Syntheses, crystal structures, and physico-chemical studies of sodium and potassium alcoholates bearing thienyl substituents and their derived luminescent samarium(III) alkoxides

Article abstract of DOI:10.1002/zaac.201000205

The synthesis, structural characterisation, electrochemistry, and luminescence properties of a series of alkali metal alcoholates and samarium( III) alkoxides with thiophene-based OR substituents are presented. The alkali metal alcoholates 7-15 were obtai

Full text of DOI:10.1002/zaac.201000205

ARTICLE
DOI: 10.1002/zaac.201000205
Syntheses, Crystal Structures, and Physico-Chemical Studies of Sodium and
Potassium Alcoholates Bearing Thienyl Substituents and their Derived
Luminescent Samarium(III) Alkoxides
Michael Veith,*[a,b] Céline Belot,[a,c] Volker Huch,[a] Laurent Guyard,[c] Michael Knorr,[c]
Abderrahim Khatyr,[c] and Claudia Wickleder[d]
Keywords: Thienylmethoxido ligands; Hetero-cubanes with alkali metals; Samarium; Electrochemistry; Luminescence
Abstract. The synthesis, structural characterisation, electrochemistry, and {[KOC(C16H13S)]4(thf)3}·½thf (11), respectively, and SmCl3 in thf solu-
luminescence properties of a series of alkali metal alcoholates and sama- tion. The molecular structures of these air-sensitive base adducts have
rium(III) alkoxides with thiophene-based OR substituents are presented. been determined by single crystal X-ray crystallography and reveal an
The alkali metal alcoholates 7–15 were obtained by deprotonation of the approximately octahedral coordination sphere around the samarium metal
carbinol with NaH or KH. Their molecular structures consist of tetranu- atoms with three methoxido ligands and three facially arranged tetrahydro-
clear alkali metal alcoholates with a distorted cubane-like M4O4 core (X- furan molecules. The electrochemical properties are essentially dominated
ray structure analyses). Each alkali metal is surrounded by three carbinol- by the oxidation of the thienyl units. The emission spectra of the carbinols
ate ligands and (depending on the derivative) by additional tetrahydro- and their derived potassium and sodium compounds display broad bands
furan
molecules.
The
mononuclear
samarium
alkoxides attributed to the π* → π transitions of the aromatic ligands. Luminescence
{Sm[OC(C4H3S)3]3(thf)3}·thf (16) and {Sm[OC(C16H13S)]3(thf)3}·thf studies performed on complexes 16 and 17 reveal the typical f–f transi-
(17) were synthesised by the salt metathesis reactions between tions of the SmIII ion. The photophysical data suggest that an energy
{[KOC(C4H3S)3]4(thf)2}·thf (7), [NaOC(C4H3S)3]4(thf)2 (8) or
transfer from the ligand to the metal atom operates.
tion with lanthanide ions are the metal binding strength and
ultraviolet (UV) absorption properties of ligands. Among sev-
eral categories of ligands, nitrogen- and oxygen-donor groups
were used in the sensitisation of lanthanide luminescence. In
particular, bidentate aromatic amines, carboxylic acids, and β-
diketonates are known to provide energy transfer to lantha-
nides ions [3]. However, to date only a few examples of lantha-
nide complexes bearing sulfur moieties have been reported [4–
6] probably due to the generally lower stability and the mis-
match between a soft sulfur-donor ligand and a hard lanthanide
metal ion. In particular, those containing thienyl rings have
been barely explored, although their transition metal counter-
parts have been investigated in detail [7]. This interest stems
from the fact that thiophene derivatives are quite attractive as
organic ligands because of their electron-rich system and their
electroactive character.
Introduction
Trivalent lanthanide compounds have received much atten-
tion within the last decade because of their luminescence prop-
erties and their applications in electronic materials and in bio-
logical systems [1]. The intraconfigurational 4f–4f transitions
are parity forbidden and their emission and absorption spectra
exhibit weak intensity upon an excitation on the lanthanide
ion. However, some organic ligands can act as an “antenna”,
absorbing and transferring energy efficiently to the metal ion
and consequently increasing their luminescence yield [2]. The
choice of the ligand for complexation plays a key role in con-
structing efficient luminescence lanthanides complexes. Two
common requirements for selecting a ligand for the coordina-
* Prof. Dr. Dr. h. c. M. Veith
E-Mail: Michael.Veith@inm-gmbh.de
[a] Institut für Anorganische Chemie
Universität des Saarlandes
Postfach 151150
Complexes containing SmIII have been less studied than
those with EuIII and TbIII, since they generally exhibit lower
intensity for the luminescence. But, trivalent samarium ions
present an orange-red emission in the spectral region [8, 9],
and have been investigated in light-converting devices together
with EuIII and TbIII analogues [9b, 9h]. Moreover, trivalent sa-
marium(III) derivatives may have attractive catalytic activity:
they can act as Lewis acid to activate Michael–aldol reaction
[10], epoxidation of alcohols [11], Meerwein–Ponndorf–Ver-
ley–Oppenauer reaction, aldol reaction [11], Diels–Alder reac-
tion [12] and Tischenko reaction [13]. For example, Imamoto
66041 Saarbrücken, Germany
[b] INM – Leibniz Institute for New Materials
Campus D2 2
66123 Saarbrücken, Germany
[c] Institut UTINAM UMR CNRS 6213
Université de Franche-Comté
16, Route de Gray,
25030 Besançon, France
[d] Inorganic Chemistry II
University of Siegen
Adolf-Reichwein-Straße
57068, Siegen, Germany
View this journal online at
wileyonlinelibrary.com
2262
© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2010, 636, 2262–2275

Sodium and Potassium Alcoholates with Thienyl Substituents and their SmIII Alkoxides
3
4
7.3 (m, 10 H, Ph), 6.5 (m, JH4–H3 = 3.4 Hz and JH4–HMe = 1.03 Hz,
et al. [14] have recently used the trivalent alkoxide complex
SmIIItris(2,6-di-tert-butyl-4-methylphenoxides) to catalyze
Michael–Michael–aldol–reaction of 3,3-dimethyl-2-butanone
with benzalacetophenone.
3
1H, 4-H Th), 6.4 (d, JH3–H4 = 3.4 Hz, 1H, 3-H Th), 2.9 (br. s, 1 H, –
4
OH), 2.4 (d, JHMe–H4 = 0.7 Hz, 3H, –CH3). ATR IR: ν(OH) =
3448 cm–1. C18H16OS: calcd. C 77.14; H 5.71 %; found C, 77.10; H,
4.46 %.
In two previous papers, we have studied the synthesis and
physico-chemical properties of a series of rare earth alkoxides
of yttrium and neodymium bearing thiophene moieties [5, 6].
We present herein the syntheses of two novel samarium(III)
alkoxides, their structural characterisation as well as electro-
chemical and photoluminescence properties. A strategy that we
have developed recently consists of the preparation of suitable
tertiary alcohols with thienyl and phenyl substituents capable
of being attached on rare earth metal atoms through a covalent
M–O–R bond, leading to coordination compounds with singu-
lar redox and luminescence properties. Furthermore, we have
investigated the deprotonation of the bulky and slightly acidic
tertiary alcohol shown in Figure 1 using potassium and sodium
hydride as bases. The resulting salts have been characterised
crystallographically. Furthermore, they have been used for the
synthesis of derivatives of samarium(III). In addition, the elec-
trochemical and luminescence properties of all these new com-
pounds have been explored.
General Procedure for Preparation of Potassium Alcoho-
lates 7, 9, 11, and 12
The carbinols [1.39 g of 1; 1.37 g of 2, 1.471 g of 3; 1.431 g of 4
(5.0 mmol)] were dissolved in thf (20 mL) and slowly added to a sus-
pension of KH (0.202 g, 5.0 mmol) in thf (5 mL). The mixture was
stirred at room temperature overnight. All the KH had reacted. The
solvents were evaporated, and solids were obtained, from which color-
less crystals can be formed in thf at 5 °C.
{[KOC(C4H3S)3]4(thf)2}·thf (7): Yield 20 % (362 mg). 1H NMR (thf/
3
4
C6D6): δ = 6.9 (dd, JH5–H4 = 4.7 Hz and JH5–H3 = 1.3 Hz, 12H,
3
4
5-H), 6.8 (dd, JH3–H4 = 3.3 Hz and JH3–H5 = 1.3 Hz, 12H, 3-H), 6.7
(dd, 3JH4–H3 = 3.3 Hz and 3JH4–H5 = 4.7 Hz, 12H, 4-H). C64H60O7S12K:
calcd. C 51.81; H 4.05 %; found C 53.02; H 3.31 %.
[KOC(C14H11S2)]4(thf)3 (9): Yield 30 % (580 mg). 1H NMR (thf/
C6D6): δ = 7.5 (m, 8 H, 5-H Th), 6.9 (m, 20 H, Ph), 6.7 (m, 8 H, 4-H
Th), 6.5 (m, 8H, 3-H Th). C72H68O7S8K4: calcd. C 59.25; H 4.66;
cannot be performed because of the sensibility.
1
{[KOC(C16H13S)]4(thf)3}·½thf (11): Yield 34 % (610 mg). H NMR
(thf/C6D6): δ = 7.3 (m, 12 H, 5-H Th, Ph), 6.9 (m, 32 H, Ph), 6.7 (m,
4H, 4-H Th), 6.4 (m, 4H, 3-H Th). C82H80O7.5S4K4: calcd. C 67.02;
H 5.40 %; found C 65.74; H 4.60 %.
[KOC(C17H15S)]4(thf)2 (12): Yield 29 % (515 mg). 1H NMR (thf/
C6D6): δ = 7.3 (m, 16 H, Ph), 7.0 (m, 24 H, Ph), 6.4 (m, 4 H, 4-H
Th), 6.2 (m, 4H, 3-H Th), 2.2 (s, 12H, –CH3). C80H76O6S4K4: calcd.
C 67.69; H 5.35 %; found C 66.60; H 6.60 %.
General Procedure for Preparation of Sodium Alcoholates
8, 10, 13–15
Figure 1. Overview of carbinols 1–6 used as starting materials.
The carbinols [1.40 g of 1; 1.37 of 2; 1.43 g of 4; 1.367 g of 5; 1.338 g
of 6 (5.0 mmol)] were dissolved in thf (20 mL) and slowly added to
a suspension of NaH (0.121g, 5 mmol) in thf (5 mL). The mixture was
stirred at room temperature overnight.
Experimental Section
Materials: All reactions were performed under nitrogen atmosphere
in a Schlenk apparatus. Tetrahydrofuran (thf) and diethyl ether were
distilled from sodium and kept under nitrogen. Dichloromethane and
acetonitrile were distilled from CaCl2 and kept under nitrogen. Tris(2-
thienyl)methanol (1), phenylbis(2-thienyl)methanol (2), diphenyl(2-
thienyl)methanol (3), phenylbis(3-thienyl)methanol (5) and di-
phenyl(3-thienyl)methanol (6) were prepared according to the litera-
ture [15].
[NaOC(C4H3S)3]4(thf)2 (8): All NaH had reacted. The solvent was
evaporated; a solid was obtained, from which colorless crystals could
1
be obtained in thf at 5°C. Yield 15 %, 243 mg. H NMR (thf/C6D6):
3
4
δ = 6.9 (dd, JH5–H4 = 4.9 Hz and JH5–H3 = 1.2 Hz, 12H, 5-H), 6.8
3
4
(dd, JH3–H4 = 3.4 Hz and JH3–H5 = 1.2 Hz, 12H, 3-H), 6.7 (dd,
3JH4–H3 = 3.7 Hz and JH4–H5 = 4.9 Hz, 12H, 4-H). C60H52O6S12Na4:
3
calcd. C 53.50; H 3.86 %; found C 52.24; H 3.56 %.
HO–C(C17H15S) (4): To a solution of 2-methylthiophene (1.57 g,
16 mmol, 1.53 mL) in diethyl ether (20 mL) was added n-butyllithium
(16 mmol, 10 mL, 1.6 m solution in hexane) at –15 °C. The solution
was stirred for 1 h, afterwards benzophenone (2.91 g, 16 mmol) in
diethyl ether was added, and the mixture was allowed to reach room
temperature and was stirred overnight. It was hydrolysed with an aque-
ous saturated sodium hydrogenocarbonate solution. The mixture was
extracted with diethyl ether, and the organic layer was dried with
[NaOC(C14H11S2)]4(thf)2 (10): The unreacted NaH was filtered. The
solvent was slowly evaporated, a light-brown solid precipitated, which
was separated from the liquid residue. The isolated yield is 32 %
3
(529 mg). 1H NMR (thf/C6D6): δ = 7.6 (dd, JH5–H4 = 6.6 Hz and
4JH5–H3 = 1.3 Hz, 8H, 5-H Th), 7.0 (m, 28 H, 4-H, Ph), 6.7 (dd,
3JH4–H3 = 4.0 Hz, 8 H, 3-H Th). C68H60O6S8Na4: calcd. C 61.81;
H 4.54 %; found C 60.61; H 4.39 %.
Na2SO4 and the solvents evaporated. The solid was washed in hexane. [NaOC(C17H15S)]4(thf)2 (13): The suspension turned into a solution.
1
A white solid was obtained. Yield 67 %, 3 g. H NMR (CDCl3): δ = The solvent was slowly evaporated, a white solid precipitated, which
Z. Anorg. Allg. Chem. 2010, 2262–2275
© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
2263

M. Veith et al.
ARTICLE
1
was filtered. Yield 14 %, 241 mg. H NMR (thf/C6D6): δ = 7.3 (m, MHz, H,H-COSY) for 16–17. All chemical shifts (δ) and coupling
16 H, Ph), 7.0 (m, 24 H, Ph), 6.4 (m, 4H, 4-H Th), 6.2 (m, 4H, 3-H constants (J) are given in ppm and Hertz, respectively. Analytical data
Th), 2.2 (s, 12H, –CH3). C80H76O6S4Na4: calcd. C 71.00; H 5.62 %; were measured with a LECO CHN–900 instrument. The ATR IR spec-
found C 71.00; H 5.59 %.
tra were performed with a Bruker Vector 22 Spectrometer equipped
with Golden Gate.
[NaOC(C14H11S2)]4(thf)2 (14): The unreacted NaH was filtered. The
solvent was slowly evaporated; colorless crystals were obtained. Yield
1
22 %, 362 mg. H NMR (thf/C6D6): δ = 7.2 (m, 16 H, Ph, 5-H Th),
Electrochemistry
7.0 (m, 12 H, Ph), 6.8 (m, 8 H, 4-H Th), 6.2 (m, 8 H, 2-H Th).
C68H60O6S8Na4: calcd. C 61.81; H 4.54 %; found C 59.54; H 5.08 %.
Cyclic voltammetric experiments were performed with an Autolab
PGSTAT 20 Potentiostat Galvanostat (Ecochemie) equipped with a
three-electrode assembly with 0.1 m [NBu4][PF6] (TBAF) as support-
ing electrolyte and CH3CN or CH2Cl2 as solvent. The working elec-
trode was a platinum disk of 1 mm in diameter; it was polished consec-
utively with polishing alumina and diamond suspension between the
runs. The reference electrode was Ag/AgClO4 (0.1 m in CH3CN). A
platinum disk was used as an auxiliary electrode. The solvent was
freshly distilled, and the solutions were prepared under nitrogen atmos-
phere and blanketed with nitrogen before the first scan. Measurements
were made at room temperature. The scan rates employed were
100 mV·s–1. The concentration of the monomeric substrates was
10–3 m for the carbinol and alkali metal alcoholates and approximately
3.15 × 10–3 m for 16 and 3.32 × 10–3 m for 17. Under these condi-
tions, the E1/2 of Cp2Fe+/0 was found to be 0.16 V (CH2Cl2) and
0.025 V (CH3CN) versus an Ag/AgClO4 reference.
[NaOC(C16H13S)]4(thf)2 (15): The reaction mixture was filtered, and
the solvent was slowly evaporated, from which a white solid precipi-
tated. Yield 31 %, 490 mg. 1H NMR (thf/C6D6): δ = 7.3 (m, 12 H,
Ph, 5-H Th), 7.0 (m, 24 H, Ph), 6.9 (d, 4 H, 4-H Th), 6.2 (s, 4 H,
2-H Th). C76H68O6S4Na4: calcd. C 70.37; H 5.24 %; found C 71.03;
H 5.09 %.
{Sm[OC(C4H3S)3]3(thf)3}·thf(16)
Method 1: To a suspension of NaH (0.104 g, 4.3 mmol) in thf (5 mL)
was slowly added tris(2-thienyl)methanol (1.21 g, 4.3 mmol) in thf
(20 mL). The mixture was stirred at room temperature overnight. Af-
terwards it was added to a suspension of SmCl3 (0.373 g, 1.4 mmol)
in thf (5 mL). The mixture was stirred at room temperature for two
days. NaCl was filtered off. The solution was concentrated and brown-
light crystals were obtained at 5°C a few days later. The isolated yield
is 24 % (430 mg).
Luminescence Studies
Solid-state emission and excitation spectra were recorded at room tem-
perature on a Jobin–Yvon Fluorolog-3 spectrometer equipped with a
1000 W Xenon lamp, two double grated monochromators for emission
and excitation, respectively, and a photomultiplier with a photon count-
ing system. The emission spectra were corrected for photomultiplier
sensitivity, the excitation spectra for lamp intensity and both for the
transmission of the monochromators.
Method 2: To a suspension of KH (0.154 g, 3.8 mmol) in thf (5 mL)
was slowly added tris(2-thienyl)methanol (1.07 g, 3.8 mmol) in thf
(20 mL). The mixture was stirred at room temperature overnight. Af-
terwards it was added to a suspension of SmCl3 (0.328 g, 1.3 mmol)
in thf (5 mL). The mixture was stirred at room temperature for two
days. KCl was filtered off. The solution was concentrated and brown-
light crystals were obtained at 5°C after a few days. The isolated yield
is 13 % (217 mg).
Crystallography
1H NMR (CDCl3): δ = 7.2 (br. s, 27 H, 3-H, 4-H, 5-H), 3.6 (br. s,
8 H, thf), 3.4 (br. s, 3 H, thf), 1.7 (br. s, 10H, thf), 1.2 (br. s,
8H, thf), 0.9 (br. s, 3H, thf). C55H59O7S9Sm: calcd. C 51.93; H 4.64 %;
found C 49.32; H 4.57 %.
The data collection was performed with an X8 ApexII CCD diffrac-
tometer with Mo-Kα radiation (λ = 0.71073 Å). Structures were solved
by direct methods and refined by full-matrix least square methods on
F2 with SHELX–97 [16]. Drawings were made with Diamond [17].
All crystals of the compounds started growing up at 5 °C during a
period of one week. No sign of deterioration during storage under
nitrogen was observed. Crystallographic data for the structure determi-
nations are listed in Table 1, and relevant bond lengths and angles are
given in Table 3, Table 4, Table 5, and Table 6. Most of the alkali
compounds (7, 8, 9, and 12) had weak reflections at higher theta val-
ues, which explains the bad R values. The structures 9 and 12 are only
generally discussed without looking into the details of bonding.
{Sm[OC(C16H13S)]3(thf)3}·thf (17)
To a suspension of KH (0.193 g, 4.8 mmol) in thf (5 mL) was slowly
added diphenyl(2-thienyl)methanol (1.28 g, 4.8 mmol) in thf (20 mL).
The mixture was stirred at room temperature overnight. Afterwards it
was added to a suspension of SmCl3 (0.410 g, 1.6 mmol) in thf
(5 mL). The mixture was stirred at room temperature for two days.
KCl was filtered off. The solution was concentrated and colorless crys-
tals were obtained at 5°C few days later. The isolated yield is 10 %
CCDC-776395, -776396, -776397, -776398, -776399, -776400, and
-776401 contain the supplementary crystallographic data for the
compounds. These data can be obtained free of charge via
http://www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cam-
bridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2
1EZ, UK (Fax: 44-1223-336-033; or E-Mail: deposit@ccdc.cam.ac.uk)
1
(190 mg). H NMR (CDCl3): δ = 7.3 (m, 33 H, Ph, 5-H Th), 6.9 (dd,
3
3
3 H, 4-H Th, JH4–H5 = 5.14 Hz, JH4–H3 = 3.97 Hz,), 6.7 (dd, 3 H,
3
3
3-H Th, JH3–H4 = 3.42 Hz, JH3–H5 = 1.22 Hz), 3.7 (m, 12H, thf), 1.8
(m, 12 H, thf). C67H71O7S3Sm: calcd. C 65.11; H 5.75 %; found C
65.18; H 6.19 %.
Results and Discussion
Samarium(III) alkoxides were prepared in the past by trans-
(200 MHz) for 4 and 7–15 and Bruker Avance 400 spectrometer (400 esterification reactions of Sm–OiPr in the presence of an ex-
Instruments
The 1H NMR spectra were recorded with a Bruker ACF–NMR
2264
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© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2010, 2262–2275

Sodium and Potassium Alcoholates with Thienyl Substituents and their SmIII Alkoxides
Table 1. X-ray crystallographic and refinement data for 7–9, 11–12, and 16–17.
Compounds
7
8
9
11
12
16
17
Empirical formula
Formula weight
Temperature /K
Crystal system
Space group
a /Å
C
64H60K4O7S12
C60H52Na4O6S12 C72H68K4O7S8
C84H82K4O7.5S3 C80H76K4O6S4
C55H59O7S9Sm C67H71O7S3Sm
1482.24
103(2)
Orthorhombic
Pccn
1345.70
103(2)
Monoclinic
C2/c
1458.14
130(2)
Monoclinic
C2/c
1464.08
130(2)
Cubic
P2(1)3
24.494(1)
24.4944(1)
24.494(1)
90
1418.05
130(2)
Monoclinic
C2/c
1270.91
130(2)
1234.77
130(2)
Rhombohedral Trigonal
R3
P31c
14.246(1)
16.743(1)
27.71(1)
90
23.19(1)
13.343(1)
22.98(1)
90
24.77(1)
24.21(1)
49.11(2)
90
23.647(1)
14.219(1)
42.900(9)
90
13.940(1)
13.940(1)
24.700(4)
90
14.568(1)
14.568(1)
15.780(1)
90
b /Å
c /Å
α /°
β /°
90
90
119.96(1)
90
91.55(1)
90
90
94.10(1)
90
90
120
90
120
γ /°
90
Volume /Å3
Z
6608.6(6)
4
6158.8(5)
4
29444(3)
16
14695.9(6)
8
14387(1)
8
4156.8(8)
3
2900.4(3)
2
ρcalc /mg·m–3
1.490
1.451
1.316
1.323
1.309
1.523
1.450
1953
1.414
1.175
1278
μ /mm–1
0.701
0.504
0.519
0.384
0.416
F(000)
3072
2784
12160
6160
5952
Crystal size /mm
Theta range for
data collection /°
Reflections
collected
0.55 × 0.3 × 0.25 0.4 × 0.28 × 0.22 0.55 × 0.37 × 0.22 0.5 × 0.2 × 0.09 0.42 × 0.40 × 0.29 0.3 × 0.44 × 0.5 0.50 × 0.37 × 0.06
1.47 to 29.40
1.83 to 34.67.
1.18 to 26.49
123598
1.18 to 28.26
1.67 to 26.44
117135
1.88 to 34.27
1.61 to 26.41
46554
105170
83983
26806
16454
Independent
reflections
Completeness to
theta /%
9114,
12917,
30203,
12157,
14786,
5629,
3955,
[R(int) = 0.0290] [R(int) = 0.0356] [R(int) = 0.0765] [R(int) = 0.1092] [R(int) = 0.0406] [R(int) = 0.0350] [R(int) = 0.0397]
99.9 (29.40°)
97.5 (34.67°)
99.1 (26.49°)
100.0 (28.26°)
99.7 (26.44°)
99.9 (34.27)°
100.0 (26.21°)
Absorption
correction
Data / restraints /
parameters
Goodness-of-fit
on F2
None
Multiscan
Multiscan
None
Multiscan
Multiscan
Multiscan
9114 / 0 / 460
2.785
12917 / 0 / 360
2.755
30203 / 4 / 1671 12157 / 0 / 589 14786 / 13 / 874 5629 / 1 / 216
3955 / 1 / 209
1.375
2.076
1.022
1.228
1.433
Final R indices
[I > 2σ(I)]
R1 = 0.0951
wR2 = 0.2853
R1 = 0.1052
wR2 = 0.2969
R1 = 0.1224
wR2 = 0.3011
R1 = 0.0626
wR2 = 0.1497
R1 = 0.1107
wR2 = 0.2368
R1 = 0.0482
wR2 = 0.1311
R1 = 0.0490
wR2 = 0.1275
Largest diff. Peak 2.130 and –1.303 4.195 and –2.547 1.207 and –1.201 1.010 and –0.516 1.386 and –1.718 2.826 and –1.752 0.916 and –0.416
and hole /e·Å–3
1
Table 2. H NMR chemical shifts for the alkali metal alcoholates 7–15 obtained in thf/C6D6.
Compounds Chemical shifts
3
4
3
4
7
6.9 (dd, JH5–H4 = 4.7 Hz and JH5–H3 = 1.3 Hz, 12 H, 5-H), 6.8 (dd, JH3–H4 = 3.3 Hz and JH3–H5 = 1.3 Hz, 12 H, 3-H), 6.7 (dd,
3JH4–H3 = 3.3 Hz and JH4–H5 = 4.7 Hz, 12 H, 4-H)
3
3
4
3
4
8
6.9 (dd, JH5–H4 = 4.9 Hz and JH5–H3 = 1.2 Hz, 12 H, 5-H), 6.8 (dd, JH3–H4 = 3.4 Hz and JH3–H5 = 1.2 Hz, 12 H, 3-H), 6.7 (dd,
3JH4–H3 = 3.7 Hz and JH4–H5 = 4.9 Hz, 12 H, 4-H)
3
9
7.5 (m, 8 H, 5-H Th), 6.9 (m, 20 H, Ph), 6.7 (m, 8 H, 4-H Th), 6.5 (m, 8 H, 3-H Th)
3
4
3
10
11
12
13
14
15
7.6 (dd, JH5–H4 = 6.6 Hz and JH5–H3 = 1.3 Hz, 8 H, 5-H Th), 7.0 (m, 28 H, 4-H, Ph), 6.7 (dd, JH4–H3 = 4.0 Hz, 8 H, 3–H Th)
7.3 (m, 12 H, 5-H Th, Ph), 6.9 (m, 32 H, Ph), 6.7 (m, 4 H, 4-H Th), 6.4 (m, 4 H, 3-H Th)
7.3 (m, 16 H, Ph), 7.0 (m, 24 H, Ph), 6.4 (m, 4 H, 4-H Th), 6.2 (m, 4 H, 3-H Th), 2.2 (s, 12 H, –CH3)
7.3 (m, 16 H, Ph), 7.0 (m, 24 H, Ph), 6.4 (m, 4 H, 4-H Th), 6.2 (m, 4 H, 3-H Th), 2.2 (s, 12 H, –CH3)
7.2 (m, 16 H, Ph, 5-H Th), 7.0 (m, 12 H, Ph), 6.8 (m, 8 H, 4–H Th), 6.2 (m, 8 H, 2-H Th)
7.3 (m, 12 H, Ph, 5-H Th), 7.0 (m, 24 H, Ph), 6.9 (d, 4 H, 4-H Th), 6.2 (s, 4 H, 2-H Th)
cess of other alcohols R'OH to provide Sm–OR' species [18].
Mononuclear phenoxide and siloxides of type Sm(OAr)3(thf)3
and Sm(OSiPh3)3(thf)3 were also obtained by alcoholysis
of the dinuclear organometallic samariumfluoride
[{(Me3Si)2C5H3}2SmF]2 in the presence of slightly acidic
ArOH or Ph3SiOH [19]. Reaction of equimolar quantities of
Sm[N(SiMe3)2]3 and Al(iBu)3 in the presence of iso-propanol
or tBuOH allowed the preparation of the mixed-metal alkoxide
complexes {[(iPr–O)(iBu)Al(μ-O–iPr)2Sm(O–iPr)(HO–iPr)](μ-
O–iPr)}2. An analogous reaction between Sm[N(SiMe3)2]3,
Al(iBu)3 and tBuOH, followed by addition of thf, produced
the thf adduct [(thf)2Sm(O–tBu)2(μ-O–tBu)2Al(iBu)2] [20].
But the most classical route to prepare samarium alkoxides and
Table 3. Selected bond lengths /Å and angles /° for compound 7.
K(1)–O(2)
2.671(3)
2.636(3)
2.652(4)
2.736(3)
87.67(9)
87.90(9)
90.4(1)
K(2)–O(3)
K(2)···K(1)
K(2)···K(2)
2.687(4)
3.611(1)
3.855(2)
K(1)–O(1)
K(2)–O(1)
K(2)–O(2)
K(1)–O(2)–K(1)
K(1)–O(2)–K(2)
K(1)–O(1)–K(2)
K(2)–O(1)–K(2)
O(2)–K(1)–O(2)
O(1)–K(1)–O(2)
O(1)–K(2)–O(3)
O(1)–K(2)–O(2)
O(1)–K(2)–O(1)
O(3)–K(2)–O(2)
C(1)–O(1)–K(1)
C(1)–O(1)–K(2)
89.7(1)
87.1(1)
127.4(1)
119.1(3)
126.6(3)
92.6(1)
91.6(1)
91.5(1)
C(14)–O(2)–K(2) 141.3(2)
C(14)–O(2)–K(1) 128.5(2)
118.5(1)
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Table 4. Selected bond lengths /Å and angles /° for
{[KOC(C16H13S)]4(thf)3}·½thf (11) (molecules A and B).
uted to the protons of the phenyl groups, a multiplet at δ = 6.5
and a doublet at 6.4 ppm of the 4-H and the 3-H of the thienyl
unit, respectively. A broad signal at 2.9 ppm due to the alcohol
function is also obtained. The latter signal, a doublet at δ =
2.4, is assigned to the protons of the methyl group.
A
B
K(1)–O(1)
2.789(3)
2.625(3)
2.696(3)
2.765(4)
1.390(9)
3.754(2)
88.50(9)
88.3(1)
K(3)–O(3)
2.790(3)
2.702(3)
2.667(3)
2.742(4)
1.400(8)
3.734(2)
86.67(9)
88.9(1)
91.35(9)
126.7(1)
124.3(1)
124.3(1)
117.9(1)
115.6(2)
119.0(2)
126.07(8)
K(2)–O(1)
K(4)–O(3)
K(2)–O(2)
K(4)–O(4)
K(2)–O(5)
K(4)–O(6)
O(2)–C(18)
O(4)–C(46)
K(2)···K(2)
K(4)···K(4)
K(2)–O(1)–K(1)
K(2)–O(1)–K(2)
O(1)–K(1)–O(1)
O(1)–K(2)–O(1)
O(1)–K(2)–O(2)
O(1)–K(2)–O(5)
O(2)–K(2)–O(5)
O(5)–K(2)–O(1)
C(1)–O(1)–K(1)
C(1)–O(1)–K(2)
C(18)–O(2)–K(2)
K(4)–O(3)–K(3)
K(4)–O(4)–K(4)
O(3)–K(3)–O(3)
O(3)–K(4)–O(6)
O(3)–K(4)–O(4)
O(3)–K(4)–O(6)
O(4)–K(4)–O(6)
C(29)–O(3)–K(3)
C(29)–O(3)–K(4)
C(46)–O(4)–K(4)
Scheme 1. Synthesis of HO–C(C17H15S) (4).
91.95(9)
94.8(1)
94.37(9)
115.9(1)
113.9(1)
137.9(1)
113.4(2)
146.0(2)
126.45(8)
Synthesis and Characterisation of the Potassium and
Sodium Thienyl-Substituted Alcoholates
We have recently prepared a series of mononuclear lanthanide
carbinol complexes bearing thienyl substituents of type
Ln(OR)3(thf)n (Ln = Nd, Er) by the above mentioned aminolysis
reaction of silylamides Ln[N(SiMe3)2]3 in the presence of thi-
enyl-functionalised carbinols [5, 6]. Unfortunately, we failed to
isolate any SmIII complexes in crystalline form using this route.
For this reason we have chosen the salt-elimination route to
prepare the targeted samarium complexes.
Table 5. Selected bond lengths /Å and angles /° for
[NaOC(C4H3S)3]4(thf)2 (8).
Na(1)–O(2)
2.323(2) Na(1)···Na(1)
2.302(2) Na(2)···Na(2)
2.488(2) Na(1)···Na(2)
2.286(2) Na(1)–S(3)
2.325(3)
3.068(2)
3.256(2)
3.290(1)
2.875(2)
Na(1)–O(1)
The targeted potassium or sodium alcoholates 7–15 were syn-
thesised straightforwardly by deprotonation of the correspond-
ing carbinol with potassium or sodium hydride according to
Scheme 2. In the course of all reactions, which were conducted
at room temperature overnight, hydrogen gas developed. The
Na(2)–O(1)
Na(2)–O(2)
Na(2)–O(3)
Na(1)–O(1)–Na(1)
Na(1)–O(1)–Na(2)
Na(2)–O(2)–Na(2)
Na(2)–O(2)–Na(1)
O(2)–Na(2)–O(1)
95.45(8) O(1)–Na(1)–O(1)
87.00(8) O(2)–Na(2)–O(2)
91.21(8) O(2)–Na(1)–O(1)
85.86(8) C(1)–O(1)–Na(1)
95.45(8)
88.79(8)
92.10(8)
125.1(2)
compounds
{[KOC(C4H3S)3]4(thf)2}·thf
(7),
[NaOC(C4H3S)3]4(thf)2 (8) [KOC(C14H11S2)]4(thf)3 (9),
{[KOC(C16H13S)]4(thf)3}·½thf (11), and [KOC(C17H15S)]4(thf)2
(12) can be isolated as colorless crystals, whose crystallographic
characterisation (see below) revealed their tetranuclear nature.
The 1H NMR spectra of these alcoholates, recorded in thf/C6D6,
show the typical aromatic signals of thienyl and/or phenyl
groups (Table 2). Unfortunately, we failed to grow single crys-
93.99(8) C(14)–O(2)–Na(2) 132.2(2)
Table 6. Selected bond lengths /Å and angles /° for 16 and 17.
16
17
Sm–O(1)
2.156(3)
2.594(3)
1.391(5)
101.1(1)
92.5(1)
2.160(4)
2.552(5)
1.395(8)
102.3(2)
90.8(2)
1
tals of 10 and 13–15. According to the H NMR spectra (Ta-
Sm–O(2)
O(1)–C(1)
O(1)–Sm–O(1)
O(1)–Sm–O(2)
O(2)–Sm–O(2)
C(1)–O(1)–Sm
73.7(1)
76.9(2)
170.53(6)
173.3(5)
those of other lanthanides is the salt elimination by reaction
between alkali metal alcoholates and a lanthanide halide [21].
Synthesis of the Carbinol 4
The hitherto unknown compound diphenyl(5-methyl-2-thi-
enyl)methanol (4) was prepared by a similar method as em-
ployed for the synthesis of other carbinols [15]. This colorless
solid was obtained by a classical nucleophilic addition of lithi-
ated 2-methylthiophene on benzophenone according Scheme 1
and isolated in 67 % yield after subsequent hydrolysis and
1
workup. The H NMR spectrum of 4, recorded in chloroform,
displays three aromatic signals: a multiplet at 7.3 ppm attrib- Scheme 2. General route of potassium or sodium alcoholates 7–15.
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Sodium and Potassium Alcoholates with Thienyl Substituents and their SmIII Alkoxides
ble 2), we presume that NaH and the carbinols 2 and 5–6 react coordinated to a tetrahydrofuran molecule (Figure 2a, Fig-
in the same manner as the other derivatives and postulate tenta- ure 3a, and Figure 4).
tively a tetrameric cage structure for the isolated solids with
The molecular units {[KOC(C4H3S)3]4(thf)2} (7) and
{[KOC(C16H13S)]4(thf)3} (11) are situated on a C2 and C3 axis
in the crystal, respectively. Tetrahydrofuran molecules are
present in the crystal lattices without interaction with the cen-
tral motif. The arrangement in 7 and 11 around K(1), in a
first approximation, is trigonal pyramidal and these for K(2)
tetrahedral. These molecular structures resemble those found
for [K(μ3-DPE)(thf)]4 or [K(μ3-DPE)(py)]4·2py [25]. The po-
tassium–oxygen mean distances are found to be 2.673(4) Å (7)
and 2.703(3) Å (11) and are in the range reported for [K(μ3-
DPE)(thf)]4 [2.641(0) and 2.720(2) Å] and [K(μ3-
DPE)(py)]4·2py [2.653(8) Å] [25]. The K–O bond lengths be-
tween K(2) and the oxygen atom of the tetrahydrofuran mole-
cule of 2.687(4) Å (7) and 2.765(4) Å (11) are in agreement
with those observed for [K(μ3-DPE)(thf)]4 [2.720(2) Å] [25].
The presence of the solvent molecules coordinated only with
two (7) or three (11) potassium atoms leads to a deformation
of the heterocubane core, as can be deduced from the O–K–O
angles.
Apparently, not all the potassium atoms are ligated to a sol-
vent molecule: two atoms for 7 and 12 and one atom for 9 and
11 have any base coordination. A closer view to the surround-
ing of these atoms shows that the thienyl or phenyl rings are
shielding the metal in a π ligand manner preventing the possi-
ble addition of a third (7 and 12) or a fourth (9 and 11) tetrahy-
drofuran molecule (Figure 2b, Figure 3b, and Figure 4). Note
that the K–S distances are between 3.251(9) and 5.518(6) Å
and therefore a coordinative bonding of sulfur to potassium is
very weak, if any.
composition
[NaOC(C14H11S2)]4(thf)2
(10),
[NaOC(C17H15S)]4(thf)2 (13), [NaOC(C14H11S2)]4(thf)2 (14),
and [NaOC(C16H13S)]4(thf)2 (15). The number of thf molecules
coordinated to the clusters follows from chemical analysis (see
Experimental Section).
Crystallographic Characterisation of the Thienyl-Substituted
Alcoholates
An important number of X-ray structure determinations on
the alkali metal alcoholates have revealed a rich diversity of
solid-state structures for these salts. Known examples show as
motif dimers, trimers, cubane-like tetramers, face fused cubic
tetramers, and hexamers [22–25].
We succeeded in growing colourless single crystals suitable
for X-ray structure determinations for compounds 7–9 and 11–
12 from thf solution at 5°C. All structure determinations reveal
the presence of tetrameric alkali metal alcoholates with a dis-
torted cubane-like M4O4 core (M = K or Na), whose most sa-
lient metric parameters are presented below. Some of the struc-
tures, besides their bad diffraction behavior, suffer from disor-
dering of the thienyl ligands.
For the potassium alcoholates 7 and 11, selected bond
lengths and angles are gathered in Table 3 and Table 4. The
asymmetric unit of 11 contains two crystallographically inde-
pendent molecules (A and B) having very close arrangements
(see Table 4). Herein, we will only refer to the molecule A.
Unfortunately, for the compounds 9 and 12, no discussion or
comparison of the bond lengths and angle values is meaningful
due to the poor quality of the crystals (high R values).
The molecular structures of 7, 9, 11, and 12 exhibit tetra-
meric units: each potassium atom is surrounded by three carbi-
We also elucidated the crystal structure of the sodium salt
[NaOC(C4H3S)3]4(thf)2 (8). Like in the case of the potassium
analogue (see above), the molecular structure of
[NaOC(C4H3S)3]4(thf)2 (8) consists of a tetrameric motif with
nolato ligands. In addition, two or three alkali metals are also a distorted cubane-like arrangement (Figure 5). This molecular
Figure 2. a) ORTEP (30 % ellipsoid) representation of {[KOC(C4H3S)3]4(thf)2}·thf (7). The carbon atoms of the heterocycles are depicted as
sticks. The hydrogen atoms and the lattice thf molecule are omitted for more clarity. Two thienyl groups are found in two split positions [S(1A)
and S(1B), S(2A) and S(2B)]. b) View of the distorted heterocubane core.
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M. Veith et al.
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Figure 3. a) ORTEP (30 % ellipsoid) representation of {[KOC(C16H13S)]4(thf)3}·½thf (11). The carbon atoms of the phenyl and thienyl groups
are depicted as sticks. The hydrogen atoms and the lattice thf molecule are omitted for more clarity. b) View of the distorted heterocubane core.
Figure 4. ORTEP (30 % ellipsoid) representation of [KOC(C14H11S2)]4(thf)3 (9) and [KOC(C17H15S)]4(thf)2 (12). The carbon atoms of the
aromatic groups are depicted as sticks. The hydrogen atoms and the lattice thf molecule are omitted for more clarity.
Figure 5. a) ORTEP (30 % ellipsoid) representation of [NaOC(C4H3S)3]4(thf)2 (8). Hydrogen atoms are omitted for more clarity. b) Environment
around the sodium atoms.
cluster is situated on a C2 axis in the crystal. In contrast to and a tetrahydrofuran molecule. The O–Na–O angles within
{[KOC(C4H3S)3]4(thf)2}·thf (7), the Na(1) atoms are sur- the Na4O4 cube are between 88.79(8) and 95.45(8)° (Table 5).
rounded by the three tris(2-thienyl)methanolato ligands and ad- The overall molecular structure of 8 is quite comparable with
ditionally ligated by a sulfur atom of the thienyl groups S(3), those reported for [Na(μ3-Ombp)(DME)]4 [23] and
with a Na(1)–S(3) distance of 2.875(2) Å. The Na(2) atoms [Na(OC6H4Me-4)(dme)]4 [24]. In contrast to cage compound
are coordinated by the three tris(2-thienyl)methanolato ligands 8, in these latter compounds each metal atom is ligated to a
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Sodium and Potassium Alcoholates with Thienyl Substituents and their SmIII Alkoxides
solvent molecule. In our case (see above), only two sodium (17) by in situ deprotonation of carbinol 3 in the presence of
atoms are surrounded by tetrahydrofuran. Additional intramo- KH (Scheme 3). Colourless crystals of 17 have been obtained,
lecular bonding as in 8 is also observed in the structures of albeit in a low yield of only 10 %.
1
[Na4(salphen)2(dme)2] and [Na4(salen)2(dme)2] [26], where
The H NMR spectrum of 16, recorded at room temperature
only two of the alkali metals are bonded to the Schiff base, in CDCl3, displays broad signals, probably due to the paramag-
whereas the other two complete their coordination sphere with netic character of the SmIII ion. A broad aromatic signal at
the oxygen atom of a dme donor. The Na–OC(C4H5S)3 bond 7.2 ppm, which integrates for 27H, is attributed to the protons
lengths lie in the range found for [Na(OC6H4Me-4)(dme)]4 of the thienyl units. The other signals at 3.4, 1.7, 1.2, and
[2.314(0) Å] [24] and [Na(μ3-Ombp)(DME)]4 (2.33 Å) [23], 0.9 ppm are assigned to the different hydrogen atoms of the
although the O–Na–O and Na–O–Na angles are different. tetrahydrofuran molecules ligated or not to the metal atom.
1
These variations of the angles can be explained by the steric
The H NMR spectrum of 17 exhibits five signals in CDCl3
difference of the ligands and solvents ligated to the sodium solution. The first, at 7.3 ppm, is a multiplet, which integrates
atoms.
for 33H attributed to the protons of the phenyl groups and the
5-H of the thienyl groups. The two others aromatic signals,
doublet of doublets at δ = 6.9 and 6.7 ppm (each integrating
for 3H), correspond to the 4-H and 3-H of the thienyl groups,
respectively. The hydrogen atoms of tetrahydrofuran are
present at δ = 3.7 and 1.8 ppm.
Synthesis of the Samarium(III) Thienyl-Substituted Methoxides
The alkaline salts of carbinols 7–15 were used to accede to
the samarium derivatives. Three equiv. of the carbinol 1 were
deprotonated in the presence of 3 equiv. NaH or KH in tetrahy-
drofuran at room temperature overnight. Subsequently, the in
situ formed salts {[KOC(C4H3S)3]4(thf)2}·thf (7) and
{[NaOC(C4H3S)3]4(thf)2}·thf (8), respectively, were added to a
suspension of 1 equivalent of SmCl3 (Scheme 3). After stirring
for further three days and work-up, brown-light single crystals
of {Sm[OC(C4H3S)3]3(thf)3}·thf (16) were obtained in a mod-
est yield of 24 % and 13 %, respectively. A similar procedure
also allowed the synthesis of {Sm[OC(C16H13S)]3(thf)3}·thf
Crystal Structures of the Samarium(III) Thienyl-Substituted
Methoxides
Single crystal X-ray structure determinations for compounds
16 and 17, which crystallise at 5°C from tetrahydrofuran as
brown-light or colourless crystals, were performed. Selected
bond lengths and angles are gathered in Table 6. Unfortu-
nately, for 17 the differentiation between the thienyl and phe-
nyl groups is difficult due to disorder of the ligands.
The molecular structures of {Sm[OC(C4H3S)3]3(thf)3}·thf
(16) and {Sm[OC(C16H13S)]3(thf)3}·thf (17) exhibit six-coor-
dinate mononuclear samarium alkoxides with three (2-thi-
enyl)methoxido or diphenyl(2-thienyl)methoxido ligands and
three tetrahydrofuran molecules around the samarium atoms,
in a facial arrangement. Both molecules are situated on a three-
fold axis in the crystals. Additional thf molecules are filling
the crystal lattice with no interaction with the molecules (Fig-
ure 6). The overall structures of 16 and 17 are similar to that in
{Nd[OC(C4H3S)3]3(thf)3}·thf [5], Sm(O-2,4,6-Me3C6H2)(thf)3
Scheme 3. Salt-elimination route leading to SmIII thienyl-functional-
ised methoxides.
Figure 6. ORTEP (30 % ellipsoid) representation of {Sm[OC(C4H3S)3]3(thf)3}·thf (16) and {Sm[OC(C16H13S)]3(thf)3}·thf (17). The thf lattice
molecule and hydrogen atoms are omitted for more clarity. For 16, one type of disordered carbon atoms of the heterocycles is depicted as sticks.
For 17, the thienyl and phenyl units are found in different positions [S(1) and S(2)].
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Table 7. Values peak potentials [V versus Ag/AgClO4] of the carbinols
and their alkali metal derivatives, in acetonitrile (10–3 m or 2 × 10–3
for 5, 14, 6, and 15) deduced from cyclic voltammetric measurements
on a platinum electrode (diameter 1 mm), scan rate 100 mV·s–1.
[20] or Sm(O-2,6-iPr2C6H3)3(thf)3 [19]. The arrangement
around the samarium atoms is distorted octahedral, as evidence
the
(C4H3S)3CO–Sm–OC(C4H3S)3
[101.1(1)°]
or
(C16H13S)OC–Sm–OC(C16H13S) [102.3(2)°] and the O(thf)–
Sm–O(thf) angles [73.7(1)° for 16 or 76.9(2)° for 17]. These
angle values are comparable with those found for Sm(O-2,6-
iPr2C6H3)3(thf)3 [102.29(6)° and 79.33(6)°, respectively] [19]
or Sm(O-2,4,6-Me3C6H2)3(thf)3 [103.4(1) and 77.5(1)°, re-
spectively] [20]. The Sm–O–C(C4H3S)3 angles of 170.5(3)°
and Sm–O–C(C16H13S) angles of 173.3(5)° are also similar to
those in {Nd[OC(C4H3S)3]3(thf)3}·thf [169.9(1)°] [5] and in
Epa /V
Epc /V
HO–C(C4H3S)3 (1)
{[KOC(C4H3S)3]4(thf)2}·thf (7)
[NaOC(C4H3S)3]4(thf)2 (8)
1.54
1.53
1.47
–0.12
–
–0.13
HO–C(C14H11S2) (2)
[KOC(C14H11S2)]4(thf)3 (9)
[NaOC(C14H11S2)]4(thf)2 (10)
1.50
1.41
1.42
–0.16
–0.18
–
Sm(O-2,4,6-Me3C6H2)3(thf)3
[170.0(3)°]
[20].
The
HO–C(C16H13S) (3)
{[KOC(C16H13S)]4(thf)3}·½thf (11)
1.55
1.50
–0.11
–0.14
Sm–OC(C4H3S)3 and Sm–OC(C16H13S) distances of 2.156(3)
and 2.160(4) Å are comparable to those in Sm(O-2,4,6-
Me3C6H2)3(thf)3 [2.160(0) Å] [20], Sm(O-2,6-iPr2C6H3)3(thf)3
[2.158(2) Å] [19] and [Sm(OC6H2tBu2-2,6-Me-4)3(thf)]·thf
[2.152(7) Å] [27]. The Sm–O(thf) distances are longer with
2.594(3) Å (16) and 2.552(5) Å (17) and are in the range of
those observed for Sm(O-2,6-iPr2C6H3)3(thf)3 [2.542(2) Å]
[19]. These distances are also in accordance with those found
for the compound {Nd[OC(C4H3S)3]3(thf)3}·thf [5].
HO–C(C17H15S) (4)
[KOC(C17H15S)]4(thf)2 (12)
[NaOC(C17H15S)]4(thf)2 (13)
1.39
1.30
1.29
–
–
–0.27
HO–C(C14H11S2) (5)
[NaOC(C14H11S2)]4(thf)2 (14)
1.62
1.67
–
–0.21
HO–C(C16H13S) (6)
[NaOC(C16H13S)]4(thf)2 (15)
1.77
1.76
–
–0.17
Electrochemical Studies
electron donating methyl group facilitates the oxidation process
manifested by a decrease of the potential [37]. The values of
the oxidation peak potentials of 5 and 6 are higher than those
obtained for 2 and 3. This is probably due to the fact that,
contrarily to 2 and 3, the two alpha positions of the thienyl
units are unsubstituted [28h]. By repetitive cyclic voltammetry
of the carbinols, no formation of polymeric films is evidenced.
This failure may be explained by the high reactivity of the cat-
ion radicals generated, which can react with a molecule of sol-
vent or undergo nucleophilic attack. These results are in good
agreement with observations performed on other molecules
with an unsubstituted α position on pyrroles [38].
The electrochemical investigation of thiophenes and its de-
rivatives is a classical technique to study the physico-chemical
properties of thienyl compounds [28]. Since the last decade,
the incorporation of transition metals or rare earth metal atoms
into the thiophene derivatives has emerged as an interesting
extension, thus combining the intrinsic properties of metal ions
with those of thienyl-based heterocycles [29–31]. It is well
known that the most stable oxidation state of the lanthanide
elements is +3 [32], but the oxidation state +2 is also well-
established, in particular for the samarium ion [33]. Neverthe-
less the value of the Sm3+/Sm2+ potential depends on the envi-
ronment around the metal [34]. In this context, we investigated
the electrochemical properties of the carbinols 1–6, those of
their derived alkali metal alcoholates 7–15 and of the sama-
rium alkoxides 16–17.
Carbinols and Alkali Metal Alcoholates
The values of peak potentials of carbinols 1–6 and the sama-
rium alkoxides 16 and 17, obtained in acetonitrile, are listed
in Table 7.
The voltammograms of 1–3 between –0.50 and +2.00 V ver-
sus Ag/AgClO4 on a platinum electrode at 100 mV·s–1 lead to
two irreversible signals (for example see Figure 7). The first
wave is assigned to the oxidation of the thienyl units [35]. The
second wave corresponds to the reduction of the carbocation.
Indeed, during the oxidation of the thienyl units, some H+ is
formed and can deprotonate the carbinols leading to a stable
carbocation [6, 36]. The voltammograms of 5 and 6 depict only
the irreversible wave due to the oxidation of the thienyl groups,
at 1.62 V and 1.77 V, respectively. Note that, in comparison
Figure 7. Cyclic voltammogram recorded on a platinum electrode (di-
ameter 1 mm) in an acetonitrile solution containing HO–C(C4H3S)3 (1)
(10–3 m) and [NBu4][PF6] (0.1 m) versus Ag/AgClO4, at 100 mV·s–1.
The voltammograms of the alkali metal alcoholates 7–15 (for
with 3, the oxidation peak potential of 4 is shifted towards a example see Figure 8) show an oxidation irreversible wave due
lower value (1.55 V for 3, 1.39 V for 4): the introduction of an to the oxidation of the thiophene moieties. For 8–9, 11, and 13–
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Z. Anorg. Allg. Chem. 2010, 2262–2275

Sodium and Potassium Alcoholates with Thienyl Substituents and their SmIII Alkoxides
15, a second wave is observed on the cyclic voltammogram are listed in Table 8 (the measurements in acetonitrile are not
from –0.13 to –0.27 V and corresponding to the reduction of possible due to the insolubility of the lanthanide alkoxides).
the carbocation generated during the process (see above). Nev-
The voltammograms exhibit only one irreversible wave at
ertheless, for the compounds 7, 10, and 12, the lifetime of the 1.62 V for 16 and at 1.56 V for 17 (Figure 9) attributed to
carbocation formed during the oxidation is not long enough to the oxidation of the thienyl moieties [35]. When potentials are
be reduced. No polymeric film is formed during the oxidation cycled, no reduction of samarium(III) to samarium(II) is visi-
process: this result matches with the findings obtained for the ble at about –0.8 V [34, 40]. To explain this lack of observa-
respective ligands. In comparison with the corresponding carbi- tion several hypotheses are possible: (i) the electron-rich or-
nol, the oxidation peak potentials are shifted towards lower val- ganic ligands make a more difficult electron transfer to the
ues by 0.01–0.10 V, probably due to the inductive effect of lanthanide ion shifting the reduction potential of the samarium
the alkali metal which increases the electronic density of the towards high negative values [34], which are not detectable in
thiophene moieties leading to an easier oxidation of this species the common electrochemical solvent; (ii) the samarium metal
or to the change in the interannular conjugation within the atom is wrapped up by the electron-rich organic ligands lead-
structure of the metal alcoholates [39]. Nevertheless, this obser- ing to the inhibition of the reduction process and to the stabili-
vation has not been made for the sodium alcoholate 14: in this sation of the metal atom.
case the oxidation peak potential is shifted towards an incom-
prehensible higher value (1.62 V for 5 and 1.67 V for 14).
Figure 9. Cyclic voltammogramm recorded at a platinum electrode on
a
dichloromethane solution containing 17 (3.32 × 10–3 m) and
[NBu4][PF6] (0.1 m) versus Ag/AgClO4, scan rate 100 mV·s–1, be-
Figure 8. Cyclic voltammograms recorded on a platinum electrode (di-
ameter 1 mm) in an acetonitrile solution [NaOC(C4H3S)3]4(thf)2 (8)
(10–3 m) and [NBu4][PF6] (0.1 m) versus Ag/AgClO4, scan rate
100 mV·s–1.
tween 0 → –1.5 → 2 and 0 V.
Luminescence Studies
As can be seen, the number of thienyl units has no significant
effect on the electrochemical properties of the compounds,
whereas the functionalisation of these groups (see 3 compared
to 4) or their different attached positions have an influence on
the oxidation values (see for example 5/6 compared to 2/3).
Recently, several studies have demonstrated that thiophene-
derived ligand systems can be promising candidates as sensitis-
ing chromophore in lanthanide compounds [41, 42]. In these
conjugated coordination compounds, the ligand acts as donor
and the lanthanide ion as acceptor. But in our compounds, the
conjugation is interrupted by the methoxido carbon atom and
also no π interaction between the thienyl and/or phenyl units
can be assumed in the solid state (spatial distance from the
aromatic groups to the metal: ≈ 5 Å). Therefore, it was in-
triguing to study, if, under these conditions, an antenna effect
is still present.
Samarium Alkoxides
The values of peak potentials of carbinols 1 and 3 and the
samarium alkoxides 16 and 17 obtained in dichloromethane
Table 8. Values peak potentials [V versus Ag/AgClO4] of the carbinols
1 and 3 and samarium alkoxides 16 and 17, in dichloromethane de-
duced from cyclic voltammetric measurements (0 → –1.5 → 1.5 → 0 V)
on a platinum electrode (diameter 1 mm) at 100 mV·s–1.
The carbinols and the alkali metal alcoholates were investi-
gated in comparison to the samarium compounds, as well to
get some insight in the ligand absorptions and emissions.
Epa /V
Carbinols and Alkali Metal Alcoholates
HO–C(C4H3S)3 (1)
1.48
1.62
1.64
1.56
{Sm[OC(C4H3S)3]3(thf)3}·thf (16)
HO–C(C4H3S)3 (3)
The solid-state emission maxima of the tertiary alcohols 1–
6 and their derived alkali metal alcoholates 7–15 are given in
Table 9.
{Sm[OC(C16H13S)]3(thf)3}·thf (17)
Z. Anorg. Allg. Chem. 2010, 2262–2275
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M. Veith et al.
ARTICLE
Table 9. Solid-state emission maxima λem /nm of the carbinols and the
alkali metal alkoxides (K, Na) with λex for excitation maximum.
compared to those of the thiophenic alcohols is due to some
distortions of these units when bonded to potassium or sodium
metals [44]. Note that the number of thienyl units, their at-
tached positions, or their functionalisation has the same effect
on the luminescence properties as those observed for their cor-
responding carbinols.
λem
HO–C(C4H3S)3 (1)
{[KOC(C4H3S)3]4(thf)2}·thf (7)
[NaOC(C4H3S)3]4(thf)2 (8)
430 (λex = 280 nm)
390 (λex = 240 nm)
393 (λex = 240 nm)
HO–C(C14H11S2) (2)
[KOC(C14H11S2)]4(thf)3 (9)
[NaOC(C14H11S2)]4(thf)2 (10)
402 (λex = 260 nm)
396 (λex = 250 nm)
408 (λex = 360 nm)
Samarium Alkoxides
HO–C(C16H13S) (3)
{[KOC(C16H13S)]4(thf)3}·½thf (11)
392 (λex = 310 nm)
385 (λex = 310 nm)
The room temperature emission spectrum of 16 (Figure 11)
upon an excitation on the organic ligand (λex = 270 nm, see
above) displays the typical Sm3+ bands at around 570, 604,
HO–C(C17H15S) (4)
527 (λex = 360 nm)
486 (λex = 390 nm)
430 (λex = 340 nm)
[KOC(C17H15S)]4(thf)2 (12)
[NaOC(C17H15S)]4(thf)2 (13)
4
and 650 nm. They are attributed to 4f5–4f5 transitions G5/2
6
4
6
HO–C(C14H11S2) (5)
[NaOC(C14H11S2)]4(thf)2 (14)
400 (λex = 260 nm)
398 (λex = 260 nm)
→ H5/2 (zero-zero band: forbidden transition), G5/2 → H7/2
4
(magnetic dipole transition), G5/2
→
6H9/2 (electric dipole
transition), respectively [9b, 9c, 9i]. Note that another sama-
rium band at 622 nm is observed, probably also due to the
4G5/2 → 6H7/2 transition: it might be a result of splitting due to
ligand field. The intense spectrum is typical for an “antenna
effect”, resulting in an energy transfer from the ligand to the
lanthanide atom [45]. Nevertheless, in addition of the Sm3+
emission, a broad band is assigned to the fluorescence from
the organic ligand in the range from 350 to 520 nm. The rela-
tive intensity between the broad band and the Sm3+ emission
lines suggests that the efficiency of the energy transfer ligand-
to-metal process (probably a dipole-dipole energy transfer
mechanism) does not seem to be maximal.
HO–C(C16H13S) (6)
398 (λex = 260 nm)
397 (λex = 260 nm)
[NaOC(C16H13S)]4(thf)2 (15)
All the emission spectra are very similar and consist of
broad, nearly Gaussian shaped bands with nearly identical
maxima, which are attributed to the π* → π transitions of the
aromatic units [43]. The carbinol ligands 1, 2, and 3 [6] fluo-
resce quite strongly in solid-state, with the peak of the emis-
sion band shifting toward lower energy with increasing number
of thienyl units (Figure 10). Furthermore, it is worth pointing
out that grafting a methyl group in position 5 of thienyl unit
generates a red shift of Δλem ≈ 135 nm for ligand 4 compared
to ligand 3 (Figure 10), which significantly decreases the en-
ergy level of the LUMO orbital [30]. On the other hand, li-
gands 5 and 6 exhibit emission maxima in similar range com-
pared with 2 and 3, respectively.
Figure 11. Solid-state emission spectrum at room temperature for com-
pound 16, λex = 270 nm.
Figure 10. Room temperature solid-state luminescence spectra. Cen-
ter: 1 (λex = 280 nm), dash line: 2 (λex = 260 nm), left: 3 (λex = 310 nm)
and right: 4 (λex = 360 nm).
4
The emission spectrum of 17, when the F7/2 level (410 nm)
is excited (Figure 12), is composed of a series of straight lines
assigned to the Sm3+ intra 4f5–4f5 transitions: G5/2
→
4
6H5/2,7/2,9/2. Note that, as 16, a samarium band at 622 nm is
For the alkali metal alcoholates, blue shifts of the emission
maxima compared to those of the thiophenic alcohols are ob-
served (excepted for 10). In general, this shift of the transitions might be a result of splitting due to ligand field.
4
6
observed, probably also due to the G5/2 → H7/2 transition: it
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Z. Anorg. Allg. Chem. 2010, 2262–2275

Sodium and Potassium Alcoholates with Thienyl Substituents and their SmIII Alkoxides
structures investigated. The molecular structures exhibit only
distorted cubane-like M4O4 cores. Each alkali metal is sur-
rounded by three carbinolato ligands and two or three alkali
ions are additionally ligated with a tetrahydrofuran molecule.
In addition, two new samarium(III) methoxides containing thi-
enyl substituents have been synthesised and structurally char-
acterised. Their X-ray structures reveal only mononuclear mol-
ecules with an octahedral coordination sphere around the metal
atom in a facial ligand arrangement. The physico-chemical
studies of the series of alkali metal alcoholates or samarium
alkoxides containing thienyl substituents have shown that their
electrochemical properties are only dominated by organic li-
gands. The emission spectra of the carbinols and potassium or
sodium alcoholates depict broad bands attributed to the aro-
matic groups. Nevertheless, the luminescence spectra of the
Sm3+ alkoxides exhibit an energy transfer from the ligand to
the lanthanide atom.
Figure 12. Solid-state emission spectrum at room temperature for
compound 17, λex = 410 nm.
To compare the influence of the samarium oxidation state on
the crystal structure, electrochemical and luminescence proper-
ties of samarium alkoxides bearing thienyl moieties, the study
of the reactivity of our alkali metal alcoholates towards SmX2
(X = Cl, I) is in progress. Furthermore, some experiments with
other rare earths such as Eu3+, Tb3+, Pr3+ and/or with other
thiophenes derivatives are underway.
The solid-state excitation spectra of 16 and 17 monitoring
4
6
the G5/2 → H9/2 transition recorded at room temperature are
given in Figure 13. They show broad bands that cover the en-
tire 250–300 nm region with a maximum at 270 nm for 16 and
the 250–395 nm region with a maximum at 273 for 17 attrib-
uted to the π → π* transitions of the organic ligands. The
spectra also present several narrow bands of the Sm3+ ion aris-
6
ing from the intraconfigurational transitions from the H5/2
ground state to the following levels: 4H9/2 (≈ 344 nm), 4F9/2 (≈
Acknowledgement
4
4
4
363 nm), L17/2 (≈ 373 nm), F7/2 (≈ 406 nm), (6P, P)5/2 (≈
We gratefully acknowledge the financial support provided by the Deut-
sche Forschungsgemeinschaft in the framework of the SPP1166 (Lan-
thanoidspezifische Funktionalitäten in Molekül und Material), by the
Saarland University and the Fonds der Chemischen Industrie. We
thank Dr. Michael Zimmer for the 1H NMR spectra of 16 and 17. M.K.
and L.G. thank the CNRS for financial support.
4
4
4
422 nm), G9/2 (≈ 450 nm), I13/2 (≈ 462 nm), I11/2 (≈
473 nm), 4I9/2 (≈ 488 nm), 4G7/2 (≈ 504 nm), 4F3/2 (≈ 526 nm),
and 4G5/2 (≈ 568 nm). These transition values are in agreement
with those found for Sm3+ doped germinate glasses and glass
ceramic and those for samarium complexes [8, 42].
References
[1] a) I. A. Hemmilä, Application of Fluorescence in Immunoassays,
Wiley, New York, 1991; b) Lanthanide Probes in Life, Chemical
and Eart Science – Theory and Pratice (Eds.: J.-C. G. Bünzli,
G. R. Choppin), Elsevier, Amsterdam, 1989; c) R. Reyes, E. N.
Hering, M. Cremona, C. F. B. Silva, H. F. Brito, C. A. Achete,
Thin Solid Films 2002, 420–421, 23–29.
[2] N. Sabatini, M. Guardigli, J. M. Lehn, Coord. Chem. Rev. 1993,
123, 201–228.
[3] a) B. Yan, H. J. Zhang, S. B. Wang, J. Z. Ni, Spectrosc. Lett.
1998, 31, 603–613; b) S. Sato, M. Wada, Bull. Chem. Jpn. 1970,
43, 1955–1962.
[4] a) H. C. Aspinall, S. A. Cunningham, Inorg. Chem. 1998, 37,
5396–5398; b) B. Cetinkaya, P. B. Hitchcock, M. F. Lappert,
R. G. Smith, J. Chem. Soc., Chem. Commun. 1992, 932–934;
c) M. Niemeyer, Eur. J. Inorg. Chem. 2001, 1969–1981; d) S. M.
Cendrowski-Guillaume, G. L. Gland, M. Nierlich, M. Ephritikh-
ine, Organometallics 2000, 19, 5654–5660; e) J. H. Melman, T. J.
Emge, J. G. Brennan, Chem. Commun. 1997, 2269–2270; f) J.
Lee, D. Freedman, J. H. Melman, M. Brewer, L. Sun, T. J. Emge,
F. H. Log, J. G. Brennan, Inorg. Chem. 1998, 37, 2512–2519;
g) S. Banerjee, T. J. Emge, J. G. Brennan, Inorg. Chem. 2004,
43, 6307–6312; h) K. Mashima, T. Shibahara, Y. Nakayama, A.
Nakamura, J. Organomet. Chem. 1998, 559, 197–209.
[5] M. Veith, C. Belot, L. Guyard, V. Huch, M. Knorr, M. Zimmer,
Eur. J. Inorg. Chem. 2008, 2397–2406.
Figure 13. Solid-state excitation spectrum at room temperature for
compound {Sm[OC(C4H3S)3]3(thf)3}·thf (16) (solid line) and
{Sm[OC(C16H13S)]3(thf)3}·thf (17) (dashed line), λem = 651 and
650 nm, respectively.
Conclusions
A series of novel potassium and sodium carbinolates contain-
ing thienyl substituents have been obtained and their crystal
Z. Anorg. Allg. Chem. 2010, 2262–2275
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2273

M. Veith et al.
ARTICLE
[6] M. Veith, C. Belot, V. Huch, H.-L. Cui, L. Guyard, M. Knorr, C.
Wickleder, Eur. J. Inorg. Chem. 2010, 879–889.
Jerzykiewicz, New J. Chem. 2000, 24, 523–526; f) G. Müller, T.
Schätzle, Z. Naturforsch. 2004, 59b, 1400–1410; g) P. A.
van der Schaaf, J. T. B. H. Jastrzebski, M. P. Hogerheide,
W. J. J. Smeets, A. L. Spek, J. Boersma, G. van Koten, Inorg.
Chem. 1993, 32, 4111–4118; h) J. Geier, H. Rüegger, H. Grützma-
cher, Dalton Trans. 2006, 129–136; i) M. B. Dinger, M. J. Scott,
Chem. Commun. 1999, 2525–2526.
[7] a) W. S. Hwang, D. L. Wang, M. Y. Chiang, J. Organomet.
Chem. 2000, 613, 231–235; b) Y. F. Tzeng, C. Y. Wu, W. S.
Hwang, C. H. Hung, J. Organomet. Chem. 2003, 687, 16–26; c) J.
Lloret, F. Estevan, P. Lahuerta, P. Hirva, J. Pérez-Prieto, M.
Sanaù, Organometallics 2006, 25, 3156–3165; d) D. Wang, D.
Cui, W. Miao, S. Li, B. Huang, Dalton Trans. 2007, 4576–4591. [23] M. L. Cole, P. C. Junk, K. M. Proctor, J. L. Scott, C. R. Strauss,
[8] G. Lakshminarayana, H. Yang, Y. Teng, J. J. Qui, Luminescence
2009, 129, 59–68.
Dalton Trans. 2006, 3338–3349.
[24] W. J. Evans, R. E. Golden, J. W. Ziller, Inorg. Chem. 1993, 32,
3041–3051.
[9] a) Y. Hasegawa, S.-I. Tsuruoka, T. Yoshida, H. Kawai, T. Kawai,
J. Phys. Chem. A 2008, 112, 803–807; b) M. D. Regulacio, M. H. [25] T. J. Boyle, N. L. Andrews, M. A. Rodriguez, C. Campana, T.
Pablico, J. Acay Vasquez, P. N. Myers, S. Gentry, M. Prushan,
Yiu, Inorg. Chem. 2003, 42, 5357–5366.
S.-W. Tam-Chang, S. L. Stoll, Inorg. Chem. 2008, 47, 1512– [26] E. Solari, S. De Angelis, C. Floriani, A. Chiesi, C. Rizzoli, J.
1523; c) Y. Hasegawa, S.-I. Tsuruoka, T. Yoshida, H. Kawai, T.
Chem. Soc., Dalton Trans. 1991, 2471.
Kawai, J. Phys. Chem. A 2008, 112, 803–807; d) J. Fang, H. You, [27] G. Qi, Y. Lin, J. Hu, Q. Shen, Polyhedron 1995, 14, 413–415.
J. Chen, J. Lin, D. Ma, Inorg. Chem. 2006, 45, 3701–3704; [28] a) S. J. Howell, C. S. Day, R. E. Noftle, Inorg. Chim. Acta 2005,
e) A. P. Bassett, S. W. Magennis, P. B. Glover, D. J. Lewis, N.
Spencer, S. Parsons, R. M. William, L. De Cola, Z. Pikramenou,
J. Am. Chem. Soc. 2004, 126, 9413–9424; f) S. Quici, M. Cavazz-
ini, G. Accosi, N. Armaroli, B. Vantura, F. Barigelleti, Inorg.
Chem. 2005, 44, 529–537; g) H. Brito, O. L. Malta, M. C. F. C.
Felinto, E. E. S. Teotonio, J. F. S. Menezes, C. F. B. Silva, C. S.
Tomiyama, C. A. A. Carvalho, J. Alloys Compd. 2002, 344, 293–
297; h) S. Petoud, S. M. Cohen, J.-C. G. Bünzli, K. N. Raymond,
J. Am. Chem. Soc. 2003, 125, 13324–13325; i) P. C. R.
Soares Santos, H. I. S. Nogueria, F. A. Almeida Paz, R. A.
Sá Ferreira, L. D. Carlos, J. Klinowski, T. Trindade, Eur. J. Inorg.
Chem. 2003, 19, 3609–3617; j) B.-L. An, M.-L. Gong, M.-X. Li,
358, 3711–3723; b) J. Dai, C. S. Day, R. E. Noftle, Tetrahedron
2003, 59, 9389–9397; c) A. Jouait, A. Al Badri, M. Goeffroy, G.
Bernardinelli, J. Organomet. Chem. 1997, 529, 143–149; d) F.
Sundholm, G. Sundholm, M. Törrönen, Synth. Met. 1992, 53,
109–114; e) F. Ç. Cebeci, H. Geyik, E. Sezer, A. S. Sarac, J. Elec-
troanal. Chem. 2007, 610, 113–121; f) A. Almutairy, F. S. Tham,
M. J. Marsella, Tetrahedron 2004, 60, 7187–7190; g) L. Guyard,
M. Nguyen Dinh An, P. Audebert, Adv. Mater. 2001, 13, 133–
136; h) F. Chérioux, L. Guyard, Adv. Funct. Mater. 2001, 11, 305–
309; i) G. Zotti, B. Vercelli, A. Berlin, S. Destri, M. Pasini, V.
Hernández, J. T. López Navarrete, Chem. Mater. 2008, 20, 6847–
6856.
J.-M. Zhang, J. Mol. Struct. 2004, 687, 1–6; k) B. Yan, Q. Wie, [29] a) K. R. Justin Thomas, J. T. Lin, J. Organomet. Chem. 2001,
J. Mol. Struct. 2004, 688, 73–78.
637–639, 139–144; b) D. Obendorf, H. Schottenberger, K. Wurst,
N. Schuler, G. Laus, J. Organomet. Chem. 2005, 690, 811–817;
c) A. Arnanz, M. L. Marcos, S. Delgado, J. González-Velasco, C.
Moreno, J. Organomet. Chem. 2008, 693, 3457–3470; d) M. O.
Wolf, M. S. Wrighton, Chem. Mater. 1994, 6, 1526–1533; e) T. L.
Stott, M. O. Wolf, Coord. Chem. Rev. 2003, 246, 89–101.
[10] H. Paulsen, S. Antons, A. Brandes, M. Logers, S. N. Muller, P.
Naab, C. Schmeck, S. Schneider, J. Stoltefuss, Angew. Chem. Int.
Ed. 1999, 38, 3373–3375.
[11] A. Lebrun, J.-L. Namy, H. B. Kagan, Tetrahedron Lett. 1991, 32,
2355–2358.
[12] P. Van de Weghe, J. Collin, Tetrahedron Lett. 1994, 35, 2545– [30] M. Beley, D. Delabouglisse, G. Houppy, J. Husson, J.-P. Petit,
2548.
[13] D. A. Evans, A. H. Hoveyda, J. Am. Chem. Soc. 1990, 112, 6447– [31] R. Sultan, K. Gadamsetti, S. Swavey, Inorg. Chim. Acta 2006,
6449. 359, 1233–1238.
[14] K. Katagiri, M. Kameoka, M. Nishiura, T. Imamoto, Chem. Lett. [32] F. A. Cotton, G. Wilkinson, Advanced Inorganic Chemistry, 4th.
2002, 31, 426–427. ed, Wiley, New York, 1980, ch. 23.
Inorg. Chim. Acta 2005, 358, 3075–3083.
[15] B. Abarca, G. Asencio, R. Ballesteros, T. Varea, J. Org. Chem. [33] D. A. Johnson, J. Chem. Soc., Dalton Trans. 1974, 1671–1675.
1991, 56, 3224–3229.
[34] A. M. Bond, G. B. Deacon, R. H. Newnham, Organometallics
1986, 5, 2312–2316.
[16] G. M. Sheldrick, Acta Crystallogr., Sect. A 2008, 64, 112–122.
[17] Diamond, Crystal and Molecular Structure Visualization. CRYS- [35] M. Turbiez, P. Frère, M. Allain, N. Gallego-Planas, J. Roncali,
TAL IMPACT, Postfach 1251, 53002 Bonn, Germany (www.crys-
talimpact.com/diamond/).
Macromolecules 2005, 38, 6806–6812.
[36] C. Belot, C. Filiatre, L. Guyard, A. Foissy, M. Knorr, Electro-
chem. Commun. 2005, 7, 1439–1444.
[18] S. Sankhla, R. N. Kapoor, Aust. J. Chem. 1967, 20, 2013–2016.
[19] Z. Xie, K. Chui, Q. Yang, T. C. W. Mak, J. Sun, Organometallics [37] O. Clot, M. O. Wolf, B. O. Patrick, J. Am. Chem. Soc. 2001, 123,
1998, 17, 3937–3944.
9963–9973.
[20] G. R. Giesbrecht, J. C. Gordon, D. L. Clark, B. L. Scott, J. G. [38] a) C. P. Andrieux, P. Hapiot, P. Audebert, L. Guyard, M.
Watkin, K. J. Young, Inorg. Chem. 2002, 41, 6372–6379.
[21] a) Y.-M. Yao, Q. Shen, Y. Zhang, M.-Q. Xue, J. Sun, Polyhedron
2001, 20, 3201–3208; b) L.-L. Zhang, Y.-M. Yao, Y.-J. Luo, Q.
Shen, J. Sun, Polyhedron 2000, 19, 2243–2247; c) J. Gromada,
A. Moretux, T. Chenal, J. W. Ziller, F. Leising, J.-F. Carpentier,
Chem. Eur. J. 2002, 8, 3773–3788; d) W. J. Evans, M. S. Sollber-
ger, T. P. Hanusa, J. Am. Chem. Soc. 1988, 110, 1841–1850;
e) W. J. Evans, M. S. Sollberger, Inorg. Chem. 1988, 27, 4417–
Nguyen Dinh An, L. Groenendaal, E. W. Meijer, Chem. Mater.
1997, 9, 723–729; b) L. Guyard, P. Hapiot, P. Neta, J. Phys.
Chem. B 1997, 101, 5698–5706; c) P. Garcia, J.-M. Pernaut, P.
Hapiot, V. Wintgens, P. Valat, F. Garnier, D. Delabouglise, J.
Phys. Chem. 1993, 97, 513–516; d) P. Bäuerle, U. Segelbacher,
A. Maier, M. Mehring, J. Am. Chem. Soc. 1993, 115, 10217–
10223; e) P. Hapiot, F. Demanze, A. Yassar, F. Garnier, J. Phys.
Chem. 1996, 100, 8397–8401.
4423; f) W. J. Evans, M. A. Ansari, J. W. Ziller, S. I. Khan, J. [39] O. Clot, Y. Akahori, C. Moorlag, D. B. Leznoff, M. O. Wolf,
Organomet. Chem. 1998, 553, 141–148; g) D. L. Clark, J. C.
Gordon, J. G. Watkin, Polyhedron 1996, 15, 2279–2289.
B. O. Patrick, M. Ishii, Inorg. Chem. 2003, 42, 2704–2713.
[40] A. I. Bhatt, I. May, V. A. Volkovich, D. Collison, M. Helliwell,
I. B. Polovov, R. G. Lewin, Inorg. Chem. 2005, 44, 4934–4940.
[22] a) D. Walther, U. Ritter, S. Geβler, J. Sieler, M. Kurnert, Z. Anorg.
Allg. Chem. 1994, 620, 101–106; b) M. B. Dinger, M. J. Scott, [41] a) Y.-F. Yuan, T. Cardinaels, K. Lunstroot, K. Van Hecke, L.
Inorg. Chem. 2000, 39, 1238–1254; c) D. J. MacDougall, B. C.
Noll, K. W. Henderson, Inorg. Chem. 2005, 44, 1181–1183;
d) J. A. Samuels, E. B. Lobkovsky, W. E. Streib, K. Folting, J. C.
Huffman, J. W. Zwanziger, K. G. Caulton, J. Am. Chem. Soc.
1993, 115, 5013–5104; e) P. Sobota, M. Klimowicz, J. Utko, L. B.
Van Meervelt, C. Görller-Walrand, K. Binnemans, P. Nockemann,
Inorg. Chem. 2007, 46, 5302–5309; b) S. Viswanathan, A. de Bet-
tencourt-Dias, Inorg. Chem. 2006, 45, 10138–10146; c) A.
de Bettencourt-Dias, S. Viswanathan, A. Rollet, J. Am. Chem.
Soc. 2007, 129, 15436–15437.
2274
www.zaac.wiley-vch.de
© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2010, 2262–2275

Sodium and Potassium Alcoholates with Thienyl Substituents and their SmIII Alkoxides
[42] E. E. S. Teotonio, M. C. F. C. Felinto, H. F. Brito, O. L. Malta, [45] J.-C. Bünzli, J. Alloys Compd. 2006, 408–412, 934–944.
A. C. Trindade, R. Najjar, W. Strek, Inorg. Chim. Acta 2004, 357,
451–460.
Received: May 11, 2010
Published Online: August 20, 2010
[43] R. S. Becker, J. Seixa de Melo, A. L. Maçanita, F. Elisei, J. Phys.
Chem. 1996, 100, 18683–18695.
[44] P. C. R. Soares-Santos, F. A. Almeida Paz, R. A. Sá Ferreira, J.
Klinowski, L. D. Carlos, T. Trindade, H. I. S. Nogueira, Polyhe-
dron 2006, 25, 2471–2482.
Z. Anorg. Allg. Chem. 2010, 2262–2275
© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
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