⋅⋅⋅O(1)
O(4)–H(8)⋅⋅⋅O(6)
2.852(8)
3.112(8)
2.825(7)
3.085(8)
3.189(9)
3.189(9)
2.907(8)
2.715(7)
2.842(8)
0.87
0.88
0.87
0.92
0.92
0.96
1.26
0.86
0.94
1.98
2.33
1.96
2.37
2.64
2.31
1.68
1.86
2.12
178
149
178
135
119
133
166
179
132
–x – 1/2 , y + 1/2, –z – 1/2
x, –y + 2, z – 1/2
x, –y + 1, z – 1/2
x, –y + 1, z + 1/2
x, y – 1, z
x, y + 1, z
x, y, z
x, –y + 2, z + 1/2
x, y , z
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY
Vol. 61
No. 11
2016

FOUR- AND FIVE-COORDINATE METAL ATOMS
1401
a
O
N
Ag
S
C
0
c
b
Fig. 3. Molecular packing of structure I from infinite bands alternating along the a axis at 1/2a intervals.
character of bonding of the independent [Ag L ] unit in hydrogen bonding (Table 2) both as proton donors
4
4
and proton acceptors.
into infinite [Ag L ] bands is shown in Fig. 2. The
4
4 n
“
width” of the [Ag L ] band is 8.12 Å (the
Figure 4 shows the photoluminescence spectra of
4
4
4
-methyl-2-quinolylthioacetic acid and its silver com-
Ag(2)⋅⋅⋅S(2A) distance). The molecular packing of
structure I consists of infinite bands alternating along
the a axis at intervals of 1/2a. The bands are combined
by an O–H⋅⋅⋅O hydrogen bond, which leads to a
supramolecular framework structure (Fig. 3). Note-
plex I. The spectrum of I shows two bands in the blue
spectral range at ~450 and ~485 nm, which are lacking in
the spectrum of the acid. They can be explained by
ligand-to-metal charge transfer (LMCT mechanism)
and electronic transitions (ds/dp) in the silver ion. Previ-
worthy is the presence of two types of water molecules ously, we have observed an analogous effect for the
in the structure—inner- and outer-sphere—involved AgReO complex with quinoxaline [11]. The set of nearly
4
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 61 No. 11 2016

1402
KOKUNOV et al.
REFERENCES
I
1
2
3
4
5
6
7
8
. R. C. Mehrotra and R. Bohra, Metal Carboxylates
(
Academic Press, London, 1983), p. 396.
. M. A. Kiskin and I. L. Eremenko, Usp. Khim. 75, 627
2006).
2
(
. A. V. Volkov, M. A. Moskvina, I. V. Karachevtsev,
et al., Vysokomol. Soedin. A 40, 45 (1998).
. G. Liu, X. Yan, Z. Lu, et al., Chem. Mater. 17, 985
(2005).
1
. Yu. V. Kokunov, Yu. E. Gorbunova, L.D. Popov, et al.,
Russ. J. Coord. Chem. 42, 323 (2016).
. A. G. Young and L. R. Hanton, Coord. Chem. Rev.
2
52, 1346 (2008).
. X. Jin, X. Xie, H. Qiun, et al., Chem. Commun., 600
2002).
450
500
550
600
λ, nm
650
700
750
(
. Y. Suenaga, K. Kitamura, Sowa T. Kuroda, et al.,
Inorg. Chim. Acta 328, 105 (2002).
Fig. 4. Photoluminescence spectra of (1) compound I and
2) the acid at λ = 403 nm and room temperature.
(
9. G. F. Swiegers and T. J. Malefetse, J. Chem. Rev. 100,
483 (2000).
ex
3
1
0. A. A. Avetisyan and I. L. Aleksanyan, Khim. Geterot-
identical bands in the range 550–700 nm is associated
with intraligand π → π* transitions in the acid.
sikl. Soedin., no. 5, 403 (2005).
11. G. M. Sheldrick, Acta Crystallogr. Sect. A 64, 112
(2008).
ACKNOWLEDGMENTS
1
2. Yu. V. Kokunov, Yu. E. Gorbunova, V. V. Kovalev, and
S. A. Kozyukhin, Russ. J. Coord. Chem. 41, 747 (2015).
This work was supported by the basic research pro-
gram of the Presidium of the RAS “Scientific Foun-
dations for the Design of New Functional Materials.”
Translated by G. Kirakosyan
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY
Vol. 61
No. 11
2016