Reaction of [Et4N]2[TeCr(CO)5} n] (n = 2, 3) toward electrophiles: Reactivity comparison and theoretical calculations

Article abstract of DOI:10.1021/om700789a

Reactions of [Et₄N]₂[Te(Cr(CO)₅} _n] (n = 2, 3) with a series of organic and inorganic electrophiles have been systematically studied and compared. When [Et₄N] ₂[Te{Cr(CO)₅)₂] was protonated with ~1.0 equiv of HBF₄ in MeCN, the monohydrido Te-Cr complex [Et ₄N][HTe{Cr(CO)₅)₂] ([Et₄N][1]) was obtained. However, similar protonation of [Et₄N] ₂[Te{Cr(CO)₅}₃] led to the formation of the decomposition product [Et₄N]₂[Te₂(Cr(CO) ₅}₄]. While methylation of [Et₄N] ₂[Te{Cr(CO)₅}₂] with CF₃SO ₃Me formed mono- and dimethylated products [Et₄N] [MeTe{Cr(CO)₅}₂] and Me₂Te{Cr(CO) ₅}₂ (2) stepwise, a similar reaction with [Et ₄N]₂[Te{Cr(CO)₅}₃] produced the monomethylated product [Et₄N][MeTe{Cr(CO)₅}3] (3). Further, when [Et₄N]₂[Te{Cr(CO)₅}_n] (n = 2, 3) was stirred in CH₂Cl₂ at 0°C, the Cl-functionalized products [Et₄N][ClH₂CTe{Cr(CO) ₅}_n] (n = 2, [Et₄N][4]; n = 3, [Et ₄N][5]) were produced, respectively. Similar reactions with CH ₂Cl₂ at room temperature produced corresponding CH ₂-bridged dimeric products [Et₄N]₂[CH ₂Te₂{Cr(CO)₅}_n] (n = 4; 6, [Et ₄N]₂[6]). If the bisbenzyl-containing reagent ClH ₂C(C₆H₄)₂-CH₂Cl reacted with [Et₄N]₂[Te{Cr(CO)₅}_n] (n = 2, 3), the corresponding CH₂(C₆H₄) ₂CH₂-bridged dimeric complexes [Et₄N] ₂[H₂C(C₆H₄)₂CH ₂Te₂{Cr(CO)₅}_n] (n = 4, [Et ₄N]₂[7]; n = 6, [Et₄N]₂[8]) were produced. [Et₄N]₂[Te{Cr(CO)₅}_n] (n = 2, 3) could further react with HgCl₂ in THF to give corresponding Hg-bridged products [Et₄N]₂[HgTe₂{Cr(CO) ₅)_n] (n = 4, [Et₄N]₂[9]; n = 6, [Et₄N]₂[10]). Complex 9 was found to transform to complex 10 upon its reaction with HgCl₂ in THF. Interestingly, the novel O₂-activation product [Et₄N][OTe{Cr(CO)₅} ₂] ([Et₄N][11]) was observed when [Et₄N] ₂[Te{Cr(CO)₅}₂] was bubbled with O₂ in MeCN. Complexes 1-11 were fully characterized by elemental analysis, spectroscopic methods, and/or single-crystal X-ray analysis. The nature of [Te{Cr(CO)₅}_n]^2- (n = 2, 3) and the resultant complexes were further investigated by molecular orbital calculations at the B 3LYP level of the density functional theory.

Full text of DOI:10.1021/om700789a

6184
Organometallics 2007, 26, 6184-6196
Reaction of [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) toward Electrophiles:
Reactivity Comparison and Theoretical Calculations
Minghuey Shieh,* Li-Fang Ho, Pei-Chi Chen, Miao-Hsing Hsu, Hui-Lung Chen,
Yu-Wen Guo, Yi-Wen Pan, and Yi-Chun Lin
Department of Chemistry, National Taiwan Normal UniVersity, Taipei 116, Taiwan, Republic of China
ReceiVed August 2, 2007
Reactions of [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) with a series of organic and inorganic electrophiles
have been systematically studied and compared. When [Et4N]2[Te{Cr(CO)5}2] was protonated with ∼1.0
equiv of HBF4 in MeCN, the monohydrido Te-Cr complex [Et4N][HTe{Cr(CO)5}2] ([Et4N][1]) was
obtained. However, similar protonation of [Et4N]2[Te{Cr(CO)5}3] led to the formation of the decomposition
product [Et4N]2[Te2{Cr(CO)5}4]. While methylation of [Et4N]2[Te{Cr(CO)5}2] with CF3SO3Me formed
mono- and dimethylated products [Et4N][MeTe{Cr(CO)5}2] and Me2Te{Cr(CO)5}2 (2) stepwise, a similar
reaction with [Et4N]2[Te{Cr(CO)5}3] produced the monomethylated product [Et4N][MeTe{Cr(CO)5}3]
(3). Further, when [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) was stirred in CH2Cl2 at 0 °C, the Cl-functionalized
products [Et4N][ClH2CTe{Cr(CO)5}n] (n ) 2, [Et4N][4]; n ) 3, [Et4N][5]) were produced, respectively.
Similar reactions with CH2Cl2 at room temperature produced corresponding CH2-bridged dimeric products
[Et4N]2[CH2Te2{Cr(CO)5}n] (n ) 4; 6, [Et4N]2[6]). If the bisbenzyl-containing reagent ClH2C(C6H4)2-
CH2Cl reacted with [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3), the corresponding CH2(C6H4)2CH2-bridged dimeric
complexes [Et4N]2[H2C(C6H4)2CH2Te2{Cr(CO)5}n] (n ) 4, [Et4N]2[7]; n ) 6, [Et4N]2[8]) were produced.
[Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) could further react with HgCl2 in THF to give corresponding Hg-
bridged products [Et4N]2[HgTe2{Cr(CO)5}n] (n ) 4, [Et4N]2[9]; n ) 6, [Et4N]2[10]). Complex 9 was
found to transform to complex 10 upon its reaction with HgCl2 in THF. Interestingly, the novel O2-
activation product [Et4N][OTe{Cr(CO)5}2] ([Et4N][11]) was observed when [Et4N]2[Te{Cr(CO)5}2] was
bubbled with O2 in MeCN. Complexes 1-11 were fully characterized by elemental analysis, spectroscopic
methods, and/or single-crystal X-ray analysis. The nature of [Te{Cr(CO)5}n]2- (n ) 2, 3) and the resultant
complexes were further investigated by molecular orbital calculations at the B3LYP level of the density
functional theory.
were reported.7 Because of our interest in the chemistry of main
group-transition metal carbonyl complexes,8-10 two monotel-
luride-bridged dichromium and trichromium anionic species
[Te{Cr(CO)5}n]2- (n ) 2, 3) were successfully synthesized from
the reaction of Te powder with Cr(CO)6 in KOH/MeOH
solutions.10a These two species can be isolated as [Et4N]+ salts
and have been proven to be important intermediates for the
Introduction
Soluble transition-metal sulfide complexes have been exten-
sively studied because of their relevance to biological and
industrial catalysts. In contrast, the chemistry of the analogues
of tellurium, the heavier congener of sulfur, has been much less
explored.1 While the chemistry of iron-containing carbonyl
telluride complexes has been well studied, the study of
chromium-containing carbonyl tellurides remained relatively rare
mainly due to a lack of practical synthetic methodologies.1-3
For the Te-Cr-CO system, the structurally characterized
examples were limited to some open structures such as
(6) Blacque, O.; Brunner, H.; Kubicki, M. M.; Nuber, B.; Stubenhoffer,
B.; Wachter, J.; Wrackmeyer, B. Angew. Chem., Int. Ed. Engl. 1997, 36,
352.
(7) Flomer, W. A.; O’Neal, S. C.; Kolis, J. W.; Jeter, D.; Cordes, A. W.
Inorg. Chem. 1988, 27, 969.
[Te2{Cr(CO)5}4]2-,4 [Te3{Cr(CO)5}4]2-,4 [Te2{Cr(CO)5}2]2- 5
,
(8) (a) Shieh M.; Liou, Y.; Peng, S.-M.; Lee, G.-H. Inorg. Chem. 1993,
32, 2212. (b) Shieh, M.; Chen, P.-F.; Peng, S.-M.; Lee, G.-H. Inorg. Chem.
1993, 32, 3389. (c) Shieh, M.; Tsai, Y.-C. Inorg. Chem. 1994, 33, 2303.
(d) Shieh, M.; Shieh, M.-H.; Tsai, Y.-C.; Ueng, C.-H. Inorg. Chem. 1995,
34, 5088. (e) Shieh, M.; Tang, T.-F.; Peng, S.-M.; Lee, G.-H. Inorg. Chem.
1995, 34, 2797. (f) Shieh, M.; Sheu, C.-m.; Ho, L.-F.; Cherng, J.-J.; Jang,
L.-F.; Ueng, C.-H.; Peng, S.-M.; Lee, G.-H. Inorg. Chem. 1996, 35, 5504.
(g) Cherng, J.-J.; Tsai, Y.-C.; Ueng, C.-H.; Lee, G.-H.; Peng, S.-M.; Shieh,
M. Organometallics 1998, 17, 255. (h) Huang, K.-C.; Shieh, M.-H.; Jang,
R.-J.; Peng, S.-M.; Lee, G.-H.; Shieh, M. Organometallics 1998, 17, 5202.
(i) Shieh, M.; Chen, H.-S.; Chi, H.-H.; Ueng, C.-H. Inorg. Chem. 2000,
39, 5561. (j) Lai, Y.-W.; Cherng, J.-J.; Sheu, W.-S.; Lee, G.-A.; Shieh, M.
Organometallics 2006, 25, 184. (k) Shieh, M.; Liou, Y.; Hsu, M.-H.; Chen,
R.-T.; Yeh, S.-J.; Peng, S.-M.; Lee, G.-H. Angew. Chem., Int. Ed. 2002,
41, 2384.
and [Te3{Cr(CO)5}]2-,5 and only several ring complexes [Te4-
{Cr(CO)5}4],6 [Te2{Cr(CO)4}2{Cr(CO)5}2]2-,4 and [Te4Cr(CO)4]2-
* To whom correspondence should be addressed. E-mail: mshieh@
ntnu.edu.tw.
(1) (a) Roof, L. C.; Kolis, J. W. Chem. ReV. 1993, 93, 1037. (b) Gysling,
H. J. Coord. Chem. ReV. 1982, 42, 133. (c) Sekar, P.; Ibers, J. A. Inorg.
Chem. 2002, 41, 450 and references therein. (d) Shriver, D. F.; Kaesz, H.
D.; Adams, R. D. The Chemistry of Metal Cluster Complexes; VCH
Publishers: New York, 1990. (e) Whitmire, K. H. AdV. Organomet. Chem.
1997, 42, 1. (f) Mathur, P. AdV. Organomet. Chem. 1997, 41, 243. (g) Shieh,
M. J. Cluster Sci. 1999, 10, 3.
(2) Goh, L. Y. Coord. Chem. ReV. 1999, 185-186, 257.
(3) Shieh, M.; Ho, L.-F.; Jang, L.-F.; Ueng, C.-H.; Peng, S.-M.; Liu,
Y.-H. Chem. Commun. 2001, 1014.
(9) (a) Huang, K.-C.; Tsai, Y.-C.; Lee, G.-H.; Peng, S.-M.; Shieh, M.
Inorg. Chem. 1997, 36, 4421. (b) Shieh, M.; Chen, H.-S.; Yang, H.-Y.;
Ueng, C.-H. Angew. Chem., Int. Ed. 1999, 38, 1252. (c) Shieh, M.; Chen,
H.-S.; Yang, H.-Y.; Lin, S.-F.; Ueng, C.-H. Chem.-Eur. J. 2001, 7, 3152.
(d) Shieh, M.; Hsu, M.-H. J. Cluster Sci. 2004, 15, 91.
(4) Roof, L. C.; Pennington, W. T.; Kolis, J. W. Inorg. Chem. 1992, 31,
2056.
(5) Stauf, S.; Reisner, C.; Tremel, W. Chem. Commun. 1996, 1749.
10.1021/om700789a CCC: $37.00 © 2007 American Chemical Society
Publication on Web 11/01/2007

Reaction of [Et4N]2[Te{Cr(CO)5}n] toward Electrophiles
Organometallics, Vol. 26, No. 25, 2007 6185
Scheme 1
construction of many chromium carbonyl telluride complexes
such as [Te2{Cr(CO)5}4]2- 4 [Te3{Cr(CO)5}4]2- 4
, , and [Te2-
{Cr(CO)4}2{Cr(CO)5}2]2-,4 which were known to be obtained
only by using Zintl ions as tellurido sources.4
Previous work revealed that metal or mixed-metal tellurido
clusters are scarce.11 Based on the lone pairs on the Te atoms
of [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) and their good solubility
in organic solvents, these anionic complexes are potentially good
candidates for further study of their interaction with either
organic or inorganic electrophiles. Although the use of metal
sulfides as synthons for such applications has been well
documented, analogous reactions for metal tellurides have been
limited.1,11,12 Hence, the reactions of [Te{Cr(CO)5}n]2- (n ) 2,
3) with electrophiles can definitely shed light on the basicity
and nucleophilicity of tellurido ligands in transition metal
complexes. In this study, we systematically described and
compared the reactions of [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3)
with a series of organic and inorganic electrophiles. The nature
of these Te-Cr complexes and their formation are also
elucidated by molecular orbital calculations at the B3LYP level
of the density functional theory.
When [Et4N]2[Te{Cr(CO)5}2] was treated with ∼0.8 equiv
of CF3SO3Me in MeCN at -40 °C, the Te-monomethylated
product [Et4N][MeTe{Cr(CO)5}2]10a was obtained in a 75%
yield. Similarly, methylation of [Me4N]2[Te{Cr(CO)5}3] with
∼0.8 equiv of CF3SO3Me in MeCN produced the monomethy-
lated product [Me4N][MeTe{Cr(CO)5}3] ([Me4N][3]) in a 90%
yield. [Et4N][MeTe{Cr(CO)5}2] could be further methylated by
the addition of ∼1.0 equiv of CF3SO3Me to form the neutral
dimethylated product Me2Te{Cr(CO)5}2 (2) in good yields.
Complex 2 could also be obtained directly from [Et4N]2[Te-
{Cr(CO)5}2] with excess CF3SO3Me in an 85% yield (Scheme
2). Complex 2 was previously reported to be obtained from the
reaction of Cr(CO)5THF with Me2Te in THF; however, there
was no crystal structure presented at that time.14
Results and Discussion
Complex 2 and [Me4N]2[3] were fully structurally character-
ized by single-crystal X-ray analysis, elemental analysis, and
spectroscopic methods. X-ray analysis showed that complex 2
and anion 3 both displayed a tetrahedral geometry, in which
the central tellurium atom for 2 was tetrahedrally coordinated
by the two methyl groups and two Cr(CO)5 fragments. The
central tetrahedral tellurium atom for 3 was coordinated by the
one methyl group and three Cr(CO)5 fragments. The infrared
spectra of 2 and 3 showed absorptions characteristic of the
terminal carbonyls. The 1H NMR spectrum of 2 gave one signal
at δ ) 2.45 for the two methyl groups attached to the Te atom,
and this value was close to that in MeTePh (δ ) 2.1),15 but
shifted downfield as compared to those in Me2Te (δ ) 1.84)14
and [MeTe{Cr(CO)5}2]- (δ ) 1.7).10a Further, the 13C NMR
spectrum of 2 showed one resonance at -0.82 for the two
Reactions of [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) with HBF4
and CF3SO3Me. Because there are one or two lone pairs on
the Te atom of [Et4N]2[Te{Cr(CO)5}n] (n ) 3, 2), the basicity
of the Te atom was tested by the reactions with acidification
and methylation agents. In a previous study, the direct acidifica-
tion of Te-Cr carbonyl clusters was reported only in the case
of the neutral complex Te[(Cp*)Cr(CO)3]2, in which protonation
was believed to occur at the Te atom.13 However, there was no
direct evidence reported for its existence at that time.
In this study, when [Et4N]2[Te{Cr(CO)5}2] was acidified with
∼1.0 equiv of HBF4 in MeCN at -40 °C, the monohydrido
complex [Et4N][HTe{Cr(CO)5}2] ([Et4N][1]) was obtained in
a 65% yield. The infrared spectra of [Et4N][1] showed the
absorptions at 2046 w, 2031 m, 1932 s, and 1879 m cm-1, which
is characteristic of the terminal carbonyls and similar to those
for [Et4N]2[Te{Cr(CO)5}2],10a but shifted a bit to higher
1
methyl groups. For the anion 3, the methyl group gave the H
and 13C NMR absorptions at δ ) 2.07 and δ ) -15.92,
respectively. As compared to those (δ ) 1.76, -30.44) in
[MeTe{Cr(CO)5}2]-,10a these values for [MeTe{Cr(CO)5}3]- (3)
shifted downfield due to the lack of a lone pair on the Te atom.
Reactions of [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) with
Organodihalides. Investigation of [Et4N]2[Te{Cr(CO)5}n] (n
) 2, 3) with organodihalides can provide some information
regarding their ability to function as building blocks for further
skeleton-expansion reactions. [Et4N]2[Te{Cr(CO)5}2] was found
to be unstable in CH2Cl2 and could react readily with CH2Cl2
at 0 °C to form the Cl-functionalized product [Et4N][ClCH2-
Te{Cr(CO)5}2] ([Et4N][4]) in an 86% yield. Complex 4 could
further act as an electrophile to react with [Et4N]2[Te{Cr-
(CO)5}2] to give the known CH2-bridged dimeric complex
[Et4N]2[H2CTe2{Cr(CO)5}4] (in a 58% yield), which could also
be obtained directly from stirring of [Et4N]2[Te{Cr(CO)5}2] in
CH2Cl2 at room temperature10a (Scheme 3). Similarly, when
[Et4N]2[Te{Cr(CO)5}3] was treated with CH2Cl2 at 0 °C, the
Cl-functionalized product [Et4N][ClCH2Te{Cr(CO)5}3] ([Et4N]-
[5]) was obtained in an 85% yield. Further stirring of [Et4N]2-
[Te{Cr(CO)5}3] in CH2Cl2 at room temperature produced the
1
frequencies. Additionally, the H NMR spectrum of [Et4N][1]
gave a signal at δ ) -10.00 for the H atom attached to the Te
atom, and its formulation was further supported by elemental
analysis. However, treatment of [Et4N]2[Te{Cr(CO)5}3] with
HBF4 failed to yield the hydrido complex because of its lower
basicity versus [Et4N]2[Te{Cr(CO)5}2]. This reaction, instead,
led to the formation of the known complex [Et4N]2[Te2{Cr-
(CO)5}4],4 which resulted from the dimerization of the decom-
posed fragment “[Te{Cr(CO)5}2]” due to weak Te-Cr bonds
(Scheme 1).
(10) (a) Shieh, M.; Ho, L.-F.; Guo, Y.-W.; Lin, S.-F.; Lin, Y.-C.; Peng,
S.-M.; Liu, Y.-H. Organometallics 2003, 22, 5020. (b) Cherng, J.-J.; Lai,
Y.-W.; Liu, Y.-H.; Peng, S.-M.; Ueng, C.-H.; Shieh, M. Inorg. Chem. 2001,
40, 1206. (c) Shieh, M.; Cherng, J.-J.; Lai, Y.-W.; Ueng, C.-H.; Peng, S.-
M.; Liu, Y.-H. Chem.-Eur. J. 2002, 8, 4522. (d) Shieh, M.; Chung, R.-L.;
Yu, C.-H.; Hsu, M.-H.; Ho, C.-H.; Peng, S.-M.; Liu, Y.-H. Inorg. Chem.
2003, 42, 5477. (e) Shieh, M.; Lin, S.-F.; Guo, Y.-W.; Hsu, M.-H.; Lai,
Y.-W. Organometallics 2004, 23, 5182. (f) Hsu, M.-H.; Chen, R.-T.; Sheu,
W.-S.; Shieh, M. Inorg. Chem. 2006, 45, 6740.
(11) Nakagawa, T.; Seino, H.; Nagao, S.; Mizobe, Y. Angew. Chem.,
Int. Ed. 2006, 45, 7758 and references therein.
(12) (a) Shieh, M.; Chen, P.-F.; Tsai, Y.-C.; Shieh, M.-H. Inorg. Chem.
1995, 34, 2251. (b) Shieh, M.; Shieh, M.-H. Organometallics 1994, 13,
920. (c) Shieh, M.; Chen, H.-S.; Lai, Y.-W. Organometallics 2004, 23,
4018.
(14) Bremer, G.; Boese, R.; Keddo, M.; Kruck, T. Z. Naturforsch. 1986,
41b, 981.
(13) Herrmann, W. A.; Rohrmann, J. J. Organomet. Chem. 1984, 273,
221.
(15) Hope, E. G.; Kemmitt, T.; Levason, W. Organometallics 1988, 7,
78.

6186 Organometallics, Vol. 26, No. 25, 2007
Shieh et al.
Scheme 2
Scheme 3
Scheme 5
NMR spectra of 6 gave signals at δ ) 4.55 and δ ) -5.45,
respectively, for the bridging CH2 group. As expected, these
values compared favorably to those (δ ) 4.53, -6.02) observed
for the CH2-bridged dimeric complex [Et4N]2[H2CTe2{Cr-
(CO)5}4].10a
Scheme 4
For comparison, reactions of [Et4N]2[Te{Cr(CO)5}n] (n ) 2,
3) with bisbenzyl-containing dichloride-ClH2C(C6H4)2CH2Cl
were further investigated. The corresponding bisbenzyl-bridged
complexes [Et4N]2[H2C(C6H4)2CH2Te2{Cr(CO)5}n] (n ) 4,
[Et4N]2[7]; n ) 6, [Et4N]2[8]) were obtained in 81% and 21%
yields, respectively (Scheme 5). [Et4N]2[Te{Cr(CO)5}n] (n )
2, 3) are considered to undergo the double nucleophilic attack
onto the bisbenzyl-containing agent ClH2C(C6H4)2CH2Cl to
form complexes 7 and 8. These complexes were fully structur-
ally characterized by X-ray analysis and spectroscopic methods.
On the basis of the X-ray analysis, complex 7 had two molecules
CH2-bridged dimeric complex [Et4N]2[H2CTe2{Cr(CO)5}6]
([Et4N]2[6]) in moderate yields. Like complex 4, complex 5 is
an effective electrophile for reacting with [Et4N]2[Te{Cr(CO)5}3]
to form [Et4N]2[6] (Scheme 4).
of [Te{Cr(CO)5}2]2- connected by the H2C(C6H4)2CH2
2+
moiety, and complex 8 had two molecules of [Te{Cr(CO)5}3]2-
linked by the H2C(C6H4)2CH22+ moiety. The 1H and 13C NMR
spectra of 7 gave signals at δ ) 3.97 and δ ) -1.28,
respectively, for the bridging CH2 segments, while those of 8
showed absorptions at δ ) 3.98 and δ ) -0.98, respectively.
Again, these absorptions reflect the similar effect of a lone pair
versus the Cr(CO)5 fragment.
Reactions of [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) with HgCl2
and O2. In addition to organic reagents, reactions of [Et4N]2-
[Te{Cr(CO)5}n] (n ) 2, 3) with mercury salts or O2 were studied
for comparison. Like organic dihalides, the reactions of [Et4N]2-
[Te{Cr(CO)5}n] (n ) 2, 3) with ∼0.5 equiv of HgCl2 in MeCN
led to the formation of the Hg-bridged dimeric complexes
[Et4N]2[HgTe2{Cr(CO)5}n] (n ) 4, [Et4N]2[9]; n ) 6, [Et4N]2-
[10]), respectively (Scheme 6). X-ray analysis showed that the
Hg-bridged complexes 9 and 10 were structurally analogous to
the organo-bridged complexes 7 and 8, respectively. Further,
complex 9 could transform to complex 10 upon treatment with
∼0.5 equiv of HgCl2 in MeCN, in which HgCl2 acted as an
oxidizing agent to cause the bond breakage and reformation of
The new complexes 4, 5, and 6 were fully characterized by
elemental analysis, spectroscopic methods, and/or single-crystal
X-ray analysis. The X-ray analysis showed that anionic 4
possessed a tetrahedral geometry, in which the central tellurium
atom was tetrahedrally coordinated by one CH2Cl group and
two Cr(CO)5 fragments, leaving one lone pair uncoordinated.
1
The H and 13C NMR spectra of the anion 4 gave signals at δ
) 4.56 and δ ) -5.37, respectively, for the CH2Cl group
attached to the Te atom. On the other hand, the X-ray analysis
showed that anionic 5 displayed a tetrahedral geometry, in which
the Te atom was tetrahedrally coordinated by one CH2Cl group
and three Cr(CO)5 fragments. The 1H and 13C NMR spectra of
5 gave signals at δ ) 4.55 and δ ) -6.41, respectively, for the
CH2Cl group attached to the Te atom, which was close to those
in complex 4. This is indicative of the comparable effect of the
lone pair and the Cr(CO)5 fragment on the NMR absorptions.
Furthermore, the infrared spectra of dianion 6 showed absorp-
1
tions characteristic of the terminal carbonyls. The H and 13C

Reaction of [Et4N]2[Te{Cr(CO)5}n] toward Electrophiles
Organometallics, Vol. 26, No. 25, 2007 6187
Scheme 6
Scheme 7
Figure 1. ORTEP diagram showing the structure and atom labeling
for 2.
9 to give 10. This was mainly due to weak Te-Cr bonds.
Clusters 9 and 10 represent rare examples of mixed-metal
telluride complexes, and further study on their cluster expansion
and physical properties is under investigation.
Moreover, it was found that [Et4N]2[Te{Cr(CO)5}n] (n ) 2,
3) showed different reactivity toward the oxygen molecule.
[Et4N]2[Te{Cr(CO)5}2] could readily react with O2 in MeCN
to give the O-bridged complex [Et4N][OTe{Cr(CO)5}2] ([Et4N]-
[11]) in an almost quantitative yield, while the reaction with
[Et4N]2[Te{Cr(CO)5}3] only formed the oxidized known com-
plex4 [Te2{Cr(CO)5}4]2- without observation of the analogous
O-bridged product (Scheme 7). The activation of O2 by [Et4N]2-
[Te{Cr(CO)5}2] is surprising as it is rare in the literature. The
detailed mechanism is not clear at this moment but should be
relatedtothelowcoordinationandhighreactivityof[Te{Cr(CO)5}2]2-.
It is noted that the Te-O bond of complex 11 was relatively
weak, which was substantiated by the ease of elimination of
the Te{Cr(CO)5}2 fragment of 11 in the ESI-MS study.
X-ray Structural Comparison of 2, [Me4N][3], [Et4N][4],
[PPN][5], [Et4N]2[7], [Me4N]2[8], [Et4N]2[9], [Et4N]2[10], and
[Et4N]2[11]. Complex 2 and anionic complexes 3, 4, 5, 7, 8, 9,
10, and 11 can be viewed to have Te-centered chromium
carbonyl-coordinated open structures. Complexes 2, 4, 7, 9, and
11 are considered to possess the Te{Cr(CO)5}2-based geometry,
in which the Te atom is tetrahedrally bonded to two Cr(CO)5
fragments and one or two ligands. While 2 consists of a Te-
{Cr(CO)5}2 core with two methyl groups as ligands (Figure 1),
4 displays a Te{Cr(CO)5}2 core coordinated with one CH2Cl
group and with one uncoordinated lone pair (Figure 3). Besides,
7, 9, and 11 are isostructural and each have two Te{Cr(CO)5}2
units that are bridged by a CH2(C6H4)2CH2 fragment, a Hg atom,
or an O atom, respectively (Figures 5, 7, and 9). On the other
hand, complexes 3, 5, 8, and 10 are considered to have the Te-
{Cr(CO)5}3-based structure, in which the Te atom is tetrahe-
drally bonded to three Cr(CO)5 fragments and one coordinated
ligand. While isostructural complexes 3 and 5 each have a Te-
{Cr(CO)5}3 core externally bonded with a Me group or with a
CH2Cl group (Figures 2 and 4), isostructural complexes 8 and
10 each have two Te{Cr(CO)5}3 units that are bridged by either
a CH2(C6H4)2CH2 or a Hg atom (Figures 6 and 8).
Figure 2. ORTEP diagram showing the structure and atom labeling
for anion 3.
in the new Te-Cr complexes are basically close to those
reported in the other related polytelluride complexes such as
[Te2{Cr(CO)5}4]2- (2.749 Å),4 [Te3{Cr(CO)5}4]2- (2.763 Å),4
[Te2{Cr(CO)5}2]2- (2.739 Å),5 and [Te3{Cr(CO)5}]2- (2.754
Å).5 It is noted, however, that the average Te-Cr bond distance
of 4 (2.720 Å) is the same as that of 5 (2.720 Å), indicative of
little steric effect of the Cr(CO)5 groups on the Te-Cr bond. A
similar situation is also observed in the cases of 7 versus 8 and
9 versus 10. The average Te-Cr bonds in 3-5 are only a bit
shorter than those in 7-10, reflecting the smaller steric effect
of mono-TeCrn- versus di-TeCrn-based (n ) 2, 3) structures. In
addition, the average Te-Cr bonds for anionic Te-Cr com-
plexes are significantly longer than that of the neutral complex
2 due to the effect of the negative charge.
The Cr-Te-Cr angles about the tellurium atom in 2, 3, 4,
5, 7, 8, 9, 10, and 11 range from 112.88° to 122.36°, which
somewhat deviated from the regular tetrahedral angle. In general,
the average Cr-Te-Cr angles for the TeCr2-based complexes
are a bit larger than those of their corresponding TeCr3-based
complexes due to the steric effect of the Cr(CO)5 moiety.
Further, the Cr-Te-Cr angle in 2 is the largest among the
TeCr2-based complexes due to the small steric hindrance of two
methyl groups, while that of 3 is the largest among the TeCr3-
based complexes due to the smallest steric hindrance of one
For comparison, the selected bond distances and bond angles
of the new Te-Cr complexes and related complexes are listed
in Table 1. As shown in Table 1, the average Te-Cr distances

6188 Organometallics, Vol. 26, No. 25, 2007
Shieh et al.
Figure 3. ORTEP diagram showing the structure and atom labeling for anion 4.
for [Te{Cr(CO)5}n]2- (n ) 2, 3) and their related products, we
looked at their frontier molecular orbitals and the main orbital
coefficients. The frontier molecular orbitals of [Te{Cr(CO)5}n]2-
(n ) 2, 3) and related products are shown in Figure 10, and the
orbital compositions, which are expressed in terms of the
contribution, are listed in Table 2. As shown in Figure 10, the
HOMOs of complexes [Te{Cr(CO)5}n]2- (n ) 2, 3) have a
slightly antibonding interaction between the p orbital of the Te
atom and d orbitals of the Cr atom, in which the significant
contribution is from the p orbital (48% and 34%, respectively)
of the central Te atom (see Table 2). It is interesting to note
that when the consecutive methylation takes place on both
[Te{Cr(CO)5}n]2- (n ) 2, 3) (which formed new complexes 2
and 3), a substantial alteration in the orbital coefficients of the
central Te atoms was observed. Our calculated results indicate
that the contribution from the p orbital of the HOMO of the
TeCr2-based complexes is (in decreasing order) [Te{Cr(CO)5}2]2-
> [MeTe{Cr(CO)5}2]- > 2, and [Te{Cr(CO)5}3]2- > 3 is found
for the TeCr3-based complexes (see Table 2). Therefore, the
incoming electrophilic MeOTf could interact with the lone pair
of the Te atom (prevailing contribution from the p orbital) of
[Te{Cr(CO)5}n]2- (n ) 2, 3), which would result in the
decreasing contribution of the p orbital of the Te atom of their
products. A similar explanation also could account for the
reactions of [Te{Cr(CO)5}n]2- (n ) 2, 3) with methylene
chloride (CH2Cl2), in which the newly formed CH2Cl-function-
alized products 4 and 5 have smaller p orbital coefficients on
the HOMOs than those of the initial reactants, [Te{Cr(CO)5}n]2-
(n ) 2, 3), respectively.
Figure 4. ORTEP diagram showing the structure and atom labeling
for anion 5.
methyl group versus other coordinated ligands. Additionally,
the Te-O-Te bond angle of 11 is 108.2(3)°, indicative of the
tetrahedral geometry around the O center, which is significantly
larger than the Te-Te-Te angle (98.4(1)°) in the related
complex4 [Te3{Cr(CO)5}4]2-. This is attributed to the diminished
s-character of the central Te atom caused by the larger size of
Te versus O. The values in these two chalcogen-bridged
complexes are smaller than the Te-C-Te angle (115.2(2)°) in
To understand the bonding nature of each complex, we also
calculated the Wiberg bond index18 and natural population
analyses (NPA)19 for complexes [Te{Cr(CO)5}2]2-, [MeTe-
{Cr(CO)5}2]-, 2, [Te{Cr(CO)5}3]2-, and 3, which are listed in
Table 3. Their corresponding structures are also illustrated in
the lower part of this table. The analysis revealed that the Te
the CH2-bridged complex [H2CTe2{Cr(CO)5}4]2- 10a
due to the
,
effect of the lone pairs of the chalcogen atom. Finally, the Te-C
bonds in complexes 2-5, 7, and 8 are within the range of
2.135-2.22 Å, which is normal.
DFT Computation. To further portray the electronic struc-
tures of the [Te{Cr(CO)5}n]2- (n ) 2, 3) and their relevant
reaction phenomena, we employed a hybrid density functional
(B3LYP16,17) with a modest basis set LanL2DZ for each
complex. The molecular geometries are taken from single-crystal
X-ray diffraction data. To examine scenarios of the framework
(16) (a) Becke, A. D. J. Chem. Phys. 1993, 98, 5648. (b) Becke, A. D.
J. Chem. Phys. 1992, 96, 2155. (c) Becke, A. D. J. Chem. Phys. 1992, 97,
9173.
(17) Lee, C.; Yang, W.; Parr, R. G. Phys. ReV. 1988, B37, 785.
(18) Wiberg, K. B. Tetrahedron 1968, 24, 1083.
(19) (a) Reed, A. E.; Weinhold, F. J. Chem. Phys. 1983, 78, 4066. (b)
Reed, A. E.; Weinstock, R. B.; Weinhold, F. J. Chem. Phys. 1985, 83,
735.

Reaction of [Et4N]2[Te{Cr(CO)5}n] toward Electrophiles
Organometallics, Vol. 26, No. 25, 2007 6189
Figure 5. ORTEP diagram showing the structure and atom labeling for anion 7.
Figure 6. ORTEP diagram showing the structure and atom labeling for dianion 8.
Figure 7. ORTEP diagram showing the structure and atom labeling for dianion 9.
atomin[Te{Cr(CO)5}2]2-,[MeTe{Cr(CO)5}2]-,2,[Te{Cr(CO)5}3]2-,
and 3 each carried -0.39, +0.40, +1.17, -0.04, and +0.68
|e|, while the average charges of the Cr atom in those complexes
were -1.36, -1.36, -1.43, -1.34, and -1.39 |e|. This indicated
the inter-site coulomb attraction between Te-Cr bond on the
[Te{Cr(CO)5}n]2- (n ) 2, 3), and their relevant methylation
derivatives occurred in the order of 2 > [MeTe{Cr(CO)5}2]-
> [Te{Cr(CO)5}2]2-, and 3 > [Te{Cr(CO)5}3]2-, respectively.
In addition, the calculated Wiberg bond indices (also called bond
orders) of the aforementioned species also reflected the same
tendency, in which more methylation occurred on both com-
plexes [Te{Cr(CO)5}n]2- (n ) 2, 3), and the larger mean Wiberg
bond indices between Te and Cr atoms (Te-Cr bond) would
be obtained (see Table 3).

6190 Organometallics, Vol. 26, No. 25, 2007
Shieh et al.
of the more significant repulsion in the Te-O bond than in the
Te-C bond. This explains why the average bond index
calculated for Te-O is smaller than that calculated for Te-C
(see Table 4).
Summary
The reactions of the monotelluride-bridged di- and trichro-
mium carbonyl anions [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) with
a series of electrophiles were systematically studied. The
tellurium atom of [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) showed
good affinity toward electrophiles in which the TeCr2- and
TeCr3-based organo- or metal-incorporated monomeric or
dimeric complexes were obtained. The nature of [Et4N]2[Te-
{Cr(CO)5}n] (n ) 2, 3) and their resultant products were also
compared and elucidated by DFT calculations. This study
provides a wide range of TeCr2- and TeCr3-based complexes
for further investigation through practical and theoretical
applications.
Figure 8. ORTEP diagram showing the structure and atom labeling
for dianion 10.
Experimental Section
All reactions were performed under an atmosphere of pure
nitrogen using standard Schlenk techniques.20 Solvents were
purified, dried, and distilled under nitrogen prior to use. Cr(CO)6
(Strem), Te powder (Strem), CF3SO3Me (Aldrich), HBF4 (Strem),
HgCl2 (Shimakyu’s), ClH2C(C6H4)2CH2Cl (Aldrich), and KOH
(Showa) were used as received. Infrared spectra were recorded on
a Perkin-Elmer Paragon 500 IR spectrometer as solutions in CaF2
cells. The 1H and 13C NMR spectra were obtained on a JEOL 400
instrument and Bruker AV 400 at 399.78 and 100.53 MHz,
respectively. EI mass spectra were taken on a Finningan TSQ 700
GC/LC/MS mass spectrometer. Elemental analyses for C, H, and
N were performed on a Perkin-Elmer 2400 analyzer at the NSC
Regional Instrumental Center at National Taiwan University, Taipei,
Taiwan. [Et4N]2[Te{Cr(CO)5}n] (n ) 2, 3) was prepared according
to the published procedures.10a
Reaction of [Et4N]2[Te{Cr(CO)5}2] with HBF4 (∼1:1.1) in
MeCN. HBF4 (0.22 mL, 1.70 mmol) was added to a MeCN
solution (30 mL) of [Et4N]2[Te{Cr(CO)5}2] (1.16 g, 1.50 mmol) at
-40 °C. The green solution became yellowish-brown instantly.
After being stirred for 60 min, the solution was filtered, and the
solvent was evaporated under vacuum. The residue was washed
with hexanes/Et2O several times and extracted with THF to give a
yellowish-brown sample of [Et4N][HTe{Cr(CO)5}2] ([Et4N][1])
(0.63 g, 0.98 mmol) (65% based on [Et4N]2[Te{Cr(CO)5}2]). IR
(νCO, MeCN): 2046 w, 2031 m, 1932 s, 1879 m cm-1. Anal. Calcd
for [Et4N][1]: C, 33.63; H, 3.29; N, 2.18. Found: C, 33.51; H,
Figure 9. ORTEP diagram showing the structure and atom labeling
for dianion 11.
Furthermore, the Wiberg bond index and natural population
analyses as well as the corresponding structures for the
X-bridged Te-X-Te complexes (X ) Hg, O, and CH2) are
displayed in Table 4. The frontier molecular orbitals are depicted
in Figure 11, and orbital compositions are listed in Table 5. It
is found that the HOMO of complex 9 in the central segment
consists of small d orbitals (2%) of the Hg atom mixed with p
orbitals (24%) of the Te atom. However, in the case of the
counterpart of complex 10, the bonding character of the HOMO
in the central segment is derived mainly from the Hg (slight p
orbitals, 3%) and Te (p orbitals, 12%) atomic orbitals (see Figure
11 and Table 4). Moreover, in regard to two isoelectronic
analogues, 11 and [H2CTe2{Cr(CO)5}4]2-, the calculations show
that the bond index between Te-O (0.72) for complex 11 is
1
2.96; N, 2.15. H NMR (400 MHz, DMSO-d6, 300 K, ppm): δ
-10.00 (s, H) (chemical shifts not given for [Et4N]+).
Reaction of [Et4N]2[Te{Cr(CO)5}3] with HBF4 (∼1:0.5) in
THF. HBF4 (0.023 mL, 0.18 mmol) was added to a THF
solution (30 mL) of [Et4N]2[Te{Cr(CO)5}3] (0.41 g, 0.43 mmol) at
-40 °C. The olive green solution became yellowish-brown instantly.
After being stirred for 60 min, the solution was filtered, and the
solvent was evaporated under vacuum. The residue was washed
several times with Et2O and extracted with THF to give a sample
of [Et4N]2[Te2{Cr(CO)5}4]4 (0.08 g, 0.06 mmol) (27% based on
[Et4N]2[Te{Cr(CO)5}3]). IR (νCO, THF): 2058 w, 2038 m, 2031 s,
smallerthanthatbetweenTe-C(0.90)for[H2CTe2{Cr(CO)5}4]2-
.
The computed results could not be clarified by means of the
natural charge because the ionic-interaction difference between
Te-O and Te-C was insignificant (see Table 4). As shown in
Figure 11, the pictorial description of the HOMO in the Te-
O-Te segment had an apparent antibonding interaction between
the O atom (p orbital, 10%) and the Te atom (p orbital, 24%,
mixed with some degree of s-character, 4%). This antibonding
phenomenon is absent in the Te-C-Te counterpart, indicative
1965 w, 1929 vs, 1907 w, 1873 s cm-1
.
Reaction of [Et4N]2[Te{Cr(CO)5}2] with CF3SO3Me (∼1:0.8)
in MeCN. CF3SO3Me (0.12 mL, 1.10 mmol) was added to a MeCN
solution (30 mL) of [Et4N]2[Te{Cr(CO)5}2] (1.10 g, 1.42 mmol) at
-40 °C. The green solution became yellowish-brown instantly.
(20) Shriver, D. F.; Drezdon, M. A. The Manipulation of Air-SensitiVe
Compounds; Wiley-VCH Publishers: New York, 1986.

Reaction of [Et4N]2[Te{Cr(CO)5}n] toward Electrophiles
Organometallics, Vol. 26, No. 25, 2007 6191
Table 1. Average Bond Distance (Å) and Bond Angles (deg) for 2, [Me4N][3], [Et4N][4], [PPN][5], [Et4N]2[7], [Me4N]2[8],
[Et4N]2[9], [Et4N]2[10], and [Et4N]2[11]
complex
Te-Cr, Å
2.6434
2.725
2.720
2.720
2.726
2.739
2.751
2.732
2.737
2.747
2.749
2.763
2.739
Cr-Te-Cr, deg
Te-C, Å
ref
Me2Te{Cr(CO)5}2 (2)
122.36(3)
115.86
118.27(4)
115.59
114.19
113.90
116.30
115.04
112.88
112.83
116.90
113.10
2.135
a
a
a
a
a
a
a
a
a
10a
4
4
5
[Me4N][MeTe{Cr(CO)5}3] ([Me4N]2[3])
[Et4N][ClCH2CTe{Cr(CO)5}2] ([Et4N][4])
[PPN][ClCH2Te{Cr(CO)5}3] ([Et4N][5])
[Et4N]2[H2C(C6H4)2CH2Te2{Cr(CO)5}4] ([Et4N]2[7])
[Me4N]2[H2C(C6H4)2CH2Te2{Cr(CO)5}6] ([Me4N]2[8])
[Et4N]2[HgTe2{Cr(CO)5}4] ([Et4N]2[9])
[Et4N]2[HgTe2{Cr(CO)5}6] ([Et4N]2[10])
[Et4N]2[OTe2{Cr(CO)5}4] ([Et4N]2[11])
[Et4N]2[CH2Te2{Cr(CO)5}4]
2.154(7)
2.140(8)
2.181(5)
2.17
2.22
2.163(2)
[PPh4]2[Te2{Cr(CO)5}4]
[PPh4]2[Te3{Cr(CO)5}4]
[K(2,2,2-crypt)]2[Te2{Cr(CO)5}2]b
[K(2,2,2-crypt)]2[Te3{Cr(CO)5}]
[PPh4]2[Te2{Cr(CO)4}2{Cr(CO)5}2]
2.754(5)
2.781 (out of plane)
2.692 (in plane)
2.587
5
4
[Te4{Cr(CO)5}4]
[PPh4]2[Te4Cr(CO)4]
6
7
2.726
a This work. b 2,2,2-crypt ) (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane).
Table 2. Calculated Percentage Contribution Ratios of the
Te and Cr Atoms to Selected Frontier Molecular Orbitals of
[Te{Cr(CO)5}n]2- (n ) 2, 3) and Their Related Complexes
washed with hexanes and extracted with ether/THF (v/v 6:1) to
yield a yellowish-orange sample of Me2Te{Cr(CO)5}2 (2) (0.29 g,
0.54 mmol) (62% based on [Et4N][MeTe{Cr(CO)5}2]).
atoms
Reaction of [Me4N]2[Te{Cr(CO)5}3] with CF3SO3Me (∼1:0.8)
in MeCN. CF3SO3Me (0.10 mL, 0.87 mmol) was added to a MeCN
solution (20 mL) of [Me4N]2[Te{Cr(CO)5}3] (0.90 g, 1.06 mmol)
in an ice-water bath. The olive green solution became yellowish-
orange instantly. After being stirred for 1 h, the solution was filtered,
and the solvent was evaporated under vacuum. The residue was
washed several times with hexanes/Et2O and extracted with THF
to yield a reddish-orange sample of [Me4N][MeTe{Cr(CO)5}3]
([Me4N][3]) (0.62 g, 0.78 mmol) (90% based on CF3SO3Me). IR
(νCO, THF): 2066 w, 2043 m, 2029 w, 1972 w, 1949 vs, 1943 vs,
1921 w, 1901 s cm-1. Anal. Calcd for [Me4N][3]:C, 30.30; H, 1.91;
complexes
Te
Cr
[Te{Cr(CO)5}2]2- (HOMO)
[Te{Cr(CO)5}2]2- (LUMO)
48% p
10% d
14% s + 15% p 3% p + 4% d
[MeTe{Cr(CO)5}2]- (HOMO) 2% s + 16% p 21% d
[MeTe{Cr(CO)5}2]- (LUMO) 23% s + 13% p 11% p + 8% d
2 (HOMO)
2 (LUMO)
6% s
2% p + 27% d
20% s + 8% p 23% s + 8% p
[Te{Cr(CO)5}3]2- (HOMO)
[Te{Cr(CO)5}3]2- (LUMO)
3 (HOMO)
2% s + 34% p 17% d
20% s + 8% p 7% p + 6% d
4% p
35% s
2% s + 9% p + 38% d
13% p + 8% d
3 (LUMO)
4 (HOMO)
4 (LUMO)
5 (HOMO)
1
2% s + 24% p 25% d
24% s + 11% p 11% p + 4% d
N, 1.77. Found: C, 30.41; H, 1.56; N, 2.05. H NMR (400 MHz,
DMSO-d6, 300 K, ppm): δ 2.07 (s, CH3) (chemical shifts not given
for [Me4N]+). 13C NMR (100 MHz, DMSO-d6, 300 K, ppm): δ
-15.92 (CH3), 218.36, 224.41 (CrCO) (chemical shifts not given
for [Me4N]+). Crystals of [Me4N][3] suitable for single-crystal X-ray
diffraction were grown from hexanes/Et2O/THF.
2% s + 3% p
3% s + 8% p + 38% d
15% p + 5% d
5 (LUMO)
36% s
After being stirred for 1 h, the solution was filtered, and the solvent
was evaporated under vacuum. The residue was washed several
times with Et2O and extracted with THF to give a yellowish-orange
sample of [Et4N][MeTe{Cr(CO)5}2]10a (0.54 g, 0.82 mmol) (75%
based on CF3SO3Me). IR (νCO, THF): 2051 w, 2030 s, 1962 w,
Reaction of [Et4N]2[Te{Cr(CO)5}2] with CH2Cl2 (at 0 °C).
CH2Cl2 (20 mL) was added to a sample of [Et4N]2[Te{Cr(CO)5}2]
(0.55 g, 0.71 mmol) in an ice-water bath. The resulting solution
was stirred at 0 °C for 2.5 h to produce a yellowish-orange solution.
The solution was filtered, and the solvent was evaporated under
vacuum. The residue was washed several times with Et2O and
extracted with THF to yield a sample of [Et4N][ClH2CTe{Cr-
(CO)5}2] ([Et4N][4]) (0.42 g, 0.61 mmol) (86% based on [Et4N]2-
[Te{Cr(CO)5}2]). IR (νCO, CH2Cl2): 2053 w, 2033 s, 1965 w, 1931
vs, 1909 w, 1889 m cm-1. Anal. Calcd for [Et4N][4]: C, 33.01; H,
1932 vs, 1906 m, 1890 s cm-1
.
Reaction of [Et4N]2[Te{Cr(CO)5}2] with CF3SO3Me (∼1:2.7)
in MeCN. CF3SO3Me (0.08 mL, 0.70 mmol) was added to a MeCN
solution (20 mL) of [Et4N]2[Te{Cr(CO)5}2] (0.20 g, 0.26 mmol)
in an ice-water bath. The green solution became reddish-orange
instantly. After being stirred for 30 min, the solution was filtered,
and the solvent was evaporated under vacuum. The residue was
washed with hexanes and extracted with ether/THF (v/v 6:1) to
yield a yellowish-orange sample of Me2Te{Cr(CO)5}2 (2) (0.12 g,
1
3.21; N, 2.03. Found: C, 32.80; H, 3.32; N, 1.99. H NMR (400
MHz, DMSO-d6, 300 K, ppm): δ 4.56 (s, CH2) (chemical shifts
not given for [Et4N]+). 13C NMR (100 MHz, DMSO-d6, 300 K,
ppm): δ -5.37 (CH2), 219.9, 226.5 (CrCO) (chemical shifts not
given for [Et4N]+). Crystals of [Et4N][4] suitable for single-crystal
X-ray diffraction were grown from hexanes/Et2O/THF.
0.22 mmol) (85% based on [Et4N]2[Te{Cr(CO)5}2]). IR (νCO
,
ether): 2077 vw, 2060 w, 1960 s, 1940 m cm-1. Mass (EI): calcd
(found), 543.8 (543.9). Anal. Calcd for 2: C, 26.60; H, 1.12.
1
Found: C, 26.88; H, 1.17. H NMR (400 MHz, CDCl3, 300 K,
ppm): δ 2.45 (s, CH3). 13C NMR (100 MHz, CDCl3, 300 K,
ppm): δ -0.82 (CH3), 211.5, 215.0, 217.6, 220.3 (CrCO). Crystals
of 2 suitable for single-crystal X-ray diffraction were grown from
hexanes/CH2Cl2.
Reaction of [Et4N]2[Te{Cr(CO)5}3] with CH2Cl2 (at 0 °C).
CH2Cl2 (20 mL) was added to a sample of [Et4N]2[Te{Cr(CO)5}3]
(0.38 g, 0.39 mmol) in an ice-water bath. The resulting solution
was stirred for 3 h to produce a yellowish-orange solution. The
solution was filtered, and the solvent was evaporated under vacuum.
The residue was washed several times with Et2O and extracted with
THF to yield a sample of [Et4N][ClCH2Te{Cr(CO)5}3] ([Et4N][5])
(0.29 g, 0.33 mmol) (85% based on [Et4N]2[Te{Cr(CO)5}3]). IR
Reaction of [Et4N][MeTe{Cr(CO)5}2] with CF3SO3Me (∼1:
1.1) in MeCN. CF3SO3Me (0.11 mL, 0.97 mmol) was added to a
MeCN solution (30 mL) of [Et4N][MeTe{Cr(CO)5}2] (0.57 g, 0.87
mmol) at -40 °C. The yellowish-orange solution became reddish-
orange instantly. After being stirred for 1 h, the solution was filtered,
and the solvent was evaporated under vacuum. The residue was
(νCO, CH2Cl2): 2068 w, 2002 m, 2047 s, 1951 vs, 1901 m cm-1
[PPN][ClCH2Te{Cr(CO)5}3] ([PPN][5]) was synthesized by a
.

6192 Organometallics, Vol. 26, No. 25, 2007
Shieh et al.
Figure 10. The spatial graphs (isovalue ) 0.02-0.04) of the selected frontier molecular orbitals of [Te{Cr(CO)5}n]2- (n ) 2, 3) and
related products.
1
similar procedure using [PPN]2[Te{Cr(CO)5}3] as the starting
material. Crystals of [PPN][5] suitable for single-crystal X-ray
diffraction were grown from MeOH/CH2Cl2. Anal. Calcd for [PPN]-
[5]: C, 48.35; H, 2.50; N, 1.08. Found: C, 48.38; H, 2.62; N, 0.82.
1H NMR (400 MHz, DMSO-d6, 300 K, ppm): δ 4.55 (s, CH2)
(chemical shifts not given for [PPN]+). 13C NMR (100 MHz,
DMSO-d6, 300 K, ppm): δ -6.41 (CH2), 215.4, 221.6, 228.3
(CrCO) (chemical shifts not given for [PPN]+).
Reaction of [Et4N]2[Te{Cr(CO)5}3] with CH2Cl2 (at rt). CH2-
Cl2 (40 mL) was added to a sample of [Et4N]2[Te{Cr(CO)5}3] (0.77
g, 0.80 mmol) at room temperature. The resulting solution was
stirred at room temperature for 20 h to produce a yellowish-orange
solution. The solution was filtered, and the solvent was evaporated
under vacuum. The residue was washed several times with Et2O
and extracted with THF to yield a sample of [Et4N]2[H2CTe2{Cr-
(CO)5}6] ([Et4N]2[6]) (0.39 g, 0.23 mmol) (58% based on [Et4N]2-
[Te{Cr(CO)5}3]). IR (νCO, CH2Cl2): 2045 m, 2034 m, 1933 vs,
1880 s cm-1. Anal. Calcd for [Et4N]2[6]: C, 33.56; H, 2.52; N,
1.67. Found: C, 33.70; H, 2.58; N, 1.68. H NMR (400 MHz,
DMSO-d6, 300 K, ppm): δ 4.55 (s, CH2) (chemical shifts not given
for [Et4N]+). 13C NMR (100 MHz, DMSO-d6, 300 K, ppm): δ
-5.45 (CH2), 213.6, 217.2, 220.5, 223.7, 227.6 (CrCO) (chemical
shifts not given for [Et4N]+). Crystals of [Et4N]2[6] suitable for
single-crystal X-ray diffraction were grown from hexanes/Et2O/
THF.
Reaction of [Et4N][ClH2CTe{Cr(CO)5}2] ([Et4N][4]) with
[Et4N]2[Te{Cr(CO)5}2] in MeCN. [Et4N]2[Te{Cr(CO)5}2] (0.24
g, 0.31 mmol) was added to a MeCN solution (20 mL) of [Et4N]-
[4] (0.21 g, 0.30 mmol) at ambient temperature. The resulting
solution was stirred for 30 min to produce an orange-brown solution.
The solution was filtered, and the solvent was evaporated under
vacuum. The residue was washed several times with Et2O and
extracted with THF to yield a reddish-orange sample of [Et4N]2[H2-
CTe2{Cr(CO)5}4]10a (0.24 g, 0.18 mmol) (58% based on [Et4N]2-
[Te{Cr(CO)5}2]). IR (νCO, THF): 2052 m, 2034 m, 1932 vs, 1887
s cm-1
.

Reaction of [Et4N]2[Te{Cr(CO)5}n] toward Electrophiles
Organometallics, Vol. 26, No. 25, 2007 6193
Table 3. Natural Bond Order and Natural Population
Analyses of [Te{Cr(CO)5}2]2-, [MeTe{Cr(CO)5}2]-, 2,
[Te{Cr(CO)5}3]2-, and 3
Table 5. Calculated Percentage Contribution Ratios of the
Te, Cr, Hg, O, and C Atoms to Selected Frontier Molecular
Orbitals of the Te-X-Te Complexes (X ) Hg, O, and CH2)
atoms
species
9 (HOMO)
Te
Cr
19% d
29% s + 19% p 1% p
12% p 32% d
X
24% p
2% d
9 (LUMO)
23% s + 1% p
10 (HOMO)
10 (LUMO)
11 (HOMO)
11 (LUMO)
3% p
30% s
34% s + 12% p 2% d
4% s + 24% p 4% p + 12% d 10% p
2% s + 38% p 6% p + 2% d 2% s + 14% p
[H2CTe2{Cr(CO)5}4]2- 26% p
16% d
1% p
(HOMO)
[H2CTe2{Cr(CO)5}4]2- 24% s + 6% p 14% p + 2% d
(LUMO)
Wiberg bond index
natural charge
Cr C
and the solvent was evaporated under vacuum. The residue was
washed several times with hexanes/Et2O and extracted with THF
to yield a yellowish-orange sample of [Et4N]2[H2C(C6H4)2CH2Te2-
{Cr(CO)5}4] ([Et4N]2[7]) (0.67 g, 0.46 mmol) (81% based on
[Et4N]2[Te{Cr(CO)5}2]). IR (νCO, THF): 2049 w, 2029 m, 1962
m, 1962 w, 1926 vs, 1905 m, 1887 s cm-1. Anal. Calcd for [Et4N]2-
[7]: C, 41.02; H, 3.58; N, 1.91. Found: C, 40.74; H, 3.64; N, 1.93.
1H NMR (400 MHz, DMSO-d6, 300 K, ppm): δ 3.97 (s, CH2), δ
7.30, 7.32, 7.49, 7.51 (m, C6H4) (chemical shifts not given for
[Et4N]+). 13C NMR (100 MHz, DMSO-d6, 300 K, ppm): δ -1.28
(CH2), 126.5, 130.2, 137.4, 142.6 (C6H4), 219.6, 220.3, 226.5
(CrCO) (chemical shifts not given for [Et4N]+). Crystals of [Et4N]2-
[7] suitable for single-crystal X-ray diffraction were grown from
Et2O/MeCN.
complex
Te-Cr
Te-C
Te
[Te{Cr(CO)5}2]2-
[MeTe{Cr(CO)5}2]-
2
0.35
-0.39 -1.36
0.36
0.93
0.91
+0.40 -1.36 -0.86
+1.17 -1.43 -0.85
-0.04 -1.34
0.37
[Te{Cr(CO)5}3]2-
0.35a
0.34b
0.35a
0.35b
3
0.92
0.68 -1.39 -0.83
a Calculated at the level of B3LYP/LANL2DZ. b Calculated at the level
of MP2/ LANL2DZ.
Table 4. Results of Natural Bond Order and Natural
Population Analyses of the Te-X-Te Complexes 9, 10, 11,
and [H2CTe2{Cr(CO)5}4]2- (X ) Hg, O, and CH2)
Reaction of [Me4N]2[Te{Cr(CO)5}3] with ClH2C(C6H4)2CH2Cl
in THF. ClH2C(C6H4)2CH2Cl (0.21 g, 0.84 mmol) was added to a
THF solution (30 mL) of [Me4N]2[Te{Cr(CO)5}3] (1.48 g, 1.74
mmol) in an ice-water bath. The olive green solution became
yellowish-brown instantly. After being stirred for 60 min, the
solution was filtered, and the solvent was evaporated under vacuum.
The residue was washed several times with hexanes/Et2O and
extracted with THF to yield a yellow sample of [Me4N]2[H2C-
(C6H4)2CH2Te2{Cr(CO)5}6] ([Me4N]2[8]) (0.31 g, 0.18 mmol) (21%
based on ClH2C(C6H4)2CH2Cl). IR (νCO, THF): 2065 w, 2043 s,
1975 w, 1944 vs, 1900 vs cm-1. Anal. Calcd for [Me4N]2[8]: C,
1
35.98; H, 2.09; N, 1.61. Found: C, 37.42; H, 2.78; N, 1.58. H
NMR (400 MHz, DMSO-d6, 300 K, ppm): δ 3.98 (s, CH2), δ 7.49,
7.32 (m, C6H4) (chemical shifts not given for [Et4N]+). 13C NMR
(100 MHz, DMSO-d6, 300 K, ppm): δ -0.98 (CH2), 126.6, 129.0,
137.8, 143.0 (C6H4), 213.6, 218.3, 220.6, 225.9 (CrCO) (chemical
shifts not given for [Me4N]+). Crystals of [Me4N]2[8] suitable for
single-crystal X-ray diffraction were grown from hexanes/Et2O/
THF.
Wiberg bond index
natural charge
Cr X
complex
Te-Cr
Te-X
Te
9 (X ) Hg)
0.35
0.33
0.40
0.37
0.50
0.46
0.72
0.90
-0.37 -1.34 +0.97
-0.07 -1.34 +0.97
+0.59 -1.40 -0.90
+0.45 -1.37 -0.94
10 (X ) Hg)
11 (X ) O)
[H2CTe2{Cr(CO)5}4]2-
(X ) CH2)
Reaction of [Et4N]2[Te{Cr(CO)5}2] with HgCl2 in MeCN.
HgCl2 (0.09 g, 0.33 mmol) was added to a MeCN solution (20
mL) of [Et4N]2[Te{Cr(CO)5}2] (0.41 g, 0.53 mmol) in an ice-
water bath. The green solution became orange instantly and was
then stirred for 30 min to produce an orange-brown solution. The
solution was filtered, and the solvent was evaporated under vacuum.
The residue was washed several times with Et2O and extracted with
THF to yield a reddish-orange sample of [Et4N]2[HgTe2{Cr(CO)5}4]
([Et4N]2[9]) (0.31 g, 0.21 mmol) (79% based on [Et4N]2[Te{Cr-
(CO)5}2]). IR (νCO, THF): 2044 s, 2032 s, 1938 vs, 1922 m, 1878
s cm-1. Anal. Calcd for [Et4N]2[9]: C, 29.00; H, 2.71; N, 1.88.
Found: C, 29.13; H, 2.52; N, 2.05. Crystals of [Et4N]2[9] suitable
for single-crystal X-ray diffraction were grown from Et2O/MeOH/
THF.
a Calculated at the level of B3LYP/LANL2DZ. b Calculated at the level
of MP2/LANL2DZ.
Reaction of [Me4N][ClCH2Te{Cr(CO)5}3] ([Me4N][5]) with
[Me4N]2[Te{Cr(CO)5}3] in MeCN. [Me4N]2[Te{Cr(CO)5}3] (0.28
g, 0.33 mmol) was added to a MeCN solution (20 mL) of [Me4N]-
[5] (0.27 g, 0.33 mmol) at ambient temperature. The resulting
solution was stirred for 26 h to produce a reddish-orange solution.
The solution was filtered, and the solvent was evaporated under
vacuum. The residue was washed several times with Et2O and
extracted with THF to yield a reddish-orange sample of [Me4N]2[H2-
CTe2{Cr(CO)5}6] ([Me4N]2[6]) (0.32 g, 0.20 mmol) (61% based
on [Me4N][5]). IR (νCO, THF): 2045 w, 2034 w, 1932 vs, 1880 s
cm-1
.
Reaction of [Et4N]2[Te{Cr(CO)5}2] with ClH2C(C6H4)2CH2Cl
in Acetone. ClH2C(C6H4)2CH2Cl (0.14 g, 0.56 mmol) was added
to an acetone solution (20 mL) of [Et4N]2[Te{Cr(CO)5}2] (0.88 g,
1.14 mmol) in an ice-water bath. The green solution became orange
instantly. After being stirred for 30 min, the solution was filtered,
Reaction of [Et4N]2[Te{Cr(CO)5}3] with HgCl2 in THF. HgCl2
(0.17 g, 0.63 mmol) was added to a THF solution (30 mL) of
[Et4N]2[Te{Cr(CO)5}3] (1.24 g, 1.29 mmol) in an ice-water bath.
The olive green solution became reddish-orange instantly and was
then stirred for 30 min to yield a red solution. The solution was

6194 Organometallics, Vol. 26, No. 25, 2007
Shieh et al.
Figure 11. The spatial graphs (isovalue ) 0.02-0.04) of the selected frontier molecular orbitals of the Te-X-Te complexes (X ) Hg,
O, and CH2).
filtered, and the solvent was evaporated under vacuum. The residue
was washed several times with Et2O and extracted with THF to
produce a red sample of [Et4N]2[HgTe2{Cr(CO)5}6] ([Et4N]2[10])
(0.51 g, 0.27 mmol) (43% based on HgCl2). IR (νCO, THF): 2057
s, 2032 s, 1980 w, 1946 vs, 1938 vs, 1895 s cm-1. Anal. Calcd for
[Et4N]2[10]: C, 29.57; H, 2.16; N, 1.50. Found: C, 29.66; H, 2.32;
N, 1.69. Crystals of [Et4N]2[10] suitable for single-crystal X-ray
diffraction were grown from Et2O/MeOH/THF.
Reaction of [Et4N]2[Te{Cr(CO)5}2] with O2 in MeCN. Oxygen
gas was bubbled through a MeCN solution (25 mL) of [Et4N]2-
[Te{Cr(CO)5}2] (0.34 g, 0.44 mmol) in an ice-water bath. The
green solution became reddish-brown instantly. After being stirred
for 1 h, the solution was filtered, and the solvent was evaporated
under vacuum. The residue was washed several times with Et2O
and extracted with CH2Cl2 to produce a reddish-brown sample of
[Et4N]2[OTe2{Cr(CO)5}4] ([Et4N]2[11]) (0.27 g, 0.21 mmol) (95%
based on [Et4N]2[Te{Cr(CO)5}2]). IR (νCO, THF): 2045 m, 2034
m, 1933 vs, 1882 s cm-1. Anal. Calcd for [Et4N]2[11]: C, 33.26;
H, 3.10; N, 2.16. Found: C, 32.87; H, 3.48; N, 2.42. Crystals of
[Et4N]2[11] suitable for single-crystal X-ray diffraction were grown
from hexanes/CH2Cl2.
Reaction of [Et4N]2[HgTe2{Cr(CO)5}4] ([Et4N]2[9]) with HgCl2
in THF. HgCl2 (0.03 g, 0.11 mmol) was added to a THF solution
(25 mL) of [Et4N]2[9] (0.40 g, 0.27 mmol) in an ice-water bath.
The orange solution became reddish-orange instantly and was then
stirred for 30 min to produce a red solution. The solution was
filtered, and the solvent was evaporated under vacuum. The residue
was washed several times with Et2O and extracted with THF to
yield a red sample of [Et4N]2[HgTe2{Cr(CO)5}6] ([Et4N]2[10]) (0.10
g, 0.05 mmol) (19% based on [Et4N]2[9]).
Reaction of [Et4N]2[Te{Cr(CO)5}3] with O2 in THF. Oxygen
gas was bubbled through a THF solution (20 mL) of [Et4N]2[Te-
{Cr(CO)5}3] (0.61 g, 0.63 mmol) at -40 °C. The olive green
solution became yellow-brown instantly. After being stirred for 30

Reaction of [Et4N]2[Te{Cr(CO)5}n] toward Electrophiles
Organometallics, Vol. 26, No. 25, 2007 6195
Table 6. Crystallographic Data for 2, [Me4N][3], [Et4N][4], and [PPN][5]
2
[Me4N][3]
[Et4N][4]
[PPN][5]
empirical formula
fw
C12H6Cr2O10Te
541.77
C20H15Cr3NO15Te
792.93
C19H22ClCr2NO10Te
691.43
C52H32ClCr3NO15P2Te
1291.81
cryst syst
space group
crystal
monoclinic
P21/n
0.18 × 0.15 × 0.09
triclinic
P1h
0.40 × 0.20 × 0.15
monoclinic
P21/n
0.20 × 0.06 × 0.05
monoclinic
P21/c
0.30 × 0.25 × 0.20
dimens, mm
a, Å
b, Å
c, Å
R, deg
â, deg
10.4279(2)
12.1706(3)
14.0655(4)
8.892(8)
12.670(5)
13.25(1)
90.90(5)
90.66(7)
91.76(6)
1492(2)
2
9.282802(2)
13.3823(1)
22.5814(5)
14.989(1)
20.001(2)
18.590(2)
99.893(1)
100.218(1)
98.42(1)
γ, deg
V, Å3
1758.56(7)
4
2.046
2.908
Nonius
2759.7(1)
4
1.664
1.968
Nonius
5513(1)
4
1.520
1.270
Nonius
Z
D(calcd), g cm-3
µ, mm-1
diffractometer
1.765
2.097
Nonius
(Kappa CCD)
0.71073
200(2)
(CAD4)
0.71073
293(2)
(Kappa CCD)
0.71073
293(2)
(CAD4)
0.71073
293(2)
radiation (λ), Å
temp, K
θ range for data collecn, deg
2.23-25.69
0.56/0.79
2752
(Rint ) 0.0767)
0.039/0.102
1.53-24.92
0.54/0.72
4059
(Rint ) 0.0267)
0.053/0.146
2.26-25.06
0.78/0.87
2757
(Rint ) 0.0748)
0.058/0.154
1.50-24.92
0.71/0.74
6591
(Rint ) 0.0279)
0.039/0.117
Tmin/Tmax
no. of indep reflns
(I > 2σ(I))
R1a/wR2a
(I > 2σ(I))
R1a/wR2a
0.054/0.129
0.073/0.157
0.116/0.183
0.077/0.136
(all data)
2
-
2
2
a The functions minimized during least-squares cycles were R1 ) ∑||Fo| - |Fc||/∑|Fo| and wR2 ) [∑[w(Fo
Fc )2]/∑[w(Fo )2]]1/2
.
Table 7. Crystallographic Data for [Et4N]2[7], [Me4N]2[8], [Et4N]2[9], [Et4N]2[10], and [Et4N]2[11]
[Et4N]2[7]
[Me4N]2[8]
[Et4N]2[9]
[Et4N]2[10]
[Et4N]2[11]
empirical formula
fw
C58H68Cr4N2O22Te2
1608.34
C60H52Cr6N2O32Te2
1880.24
C36H40Cr4HgN2O20Te2
1484.49
C46H40Cr6HgN2O30Te2
1868.59
C36H40Cr4N2O21Te2
1299.90
cryst syst
space group
crystal
monoclinic
P21/n
0.80 × 0.60 × 0.44
monoclinic
P21/n
0.20 × 0.11 × 0.07
monoclinic
P21/c
0.21 × 0.16 × 0.12
triclinic
P1h
0.16 × 0.09 × 0.03
orthorhombic
Fddd
0.30 × 0.25 × 0.10
dimens, mm
a, Å
b, Å
c, Å
R, deg
â, deg
9.357(3)
36.21(1)
10.548(3)
9.8092(1)
18.6258(2)
41.9228(5)
15.2744(2)
11.0433(2)
30.4798(6)
10.2579(2)
12.6000(2)
12.9949(3)
89.3168(7)
72.3148(7)
85.5263(1)
1595.24(5)
1
1.945
4.361
Nonius
(Kappa CCD)
11.744(3)
35.263(6)
51.38(1)
94.136(5)
94.850(7)
93.7891(6)
γ, deg
V, Å3
3564(2)
2
1.499
7632.1(2)
4
1.636
1.656
Nonius
(Kappa CCD)
0.71073
200(2)
5129.9(2)
4
1.922
4.988
Nonius
(Kappa CCD)
0.71073
200(2)
21 276(8)
16
1.623
1.940
Nonius
(CAD4)
0.71073
293(2)
Z
D(calcd), g cm-3
µ, mm-1
diffractometer
1.465
Siemens
(SMART CCD)
0.71073
293(2)
radiation (λ), Å
temp, K
0.71073
200(2)
θ range for data collecn, deg
2.01-25.00
0.77/0.96
5917
(Rint ) 0.0470)
0.085/0.211
2.08-25.96
0.74/0.87
8398
(Rint ) 0.0999)
0.056/0.140
1.83-25.06
0.40/0.46
6612
(Rint ) 0.0574)
0.046/0.109
2.09-25.03
0.61/0.73
4465
(Rint ) 0.0702)
0.044/0.103
1.58-24.91
0.71/0.82
2707
(Rint ) 0.0000)
0.035/0.085
Tmin/Tmax
no. of indep reflns
(I > 2σ(I))
R1a/wR2a
(I > 2σ(I))
R1a/wR2a
0.089/0.214
0.118/0.191
0.073/0.135
0.066/0.135
0.102/0.105
(all data)
2
2
2
a The functions minimized during least-squares cycles were R1 ) ∑||Fo| - |Fc||/∑|Fo| and wR2 ) [∑[w(Fo - Fc )2]/∑[w(Fo )2]]1/2
.
min, the solution was filtered, and the solvent was evaporated under
vacuum. The residue was washed several times with Et2O and
extracted with THF to produce a sample of [Et4N]2[Te2{Cr(CO)5}4]-
(0.11 g, 0.09 mmol) (29% based on [Et4N]2[Te{Cr(CO)5}3]), which
was further confirmed by X-ray analysis. IR (νCO, THF): 2058 w,
[Et4N]2[11]. Selected crystallographic data for 2, [Me4N][3], [Et4N]-
[4], [PPN][5], [Et4N]2[7], [Me4N]2[8], [Et4N]2[9], [Et4N]2[10], and
[Et4N]2[11] are shown in Tables 6 and 7. Selected distances and
angles for 2, [Me4N][3], [Et4N][4], [PPN][5], [Et4N]2[7], [Me4N]2-
[8], [Et4N]2[9], [Et4N]2[10], and [Et4N]2[11] are shown in Table 8.
Data collection for 2, [Et4N][4], [Me4N]2[8], [Et4N]2[9], and [Et4N]2-
[10] was conducted using a Brucker-Nonius Kappa CCD diffrac-
tometer with graphite-monochromated Mo KR radiation at 298 K.
2038 m, 2031 s, 1965 w, 1929 vs, 1907 w, 1873 s cm-1
.
X-ray Structural Characterization of 2, [Me4N][3], [Et4N]-
[4], [PPN][5], [Et4N]2[7], [Me4N]2[8], [Et4N]2[9], [Et4N]2[10], and

6196 Organometallics, Vol. 26, No. 25, 2007
Shieh et al.
Table 8. Selected Bond Distances (Å) and Bond Angles (deg)
for 2, [Me4N][3], [Et4N][4], [PPN][5], [Et4N]2[7], [Me4N]2[8],
[Et4N]2[9], [Et4N]2[10], and [Et4N]2[11]
using a Nonius (CAD-4) diffractometer with graphite-monochro-
mated Mo KR radiation at 293 K in the 2θ range of 2.0-50°. An
empirical absorption correction by azimuthal (ψ) scans was
applied.21 Data collection for [Et4N]2[7] was conducted using a
Siemens SMART CCD (charged coupled device) diffractometer.
The structures were solved by direct methods and were refined by
SHELXL packages.22 All of the non-hydrogen atoms for 2, [Me4N]-
[3], [Et4N][4], [PPN][5], [Et4N]2[7], [Me4N]2[8], [Et4N]2[9], [Et4N]2-
[10], and [Et4N]2[11] were refined with anisotropic temperature
factors. Additional crystallographic data in the form of CIF files
are available as Supporting Information.
2
Te(1)-C(11)
Te(1)-C(12)
Te(1)-Cr(1)
Te(1)-Cr(2)
2.135(7)
2.135(5)
2.6400(9)
2.6468(9)
C(11)-Te(1)-C(12)
C(11)-Te(1)-Cr(1)
C(12)-Te(1)-Cr(1)
C(11)-Te(1)-Cr(2)
C(12)-Te(1)-Cr(2)
Cr(1)-Te(1)-Cr(2)
93.2(3)
110.3(2)
105.7(2)
112.4(2)
108.7(2)
122.36(3)
[Me4N][3]
Te(1)-C(16)
Te(1)-Cr(1)
Te(1)-Cr(2)
Te(1)-Cr(3)
2.154(7)
2.717(2)
2.723(3)
2.734(2)
C(16)-Te(1)-Cr(1)
C(16)-Te(1)-Cr(2)
Cr(1)-Te(1)-Cr(2)
C(16)-Te(1)-Cr(3)
Cr(1)-Te(1)-Cr(3)
Cr(2)-Te(1)-Cr(3)
100.2(2)
103.2(2)
118.41(6)
102.3(2)
114.37(6)
114.80(6)
Computational Details. All calculations reported in this study
were performed via the density functional theory (DFT) with
Becke’s three-parameter (B3) exchange functional and the Lee-
Yang-Parr (LYP) correlation functional (B3LYP)16,17 or the
second-order Møller-Plesset (MP2)23 method with a LanL2DZ
basis set using the Gaussian 03 series of packages.24 The geometries
of all of the calculated complexes were taken from the crystal
structures without further modification. Wiberg bond indices18 and
natural charges19 were evaluated using the Weinhold NBO method.25
Graphic representations of the molecular orbitals were obtained
using Gaussview 3.0.
[Et4N][4]
Te(1)-C(11)
Te(1)-Cr(2)
Te(1)-Cr(1)
2.140(8)
2.713(1)
2.726(1)
C(11)-Te(1)-Cr(2)
C(11)-Te(1)-Cr(1)
Cr(1)-Te(1)-Cr(2)
98.9(2)
103.6(2)
118.27(4)
[PPN][5]
Te(1)-C(16)
Te(1)-Cr(2)
Te(1)-Cr(1)
Te(1)-Cr(3)
2.181(5)
C(16)-Te(1)-Cr(2)
C(16)-Te(1)-Cr(1)
Cr(2)-Te(1)-Cr(1)
C(16)-Te(1)-Cr(3)
Cr(2)-Te(1)-Cr(3)
Cr(1)-Te(1)-Cr(3)
105.4(2)
104.2(2)
117.25(3)
97.0(1)
112.13(3)
117.39(3)
2.7097(9)
2.7164(9)
2.7329(8)
Acknowledgment. This work was supported by National
Science Council of Taiwan (NSC 95-2113-M-003-009-MY3 to
M.S.). We are also grateful to the National Center for High-
Performance Computing, where the Gaussian package and
computer time were provided. Our gratitude also goes to the
Academic Paper Editing Clinic, NTNU.
[Et4N]2[7]
Te(1)-C(11)
Te(1)-Cr(1)
Te(1)-Cr(2)
2.17(1)
2.724(2)
2.727(2)
C(11)-Te(1)-Cr(1)
C(11)-Te(1)-Cr(2)
Cr(1)-Te(1)-Cr(2)
100.8 (3)
106.5(3)
114.19(6)
[Me4N]2[8]
Te(1)-C(31)
Te(1)-Cr(3)
Te(1)-Cr(2)
Te(1)-Cr(1)
Te(2)-C(44)
Te(2)-Cr(6)
Te(2)-Cr(5)
Te(2)-Cr(4)
2.226(7)
2.726(1)
2.734(1)
2.756(1)
2.214(8)
2.734(1)
2.738(1)
2.744(1)
C(31)-Te(1)-Cr(3)
C(31)-Te(1)-Cr(2)
Cr(3)-Te(1)-Cr(2)
C(31)-Te(1)-Cr(1)
Cr(3)-Te(1)-Cr(1)
Cr(2)-Te(1)-Cr(1)
C(44)-Te(2)-Cr(6)
C(44)-Te(2)-Cr(5)
Cr(6)-Te(2)-Cr(5)
C(44)-Te(2)-Cr(4)
Cr(6)-Te(2)-Cr(4)
Cr(5)-Te(2)-Cr(4)
106.9(2)
106.2(2)
113.12(4)
98.2(2)
113.26(4)
117.17(4)
110.1(2)
99.2(2)
113.17(4)
106.40(2)
114.30(4)
112.36(4)
Supporting Information Available: X-ray crystallographic files
in CIF format for 2, [Me4N][3], [Et4N][4], [PPN][5], [Et4N]2[7],
[Me4N]2[8], [Et4N]2[9], [Et4N]2[10], and [Et4N]2[11]. Computational
detailsforcomplexes[Te{Cr(CO)5}n]2-(n)2,3),[MeTe{Cr(CO)5}2]-,
2, 3, 4, 5, 9, 10, 11, and [H2CTe2{Cr(CO)5}4]2-. This material is
available free of charge via the Internet at http://pubs.acs.org.
OM700789A
[Et4N]2[9]
Hg(1)-Te(1)
Hg(1)-Te(2)
Te(1)-Cr(2)
Te(1)-Cr(1)
Te(2)-Cr(4)
Te(2)-Cr(3)
2.6395(6)
2.6398(6)
2.751(1)
2.781(1)
2.726(1)
2.745(1)
Te(1)-Hg(1)-Te(2)
Hg(1)-Te(1)-Cr(2)
Hg(1)-Te(1)-Cr(1)
Cr(2)-Te(1)-Cr(1)
Hg(1)-Te(2)-Cr(4)
Hg(1)-Te(2)-Cr(3)
Cr(4)-Te(2)-Cr(3)
173.79(2)
98.56(3)
(21) North, A. C. T.; Philips, D. C.; Mathews, F. S. Acta Crystallogr.
1968, A24, 351.
(22) Sheldrick, G. M. SHELXL97, version 97-2; University of Go¨ttin-
gen: Germany, 1997.
98.75(3)
115.67(4)
103.83(3)
105.64(3)
116.92(4)
(23) Møller, C.; Plesset, M. S. Phys. ReV. 1934, 46, 618.
(24) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb,
M. A.; Cheeseman, J. R.; Montgomery, J. A., Jr.; Vreven, T.; Kudin, K.
N.; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.;
Mennucci, B.; Cossi, M.; Scalmani, G.; Rega, N.; Petersson, G. A.;
Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.;
Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Klene, M.; Li,
X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Bakken, V.; Adamo, C.;
Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.;
Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.;
Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich,
S.; Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A.
D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A.
G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.;
Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham,
M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.;
Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; Pople, J. A. Gaussian
03, revision B.04; Gaussian, Inc.: Wallingford, CT, 2004.
[Et4N]2[10]
Hg(1)-Te(1)
Cr(1)-Te(1)
Cr(2)-Te(1)
Cr(3)-Te(1)
2.6955(4)
2.731(1)
2.741(1)
2.725(1)
Te(1)-Hg(1)-Te(1a)
Hg(1)-Te(1)-Cr(3)
Hg(1)-Te(1)-Cr(1)
Cr(3)-Te(1)-Cr(1)
Hg(1)-Te(1)-Cr(2)
Cr(3)-Te(1)-Cr(2)
Cr(1)-Te(1)-Cr(2)
180.00(2)
106.39(3)
104.06(3)
112.87(4)
98.87(3)
114.90(4)
117.35(4)
[Et4N]2[11]
O(11)-Te(1a)
O(11)-Te(1)
Cr(1)-Te(1)
Cr(2)-Te(1)
2.252(5)
2.252(5)
2.746(1)
2.728(1)
Te(1a)-O(11)-Te(1)
O(11)-Te(1)-Cr(2)
O(11)-Te(1)-Cr(1)
Cr(3)-Te(1)-Cr(1)
108.2(3)
94.8(2)
106.11(5)
112.88(3)
An empirical absorption correction by multiscans was applied. Data
collection for [Me4N][3], [PPN][5], and [Et4N]2[11] was conducted
(25) Reed, A. E.; Curtiss, L. A.; Weinhold, F. Chem. ReV. 1988, 88,
899.