Synthesis and complexation of dichalcogenoethers with cyclopropyl backbones, (CH2EMe)2 (E = Se or Te)

Article abstract of DOI:10.1016/j.jorganchem.2010.02.010

The reaction of LiTeMe with C(CH₂Br)₄ in thf gives {A figure is presented}(CH₂TeMe)₂ irrespective of the ratio of reactants, in contrast to the reaction with LiSeMe, which gives either C(CH₂SeMe)₄ or {A figure is presented}(CH₂SeMe)₂ depending upon the reaction conditions. The synthesis and properties of [{A figure is presented}(CH₂TeMe₂)₂]I₂, {A figure is presented}(CH₂TeMeI₂)₂, [Mn(CO)₃Cl{{A figure is presented}(CH₂EMe)₂}] (E = Se or Te) and [MCl(η⁶-p-cymene){{A figure is presented}(CH₂EMe)₂}]PF₆ (M = Ru or Os) are described. X-ray crystal structures are reported for [{A figure is presented}(CH₂TeMe₂)₂]I₂, [Mn(CO)₃Cl{{A figure is presented}(CH₂TeMe)₂}], [MCl(η⁶-p-cymene){{A figure is presented}(CH₂TeMe)₂}]PF₆ (M = Ru, E = Se or Te and M = Os, E = Se). The effect of the cyclopropyl ring in the ligand backbone is to open up the C-C-C angle within the chelate ring, compared with trimethylene linked analogues. Selenium-carbon bond fission occurs on attempted quaternisation of o-C₆H₄(CH₂SeMe)₂ or {A figure is presented}(CH₂SeMe)₂ with MeI yielding [Me₃Se]I.

Full text of DOI:10.1016/j.jorganchem.2010.02.010

Journal of Organometallic Chemistry 695 (2010) 1346–1352
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Synthesis and complexation of dichalcogenoethers with cyclopropyl backbones,
(CH2)2C
(CH2EMe)2 (E = Se or Te)
*
William Levason , Luke P. Ollivere, Gillian Reid, Michael Webster
School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 5 January 2010
(CH ) C
The reaction of LiTeMe with C(CH2Br)4 in thf gives
(CH2TeMe)2 irrespective of the ratio of reactants,
2
2
Received in revised form 3 February 2010
Accepted 10 February 2010
Available online 17 February 2010
(CH ) C
in contrast to the reaction with LiSeMe, which gives either C(CH2SeMe)4 or
(CH2SeMe)2 depending
2
2
(CH ) C
(CH ) C
(CH2Te-
upon the reaction conditions. The synthesis and properties of [
(CH2TeMe2)2]I2,
2
2
2 2
(CH ) C
(CH ) C
MeI2)2, [Mn(CO)3Cl{
(CH2EMe)2}] (E = Se or Te) and [MCl(g6-p-cymene){
(CH2EMe)2}]PF6
2
2
2 2
Keywords:
Selenoether
Telluroether
Ruthenium
Osmium
(CH ) C
[
(M = Ru or Os) are described. X-ray crystal structures are reported for
(CH ) C (CH ) C
(CH2TeMe)2}]PF6 (M = Ru, E = Se or Te and
(CH2TeMe2)2]I2,
2
2
[Mn(CO)3Cl{
(CH2TeMe)2}], [MCl(g6-p-cymene){
2
2
2 2
M = Os, E = Se). The effect of the cyclopropyl ring in the ligand backbone is to open up the C–C–C angle
Manganese
within the chelate ring, compared with trimethylene linked analogues. Selenium–carbon bond fission
(CH ) C
occurs on attempted quaternisation of o-C6H4(CH2SeMe)2 or
(CH2SeMe)2 with MeI yielding
2
2
[Me3Se]I.
Ó 2010 Elsevier B.V. All rights reserved.
1. Introduction
2. Experimental
Detailed studies have shown that neutral selenium and tellu-
rium donor ligands (chalcogenoethers R2E, E = Se or Te) are better
donors than the more familiar sulphur analogues. They also exhibit
ready oxidation at the heteroatom, and cleavage of the weaker and
more reactive E–C bonds, properties less commonly found with
thioethers [1–3]. We recently reported the synthesis and some
metal carbonyl complexes of the tetradentates 1,2,4,5-
C6H2(CH2EMe)4 (E = S or Se) and C(CH2EMe)4 [4], and found that
when E = Se, the reaction of MeSeLi with C(CH2Br)4 produces either
Infrared spectra were recorded as Nujol mulls between CsI
plates over the range 4000–200 cmꢀ1 or as chlorocarbon solutions
in NaCl solution cells over the range 2200–1700 cmꢀ1, using Per-
kin–Elmer 983G or PE Spectrum100 instruments. 1H and 13C{1H}
NMR spectra were recorded at ambient temperatures unless stated
otherwise, using a Bruker AV300 spectrometer and referenced
internally to the solvent resonance, and 77Se{1H}, 125Te{1H} and
55Mn NMR spectra on a Bruker DPX400 spectrometer and are ref-
erenced to external neat SeMe2, neat TeMe2, and aqueous KMnO4
respectively. Mass spectra were obtained using a VG Biotech plat-
form. Microanalyses were undertaken by Medac Ltd. Electrochem-
ical measurements were undertaken using an Ecochemie PGStat20
with 0.1 mol dmꢀ3 [NBu4][BF4] in dry MeCN as electrolyte. All
C(CH2SeMe)4 or (CH2)2C(CH2SeMe)2 depending upon the reaction
conditions. The corresponding (CH2)2C(CH2TeMe)2 was mentioned
some years ago in a paper dealing with the synthesis of ditelluroe-
thers [5], but the reaction was not investigated in detail. In the
present paper we have explored the synthesis of the cyclopropyl-
based telluroethers, and report some organotellurium derivatives,
and a series of metal complexes of the 1,1-bis(methyl selenometh-
yl/telluromethyl)cyclopropanes. The use of selenium compounds,
mostly based upon selenoalkenes, as reagents for the formation
of cyclopropyl rings in organic synthesis, is well established [6].
preparations were carried out under
a
N2 atmosphere.
6-p-cymene)}2]
6-p-cymene)}2] [8] were made by literature methods.
(CH SeMe) [4], [Mn(CO)5Cl] [7], [{RuCl2(
g
(CH2)2C
2
2
and [{OsCl2(
g
2.1. 1,1-Bis(methyltelluromethyl)cyclopropane, (CH2)2C(CH2TeMe)2
Freshly ground tellurium, powder (3.02 g, 29.3 mmol) was
added to dry THF (25 mL) under nitrogen. The solution was then
frozen with liquid nitrogen. MeLi solution (15.6 mL of 1.6 M solu-
tion in diethyl ether, 24.9 mmol) was then added via syringe and
* Corresponding author. Fax: +44 023 80593781.
E-mail address: wxl@soton.ac.uk (W. Levason).
0022-328X/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2010.02.010

W. Levason et al. / Journal of Organometallic Chemistry 695 (2010) 1346–1352
1347
the mixture left to thaw for 40 min., then stirred at 0 °C for 2 h. The
flask was then placed in an acetone slush bath (195 K) and penta-
erythrityl tetrabromide (2.5 g, 6.5 mmol) in THF (30 mL) was
added dropwise, and then stirred for a further 2 h. The reaction
mixture was hydrolysed with saturated NaCl solution (25 mL).
The product was extracted with diethyl ether (3 ꢁ 20 mL), the
ether extracts dried over MgSO4, filtered, and the solvent and
Me2Te2 removed under high vacuum to yield a dark red oil. Yield:
1.2 g, (52% based on C(CH2Br)4). 1H NMR (CDCl3): 0.65 (s, [4H],
CH2cyclopropyl), 1.87 (s, [6H], TeMe), 2.80 (s, [4H], CH2Te). 13C{1H}
NMR (CDCl3): ꢀ22.0 (TeMe), 16.4 (CH2Te), 17.7 (CH2C), 22.3
(Cquaternary). 125Te{1H} NMR (CH2Cl2): 63.1.
0.12 g (88%) (yield of [C9H11Se]I). 1H NMR (CDCl3): 1.95 (s, [3H],
Me), 4.25 (s, [4H], CH2), 7.1 (m, [4H] CHaromatic). 77Se{1H} NMR
(CDCl3): 406. ES+-MS: m/z = 199 [C9H11Se]+. NMR and mass spec-
trometry analysis of the filtrate from this reaction showed it also
contains [Me3Se]I
(
77Se{1H} NMR (acetone): 259; ES+-MS:
m/z = 125 [Me3Se]+).
2.6. [Chloro{1,1-bis(methylselenomethyl)cyclopropane}-
6-p-cymene)ruthenium(II)] hexafluorophosphate
(g
[Ru(g
6-p-cymene)Cl2]2 (0.12 g, 0.19 mmol) in dry ethanol
(10 mL) was added to (CH2)2C(CH2SeMe)2 (0.10 g, 0.39 mmol) in
dry ethanol (5 mL) and refluxed for 2 h. [NH4][PF6] (0.065 g,
0.4 mmol) in dry degassed ethanol (5 mL) was added, the solution
was then allowed to cool and stirred overnight. The pale orange
precipitate was filtered off, washed with cold ethanol (2 ꢁ 5 mL)
and dried in vacuo. Yield: 0.17 g (65%). Crystals were grown by
refrigerating the filtrate. Anal. Calc. for C17H28ClF6PRuSe2: C, 30.4;
H, 4.2. Found: C, 30.3; H, 4.3%. 1Y NVR (CD3CN): 0.62 (m, [2H],
CY2cyclopropyl), 0.80 (m, [2H], CY2cyclopropyl), 1.32 (d, [6H], J = 7 Hz,
CH(CH3)2), 2.24 (s, [3H], cymene-CH3), 2.28, 2.45, 2.48 (major),
2.55 (4 ꢁ s, [6Y], SeMe), 2.80 (m, [H], CH), 3.37, 3.41, 3.50 (major),
3.53 (major), 3.75, 3.79 (6 ꢁ s, [4Y], CY2Se), 5.60–5.84 (overlapping
d, [4H], CHaromatic). 77Se{1H} NMR (CH2Cl2): 147.8, 123.8, 117.7
(major), 71.8; (CH3CN): 135.1, 113.7, 110.3 (major), 62.5. IR (Nujol,
2.2. 1,1-Bis(dimethyltelluromethyl)cyclopropane di-iodide,
[
(CH TeMe ) ]I
(CH2)2C
2 2 2
2
(CH TeMe) (0.10 g, 0.28 mmol) was stirred with an ex-
(CH2)2C
2
2
cess of iodomethane (1.5 mL) in CH2Cl2 (20 mL) for 30 min. The
yellow solid was collected by filtration, washed with CH2Cl2 and
dried in vacuo. Yield: 0.13 g (77%). Anal. Calc. for C9H20I2Te2: C,
17.0; H, 3.2. Found: C, 16.8; H, 3.1%. 1H NMR (d6-dmso): 0.92 (s,
[4H], CH2cyclopropyl), 2.25 (s, [12H], TeMe), 3.20 (s, [4H], CH2Te).
125Te{1H} NMR (N,N-dimethylformamide/d6-acetone): 470.8. ES+-
MS: m/z = 511 [MꢀI]+. Crystals were grown by cooling a dmso/
methanol solution of the compound at 255 K.
cmꢀ1): 839 (PF), 557 d(PF). ES+-MS: m/z = 527 [C17H28ClRuSe2]+.
t
2.3. 1,1-Bis(methyldi-iodotelluromethyl)cyclopropane,
(CH TeMeI )
(CH2)2C
2
2 2
2.7. [Chloro{1,1-bis(methyltelluromethyl)cyclopropane}-
6-p-cymene)ruthenium(II)] hexafluorophosphate
(g
(CH TeMe) (0.19 g, 0.54 mmol) in dry degassed THF
(CH2)2C
2
2
(20 mL) was stirred in a foil wrapped Schlenk tube, iodine
(0.27 g, 1.1 mmol) in dry degassed THF (20 mL) was added via a
syringe and stirred for a further 2 h. The solvent was then reduced
in volume to 5 mL before dry diethyl ether (10 mL) was added. The
dark red solid was collected via a filter cannula, washed with cold
diethyl ether and dried in vacuo. Yield: 0.41 g (51%). Anal. Calc. for
C7H14I4Te2: C, 9.8; H, 1.6. Found: C, 10.2; H, 1.6%. 1H NMR (d6-
dmso, poorly soluble and solvent resonance partially obscures sig-
nal): 0.99 (s, [4H], CH2cyclopropyl), 2.65 (s, [12H], TeMe), 3.12 (br,
[4H], CH2Te). 125Te{1H} NMR (d6-dmso): 598.
[Ru(
g
6-p-cymene)Cl2]2 (0.086 g, 0.14 mmol) in THF (10 mL)
was added to Schlenk tube containing (CH2)2C(CH2TeMe)2
a
(0.10 g, 0.28 mmol) in dry degassed ethanol (10 mL). The dark
red solution was then stirred at room temperature for 2 h.
[NH4][PF6] (0.05 g, 0.3 mmol) in dry degassed ethanol (5 mL) was
added and the solution was stirred for a further 1 h before filtering
to remove small amounts of insoluble material. The filtrate was
then reduced in volume by 50% and placed in the freezer overnight.
The bright red solid deposited was filtered off, washed with hexane
(2 ꢁ 5 mL) and dried in vacuo. Yield 0.165 g (76%). Crystals were
grown by refrigerating the filtrate. Anal. Calc. for
C17H28ClF6PRuTe2: C, 26.6; H, 3.7. Found: C, 26.6; H, 3.4%. 1Y
NVR (CD3Cl3): 0.51, 0.77, 1.00 (3 ꢁ m, [4H], CY2cyclopropyl), 1.27
(overlapping d, [6H], CH(CH3)2), 2.19 (s, [3H], cymene-CH3), 2.24,
2.25, 2.27, 2.30 (4 ꢁ s, [6Y], TeMe), 2.76 (m, [H], CH), 3.10, 3.14,
3.46 (major), 3.50 (major), 3.67, 3.71 (6 ꢁ s, [4Y], CY2Te), 5.50–
5.90 (overlapping m, [4H], CHaromatic). 125Te{1H} NMR (CH2Cl2):
2.4. Reaction of
(CH SeMe) with MeI
2 2
(CH2)2C
(CH SeMe) (0.2 g, 0.78 mmol) was placed in a Schlenk
(CH2)2C
2
2
tube and degassed acetone (10 mL) was added via syringe. An ex-
cess of iodomethane (2.5 mL) in degassed acetone (10 mL) was
then added and the mixture was heated to 40 °C for 2 h. The white
precipitate was collected via a filter cannula and dried under high
vacuum to yield a white solid. Yield: 0.16 g (41% based upon Se). 1H
NMR (D2O): 2.7 s. Lit [9] (D2O) 2.7. 77Se{1H} NMR (dmso): 256. Lit
[9] 253. ES+-MS: m/z = 125 [Me3Se]+. The filtrate was refrigerated
for 2 days when large yellow crystals formed. The crystal structure
was determined and shown to be [Me3Se]I (orthorhombic, Pnma,
a = 13.960, b = 7.944, c = 6.158 Å), which is in excellent agreement
with the literature data [10].
283.1, 265.8 (major), 264.0. IR (Nujol, cmꢀ1): 839
t(PF), 557
d(PF). ES+-MS: m/z = 627 [C17H28ClRuTe2]+.
2.8. [Chloro{1,1-bis(methylselenomethyl)cyclopropane}-
(g
6-p-cymene)osmium(II)] hexafluorophosphate
[Os(g
6-p-cymene)Cl2]2 (0.15 g, 0.20 mmol) in dry degassed eth-
Schlenk tube containing
anol (30 mL) was added to
a
2.5. Reaction of o-C6H4(CH2SeMe)2 with MeI
(CH SeMe) (0.10 g, 0.39 mmol) in dry degassed ethanol
(CH2)2C
2
2
o-C6H4(CH2SeMe)2 (0.2 g, 0.66 mmol) was placed in a Schlenk
tube containing 10 mL of degassed acetone. An excess of iodo-
methane (2.5 mL) in degassed acetone (10 mL) was then added
and the mixture was heated to 40 °C for 2 h. The resulting white
precipitate was collected via a filter cannula and dried under high
vacuum. Crystals were grown by placing the filtrate in the freezer
for a week, shown to be [C9H11Se]I (X-ray study – below). Yield:
(10 mL). The dark yellow solution was then stirred at 70 °C for
1 h. [NH4][PF6] (0.031 g, 0.20 mmol) in dry degassed ethanol
(15 mL) was added, the solution was then stirred overnight before
filtering to remove small amounts of insoluble material. The filtrate
was reduced in volume by 50% and placed in the freezer overnight.
The yellow solid deposited was filtered off, washed with hexane
(2 ꢁ 5 mL) and dried in vacuo. Yield: 0.21 g (71%). Crystals were

1348
W. Levason et al. / Journal of Organometallic Chemistry 695 (2010) 1346–1352
Table 1
Crystal data and structure refinement detailsa.
Complex
[(CH2)C(CH2TeMe2)2]I2
[o-C6H
Me]I
4(CH2)2Se
[Mn(CO) Cl{
(CH TeMe) }]
(CH2)2C
3
2
2
Formula
M
Crystal system
Space group
a (Å)
C9H20I2Te2
637.25
monoclinic
P21/n (#14)
10.9852(15)
13.472(2)
11.9328(15)
90
C9H11ISe
325.04
monoclinic
P21/n (#14)
7.8050(10)
11.2813(15)
11.5214(15)
90
C10H14ClMnO3Te2
527.80
monoclinic
P21/n (#14)
9.1254(15)
15.567(4)
11.321(3)
90
b (Å)
c (Å)
a
(°)
b (°)
114.696(10)
90
1604.5(4)
4
97.474(10)
90
1005.8(2)
4
107.847(15)
90
1530.7(6)
4
c
(°)
U (Å3)
Z
l(Mo K
a
) (mmꢀ1
)
7.453
6.741
4.766
F(0 0 0)
1136
608
976
Total number of reflections
Unique reflections
Rint
13490
3583
0.102
11656
2269
0.024
21722
3508
0.038
Number of parameters, restraints
118, 17
0.088
100, 0
0.023
156, 0
0.030
b
R1 [Io > 2r(Io)]
R1 (all data)
0.163
0.220
0.025
0.051
0.035
0.063
b
wR2 [Io > 2
r
(Io)]
wR2 (all data)
0.278
0.052
0.065
Complex
[Ru(p-cymene)Cl{
(CH SeMe) }]
(CH2)2C
[Ru(p-cymene)Cl{
(CH TeMe) }]
(CH2)2C
[Os(p-cymene)Cl{
(CH SeMe) }]
(CH2)2C
2 2
2
2
2
2
[PF6]
[PF6]
[PF6]
Formula
M
C17H28ClF6PRuSe2
671.80
C17H28ClF6PRuTe2
769.08
C17H28ClF6OsPSe2
760.93
Crystal system
Space group
a (Å)
b (Å)
c (Å)
orthorhombic
P212121 (#19)
12.3668(15)
12.4682(10)
15.028(2)
90
orthorhombic
P212121 (#19)
12.5305(15)
12.5472(10)
15.2251(10)
90
orthorhombic
P212121 (#19)
12.363(2)
12.4710(14)
15.056(2)
90
a
(°)
b (°)
90
90
90
c
(°)
90
2317.2(5)
4
90
2393.7(4)
4
90
2321.3(6)
4
U (Å3)
Z
l
(Mo K
a
) (mmꢀ1
)
4.051
3.270
8.862
F(0 0 0)
1312
1456
1440
Total number of reflections
Unique reflections
Rint
15487
5104
0.034
21520
5219
0.038
20612
5282
0.056
Number of parameters,
254, 0
241, 6
258, 0
restraints
b
R1 [Io > 2
r
(Io)]
0.028
0.031
0.062
0.064
0.034
0.038
0.080
0.083
0.032
0.037
0.064
0.065
R1 (all data)
wR2 [Io > 2
wR2 (all data)
b
r(Io)]
a
Common items: temperature = 120 K; wavelength (Mo Ka) = 0.71073 Å; h(max) = 27.5°.
R1
=
R
||Fo| ꢀ |Fc||/
R
|Fo|. wR2 = [
R
wðF2o ꢀ F2c Þ /
R .
wF4o ]1/2
b
2
grown from the filtrate at ꢀ18 °C. Anal. Calc. for C17H28ClF6OsPSe2:
C, 26.8; H, 3.7. Found: C, 25.4; H, 3.4%. 1Y NVR (CD3CN): 0.58–0.72
(m, [4H], CY2cyclopropyl), 1.27 (major), 1.30 (2 ꢁ d, [6H], CH(CH3)2),
2.16 (major), 2.19 (2 ꢁ s, [3H], cymene-CH3), 2.27, 2.40 (major),
2.49, 2.58 (4 ꢁ s, [6Y], SeMe), 2.90 (m, [H], CH), 3.46, 3.50, 3.62
(major), 3.65 (major), 3.82, 3.86 (6 ꢁ s, [4Y], CY2Se), 5.76–6.05
(overlapping d, [4H], CHaromatic). 77Se{1H} NMR (CH3CN): 92.9,
(CH2)2C(CH2TeMe)2 (0.10 g, 0.28 mmol) in dry degassed ethanol
(10 mL). The orange solution was then stirred at 50 °C for 1 h.
[NH4][PF6] (0.023 g, 0.14 mmol) in dry degassed ethanol (15 mL)
was added, the solution was then stirred overnight before filtering
to remove small amounts of insoluble material. The filtrate was
then reduced in volume by 50% and placed in the freezer overnight.
The orange solid was filtered, washed with hexane (2 ꢁ 5 mL) and
dried in vacuo. Yield: 0.07 g (57%). 1Y NVR (CD3CN): (see text)
0.50–0.91 (overlapping m, [4H], CY2cyclopropyl), 1.24–1.29 (3 over-
lapping d, [6H], CH(CH3)2), 2.15, 2.16 (2 ꢁ s, [3H], cymene-CH3),
2.25, 2.29, 2.37, 2.41 (4 ꢁ s, [6Y], TeMe), 2.6–2.8 (m, [H], CH),
3.14, 3.18, 3.42, 3.52, 3.53 (major), 3.56 (major), 3.69, 3.73 (8 ꢁ s,
[4Y], CY2Te), 5.67–6.10 (overlapping m, [4H], CHaromatic). 125Te{1H}
NMR (CH3CN): 185.4, 164.5, 159.5 (major), 58.0. IR (Nujol, cmꢀ1):
68.4, 65.8 (major), 47.2. IR (Nujol, cmꢀ1): 839
t(PF), 557 d(PF).
ES+-MS: m/z = 617 [C17H28ClOsSe2]+.
2.9. [Chloro{1,1-bis(methyltelluromethyl)cyclopropane}-
6-p-cymene)osmium(II)] hexafluorophosphate
(g
[Os(
g
6-p-cymene)Cl2]2 (0.11 g, 0.14 mmol) in dry degassed eth-
anol (30 mL) was added to Schlenk tube containing
839 t
(PF), 557 d(PF). ES+-MS: m/z = 715 [C17H28ClOsTe2]+.
a

W. Levason et al. / Journal of Organometallic Chemistry 695 (2010) 1346–1352
1349
2.10. Chlorotricarbonyl{1,1-
Ka X-radiation (k = 0.71073 Å), and with the crystals held at 120 K
bis(methylselenomethyl)cyclopropane}manganese(I)
in a dinitrogen gas stream. Structure solution and refinement were
straightforward [11–13], except as described below, and H atoms
were introduced into the models in calculated positions using
[Mn(CO)5Cl] (0.09 g, 0.38 mmol) was dissolved in CHCl3 (50 mL)
the default C–H distances. The diffraction data for [(CH2)2C(CH2Te-
Me2)2]I2 were of modest quality and needed several SHELXL DELU
commands to restrain the anisotropic atomic displacement param-
and (CH2)2C(CH2SeMe)2 (0.10 g, 0.38 mmol) in CHCl3 (20 mL)
added. The mixture was refluxed for 3 h, cooled, and the solvent re-
moved in vacuo. The residue was washed with hot CHCl3
(3 ꢁ 20 mL). The bright orange solid was dried in vacuo. Yield:
0.11 g (68%). Anal. Calc. for C10H14ClMnO3Se2ꢂ1/2CHCl3: C, 26.7;
H, 3.1. Found: C, 26.2; H, 3.7%. 1H NMR (CDCl3): peaks too broad
to assign. 13C{1H} NMR (CH2Cl2/CDCl3): 10.88, 11.43, 12.77,
13.46, 14.61 (CH2cyclopropyl), 15.16, 17.56, 18.00, 19.05 (MeSe),
21.65, 30.02 (Cquaternary), 32.50, 34.60, 35.10, 39.17 (CH2Se), 219
(vbr) CO. 77Se{1H} NMR (CH2Cl2): 74.4, 76.7, 108.9, 136.5. 55Mn
eters (adp). The data for [Ru(p-cymene)Cl{(CH2)2C(CH2Te-
Me)2}][PF6] were initially collected for
a tetragonal system
(a ꢃ b), but a solution only emerged in an orthorhombic space
group. The anion showed large adp values for the F atoms, and this
was modelled using the EADP command on trans F atoms and
restraining all the P–F distances to be the same (DFIX/FVAR). Se-
lected bond lengths and angles for the metal complexes are given
in Tables 2 and 3.
NMR (CH2Cl2): ꢀ205, ꢀ230, ꢀ290. IR (CH2Cl2, cmꢀ1):
t(CO) 2028,
1948, 1916.
2.11. Chlorotricarbonyl{1,1-
bis(methyltelluromethyl)cyclopropane}manganese(I)
3. Results
3.1. Synthesis of the telluroether and organotellurium(IV) derivatives
[Mn(CO)5Cl] (0.09 g, 0.38 mmol) was dissolved in dry CHCl3
(50 mL) and (CH TeMe) (0.14 g, 0.38 mmol) in CHCl3
We recently reported [4] that the reaction of MeSeLi with
C(CH2Br)4 produces C(CH2SeMe)4 when the molar ratio of the reac-
tants is 4.5:1, whilst increasing the amount of MeSeLi, progres-
(CH2)2C
2
2
(20 mL) was added. The mixture was heated at 40 °C for 3 h,
cooled, and the solvent removed in vacuo. The residue was washed
with hot CHCl3 (3 ꢁ 20 mL). The resulting red solid was filtered and
then dried in vacuo. Yield: 0.14 g (68%). Anal. Calc. for
C10H14ClMnO3Te2: C, 22.8; H, 2.7. Found: C, 23.6; H, 2.3%. 1H
NMR (CDCl3): very broad, see text. 13C{1H} NMR (CH2Cl2/CDCl3):
ꢀ21.73, ꢀ13.17, ꢀ10.67, ꢀ10.30 (TeMe), 16.66, 17.98, 19.17,
20.87, 22.77, 24.68 (CH2Te + CH2cyclopropyl), 220 (vbr) CO.
125Te{1H} NMR (CH2Cl2): 194.5, 183.8, 61.1 (major), 45.2. 55Mn
sively forms (CH2)2C(CH2SeMe)2, the yield being ꢄ90% with an
8:1 molar ratio. We have now re-examined the corresponding
reactions of MeTeLi with C(CH2Br)4, which was reported [5] to give
only (CH2)2C(CH2TeMe)2, to establish whether the tetratelluro-
ether, C(CH2TeMe)4, could be obtained. However, using varying
molar ratios of MeTeLi to C(CH2Br)4 (ꢄ4:1 through 8:1) and reaction
NMR (CH2Cl2): ꢀ615, ꢀ646, ꢀ688. IR (CH2Cl2. cmꢀ1):
t(CO) 2012,
temperatures of 200 K to ambient gave only (CH2)2C(CH2TeMe)2
1943, 1904.
(
125Te NMR: d = 63.1) and Me2Te2 as significant tellurium-contain-
ing products. In situ 125Te{1H} NMR spectra taken from reaction
mixtures at various stages also failed to show evidence for the
tetratelluroether (since 125Te chemical shifts are approximately
additive with the substituents [5,14], the tetratelluroether is ex-
pected to have a resonance at d ꢄ30). The cyclopropyltelluroether
was fully characterised spectroscopically and as the Te(IV) deriva-
2.12. X-ray crystallography experimental
Details of the crystallographic data collection and refinement
parameters are given in Table 1. The crystallisation details are pro-
vided under the section for each compound. Data collection used a
Nonius Kappa CCD diffractometer fitted with monochromated Mo
tives, [(CH2)2C(CH2TeMe2)2]I2 and (CH2)2C(CH2TeMeI2)2, formed on
reaction with excess MeI and I2 respectively (Sections 2.2, 2.3). The
conversion to the Te(IV) derivatives is accompanied by large,
high-frequency shifts in the 125Te NMR resonances as expected
[5,15]. Rather poor quality crystals were obtained by refrigerating
Table 2
Selected bond lengths (Å) and angles (°) for fac-[Mn(CO) Cl{
(CH TeMe) }].
2 2
(CH2)2C
3
Mn1ꢀTe1
2.6394(7)
2.6285(8)
2.4053(11)
3.712(1)
Mn1ꢀC8
1.813(4)
1.806(4)
1.785(4)
1.139(5)–1.150(5)
88.65(3)
89.98(3)
89.13(12)
90.26(12)
90.1(2)–91.8(2)
Mn1ꢀTe2
Mn1ꢀC9
Mn1ꢀCl1
Mn1ꢀC10
a dmso/MeOH solution of [(CH2)2C(CH2TeMe2)2]I2 at 255 K. The
structure (Fig. 1) provides conclusive proof of the ligand backbone
and shows pyramidal TeC3 units with longer TeꢂꢂꢂI (secondary)
interactions in the range 3.803–3.568 Å completing a distorted
octahedron about Te2 and a distorted square pyramid about Te1.
The Te–C and Te–I distances are similar to those in other telluroni-
Te1ꢂꢂꢂTe2
C–O
Te1ꢀMn1ꢀTe2
C8ꢀMn1ꢀCl1
C9ꢀMn1ꢀCl1
C9ꢀMn1ꢀTe1
C10ꢀMn1ꢀTe1
89.62(2)
Cl1ꢀMn1ꢀTe1
Cl1ꢀMn1ꢀTe2
C8ꢀMn1ꢀTe2
C10ꢀMn1ꢀTe2
C–Mn1–C
91.03(13)
88.96(13)
89.42(12)
90.20(12)
Table 3
Selected bond lengths (Å) and angles (°) for [M(p-cymene)Cl{
(CH EMe) }] + (M = Ru or Os, E = Se; M = Ru, E = Te).
2 2
(CH2)2C
M = Ru, E = Se
M = Ru, E = Te
M = Os, E = Se
Ru1ꢀSe1
2.4856(5)
2.4972(6)
2.3960(10)
2.178(4)ꢀ2.238(4)
87.87(2)
Ru1ꢀTe1
2.6222(6)
2.6231(7)
2.4097(15)
2.188(7)ꢀ2.251(6)
88.17(2)
Os1ꢀSe1
2.4954(7)
2.5034(7)
2.4041(14)
2.181(6)ꢀ2.231(6)
87.70(2)
Ru1ꢀSe2
Ru1ꢀTe2
Os1ꢀSe2
Ru1ꢀCl1
Ru1ꢀCl1
Os1ꢀCl1
Ru1ꢀCring
Ru1ꢀCring
Os1ꢀCring
Se1ꢀRu1ꢀSe2
Cl1ꢀRu1ꢀSe2
Cl1ꢀRu1ꢀSe1
Te1ꢀRu1ꢀTe2
Cl1ꢀRu1ꢀTe2
Cl1ꢀRu1ꢀTe1
Se1ꢀOs1ꢀSe2
Cl1ꢀOs1ꢀSe2
Cl1ꢀOs1ꢀSe1
88.58(3)
88.36(3)
88.67(4)
88.33(4)
87.83(4)
87.90(4)

1350
W. Levason et al. / Journal of Organometallic Chemistry 695 (2010) 1346–1352
Fig. 2. Structure of [o-C6H
Me]I showing the weakly associated centro-
4(CH2)2Se
symmetric dimer unit. Ellipsoids are drawn at the 50% probability level and H
atoms have been omitted for clarity. Symmetry operation: a = 1ꢀx, ꢀy, ꢀz. Selected
bond lengths (Å) and angles (°): Se1ꢀC1 1.949(3), Se1ꢀC8 1.961(3), Se1ꢀC9
1.940(3), C1ꢀSe1ꢀC8 91.00(12), C1ꢀSe1ꢀC9 97.28(13), C8ꢀSe1ꢀC9 97.62(14),
Se1ꢂꢂꢂI1 3.589(1), Se1ꢂꢂꢂI1a 3.599(1).
structure (Fig. 2) shows the cations are weakly linked into dimers
via long SeꢂꢂꢂIꢂꢂꢂSe bridges (Se1ꢂꢂꢂI1 3.589(1), Se1ꢂꢂꢂI1a 3.599(1) Å). A
possible mechanism for the rearrangement is that quaternisation
of one selenium by MeI (or coordination to the Group 13 Lewis
acid), polarises the Se–C H2 bond, which is then attacked by the
a
second selenium, forming the cyclic selenonium cation and elimi-
nating Me2Se (Scheme 1). The Me2Se formed is then quaternised to
[Me3Se]I. A different selenonium derivative [C17H19Se]2[TiCl6] was
obtained from the reaction of o-C6H4(CH2SeMe)2 with TiCl4 [22],
but the diselenoether ligand has produced a wide range of com-
plexes with later transition metals in which it functions as a chelat-
ing bidentate as expected [23]. In contrast, the ditelluroether
o-C6H4(CH2TeMe)2 quaternises ‘‘normally” to form o-C6H4(CH2Te-
Me2I)2 which has a dimer structure composed of a Te4I4 cubane
core [24]. It is clear that there is also a subtle balance between nor-
mal quaternisation and elimination in these systems, possibly the
less electronegative Te centre makes the Te–C bond less polar
and hence the mechanism in Scheme 1 is disfavoured.
Fig. 1. (a) Structure of the cation in [
(CH TeMe ) ]I2 showing the numbering
2 2 2
(CH2)2C
scheme adopted. Ellipsoids are drawn at the 60% probability level and H atoms have
been omitted for clarity. Selected bond lengths (Å) and angles (°): TeꢀC 2.10(2)–
2.18(2), Te1ꢂꢂꢂTe2 4.925(2), C4–C1–C7 116.9(2), C2–C1–C3 58.7(12), Te–C–C
112.3(13), 115.1(12). (b) Shows the additional long range TeꢂꢂꢂI interactions
3.568–3.803 Å making Te1 [3 + 2] (approx. square pyramidal) and Te2 [3 + 3]
(approx. octahedral) coordinate.
um salts [16–18], although detailed comparisons are not justified
due to the modest crystal quality.
The formation of either the C(CH2SeMe)4 or
may be achieved depending upon the reaction conditions, whereas
(CH SeMe)
(CH2)2C
2 2
(CH TeMe) is the only product in the C(CH2Br)4/LiTeMe
(CH2)2C
2
2
reaction, shows the subtle balance between substitution and elim-
ination in these systems. We note that the tritelluroethers
MeC(CH2TeR)3 (R = Me or Ph) are prepared without difficulty
[5,26]. Unsurprisingly, C(CH2SMe)4 is the only product of the reac-
tion of C(CH2Br)4 with P4 molar equivalents of LiSMe [4], reflect-
ing the stronger S–C bond which resists elimination of Me2S2. The
fragility of the C–Se bonds in these systems was also shown in the
3.2. Metal complexes of
(CH EMe) (E = Se or Te)
(CH2)2C
2
2
3.2.1. Manganese(I) carbonyl complexes
The reaction of Mn(CO)5Cl with (CH2)2C(CH2EMe)2 (E = Se or Te)
in hot chloroform gave orange-red fac-[Mn(CO) Cl{
(CH2)2C
3
(CH2EMe)2}] as the sole product in each case. Pyramidal inversion
at the chalcogen centres is slow on the NMR timescales for these
complexes, both of which show three 55Mn NMR resonances of dis-
parate intensities, corresponding to the three invertomers meso-1,
meso-2 and DL with four corresponding 77Se or 125Te resonances
(the meso forms have equivalent SeMe/TeMe groups either syn or
anti to the Mn–Cl unit, whilst in the DL form two resonances of
equal intensity are seen) [25,26]. As is common in complexes of
manganese carbonyl halides, the resonances of the carbonyl groups
in the 13C{1H} NMR spectra and the 1H NMR resonances are exten-
sively broadened by the quadrupolar manganese nucleus and the
latter in particular provide little useful data. The two cyclopro-
pyl-based ligands generate six-membered chelate rings and are
directly comparable to the complexes of MeE(CH2)3EMe (E = Se,
Te), and comparison of the carbonyl stretching frequencies in the
IR spectra, the 55Mn chemical shifts, and the coordination shifts
in the 77Se and 125Te NMR spectra, show very similar trends
[25,26], the cyclopropyl unit in the ligand backbone having mini-
mal spectroscopically identifiable effects at the metal centre, and
there is no evidence in these systems of any reaction at the
three-membered ring.
reaction of (CH2)2C(CH2SeMe)2 with MeI in warm acetone solution,
which was expected to lead to the corresponding quaternary deriv-
ative [
(CH SeMe ) ]I , as observed with other aliphatic
(CH2)2C
2
2 2 2
diselenoethers [19]. Unexpectedly, the selenium-containing prod-
uct of this reaction was identified as [Me3Se]I from the 77Se NMR
resonance at +256 (lit. [9] +253), and the major feature in the ES+
mass spectrum at m/z = 125 [Me3Se]+. Crystals obtained from the
solution were also confirmed to be [Me3Se]I by an X-ray study.
The structure has previously been reported [10] and as our data
are in excellent agreement, it is not discussed further. The [Me3Se]I
is not a minor by-product since the 77Se NMR spectrum of the bulk
product showed no other significant selenium species.
A related rearrangement was observed on reaction of o-
C6H4(CH2SeMe)2 with MeI. In this case the major products were
the selenonium species [o-C6H
ion in the former species has been obtained previously from reac-
tion of the diselenoether with GaCl3 or InCl3 [20,21], where it was
Me]I and [Me3Se]I. The cat-
4(CH2)2Se
isolated as [o-C6H
Me][MCl4] (M = Ga or In) and character-
4(CH2)2Se
ised by an X-ray structure (Ga salt), its characteristic 77Se chemical
shift and by ES+ mass spectrometry. In the present iodide salt the

W. Levason et al. / Journal of Organometallic Chemistry 695 (2010) 1346–1352
1351
+
+
SeMe2
SeMe
SeMe
SeMe
MeI
SeMe
+
Me2Se
MeI
[Me3Se]I
Scheme 1.
Fig. 3. Structure of [Mn(CO) Cl{
(CH TeMe) }] showing the numbering
2 2
(CH2)2C
3
scheme adopted. Ellipsoids are drawn at the 50% probability level and H atoms
have been omitted for clarity.
Fig. 4. Structure of the cation in [Ru(p-cymene)Cl{
(CH TeMe) }][PF ] show-
(CH2)2C
2
2
6
Red crystals of fac-[Mn(CO)3Cl{(CH2)2C(CH2TeMe)2}] obtained
from CHCl3 solution were found to contain the DL form (Fig. 3,
Table 2). The angles about the manganese centre are very close to
the idealised 90°, with d(Mn–C) shorter trans to Cl (1.785(4) Å) than
trans to Te (1.806(4), 1.813(4) Å). The Mn–Te bond lengths are very
similar to those in other structurally characterised telluroethercom-
ing the numbering scheme adopted. Ellipsoids are drawn at the 50% probability
level and H atoms have been omitted for clarity. The numbering scheme adopted for
Se-containing cyclopropyl ligand is the same in the Ru and Os compounds.
a considerable chemical shift range, reflecting the orientations of
plexes
with
manganese
carbonyl,
e.g.
fac-[Mn(CO)3Cl
the EMe groups with respect to the p-cymene and Cl ligands, and
{o-C6H4(TeMe)2}] and fac-[Mn(CO)3{MeC(CH2TeMe)3}][CF3SO3]
[26]. The constrained geometry of the cyclopropane ring (e.g.
C2ꢀC1ꢀC3 = 59.7°) is compensated for by a widening of the
C4ꢀC1ꢀC6 angle within the chelate ring (116.7°), leading to Te–
Mn–Te = 89.62(2)°.
are also moderately solvent dependent, for example in [RuCl(g6
-
p-cymene){(CH2)2C(CH2SeMe)2}]+, the chemical shifts are ꢄ7–
10 ppm to lower frequency in CH3CN compared to CH2Cl2 solution.
The coordination shifts in the 77Se and 125Te spectra are greater for
corresponding Ru complexes than for the Os analogues as expected
[2].
Crystals of three Ru and Os complexes were obtained and the
structures (Fig. 4, Tables 1 and 3) show they are isomorphous
(P212121) with meso coordinated chalcogenenoethers. The i-propyl
group in the p-cymene lies on the opposite side of the ME2 plane to
the chalcogenoether methyl groups.
3.2.2. Ruthenium and osmium complexes
The [M(g
6-p-cymene)Cl]+ (M = Ru or Os) units also proved to be
suitable metal fragments to bind the chalcogenoethers, giving ro-
bust and soluble complexes and without reaction at the cyclopro-
pyl rings. The reaction of two molar equivalents of
(CH2)2C(CH2EMe)2 (E = Se or Te) with [{MCl2(
ethanol, followed by addition of [NH4][PF6] gave good yields of or-
ange (E = Se) or red (E = Te) complexes [MCl(
6-p-cyme-
g
6-p-cymene)}2] in
Cyclic voltammetry measurements were undertaken on solu-
tions
of
[MCl(g
6-p-cymene){(CH2)2C(CH2EMe)2}][PF6]
in
g
0.1 mol dmꢀ3 nBu4NBF4 in dry MeCN. The voltammograms each
show an irreversible oxidation at +0.90 (M = Ru, E = Se), +1.01
(M = Ru, E = Te) and +1.10 V (M = Os, E = Se) versus [Fe(Cp)2]/
[Fe(Cp)2]+ at a scan-rate of 0.1 V sꢀ1 (the Os telluroether complex
was not sufficiently soluble in the base electrolyte solution). These
processes are attributed to irreversible MII/III couples. Electrochem-
ical data are available for several Ru and Os complexes with sele-
noether and telluroether ligands. These are mostly of the form
trans-[MX2(dichalcogenoether)2] [27], and [RuX2(tetraselenoe-
ther)] [28]. Such species usually exhibit reversible II/III redox cou-
ples with E1/2 values around 0 to +0.2 V versus [Fe(Cp)2]/[Fe(Cp)2]+,
with the E1/2 values largely insensitive to chalcogen type and
halide. The irreversibility observed for the p-cymene complexes
here is also observed for [Ru(p-cymene)Cl(SMe2)2]+/2+ [29], possi-
bly reflecting stabilisation of the low spin d6 configuration by the
arene co-ligand.
ne){(CH2)2C(CH2EMe)2}][PF6]. The complexes show ions with the
correct isotope pattern for the [MCl(
6-p-cymene)-
g
{
(CH2)2C(CH2EMe)2}]+ cation in the ES+ mass spectra.
The 1H NMR spectra are very complicated, however, both these
and the 77Se/125Te NMR spectra are fully consistent with slow
pyramidal inversion at the coordinated chalcogen donor atoms,
revealing one major meso form (probably that seen in the X-ray
structures – below), as well as minor amounts of the DL and some-
times the second meso form. For example, [OsCl(g
6-p-cyme-
ne){(CH2)2C(CH2TeMe)2}]+ shows four 125Te resonances, a major
peak at d = 159 corresponding to a meso invertomer and three
much weaker peaks due to the DL (two singlets at 185.4 and
164.5 ppm) and the second meso form (58.0 ppm). The chemical
shifts in the 77Se and 125Te NMR spectra for the stereoisomers span

1352
W. Levason et al. / Journal of Organometallic Chemistry 695 (2010) 1346–1352
(b) C. Paulmier, Selenium Reagents and Intermediates in Organic Synthesis,
4. Conclusions
Pergamon, Oxford, 1986;
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[8] J.P. Fackler, Inorg. Synth. 21 (1982) 75;
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[9] W. McFarlane, R.J. Wood, J. Chem. Soc. (A) (1972) 1397.
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1958.
The formation of (CH2)2C(CH2TeMe)2 and Me2Te2 as the only
significant products of the reaction of C(CH2Br)4 with LiTeMe has
been confirmed, and the reaction chemistry of this novel ligand
and its selenium analogue has been explored with selected metal
reagents. Some new organotellurium species have also been thor-
oughly characterised. The cyclopropyl unit seems unreactive in
[11] (a) G.M. Sheldrick, SHELXS-97, Program for Crystal Structure Solution,
University of Göttingen, Germany, 1997;
(b) G.M. Sheldrick, SHELXL-97, Program for Crystal Structure Refinement,
University of Göttingen, Germany, 1997.
[12] G.M. Sheldrick, SADABS, Absorption Correction Program, Bruker AXS Inc., 2007.
[13] H.D. Flack, Acta Crystallogr., Sect. A 39 (1983) 876.
[14] D.H. O’Brien, N. Deren, C.K. Huang, K.J. Irgolic, F.F. Knapp, Organometallics 2
(1983) 305.
metal complexation chemistry, although the
(but not the telluroether) is cleaved upon quaternisation with MeI.
(CH SeMe)
2 2
(CH2)2C
Acknowledgements
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We thank Dr. M. Jura and Dr. W. Zhang for assisting with the X-
ray data collections.
Appendix A. Supplementary material
CCDC 755214, 755215, 755216, 755217, 755218 and 755219
contain the supplementary crystallographic data for the six struc-
tures reported in the order they appear in Table 1. These data can
be obtained free of charge from The Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif. Supplemen-
tary data associated with this article can be found, in the online
version, at doi:10.1016/j.jorganchem.2010.02.010.
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