The reactivity of perfluoroaryltellurium(IV) dihalides towards cyanide, crystal structures of (C6F5)3TeCl and C6F5TeTeC6F5

Article abstract of DOI:10.1016/S0022-1139(01)00523-1

The reactivity of R₂TeHal₂ (R=C₆F₅, 4-CF₃C₆F₄; Hal=F, Cl, Br) towards AgCN and Me₃SiCN was examined. The perfluoroaryl substituted tellurium(IV) difluorides reacted wi

Full text of DOI:10.1016/S0022-1139(01)00523-1

Journal of Fluorine Chemistry 112 ꢀ2001) 207±212
The reactivity of per¯uoroaryltelluriumꢀIV) dihalides towards cyanide,
crystal structures of ꢀC6F5)3TeCl and C6F5TeTeC6F5
*
Thomas M. Klapotke , Burkhard Krumm, Peter Mayer, Kurt Polborn, Oliver P. Ruscitti
È
Department of Chemistry, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13!D), D-81377 Munich, Germany
Received 24 April 2001; accepted 31 August 2001
Dedicated to Prof. Dr. Karl O. Christe on the occasion of his 65th birthday
Abstract
The reactivity of R2TeHal2 ꢀR ˆ C6F5, 4-CF3C6F4; Hal ˆ F, Cl, Br) towards AgCN and Me3SiCN was examined. The per¯uoroaryl
substituted telluriumꢀIV) di¯uorides reacted with AgCN and Me3SiCN to give the telluriumꢀIV) dicyanides ꢀC6F5)2TeꢀCN)2 ꢀ1) and
ꢀCF3C6F4)2TeꢀCN)2 ꢀ2). Treatment of the corresponding tellurium dichlorides and tellurium dibromides with AgCN and Me3SiCN did not
result in the formation of 1 and 2. Performing the reaction in a haloform as solvent gave the trisꢀper¯uoroaryl)telluronium halides
ꢀC6F5)3TeCl ꢀ3), ꢀC6F5)3TeBr ꢀ4), ꢀCF3C6F4)3TeCl ꢀ5) and ꢀCF3C6F4)3TeBr ꢀ6), whereas the counter ion of the telluronium ion depended on
the used solvent, CHCl3 or CHBr3. All new compounds were investigated by analytical and spectroscopic methods. The constitution of 3±6
was con®rmed by the determination of the crystal structure of 3. The reaction of C6F5Li with I2 led mainly to the monotelluride ꢀC6F5)2Te
and gave the hoped-for ditelluride C6F5TeTeC6F5 ꢀ7) only as a by-product. The crystal structure of 7 was determined. # 2001 Elsevier
Science B.V. All rights reserved.
Keywords: Cyanide; Per¯uoroaryl; Tellurium; X-ray crystallography
1. Introduction
diorgano ditellurides seem to be problematic. Photochemical
syntheses are reported for C6F5TeTeC6F5 [15] and CF3Te-
TeCF3 [16,17], compounds that are not accessible by the
usual methods to prepare ditellurides. Because of the poor
reproducibility of the photolytic reaction to give C6F5Te-
TeC6F5 [18], we decided to re-examine this compound and
search for alternative routes of preparation.
The family of telluriumꢀIV) dipseudohalides is limited to
few examples, such as ꢀC6H5)2TeꢀNCS)2 [1,2], Cl2TeꢀNSO)2
[3], ꢀC6F5)2TeꢀNSO)2 [4] and ꢀCF3)2TeꢀNSO)2 [5]. Further-
more the ionic triphenyltelluroniumꢀIV) pseudohalides
Ph3TeX ꢀX ˆ OCN, SCN, N3, CN) are known [6]. The
preparation of a ¯uorinated derivative, ꢀC6F5)3TeCl, by
reaction of C6F5Li with TeCl4 [7], was shown to be not
reproducible in our studies. Recently, we reported about the
synthesis of some ¯uorinated and non-¯uorinated diorga-
notelluriumꢀIV) diazides and organotelluriumꢀIV) triazides
[8,9], potentially explosive compounds. So far, diorgano-
telluriumꢀIV) dicyanides are still elusive compounds and no
data available. In this contribution, we wish to report our
studies on the reactivity of per¯uoroaryltelluriumꢀIV) diha-
lides R2TeHal2 ꢀR ˆ C6F5, CF3C6F4; Hal ˆ F, Cl, Br)
towards AgCN and Me3SiCN.
2. Results and discussion
The reaction of R2TeF2 ꢀR ˆ C6F5, CF3C6F4) with AgCN
or Me3SiCN gave the bisꢀper¯uoroaryl)telluriumꢀIV) dicya-
nides ꢀC6F5)2TeꢀCN)2 ꢀ1) and ꢀCF3C6F4)2TeꢀCN)2 ꢀ2) in
good yields ꢀEq. ꢀ1)). No difference in the reactivity employ-
ing AgCN or Me3SiCN in this reaction was observed.
CH2CL2
!
R2TeF2 ‡ 2 M e SiCN
R2TeꢀCN†
3
2
À2Me3SiF
Although, the synthesis of aliphatic and aromatic diorga-
noditellurides is well known [10±14], routes to per¯uorinated
R ˆ C6F5ꢀ1†; CF3C6F4ꢀ2†
ꢀ1)
With 1 and 2 the first members of diorganotelluriumꢀIV)
dicyanides were prepared. They are stable in the solid state,
but very sensitive against moisture and decompose rapidly
on air and in solution mainly under formation of the
* Corresponding author. Tel.: ‡49-89-2180-7491;
fax: ‡49-89-2180-7492.
E-mail address: thomas.m.klapoetke@cup.uni-muenchen.de
È
ꢀT.M. Klapotke).
0022-1139/01/$ ± see front matter # 2001 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 1 1 3 9 ꢀ 0 1 ) 0 0 5 2 3 - 1

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T.M. Klapotke et al. / Journal of Fluorine Chemistry 112 !2001) 207±212
208
monotellurides R2Te ꢀconfirmed by 19F and 125Te NMR) and
probably dicyanogen. Somewhat surprisingly they are less
stable than the corresponding diorganotelluriumꢀIV) dia-
zides, which is probably due to the presence of four tellurium
carbon bonds. A general tendency of C4Te compounds to
decompose into C2Te and C2 is reported and a similar
behavior was also observed in our case with C2TeꢀCN)2.
The tetra-aryl derivatives Ph4Te and ꢀC6F5)4Te [19,20] tend
to decompose into diaryltellurium and the corresponding
biphenyls. The dicyanides 1 and 2 can be identified by the
presence of nCN vibrations which are of diagnostic value. In
the Raman spectrum 1 reveals two peaks of medium inten-
sity for nCN at 2155 and 2148 cmÀ1, whereas nCN for 2 three
peaks with strong intensity at 2165/2157/2140 cmÀ1 are
observed. For nTeC peaks are found at 492/444/387 cmÀ1
for 1 and 503/440/391 cmÀ1 for 2.
complete conversion a large excess of AgCN is required.
The reactions with Me3SiCN were signi®cantly slower. It
was found that the type of the halogen in the product
depends on the used solvent ꢀEq. ꢀ2)) and not on the tell-
uriumꢀIV) dihalide.
ꢀ2)
where R ˆ C6F5 ꢀ3,4), CF3C6F4 ꢀ5,6), Hal ˆ Cl; Br.
With chloroform as solvent always chlorides 3 and 5 were
formed, even when the corresponding dibromides were
reacted with AgCN. In case of bromoform as solvent always
the bromides 4 and 6 were isolated. This indicates that the
halide of the products is originated from the solvent. During
the long reaction time, up to 14 days in case of the formation
However, treatment of R2TeCl2 and R2TeBr2 ꢀR ˆ C6F5,
CF3C6F4) with AgCN or Me3SiCN resulted in a more
complex reaction under formation of trisꢀper¯uoroaryl)
telluroniumꢀIV) halides ꢀC6F5)3TeCl ꢀ3), ꢀC6F5)3TeBr ꢀ4),
ꢀCF3C6F4)3TeCl ꢀ5) and ꢀCF3C6F4)3TeBr ꢀ6). For a
of the telluronium chlorides, C6F5H was observed in the 19
F
NMR spectrum. Unfortunately no other products, that might
Fig. 1. ꢀa) ORTEP plot of the molecular structure of 3 with thermal ellipsoids at 50% probability level. Fluorine atoms and benzene are omitted for clarity.
Ê
Selected bond lengths ꢀA) and angles ꢀ8): Teꢀ1)±Cꢀ1) 2.108ꢀ4); Teꢀ1)±Cꢀ7) 2.207ꢀ4); Teꢀ1)±Cꢀ13) 2.119ꢀ4); Teꢀ1)±Clꢀ1) 2.670ꢀ2); Teꢀ1† Á Á Á Clꢀ2A† 3.47;
Cꢀ1)±Teꢀ1)±Cꢀ7) 87.8ꢀ2); Cꢀ1)±Teꢀ1)±Cꢀ13) 102.3ꢀ2); Cꢀ1)±Teꢀ1)±Clꢀ1) 85.1ꢀ2); Cꢀ7)±Teꢀ1)±Cꢀ13) 93.5ꢀ2); Cꢀ7)±Teꢀ1)±Clꢀ1) 171.1ꢀ2);
Cꢀ1†ÀTeꢀ1† Á Á Á Clꢀ2A† 143.5; Cꢀ7†ÀTeꢀ1† Á Á Á Clꢀ2A† 72.2; Cꢀ13†ÀTeꢀ1† Á Á Á Clꢀ2A† 108.07; Clꢀ1†ÀTeꢀ1† Á Á Á Clꢀ2A† 116.5. ꢀb) View of the TeC3Cl
skeletons of 3.

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T.M. Klapotke et al. / Journal of Fluorine Chemistry 112 !2001) 207±212
209
Ê
The tellurium carbon distances Teꢀ1)±Cꢀ1) 2.108ꢀ4) A,
give more insight in this reaction, could be detected. In other
solvents such as CH2Cl2, CH3CN or THF no reaction at all
occurred. The telluronium halides 3±6 show in the vibra-
tional spectra very similar values for the nTeHal and nTeC
vibrations likely to a partial ionic character of these com-
pounds. This makes an exact assignment for nTeCl, nTeBr and
nTeC dif®cult. As one would expect, the 125Te NMR reso-
nances of 3±6 are also very similar and found within a narrow
range ꢀd ˆ 400±380). They are clearly identi®ed by their
elemental analysis in addition to the crystal structure of 3.
For a possible alternative synthesis of the ditelluride
C6F5TeTeC6F5 ꢀ7) the generation of C6F5TeLi by the reac-
tion of C6F5Li and Te was attempted, as is described for
C6H5Li and Te [21]. Lithium penta¯uorophenyltellurolate
was reacted with iodine to give the intermediate C6F5TeI.
The tellurenyl iodide should then decompose into the ditel-
luride and iodine, due to the low stability of organotellurenyl
halides [22,23]. However, the formed C6F5TeI reacted
immediately with still remaining C6F5Li to the monotellur-
ide ꢀC6F5)2Te, which was obtained as the main product
ꢀEq. ꢀ3)). Bisꢀpenta¯uorophenyl) ditelluride ꢀ7) was identi-
®ed and isolated only as a minor product with yields lower
than 4%.
Ê
Ê
Teꢀ1)±Cꢀ7) 2.207ꢀ4) A and Teꢀ1)±Cꢀ13) 2.119ꢀ4) A are
in the usual range [24], with one signi®cant longer axial
TeC bond. The tellurium chlorine distance Teꢀ1)±Clꢀ1)
Ê
2.670ꢀ2) A is slightly elongated compared to the Te Cl bond
Ê
in R2Te Cl2 derivatives ꢀ2.4±2.5 A [24,25]). In fact this does
not indicate a total ionic character, such as found in Ph3 TeX
derivatives, qualifying the term ``telluronium halide'' only
in part with our per¯uoroaryl substituents. The distances
from a tellurium atom to a chlorine atom of a second
Ê
Ê
molecule is Teꢀ1A† Á Á Á Clꢀ1† 3.47 A ꢀrvdW ˆ 3:81 A) and
in the range expected for tellurium chlorine interactions
ꢀFig. 1a). This interaction, including the free electron pair
at Te, leads to a distorted octahedral coordination of the
tellurium atom ꢀFig. 1b).
The ditelluride 7 crystallizes in the trigonal space group R3
Ê
with Z ˆ 18 ꢀFig. 2). The Te±Te distance is with 2.7028ꢀ5) A
Ê
slightly longer as found in CF3TeTeCF3 ꢀ2.669ꢀ3) A) [26]
Ê
and similar as in C6H5TeTeC6H5 ꢀ2.712ꢀ2) A) [27]. The
Ê
Te±C distances in 7 ꢀ2.124ꢀ3) A) are again shorter compared
Ê
to those of CF3TeTeCF3 ꢀ2.186ꢀ6)/2.175ꢀ6) A), similar as in
Ê
C6H5TeTeC6H5 ꢀ2.09ꢀ1)/2.16ꢀ1) A). The C±Te±Te angles in
7 ꢀ98.94ꢀ8)/98.35ꢀ8)8) are found to be similar as in C6H5-
TeTeC6H5 ꢀ100.3ꢀ5)/97.4ꢀ4)8), but larger than in CF3Te-
TeCF3 ꢀ96.3ꢀ1)/95.3ꢀ1)8). The dihedral angle C±Te±Te±C in
7 is larger ꢀ91.8ꢀ1)8) than in CF3TeTeCF3 ꢀ88.3ꢀ2)8) or
C6H5TeTeC6H5 ꢀ88.558). This is probably due to the larger
sterical demand of the ¯uorine atoms of the C6F5 groups
compared to the CF3 groups in CF3TeTeCF3 and the phenyl
groups in C6H5TeTeC6H5. Crystal data and structure re®ne-
ments for 3 and 7 are given in Table 1.
1:Te=2:I2=Et2O=25 ꢁC
C6F5LiÀÀÀÀÀÀÀÀÀÀÀÀ! ꢀC6F5†2Te ‡ C6F5TeTeC6F5
ꢀ3)
ÀLiI
ꢀ7†<4%
60À70%
2.1. Crystal structures
The telluronium chloride 3 crystallizes in the monoclinic
space group P21 with Z ˆ 4 with benzene ꢀ1/2) as solvate.
Ê
Fig. 2. ORTEP plot of the molecular structure of 7 with thermal ellipsoids at 50% probability level. Selected bond lengths ꢀA) and angles ꢀ8): Teꢀ1)±Cꢀ11)
2.124ꢀ3); Teꢀ1)±Teꢀ2) 2.7028ꢀ5); Teꢀ2)±Cꢀ12) 2.124ꢀ3); C±F 1.329ꢀ5)±1.341ꢀ4); Cꢀ11)±Teꢀ1)±Teꢀ2) 98.94ꢀ8); Teꢀ1)±Teꢀ2)±Cꢀ12) 98.35ꢀ8); Cꢀ11)±Teꢀ1)±
Teꢀ2)±Cꢀ12) 91.8ꢀ1).

È
T.M. Klapotke et al. / Journal of Fluorine Chemistry 112 !2001) 207±212
210
Table 1
Crystal data and structure refinements for 3 and 7
3
7
Empirical formula
Formula weight
Temperature ꢀK)
Crystal size ꢀmm)
Crystal color and habit
Crystal system
C
21H3ClF15Te
C12F10Te2
589.31
200ꢀ3)
703.28
295ꢀ2)
0.20 Â 0.33 Â 0.43
Colorless platelet
Monoclinic
P21/c
0.35 Â 0.30 Â 0.25
Red prismatic
Trigonal
Space group
Ê
a ꢀA)
Ê
b ꢀA)
R3
10.946ꢀ3)
21.883ꢀ7)
9.415ꢀ6)
14.4006ꢀ7)
14.4006ꢀ7)
36.281ꢀ2)
Ê
c ꢀA)
b ꢀ8)
g ꢀ8)
102.00ꢀ4)
120.00
Ê 3
Volume ꢀA )
Z
2206ꢀ2)
4
6516ꢀ3)
18
r ꢀcalcd.) ꢀg cmÀ3
)
2.118
2.703
m ꢀmmÀ1
Fꢀ0 0 0)
)
1.605
4.136
1332
3688
4788
7807
Reflections collected
Independent reflections
Observed reflections
Data/restraints/parameters
Goodness-of-fit on F2
R1, wR2 [I > 2sꢀI)]
R1, wR2 ꢀall data)
3452 ꢀRint ˆ 0.0112)
3002
2763 ꢀRint ˆ 0.0265)
2763
3452/0/344
1.272
2763/0/217
1.140
0.0318, 0.0791
0.0390, 0.0815
0.626/À0.739
0.0226, 0.0532
0.0246, 0.0542
0.656/À0.420
Ê 3
Larger diffraction peak/hole ꢀe/A )
3. Experimental section
at 25 8C, and is washed with 2 ml cold ꢀÀ18 8C) CH2Cl2.
The cyanides were obtained as colorless solids.
3.1. General experimental procedures
3.2.1. !C6F5)2Te!CN)2 !1)
All reactions were carried out under nitrogen as inert gas
atmosphere using standard Schlenk techniques. Solvents
were dried by standard methods. Commercially available
chemicals were used as received. The diaryltelluriumꢀIV)
dihalides were synthesized according to [24]. IR spectra
were recorded as nujol mulls or as neat liquids between KBr
plates on a Nicolet 520 FT±IR spectrometer and on a Perkin-
Elmer Spectrum One FT±IR spectrometer, Raman spectra
on a Perkin-Elmer 2000 NIR FT-Raman spectrometer. The
NMR spectra were recorded on Jeol 400Eclipse and EX400
instruments; chemical shifts are with respect to ꢀCH3)4Si
ꢀ13C), CFCl3 ꢀ19F), CH3NO2 ꢀ14N) and ꢀCH3)2Te ꢀ125Te).
The 13C NMR spectra were recorded ¯uorine decoupled
except for 7. Mass spectral data were obtained from a
Finnigan MAT 90 instrument. Elemental analysis were
performed in-house.
Yield 85%, mp 98±101 8C. Raman: n ˆ 2155/2148 ꢀ52/
50, nCN), 1640 ꢀ21), 1521 ꢀ10), 1401 ꢀ11), 1154 ꢀ12), 1093
ꢀ14), 804 ꢀ15), 771 ꢀ12), 640 ꢀ17), 619 ꢀ16), 586 ꢀ60), 492
ꢀ100), 444 ꢀ53), 385 ꢀ87), 353 ꢀ48), 317 ꢀ40), 281 ꢀ53), 229
ꢀ29), 200 ꢀ75), 130 ꢀ57) cmÀ1. IR: n ˆ 2143 m, 1638 s, 1593
m, 1502 vs, 1519 vs, 1397 s, 1291 m, 1260 m, 1090 s, 1038
w, 1005 m, 978 s, 802 m, 619 m, 580 m cmÀ1 19F NM R
.
[C6D6]: d ˆ À125.0/À127.4 ꢀ2F, m, 2/6-F), À140.1 ꢀ1F, tt,
4
3JFF ˆ 21:8 Hz, JFF ˆ 6:7 Hz, 4-F), À155.6 ꢀ2F, m, 3-F).
13C NM R [CD6]: d ˆ 146.3 ꢀC-2), 144.0 ꢀC-4), 137.2 ꢀC-
6
3), 122.7 ꢀCN), 99.7 ꢀC-1). 14N NM R ꢀDn1/2 ꢀHz)) [C6D6]:
d ˆ À121 ꢀ110, CN). 125Te{19F} NMR [C6D6]: d ˆ 177.
‡
EIMS 70 eV, m/z ꢀrel. int.): 594 [C6F5TeTeC6F5] ꢀ3), 464
[MÀ2CN] ꢀ97), 297 [C6F5Te] ꢀ100), 167 [C6F5] ꢀ6), 149
‡
‡
‡
‡
‡
‡
[TeF] ꢀ15), 130 [Te] ꢀ15), 117 [C3F5] ꢀ34). Anal. Calcd.
for C14F10N2Te: C, 32.7; N, 5.4. Found: C, 32.0; N, 4.1.
3.2. General procedure for the preparation of
!C6F5)2Te!CN)2 !1) and !CF3C6F4)2Te!CN)2 !2)
3.2.2. !CF3C6F4)2Te!CN)2 !2)
Yield 81%, mp 111±114 8C ꢀdec.). Raman: n ˆ 2165/
2157/2140 ꢀ39/85/51 nCN), 1647 ꢀ16), 1607 ꢀ7), 1493 ꢀ7),
1461 ꢀ10), 1424 ꢀ8), 1332 ꢀ13), 1154 ꢀ8), 992 ꢀ7), 926 ꢀ17),
789 ꢀ15), 717 ꢀ39), 538 ꢀ16), 503 ꢀ100), 440 ꢀ50), 391 ꢀ71),
374 ꢀ90), 342 ꢀ27), 299 ꢀ71), 280 ꢀ73), 189 ꢀ66), 145 ꢀ42),
120 ꢀ120) cmÀ1. IR: n ˆ 2161 w, 2153 m, 2141 w, 2135 w,
1646 m, 1603 m, 1322 vs, 1298 m, 1257 m, 1194 m, 1174 m,
Into a solution of 1.6 mmol R2Te in 8 ml CH2Cl2 are
added at 0 8C within 5 min 1.7 mmol XeF2. After stirring for
15 min the mixture is allowed to warm up to 25 8C. After
further 20 min 3.4 mmol Me3SiCN is added and a colorless
solid precipitated. The solid is separated after stirring for 1 h

È
T.M. Klapotke et al. / Journal of Fluorine Chemistry 112 !2001) 207±212
211
1044 w, 981 s, 925 s, 854 w, 788 m, 715 s, 666 w, 647 m, 547
w, 425 m cmÀ1
À141.3 ꢀ2F, m, 3-F). 13C{19F} NMR [CDCl3]: d ˆ 146.4
ꢀ2JTeC ˆ 27:9 Hz, C-2), 144.3 ꢀC-4), 138.1 ꢀ3JTeC ˆ 7:9 Hz,
C-3), 105.2 ꢀ1JTeC ˆ 275:3 Hz, C-1). 125Te NMR [CDCl3]:
.
19F NM R [C D6]: d ˆ À56.8 ꢀ3F, m, 4-CF3),
6
À122.1/À125.1 ꢀ2F, m, 2/6-F), À133.9 ꢀ2F, m, 3-F). Other
‡
NMR spectra were not possible due to the extremely low
solubility of 2. EIMS 70 eV, m/z ꢀrel. int.): 564 [MÀ2CN]
d ˆ 390 ꢀm). EIMS 70 eV, m/z ꢀrel. int.): 781 [MÀCl] ꢀ10),
‡
‡
‡
762 [MÀClÀF] ꢀ5), 599 [MÀCF3C6F4] ꢀ5), 564
‡
‡
‡ ‡
ꢀ100), 545 [MÀ2CN±F] ꢀ22), 434 [ꢀCF3C6F4)2] ꢀ5), 415
[ꢀCF3C6F4)2Te]
ꢀ100), 545 [MÀClÀF]
ꢀ10), 347
‡
‡
‡
‡
‡
[ꢀCF3C6F4)2±F]
ꢀ4), 347 [CF3C6F4Te]
ꢀ81), 217
[CF3C6F4Te] ꢀ55), 252 [CF3C6F4Cl] ꢀ3), 217 [CF3C6F4]
ꢀ15), 198 [CF3C6F3] ꢀ10), 179 [CF3C6F2] ꢀ5), 130 [Te]
‡
‡
‡
‡
‡
‡
[CF3C6F4] ꢀ12), 198 [CF3C6F3] ꢀ26), 179 [CF3C6F2]
‡
‡
‡
ꢀ48), 149 [TeF] ꢀ11), 130 [Te] ꢀ10), 117 [C5F3] ꢀ8), 93
‡
ꢀ20). Anal. Calcd. for C21ClF21Te: C, 31.0; Cl, 4.4. Found:
C, 31.2; Cl, 4.4.
‡
‡
[C3F3] ꢀ8), 69 [CF3] ꢀ7), 52 [ꢀCN)2] ꢀ5). Anal. Calcd. for
C16F14N2Te: C, 31.3; N, 4.6. Found: C, 30.7; N, 4.1.
3.4. General procedure for !C6F5)3TeBr !5) and
!CF3C6F4)3TeBr !6)
3.3. General procedure for !C6F5)3TeCl !3) and
!CF3C6F4)3TeCl !4)
Into a solution of 8.5 mmol R2TeX2 ꢀX ˆ Cl, Br) in
120 ml CHBr3 are added 101.7 mmol AgCN and the mixture
is stirred at 25 8C for 6 days ꢀmonitored by 19F NM R
spectroscopy). The solid is separated and washed three
times with 10 ml CHBr3. The solvent is removed under
vacuum from the combined extracts, and the remaining
residue is recrystallized from benzene to yield colorless
solids.
Into a solution of 8.5 mmol R2TeX2 ꢀX ˆ Cl, Br)
in 120 ml CHCl3 are added 101.7 mmol AgCN and the
mixture is stirred at 25 8C for 14 days ꢀmonitored by 19F
NMR spectroscopy). The solid is separated and washed
three times with 10 ml CHCl3. The solvent is removed under
vacuum from the combined extracts, and the remaining
residue is recrystallized from benzene to yield colorless
solids.
3.4.1. !C6F5)3TeBr !5)
3.3.1. !C6F5)3TeCl !3)
Yield 35%, mp 205À206 8C ꢀdec.). Raman: n ˆ 1637
ꢀ35), 1599 ꢀ22), 1440 ꢀ13), 1408 ꢀ17), 1373 ꢀ10), 1273 ꢀ21),
1172 ꢀ14), 1081 ꢀ30), 990 ꢀ28), 946 ꢀ19), 681 ꢀ23), 657 ꢀ25),
613 ꢀ17), 585 ꢀ55), 490 ꢀ100), 443 ꢀ31), 385 ꢀ34), 349 ꢀ36),
283 ꢀ22), 233 ꢀ9), 198 ꢀ44), 168 ꢀ62), 120 ꢀ13) cmÀ1. IR:
n ˆ 1638 m, 1518 vs, 1500 vs, 1474 vs, 1452 m, 1396 m,
1385 m, 1369 s, 1337 m, 1288 m, 1275 m, 1148 m, 1137 m,
1091 s, 1079 s, 1040 w, 1032 w, 1006 m, 977 s, 969 s, 797 m,
Yield 38%, mp 175±176 8C. Raman: n ˆ 1638 ꢀ38), 1602
ꢀ22), 1580 ꢀ21), 1519 ꢀ23), 1480 ꢀ21), 1402 ꢀ24), 1372 ꢀ22),
1279 ꢀ26), 1145 ꢀ25), 1090 ꢀ27), 1074 ꢀ30), 1043 ꢀ24), 802
ꢀ26), 775 ꢀ36), 619 ꢀ36), 587 ꢀ71), 490 ꢀ100), 444 ꢀ70), 385
ꢀ65), 349 ꢀ56), 282 ꢀ43), 240 ꢀ41), 229 ꢀ41), 205 ꢀ82), 189
ꢀ62), 172 ꢀ82), 126 ꢀ60) cmÀ1. IR: n ˆ 1738 w, 1718 w, 1637
s, 1553 m, 1516 vs, 1500 vs, 1493 vs, 1475 vs, 1423 w, 1397
m, 1367 s, 1336 w, 1292 w, 1279 m, 1261 w, 1180 m, 1154
m, 1134 w, 1090 vs, 1077 vs, 1047 m, 1030 m, 1003 m, 978
vs, 799 m, 760 w, 748 w, 715 w, 616 m, 584 m, 484 m, 378 m,
684 m, 608 w, 584 w, 483 w, 379 w, 312 w cmÀ1 19F NM R
.
[CDCl3]: d ˆ À126.1 ꢀ2F, m, 2-F), À144.1 ꢀ1F, t,
3JFF ˆ 20:3 Hz, 4-F), À155.7 ꢀ2F, m, 3-F). 13C{19F}
NMR [CDCl3]: d ˆ 146.7 ꢀ2JTeC ˆ 28:1 Hz, C-2), 144.5
360 m, 348 w, 312 w cmÀ1
.
19F NMR [CDCl3]: d ˆ À126.5
3
ꢀ2F, m, 2-F), À144.5 ꢀ1F, t, JFF ˆ 19:1 Hz, 4-F), À156.0
ꢀ2F, m, 3-F). 13C{19F} NMR [CDCl3]: d ˆ 146.7
ꢀ2JTeC ˆ 28:1 Hz, C-2), 144.4 ꢀC-4), 137.8 ꢀ3JTeC ˆ 8:1
Hz, C-3), 106.0 ꢀ1JTeC ˆ 275:6 Hz, C-1). 125Te NMR
[CDCl3]: d ˆ 384 ꢀm). EIMS 70 eV, m/z ꢀrel. int.): 631
ꢀC-4), 137.8 ꢀ3JTeC ˆ 7:7 Hz, C-3), 104.6 ꢀ1JTeC
ˆ
272:5 Hz, C-1). 125Te NMR [CDCl3]: d ˆ 398 ꢀm). EIMS
‡
‡
70 eV, m/z ꢀrel. int.): 631 [MÀBr] ꢀ11), 612 [MÀBr-F]
‡
‡
ꢀ3), 464 [ꢀC6F5)2Te] ꢀ79), 445 [C6F5Te] ꢀ4), 334
[ꢀC6F5)2] ꢀ13), 297 [C6F5Te] ꢀ100), 204 [C3F2Te]
‡
‡
‡
‡
‡
‡
‡
‡
‡
[MÀCl] ꢀ10), 499 [MÀC6F5] ꢀ5), 464 [ꢀC6F5)2Te]
ꢀ11), 167 [C6F5] ꢀ99), 148 [C6F4] ꢀ24), 130 [Te] ꢀ25),
‡
‡
‡
ꢀ100), 334 [ꢀC6F5)2] ꢀ5), 297 [C6F5Te] ꢀ70), 202
[C6F5Cl] ꢀ5), 167 [C6F5] ꢀ30), 148 [C6F4] ꢀ15), 130
117 [C5F3] ꢀ30). Anal. Calcd. for C18BrF15Te: C, 35.2; Br,
13.0. Found: C, 35.0; Br, 12.2.
‡
‡
‡
‡
[Te] ꢀ20). Anal. Calcd. for C18ClF15Te: C, 32.5; Cl, 5.3.
Found: C, 32.7; Cl, 5.4.
3.4.2. !CF3C6F4)3TeBr !6)
Yield 31%, mp 285±288 8C. Raman: n ˆ 1646 ꢀ23), 1600
ꢀ22), 1595 ꢀ20), 1396 ꢀ14), 1326 ꢀ11), 1181 ꢀ12), 1048 ꢀ5),
994 ꢀ16), 786 ꢀ29), 716 ꢀ42), 691 ꢀ33), 501 ꢀ100), 443 ꢀ69),
410 ꢀ63), 312 ꢀ67), 282 ꢀ31), 164 ꢀ47), 121 ꢀ44) cmÀ1. IR:
n ˆ 1644 m, 1600 m, 1597 w, 1493 w, 1474 m, 1398 m, 1326
m, 1293 m, 1212 m, 1180 w, 1049 w, 995 vs, 926 s, 787 m,
715 s, 646 w, 688 w, 499 w ꢀcmÀ1). 19F NMR [CDCl3]:
d ˆ À57.5 ꢀ3F, t, 4JFF ˆ 23:0 Hz, 4-CF3), À136.9 ꢀ2F, m, 2-
F), À140.9 ꢀ2F, m, 3-F). 13C{19F} NMR [CDCl3]: d ˆ 146.4
ꢀ2JTeC ˆ 28:0 Hz, C-2), 144.6 ꢀC-4), 137.7 ꢀC-3), 104.3
3.3.2. !CF3C6F4)3TeCl !4)
Yield 38%, mp 262±263 8C. Raman: n ˆ 1646 ꢀ25), 1602
ꢀ20), 1595 ꢀ20), 1396 ꢀ15), 1325 ꢀ16), 1180 ꢀ12), 1049 ꢀ7),
994 ꢀ15), 783 ꢀ30), 716 ꢀ36), 690 ꢀ29), 502 ꢀ100), 443 ꢀ72),
403 ꢀ64), 308 ꢀ53), 282 ꢀ40), 163 ꢀ47), 119 ꢀ41) cmÀ1. IR:
n ˆ 1646 m, 1602 m, 1595 w, 1493 w, 1396 m, 1325 m, 1292
m, 1180 w, 1049 w, 994 vs, 924 s, 783 m, 716 s, 646 w,
690 w, 502 w cmÀ1
ꢀ3F, t, JFF ˆ 22:7 Hz, 4-CF3), À137.1 ꢀ2F, m, 2-F),
.
19F NMR [CDCl3]: d ˆ À57.7
4

È
T.M. Klapotke et al. / Journal of Fluorine Chemistry 112 !2001) 207±212
212
ꢀ1JTeC ˆ 273:0 Hz, C-1). 125Te NMR [CDCl3]: d ˆ 396 ꢀm).
Acknowledgements
‡
EIMS 70 eV, m/z ꢀrel. int.): 781 [MÀBr] ꢀ12), 762 [MÀBr-
‡
‡
Financial support of this research by the Ludwig-
Maximilians-University of Munich and the Fonds der
Chemischen Industrie is gratefully acknowledged.
F] ꢀ5), 643 [MÀCF3C6F4] ꢀ3), 564 [ꢀCF3C6F4)2Te] ꢀ66),
‡
‡
434 [ꢀCF3C6F4)2] ꢀ24), 347 [CF3C6F4Te] ꢀ100), 217
[CF3C6F4] ꢀ26), 198 [CF3C6F3] ꢀ13), 179 [CF3C6F2]
‡
‡
‡
‡
‡
ꢀ4), 130 [Te] ꢀ34), 79 [Br] ꢀ3). Anal. Calcd. for
C21BrF21Te: C, 29.4; Br, 9.3. Found: C, 28.7; Br, 8.7.
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3
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1
1
ꢀdm, JCF ˆ 244:5 Hz, C-2), 143.2 ꢀdm, JCF ˆ 256:8 Hz,
1
C-4), 136.1 ꢀdm, JCF ˆ 254:4 Hz, C-3), 79.4 ꢀtm,
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3.6. X-ray crystallography
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obtained, free of charge, on application to CCDC, 12 Union
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È
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È
[28] G.M. Sheldrick, SHELXS 86, University of Gottingen, 1986.
È
[29] G.M. Sheldrick, SHELXL 97, University of Gottingen, 1997.