Ferrocenecarboselenoic acid: Synthesis and some reactions

Article abstract of DOI:10.1002/zaac.201200369

The first ferrocenecarboselenoic acid was synthesized and characterized. The existence of tautomeric equilibrium between the selenol (FcCOSeH) and selenoxo forms (FcCSeOH) in polar solvents was proven by ¹H-, ¹³C- and ⁷⁷Se-NMR spectra. The selenoxo form exists predominantly in a polar solvent at low temperature below -70 °C. Treatment of this acid with lithium, sodium, and potassium hydrides and with rubidium and cesium fluorides gave the corresponding alkali metal ferrocenecarboselenoates in quantitative yields. Treatment with 4-methylphenyl isocyanate at room temperature led to ferrocenoyl 4-methylphenylcarbamoyl selenide FcCOSeC(O)NHC₆H₄Me-4 in high yield. A similar reaction with phenyl isothiocyanate formed a mixture of FcCOSeC(S)NHPh and FcCOSeC(SH)=NPh in moderate to good yield. The carboselenoic acid readily reacted with piperidine to give piperidinium ferrocenecarboselenoate in good yield. Air oxidation of this selenoic acid afforded diferrocenoyl selenide as a major product along with diferrocenoyl diselenide. The structures of the selenide (FcCO)₂Se and diselenide (FcCOSe)₂ were examined by single-crystal X-ray analysis. Copyright

Full text of DOI:10.1002/zaac.201200369

ARTICLE
DOI: 10.1002/zaac.201200369
Ferrocenecarboselenoic Acid: Synthesis and Some Reactions
Toshinori Takahashi,[a] Osamu Niyomura,[b] Shinzi Kato,*[a,b,c] and Masahiro Ebihara[a]
Keywords: Ferrocenecarboselenoic acid; Acyl carbamoyl selenide; Acyl carbamothioyl selenide; Piperidinium ferrocenecarbose-
lenoate; Diferrocenoyl selenide
Abstract. The first ferrocenecarboselenoic acid was synthesized and cenoyl 4-methylphenylcarbamoyl selenide FcCOSeC(O)NHC6H4Me-4
characterized. The existence of tautomeric equilibrium between the
selenol (FcCOSeH) and selenoxo forms (FcCSeOH) in polar solvents mixture of FcCOSeC(S)NHPh and FcCOSeC(SH)=NPh in moderate
was proven by 1H-, 13C- and 77Se-NMR spectra. The selenoxo form
to good yield. The carboselenoic acid readily reacted with piperidine
exists predominantly in a polar solvent at low temperature below to give piperidinium ferrocenecarboselenoate in good yield. Air oxi-
in high yield. A similar reaction with phenyl isothiocyanate formed a
–70 °C. Treatment of this acid with lithium, sodium, and potassium
hydrides and with rubidium and cesium fluorides gave the correspond-
ing alkali metal ferrocenecarboselenoates in quantitative yields. Treat-
ment with 4-methylphenyl isocyanate at room temperature led to ferro-
dation of this selenoic acid afforded diferrocenoyl selenide as a major
product along with diferrocenoyl diselenide. The structures of the sele-
nide (FcCO)2Se and diselenide (FcCOSe)2 were examined by single-
crystal X-ray analysis.
Introduction
Results and Discussion
Synthesis
Ferrocenecarboselenoic acid is one of the most important
starting compounds for the synthesis of ferrocenecarboselenoic
acid derivatives. In general, the most effective method for the
synthesis of carbochalcogenoic acids (RCEEЈH, R = alkyl,
aryl; E, EЈ = O, S, Se, Te; E, EЈ ϶ O) may be acidolysis of
After we considered the synthesis of arenecarboselenoic ac-
ids,[5] acidolyses of sodium (1a) and potassium ferrocenecar-
boselenoates (1b) with hydrogen chloride were examined
(Scheme 1). As a result, treatment of an excess of the salts 1
their alkali and alkali earth metal salts or ammonium salts with with hydrogen chloride led to the expected ferrocenecarbo-
selenoic acid (2) in high yields. For example, a dry hydrogen
chloride/ether solution was added to a suspension of the potas-
sium salt 1b in ether, and the mixture was stirred at 0 °C for
10 min. Filtration of the insoluble parts and removal of the
solvent under reduced pressure gave ferrocenecarboselenoic
acid 2 as a dark red oil in 95% yield. Under conditions similar
to those using the sodium salt 1a, compound 2 was obtained
in a yield of 92%. To avoid decomposition of the formed acid
2, the use of excess salts 1 and oxygen-free conditions are
required.
hydrogen chloride under oxygen-free conditions. Previously,
we reported the synthesis and isolation of a variety of alkali
metal and secondary and tertiary ammonium carbothioates[1]
and carbodithioates.[2] In addition, we have isolated ferro-
cenecarbo-thioic[3] and -dithioic acids,[4] and arenecarbose-
lenoic acids,[5] and we succeeded in the preparation of alkali
metal ferrocenecarboselenoates.[6] We describe herein the syn-
thesis and some reactions of ferrocenecarboselenoic acid.
* Prof. Dr. S. Kato
Fax: 81-52-222-2442
E-Mail: kshinzi@nifty.com
[a] Faculty of Engineering
Department of Chemistry
Gifu University
Scheme 1.
Gifu, Japan
1
[b] Department of Applied Chemistry
School of Engineering
The structure of the acid 2 was confirmed by IR and H,
13C, and 77Se NMR spectroscopy, and by conversion into
ferrocenoyl 4-methylphenylcarbamoyl (5) and phenylcarbamo-
thioyl selenides (6) (see Scheme 6) and into piperidinium (7),
rubidium (8), cesium (9) and lithium ferrocenecarboselenoates
(10) (see Scheme 7). Thus, in the IR spectrum, characteristic
absorption bands are observed at 2357 cm–1 and 1694 cm–1,
which can be ascribed to ν(SeH) and ν(C=O) stretching fre-
Chubu University
Aichi, Japan
[c] Present address:
Maruno-uchi 2–14–32
Lions-City Maruno-uchi 1105, Naka-ku
Nagoya 460–0002, Japan
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/zaac.201200369 or from the au-
thor.
108
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Ferrocenecarboselenoic Acid: Synthesis and Some Reactions
quencies, respectively. The 1H, 13C, and 77Se NMR spectra ened with a further decrease in temperature to –70 °C. Similar
show characteristic signals at δ = 2.93, δ = 190.6 and δ = trends of signals due to the OH protons and selenocarbonyl
415.9, respectively, which can be ascribed to SeH proton, carb- carbon and selenium atoms of compound 2 were observed in
onyl carbon, and SeH selenium, respectively. These values both [D8]THF and [D6]acetone (Figure S1a and b, Supporting
were comparable to those of common arenecarboselenoic acids Information). These spectroscopic data suggest that rapid equi-
[ν(Se-H) = 2289–2320 cm–1; ν(C=O) = 1682–1694 cm–1, librium exists between the selenol form I and selenoxo form
1H-Se: δ = 2.37–4.48, 13C: δ = 187.6–193.4].[5a]
II in THF at room temperature. At low temperature, the sele-
Ferrocenecarboselenoic acid (2) is labile toward oxygen and noxo form II exists predominantly (Scheme 4), whereas the
temperature. Upon exposure to air, compound 2 was quickly OH proton of II is presumed to form a hydrogen bond with
oxidized to give a mixture of diferrocenoyl selenide 3 and dis- the oxygen atoms of the polar solvent molecules (Scheme 5).
elenide 4 along with a small amount of elemental selenium
(Scheme 2). With regard to formation of the selenoic anhy-
dride 3, a possible route (Scheme 3, pass A) via deselenation
of the diselenide 4 is considered because we did not detect any
hydrogen selenide (Scheme 3, pass B).
Scheme 4.
Scheme 2.
Scheme 5.
Reactions
With 4-Methylphenyl Isocyanate and Phenyl Isothiocyanate
Previously, we reported that arenecarbochalcogenoic acids
(ArCEEЈH, E = O, S; EЈ = S, Se, Te) react with aryl
isocyanates (ArЈNCO) to give the addition products
Scheme 3.
We previously showed that carbochalcogenoic acids such as
carbo-thioic, -selenoic, and -telluroic acids exist in a chalco-
genoxo form RCEOH (E = S, Se, Te) at low temperature in
polar solvents such as tetrahydrofuran (THF) and methanol.[5b]
To confirm such equilibrium, variable low-temperature NMR
spectra of ferrocenecarboselenoic acid (2) were measured in
[D4]MeOH (Figure 1).
ArCEEЈC(O)NHArЈ (E = O, S; EЈ = S, Se), the tautomer
ArCEEЈC(=NArЈ)(OH), which can also be detected spectro-
scopically.[3,5,7a] In fact, ferrocenecarboselenoic acid (2) was
found to readily react with 4-methylphenyl isocyanate in ether
at 25 °C to give the expected (ferrocenoyl)(4-methylphenyl-
carbamoyl) selenide (5) in 94% yield as red crystals, which
showed two characteristic signals at δ = 198.9 and δ = 157.1
in the 13C NMR spectrum, which can be ascribed to the carb-
onyl and carbamoyl carbon chemical shifts, respectively.
Under the same conditions, the reaction with phenyl isothio-
cyanate led to the corresponding adduct ferrocenoyl phenyl-
carbamothioyl selenide (6) in quantitative yield as red micro
1
crystals. In contrast to the results with compound 5, the H
NMR spectrum of this adduct showed two broad signals at δ
= 10.2 and δ = 13.3, which can be ascribed to OH and SH
protons, respectively. In the 13C NMR spectrum, two small
signals are seen at δ = 185.7 and δ = 202.6, which can be
ascribed to the C=O and C=S groups, respectively, and two
small signals are seen at δ = 187 and δ = 198.1, indicating the
Figure 1. Variable low temperature NMR spectra of compound 2 in
[D4]MeOH.
As shown in Figure 1, broad signals ascribable to OH proton existence of C=O and C=N groups, respectively. In addition,
and 13C=Se carbon appear near δ = 4.8 and 216, respectively, the 77Se NMR spectrum showed two signals at δ = 712.9 and δ
and are sharpened with a further decrease in temperature to = 698.5, which can be ascribed to SeC=S and SeC=N selenium,
–30 °C, –50 °C, and –70 °C. Signals due to carbonyl and sele- respectively. These results appear to indicate the existence of
nocarbonyl carbon atoms were not observed at room tempera- the tautomer 6b of compound 6a. The proton ratio of NH and
ture. The 77Se=C NMR spectra near δ = 703 at –50 °C is sharp- SH in 6 was 73:27 (Scheme 6).
Z. Anorg. Allg. Chem. 2013, 108–114
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109

T. Takahashi, O. Niyomura, S. Kato, M. Ebihara
ARTICLE
X-ray Structural Analysis
Although several attempts to crystallize the acid 2 were un-
successful, single crystals of compounds diferrocenoyl sele-
nide 3 and diselenide 4 were obtained. The molecular structure
of compound 3 is shown in Figure 2. Final atomic positional
parameters are listed in Table 1. Selected bond lengths and
angles are shown in Table 2.
Scheme 6.
With Piperidine, RbF, CsF, and LiH or BuLi
Previously, we reported the synthesis of piperidinium arene-
carbothioates[8] and -carbodithioates[9] from the corresponding
carbothioic and carbodithioic acids with piperidine. As ex-
pected, the reaction of 2 with piperidine in ether readily pro-
ceeded at 25 °C to give piperidinium ferrocenecarboselenoate
(7) in 82% yield as orange crystals (Scheme 7). The salt 7
readily reacted with methyl iodide at room temperature to lead
to Se-methyl ferrocenecarboselenoate (11) in quantitative yield
(Scheme 8).
Figure 2. Ortep drawing of (FcCO)2Se (3). A black dotted line shows
the intramolecular contact.
Table 1. Crystal data and data collection of (FcCO)2Se (3).
Empirical formula
C22H18Fe2O2Se
Formula weight
Color
Crystal system
Unit-cell dimensions
a /Å
505.04
red, prismatic
triclinic
15.508(3)
16.441(1)
7.677(3)
96.85(2)
85.05
b /Å
c /Å
β /°
γ /°
Volume of unit cell /Å3
Space group
Z
1931.2(9)
¯
P1 (#2)
4
D(calcd.) /g·cm–3
Crystal size /mm
μ (Mo-Kα) /cm–1
T /°C
1.737
0.17ϫ0.26ϫ0.34
34
23.0
λ (Mo-Kα) /Å
2θ max /°
0.71069
55.0
No. of measured reflections
No. ofobservations [IϾ3 (I)]
No. of variables
9177
3848
487
0.047
0.124
1.005
Scheme 7.
a)
R2
wR2
b)c)
Goodness-of-fit on F2
a) Rw = [(|Fo|–|Fc|)2/ w|Fo|2]1/2. b) w = [σ(Fo)+p2(Fo)2/4]–1. c) Large
R-values appear to be most likely due to poor quality of single crystals.
The C=O and C–Se distances are comparable to those of
[10]
common diaroyl diselenides[7b] and the reported (FcCOSe)2
(Ortep drawing see Figure S2 and Tables S1 and S2, Support-
ing Information). The selenocarboxyl group and the substituted
Cp ring plane are coplanar, which appears to be the general
Scheme 8.
Under similar conditions, the reactions of the acid 2 with trend for ferrocenecarbochalcogenoic acid derivatives.[6,10]
rubidium and cesium fluorides gave the corresponding rubid-
The C(11)=O(11)···O(21)=C(21) distance is significantly
ium (8) and cesium ferrocenecarboselenoates (9) in respective short [2.854(4) Å], indicating an intramolecular interaction.
yields of 62% and 70%. Moreover, the reactions with lithium The torsion angle O(11)–C(11)···C(21)–O(21) is 29.6°, which
hydride and butyllithium led to lithium ferrocencarboselenoate is comparable to that (30.6°) of bis(2-methoxybenzoyl) sul-
in good yields, respectively.
fide.[11]
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Ferrocenecarboselenoic Acid: Synthesis and Some Reactions
Table 2. Selected bond lengths /Å, angles /°, and torsion angles /° of ure 3(d)] are formed by both the C=O···H hydrogen bonding
(FcCO)2Se3 (3).
and H···H short contacts, where small columns (7.2ϫ7.8 Å)
such as (A) are formed.
Bond lengths
Se(11)–C(11)
Se(11)–C(21)
C(11)–O(11)
C(21)–O(21)
O(11)···O(21)
1.981(2)
1.980(3)
1.175(2)
1.191(2)
2.854(4)
Diferrocenoyl Diselenide 4
In addition to the two structural features of compound 4
reported by Singh et al. [intramolecular contacts between the
carbonyl oxygen and the opposite selenocarboxyl selenium
atom, C(11)=O(11)···Se(21) 3.179(3) Å and C(21)=O(21)
···Se(11) 3.189(3) Å, and intermolecular hydrogen bonding be-
tween the carbonyl oxygen and Cp ring hydrogen atoms],[10]
weak intermolecular CH-π-bonding and H···H short contacts
are observed between the Cp ring carbon and the Cp ring hy-
drogen atoms of neighboring molecules and between Cp ring-
hydrogen atoms, respectively[13] (see Figure S3, Supporting In-
formation).
Angles
C(11)–Se(11)–C(21)
O(11)–C(11)–Se(11)
O(21)–C(21)–Se(11)
95.3(1)
121.5(2)
118.5(2)
Torsion angles
O(11)–C(11)–Se(11)–C(21)
O(21)–C(21)–Se(11)–C(11)
O(12)–C(11)–C(12)–C(13)
O(21)–C(21)–C(22)–C(23)
Se(11)–C(11)–C(12)–C(13)
Se(11)–C(21)–C(21)–O(21)
C(13)–C(12)–C(22)–C(23)
29.6(2)
35.3(2)
20.1(3)
10.7(3)
23.1(4)
17.3(2)
66.0(3)
Experimental Section
Instrumentation: The melting points were measured with a Yanagim-
oto micro-melting point apparatus and uncorrected. The IR spectra
were measured with a PERKIN ELMER FT-IR 1640 and a JASCO
grating IR spectrophotometer IR-G. The 1H-NMR and 13C-NMR spec-
tra were recorded with JNM-α-400 instruments at 399.7 and
100.4 MHz, respectively, with tetramethylsilane as an internal stan-
dard. The 77Se NMR (76 MHz) spectra were obtained with a JEOL α-
400 spectrometer, and 77Se chemical shifts are expressed in δ values
deshielded with respect to neat Me2Se as an external standard. All
Intermolecular hydrogen bonding between carbonyl oxygen
atoms and the hydrogen atoms of neighboring molecules, and
weak CH-π-bonding and H···H short contacts are observed be-
tween the Cp ring carbon atoms and the Cp ring hydrogen
atoms of neighboring molecules and between Cp ring-hydro-
gen atoms[13], respectively [Figure 3(a)]. For Figure 3(b), a lin-
ear molecular chain formed by both O···H hydrogen bond and
CH-π-bonding is shown. In addition, two-dimensional sheet
[Figure 3(c)] and three-dimensional arrangements [Fig- spectra were acquired in the proton-decoupled mode; generally 0.05–
Figure 3. Intermolecular short contacts and molecular arrangement of (FcCO)2Se (3). (a) Dashed numbering atoms show ones of neighboring
molecules (distances in Å) (b) Linear chain. (c) 2D Sheet formed by intermolecular short contact of these linear chains (the opposite molecule
of the pairs is omitted for clarity). (d) 3D Networks formed by stacking of these sheets and the central (A) is one of the large holes of
9.21ϫ5.53 Å).
Z. Anorg. Allg. Chem. 2013, 108–114
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T. Takahashi, O. Niyomura, S. Kato, M. Ebihara
ARTICLE
0.3 mmol solutions in CDCl3 (0.4 mL) were used. Electron spectra From Potassium Ferrocenecarboselenoate. An dry ether solution of
were measured with a JASCO U-Best 55. Elemental analyses were hydrogen chloride (1.0 m, 1.3 mL, 1.3 mmol) was added to a suspen-
performed by the Elemental Analysis Center of Kyoto University.
sion of freshly prepared potassium ferrocenecarboselenoate (1b)
(461 mg, 1.39 mmol) in dry ether (15 mL) in a 20 mL two necked
round-bottomed flask at 0 °C in an argon atmosphere. The color of the
suspension rapidly changed from orange to dark red. The mixture was
stirred at the same temperature for 10 min. The insoluble part (KCl
and an excess of 1b) were filtered off. Removal of the solvent under
reduced pressure (20 °C/0.2 Torr) gave 361 mg (95%) of ferrocenecar-
boselenoic acid (2) as dark purple oil. The IR, 1H, and 13C NMR
Materials: Sodium ferrocenecarboselenoates (1a) and potassium fer-
rocenecarboselenoates (1b) were prepared by the reaction of ferro-
cenoyl chloride with the corresponding alkali metal selenides as de-
scribed in the literature.[6] Rubidium and cesium fluorides, 4-meth-
ylphenyl isocyanate, phenyl isothiocyanate, and piperidine were pur-
chased from Kanto Kagaku Co. Ltd. and used without further purifica-
tion. Silica gel used on column chromatography was run on silica gel spectra of 2 were consistent with those of the authentic compound
60 of Kanto Chemical Co., Ltd. Diethyl ether was distilled from so- prepared by similar acidolysis of sodium ferrocenecarboselenoates
dium/benzophenone ketyl prior to use. Hexane and petroleum ether (1b) with hydrogen chloride and was identified by conversion into
(bp: 40–60 °C) were distilled from sodium metal. Acetonitrile, dichlo- ferrocenoyl 4-methylbenzenecarbamoyl selenide (5) (described later).
romethane, and chloroform were distilled from phosphorus pentoxide. IR (KBr, neat): ν˜ = 2357 (Se–H), 1715, 1694 (C=O), 1682, 1434,
Methanol was distilled from magnesium powder. The distillation of 1240, 1107, 1044, 1027, 1002, 933, 821, 774, 722, 676, 534, 486 cm–1.
these solvents was carried in a nitrogen atmosphere. All air sensitive
1H NMR (CDCl3): δ = 2.68 (br. s, 1 H, SeH), 4.21 (s, 5 H, Cp), 4.46
compounds were prepared and handled in an argon atmosphere. (t, J = 1.8 Hz, 2 H, Cp meta), 4.68 (t, J = 1.8 Hz, 2 H, Cportho) ppm.
[D4]Methanol, [D6]acetone, and [D8]THF were purchased from Ald- 13C NMR (CDCl3): δ = 70.7 (Cportho), 70.9 (Cp), 71.2 (Cpmeta), 81.5
rich.
(Cpipso), 190.7 (C=O) ppm. 77Se NMR (CDCl3): δ = 415.9 ppm.
Air Oxidation of Ferrocenecarboselenoic Acid (2): Ferrocene-
carboselenoic acid (2) (306 mg), freshly prepared by HCl acidolysis
of potassium ferrocencarboselenoate (1b) was stirred in THF (5 mL)
at 21–25 °C for 24 h. Removal of the solvent and fractional crystalli-
zation of the resulting residue from dichloromethane and hexane gave
diferrocenoyl selenide (3) (188 mg, 62%) and a mixture (32 mg) of
diferrocenoyl diselenide (4) and elemental selenium (brown red). The
structures of 3 and 4 were confirmed by IR, 13C, and 77Se NMR spectra
with those of the authentic examples.
X-ray Measurements: The measurement was carried out with a Ri-
gaku AFC7R four-circle diffract meter with graphite-monochromated
Mo-Kα radiation (λ = 0.71069 Å). All of the structures were solved
and refined using the teXsan crystallographic software package on an
IRIS Indigo computer. The crystal of compound 4 was coated with an
epoxy resin and mounted on a glass fiber. The cell dimensions were
determined from a least-squares refinement of the setting diffract-me-
ter angles for 25 automatically centered reflections. Lorentz and polar-
ization corrections were applied to the data, and empirical absorption
corrections (ψ-scans[14]) were also applied. The structures were solved
by direct method using SHELXS-86[15] and expanded using
DIRDIF94.[16] Scattering factors for neutral atoms were from Cromer
and Waber[17] and anomalous dispersion[18] was used. The function
minimized was Σw(|Fo|-|Fc|)2, and the weighting scheme employed was
w = [σ2(Fo)+p2(Fo)2/4]–1. A full-matrix least-squares refinement was
executed with non-hydrogen atoms being anisotropic. The final least-
square cycle included fixed hydrogen atoms at calculated positions of
which each isotropic thermal parameter was set to 1.2 times of that of
the connecting atom.
Diferrocenoyl Selenide (3): Ferrocenoyl chloride (168 mg,
0.68 mmol) was added to a suspension of potassium ferrocenecarbose-
lenoate (1b) (236 mg, 0.71 mmol) in diethyl ether (10 mL) at 20 °C.
The color of the suspension rapidly changed from orange to red brown.
The mixture was stirred at the same temperature for 1 h. Dichlorometh-
ane (5 mL) was added and the precipitates (KCl) were filtered off.
Removal of the solvent under reduced pressure (20 °C, 0.2 Torr) gave
260 mg (76%) of diferrocenoyl selenide (3) as red orange solid.
Recrystallization of this solid (290 mg) from a mixed solvent (12 mL)
of dichloromethane/hexane (2:10) at 0 °C for 30 min gave 68 mg
(11%) of chemically pure 3 as red needles. Mp. 181–183 °C.
C22H18Fe2O2Se (505.02): C 52.33 (calcd. 52.32), H 3.70 (3.59)%. IR
(KBr): ν˜ = 3102, 1708 (C=O), 1687, 1655, 1433, 1372, 1333, 1236,
1106, 1038, 1002, 932, 832, 804, 763, 684, 671, 592, 553. 534, 492
Preparation of Single Crystals of Diferrocenoyl Selenide (3) and
Diferrocenoyl Diselenide (4): Diferrocenoyl selenide (3) (250 mg)
was dissolved in chloroform (8 mL), and ether (3 mL) was added drop-
wise. The solution was allowed to stand at 20 °C for 2 h to give red
needles of compound 3. One of the single needles was cut to the size
of 0.17ϫ0.26ϫ0.34 mm.
1
cm–1. H NMR (CDCl3): δ = 4.34 (s, 10 H, Cp), 4.58 (t, J = 1.96 Hz,
4 H, Cpmeta), 4.86 (t, J = 1.96 Hz, 4 H, Cportho) ppm. 13C NMR
(CDCl3): δ = 70.0 (Cportho), 70.8 (Cp), 72.8 (Cpmeta), 81.8 (Cpipso),
187.8 (C=O) ppm. 77Se NMR (CDCl3): δ = 764.5 ppm.
Diferrocenoyl diselenide (4) (184 mg) was dissolved in chloroform
(14 mL), and ether (2 mL) was added dropwise. The solution was al-
I2-KI Oxidation of Potassium Ferrocenecarboselenoate (1b): A
lowed to stand at 20 °C for 2 d to give red needles of compound 4. methanol solution (3 mL) containing I2-KI (82 mg, 0.32 mmol) was
One of the single needles was cut to the size of 0.17ϫ0.09ϫ0.20 mm. added to solution of potassium ferrocenecarboselenoate (1b)
(188 mg, 0.57 mmol) in methanol (10 mL) at 0 °C and the mixture was
a
Ferrocenecarboselenoic Acid (2): The preparation procedures using stirred for l h. Aqueous sodium thiosulfate (ca. 5%, 20 mL) was added
potassium ferrocenecarboselenoate (1b) are described in detail.[19]
and extracted with dichloromethane (25 mL). The organic layer was
washed with water (ca. 5 30 mLϫ5) and dried with Na2SO4 (ca. 2 g)
for 15 min. Removal of the solvent under reduced pressure (20 °C,
From Sodium Ferrocenecarboselenoate: The reaction of hydrogen
chloride (1.30 mmol) in a dry diethyl ether solution (1.0 mL) and 0.2 Torr), followed by recrystallization from dichloromethane/hexane
freshly prepared sodium ferrocenecarboselenoate (1a) (460 mg,
(1:5) at –20 °C for 4 h gave 136 mg (87%) of diferrocenoyl diselenide
1.46 mmol) in diethyl ether (20 mL) at 0 °C for 10 min gave ferrocene-
(4) as red micro crystals. Mp: 170–172 °C (dec.) (163–165 °C[10]).
1
carboselenoic acid (2) (269 mg) [92%, purity Ͼ95% by H-NMR of C22H18Fe2O2Se2 (583.99): C 44.68 (calcd. 45.25), H 3.05 (3.11)%. IR
(ferrocenoyl)(4-methylphenylcarbamoyl) selenide and (ferrocenoyl) (KBr): ν˜ = 3630, 2361, 2344, 1718, 1680 (C=O), 1654, 1560, 1542,
(phenylcarbamothioyl) selenide]
1508, 1459, 1431, 1367, 1262, 1239, 1106, 1038, 932, 822, 774, 670,
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Ferrocenecarboselenoic Acid: Synthesis and Some Reactions
1
544, 492) cm–1. H NMR (CDC13): δ = 4.32 (s, 10 H, Cp), 4.53 (t, J
ferrocencarboselenoate with hydrogen chloride) with phenyl isothiocy-
= 1.95 Hz, 4 H, Cpmeta), 4.88 (t, J = 1.95 Hz, 4 H, Cportho) ppm. 13C anate. In addition, the structure was identified by conversion into Se-
NMR (CDC13): δ = 69.7 (Cportho), 71.2 (Cp), 72.7 (Cpmeta), 785 methyl ferrocenecarboselenoate (see a part of the reaction with iodo-
(Cpipso), 186.7 (C=O) ppm. 77Se NMR (CDCI3): δ = 581.7 ppm.
methane in the Experimental Section below). IR (nujol, neat): ν˜ =
3079, 3058, 2925, 2860, 2763 (N-H), 2364, 2344, 1654, 1598, 1507
(C=O), 1455, 1430, 1407, 1380, 1330, 1290, 1274, 1230, 1205, 1156,
1103, 1039, 1026, 998, 943, 869, 839, 828, 815, 694, 670, 568, 558,
Ferrocenoyl 4-Methylbenzenecarbamoyl Selenide (5): A solution of
4-methylphenyl isocyanate (86 mg, 0.65 mmol) in diethyl ether (1 mL)
was added to a solution of ferrocenecarboselenoic acid (2) (188 mg,
0.64 mmol) in the same solvent (10 mL) in a 20 mL two necked round-
bottomed flask at 0 °C in an argon atmosphere. The mixture was stirred
at room temperature (25 °C) for l h. Removal of the solvent under
reduced pressure (25 °C, 0.2 Torr) followed by recrystallization of the
resulting residue from a mixed solvent (26 mL) of dichloromethane/
hexane (1:25) at 0 °C gave 256 mg (94%) of ferrocenoyl 4-methyl-
benzenecarbamoyl selenide (5) as orange micro crystals. Mp: 107–
113 °C (dec.). C19H17FeNO2Se: C 53.38 (calcd. 53.55), H 4.02 (4.18)
%. IR (KBr, neat): ν˜ = 3038, 1704 (C=O), 1645 (NC=O), 1602, 1542,
1514, 1432, 1372, 1330, 1310, 1293, 1246, 1153, 1108, 1047, 1030,
1010, 934, 866, 825, 808, 790, 740, 674, 616, 550, 508, 497 cm–1. 1H
NMR (CDCl3): δ = 2.34 (s, 3 H, CH3), 4.31 (s, SH, Cp), 4.68 (t, J =
1.95 Hz, 2 H, Cpmeta), 4.89 (t, J = 1.95 Hz, 2 H, Cportho), 7.16 (δ, J =
8.4 Hz, 2 H, Ph), 7.48 (δ, J = 8.4 Hz, 2 H, Ph), 10.34 (br. s, 1 H, NH)
ppm. 13C NMR (CDC13): δ = 21.0 (CH3), 69.3 (Cportho), 71.4 (Cp),
73.5 (Cpmeta), 79.8 (Cpipso), 119.9, 129.7, 1345, 134.9 (Ph), 157.1
(NC=O), 198.9 (SeC=O) ppm. 77Se NMR (CDC13): δ = 633.9 ppm.
1
549, 449, 482 cm–1. H NMR (CDC13): δ = 1.56 (quint, J = 5.7 Hz,
2 H, NCH2CH2CH2), 1.81 (quint, J = 5.7 Hz, 4 H, NCH2CH2), 3.18
(t, J = 5.6 Hz, 4 H, NCCH2CH2), 4.12 (s, 5 H, Cp), 4.31 (t, J = 1.6 Hz,
2 H, Cpmeta), 4.85 (t, J = 1.6 Hz, 2 H, Cportho), 9.09 (br. s, 2 H, NH2)
ppm. 13C NMR (CDCl3):
δ = 22.4 (NCCH2CH2CH2), 22.6
(NCCH2CH2), 44.5 (NCCH2), 70.8 (Cportho), 70.9 (Cpmeta), 89.5
(Cpipso), 215.4 (C=O) ppm. 77Se NMR (CDCl3): δ = 399.5 ppm.
Reaction of Piperidinium Ferrocenecarboselenoate (7) with Iodo-
methane: Iodomethane (2 mL, 32 mmol) and piperidinium ferrocene-
carboselenoate 7 (66 mg, 0.18 mmol) were stirred at 20 °C for 1 h in
an argon atmosphere and diethyl ether (10 mL) was added. Filtration
of insoluble part (piperidinium iodide) and removal of the solvent and
excess of methyl iodide under reduced pressure (25 °C, 0.2 Torr) gave
53 mg (99%) of Se-methyl ferrocenecarboselenoate as orange micro
crystals. The IR and 1H NMR spectra of the Se-methyl ester were
exactly consistent with that of the authentic sample obtained from the
reaction of potassium ferrocenecarboselenoate (1b) with iodomethane.
Ferrocenoyl Phenylcarbamothioyl Selenide (6): A solution of
phenyl isothiocyanate (157 mg, 1.16 mmol) in diethyl ether (5 mL)
was added to a solution of ferrocenecarboselenoic acid (2) (342 mg,
1.17 mmol) in the same solvent (9 mL) in a 20 mL two necked round-
bottomed flask at 0 °C in an argon atmosphere. The mixture was stirred
at room temperature (30 °C) for 2 h. Removal of the solvent under
reduced pressure (30 °C, 0.2 Torr), followed by recrystallization of the
resulting residue from a mixed solvent (13 mL) of dichloromethane/
hexane (3:10) at 0 °C gave 479 mg (96%) of ferrocenoyl phenylcarba-
Rubidium Ferrocenecarboselenoate (8): Rubidium fluoride (77 mg,
0.74 mmol) was added to a solution of ferrocenecarboselenoic acid (2)
(219 mg, 0.75 mmol) in diethyl ether (15 mL) in a 20 mL two necked
round-bottomed flask at 0 °C in an argon atmosphere. The mixture was
stirred at room temperature (23 °C) for 11 h. Orange solid was grad-
ually deposited. Filtration of the solid gave 146 mg (52%) of rubidium
1
ferrocenecarboselenoate (8) as orange micro crystals. The IR, and H,
13C and 77Se NMR spectra of compound 8 were exactly consistent
with those of the authentic sample prepared from the reaction of O-
trimethylsilyl ferocenecarboselenoate with RbF.[6] IR (nujol, neat): ν˜
= 3090, 2925, 2854, 2658, 2026, 1833, 1686, 1537, 1520 (C=O), 1460,
1429, 1368, 1335, 1233, 1104, 1038, 1029, 1010, 942, 854, 844, 834,
mothioyl selenide (6) as orange micro crystals. The IR and 1H and 13
C
NMR spectra were exactly consistent with those of the authentic sam-
ple obtained by the reaction of ferrocencarboselenoic acid (prepared
from acidolysis of sodium ferrocencarboselenoate with hydrogen
chloride) with phenyl isothiocyanate. IR (KBr, neat): ν˜ = 3630, 3483,
3097, 2966, 2346, 1684 (C=O), 1655, 1595, 1545, 1493, 1436, 1387,
1332, 1285, 1248, 1157, 1106, 1047, 1029, 1002, 933, 824, 798, 775,
690, 675, 547, 495 cm–1. 1H NMR (CDCl3) (a = 6a, b = 6b): δ = 4.19
(s, SH, Cp)a, 4.21 (s, SH, Cp)b, 4.48 (s, 2 H, Cpmeta)b, 4.57 (t, J =
1.95 Hz, 2 H, Cpmetaa, 4.74 (t, J = 1.95 Hz, 2 H, Cportho)a, 4.81 (s, 2
H, Cportho)b, 7.07–7.83 (m, 5 H, Ph), 12.22 (br., 1 H, NH)a, 13.31 (br.
s, 1 H, SH)b ppm. 13CNMR (CDCl3): δ = 68.6 (Cportho)a, 68.8
(Cportho)b, 71.1 (Cp)b, 71.2 (Cp)a, 73.7 (Cpmeta)a, 73.8 (Cpmeta)b, 78.2
(Cpipso)a, 78.3 (Cpipso)b, 122.3, 123.2, 125.5, 126.1, 128.7, 129.3,
138.4, 138.9 (Ph), 185.7 (C=O)a, 187.5 (C=O)b, 198.1 (C=N)b, 202.6
(C = S)a ppm. 77Se NMR (CDCl3): δ = 698.5b, 712.9a ppm. HRMS
(20 eV): calcd. for C18H14FeNOSSe: m/z 427.93153 (calcd.
427.93107).
1
813, 695, 546, 505, 486 cm–1. H NMR (CD3OD): δ = 4.18 (s, 5 H,
Cp), 4.35 (t, J = 1.95 Hz, 2 H, Cpmeta), 4.86 (t, J = 1.95 Hz, 2 H,
Cportho) ppm. 13C NMR (CD3OD): δ = 71.2 (Cp), 71.5 (Cportho), 71.6
(Cpmeta), 91.0 (Cpipso), 215.2 (C=O) ppm. 77Se NMR (CD3OD): δ =
351.2 ppm.
Cesium Ferrocenecarboselenoate (9): Cesium fluoride (65 mg,
0.43 mmol) was added to a solution of ferrocenecarboselenoic acid (2)
(123 mg, 0.42 mmol) in diethyl ether (8 mL) in a 20 mL two necked
round-bottomed flask at 0 °C in an argon atmosphere. The mixture was
stirred at room temperature (20 °C) for 5 h. Orange solid was gradually
deposited. Filtration of the solid gave 125.2 mg (70%) of cesium ferro-
cenecarboselenoate (9) as orange micro crystals. The structure was
determined by comparison of the IR, and 1H, 13C and 77Se NMR spec-
tra with those of the authentic sample prepared from the reaction of
O-trimethylsilyl ferocenecarboselenoate with CsF.[6] IR (nujol, neat):
ν˜ = 2984, 2833, 1998, 1537, 1520 (C=O), 1471, 1431, 1231, 1104,
1036, 1011, 940, 891, 853, 843, 813, 723, 695, 595, 545, 504, 485
Piperidinium Ferrocenecarboselenoate (7)[20]: A solution of piperi-
dine (41 mg, 0.48 mmol) in diethyl ether (1 mL) was added to a solu-
tion of ferrocenecarboselenoic acid (2) (140 mg, 0.48 mmol) in the
same solvent (19 mL) in a 20 mL two necked round-bottomed flask at
0 °C in an argon atmosphere. The mixture was stirred at room tempera-
ture (25 °C) for l h. Filtration of the resulting precipitates gave 128 mg
(82%) of piperidinium ferrocenecarboselenoate (7) as orange micro
crystals. The IR, and 1H, 13C and 77Se NMR spectra were exactly
consistent with those of the authentic sample obtained from the reac-
1
cm–1. H NMR (CD3OD): δ = 4.18 (s, 5 H, Cp), 4.35 (t, J = 1.95 Hz,
2 H, Cpmeta), 4.86 (t, J = 1.95 Hz, 2 H, Cportho) ppm. 13C NMR
(CD3OD): δ = 71.1 (Cp), 71.5 (Cportho, Cpmeta), 90.8 (Cpipso), 215.3
(C=O) ppm. 77Se NMR (CD3OD): δ = 361.2 ppm.
Lithium Ferrocenecarboselenoate (10): A solution of ferrocenecar-
boselenoic acid (2) (219 mg, 0.75 mmol) in diethyl ether (10 mL) was
tion of ferrocencarboselenoic acid (prepared by acidolysis of sodium added to a suspension of lithium hydride (6.3 mg, 0.79 mmol) in di-
Z. Anorg. Allg. Chem. 2013, 108–114
© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de 113

T. Takahashi, O. Niyomura, S. Kato, M. Ebihara
ARTICLE
[7] a) H. Kageyama, K. Tani, S. Kato, T. Kanda, Heteroat. Chem.
2001, 12, 250–258; b) O. Niyomura, K. Tani, S. Kato, Heteroat.
Chem. 1999, 10, 373–379.
[8] S. Kato, W. Akada, M. Mizuta, Int. J. Sulfur Chem. Sect. A 1972,
2, 279–282.
[9] S. Kato, W. Akada, M. Mizuta, Bull. Chem. Soc. Jpn. 1972, 45,
3492; S. Kato, M. Akada, M. Mizuta, Int. J. Sulfur Chem. Sect.
A 1973, 8, 359.
[10] S. Kumar, S. K. Tripathi, H. B. Singh, G. J. Wolmershauser, J.
Organomet. Chem. 2004, 689, 3046–3055.
[11] O. Niyomura, Y. Kito, M. Ishida, M. Ebihara, S. Hayashi, W.
Nakanishi, Z. Anorg. Allg. Chem. 2012, 638, 2508–2520.
[12] A. Bondi, J. Phys. Chem. 1964, 68, 441–451.
[13] M. Nishio, The CH/π Interaction. Evidence, Nature and Conse-
quences, Wiley-VCH, New York, 1998; M. Nishio, CrystEng-
Comm 2004, 6, 138–158; O. Takahashi, Y. Kohno, M. Nishio,
Chem. Rev. 2010, 110, 6049–6076.
[14] A. C. T. North, D. C. Phillips, F. S. Mathews, Acta Crystallogr.,
Sect. A 1968, 24, 351–359.
[15] G. M. Sheldrick, in: Crystallographic Computing 3, (Eds.: G. M.
Sheldrick, C. Kruger, R. Goddard), Oxford University Press,
1985, pp.175–189.
ethyl ether (10 mL) at 0 °C in an argon atmosphere. The mixture was
stirred at 23 °C for 1 h. Filtration of the resulting precipitates gave
133 mg (56%) of lithium ferrocenecarboselenoate (10) as orange
micro crystals. The structure was determined by comparison of the IR,
1
and H, 13C and 77Se NMR spectra of the authentic sample prepared
from the reaction of lithium selenide with ferrocenoyl chloride[6] and
by conversion into Se-methyl ferrocenecarboselenoate. IR (nujol,
neat): ν˜ = 3850, 2976, 2880, 2839, 1708, 1678, 1454 (C=O), 1424,
1376, 1330, 1232, 1104, 1040, 1002, 955, 932, 872, 844, 825, 776,
1
673, 594, 557, 495 cm–1. H NMR (CD3OD): δ = 4.18 (s, 5 H, Cp),
4.37 (s, 2 H, Cpmeta), 4.87 (s, 2 H, Cportho) ppm. 13C NMR (CD3OD):
δ = 71.1 (Cp), 71.5 (Cportho), 71.8 (Cpmeta), 90.9 (Cpipso), 215.9
(COSe) ppm. 77Se NMR (CD3OD): δ = 351.1 ppm.
Crystallographic data (excluding structure factors) for the structure in
this paper have been deposited with the Cambridge Crystallographic
Data Centre, CCDC, 12 Union Road, Cambridge CB21EZ, UK. Copies
of the data can be obtained free of charge on quoting the depository
number CCDC-895791 (3) (Fax: +44-1223-336-033; E-Mail:
deposit@ccdc.cam.ac.uk, http://www.ccdc.cam.ac.uk).
[16] The DIRDIF-94 program system was used: P. T. Beukskens, G.
Admiraal, G. Beurskiens, W. P. Bosman, R. de Gelder, R. Israel,
J. M. M. Smits, in: Technical Report of the Crystallography Labo-
ratory; University of Nijmegen; The Netherlands, 1994.
[17] D. T. Cromer, J. T. Waber, in: International Tables for X-ray Crys-
tallography; The Kynoch Press: Birmingham, England, 1974; vol.
IV, Table 2.2A.
Supporting Information (see footnote on the first page of this article):
Additional tables and figures of the compounds.
Acknowledgements
[18] D. C. Creagh, W. J. McAuley, in: International Tables for X-ray
Crystallography; (Ed.: A. J. C. Wilson), Kluwer Academic Pub-
lishers, Boston, 1992, vol. C, Table 4.2.6.8, pp. 219–222.
[19] In general, chalcogenocarboxylic acids are very labile thermally
and sensitive towards oxygen. In fact, ferrocencarboselenoic acid
(2) was too labile to isolate. Its high resolution mass spectroscopy
did not show any mother peak. Therefore, the acid 2 was charac-
terized by 1H, 13C, and 77Se NMR and IR spectra and by conver-
sion into more stable (ferrocenoyl)(4-methylphenylcarbamoyl)
selenide (5) and (ferrocenoyl)phenylcarbamothioyl selenide (6),
which were quantitatively obtained by addition reaction to 4-
methylphenyl isocyante and phenyl iosthiocyanate, respectively.
[20] Piperidinium ferrocenecarboselenoate (7) similar to alkali metal
ferrocencarboselenoates was hygroscopic and too sensitive
towards oxygen to isolate and in addition, its high resolution mass
spectroscopy (HRMS) also did not show any mother peaks. The
structure of compound 7, therefore, was charcterized by its IR,
and 1H, 13C and 77Se NMR spectra and by conversion into Se-
methyl ferrocenecarboselenoate.
This work was supported by the Grant-in-Aids for Scientific Research
(B) and on Priority Areas provided by the Ministry of Education, Sci-
ence, Sport and Culture, Japan. S. K. thanks Professor Takashi Kawa-
mura of Gifu University for X-ray structure analyses.
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Chem. 2013, published online, DOI:10.1002/zaac.201200368.
Received: August 15, 2012
Published Online: December 20, 2012
114
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© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2013, 108–114