Synthesis and molecular structure of tricarbonyl(diphenyl ditelluride)diiodoiron (CO)3FeI2(Te2Ph 2) and tricarbonyldiiodo[iodo(phenyl)tellurido]iron (CO) 3FeI2(PhTeI): First example of the coordination of unstable PhTeI to the transition metal atom

Article abstract of DOI:10.1134/S107032840811002X

A reaction of the tetramer [PhTeI]₄ with Fe(CO)₅ gave the monomeric complex (CO)₃FeI₂(Ph₂Te ₂) (I) containing a diphenyl ditelluride molecule linked with cis-tricarbonyldiiodoiron. According to X-ray diffraction data, the Fe-Te distance in complex I (2.5724(6) A) is appreciably shorter than the sum of the covalent Fe and Te radii and the Te-Te bond (2.7705(5) A) is only slightly longer than that in free Ph₂Te₂ (2.705(1) A). In the reaction of Fe(CO)₅ with PhTeI₃, a complex with PhTeI as a ligand to the transition metal atom was obtained for the first time. Unlike free PhTeI, the resulting complex (CO)₃FeI ₂(PhTeI) (II) is stable in air at room temperature for several days. According to X-ray diffraction data, the ligand PhTeI (Te-C 2.126(4) A, Te-I(3) 2.7548(5) A) is stabilized by the coordination of tellurium to both the iron (Te-Fe 2.5451(6) A) and iodine atoms (Te(1)-I(1) 3.1634(5) A). The latter coordination probably involves the vacant d orbital of tellurium and the lone electron pair on the iodide ligand.

Full text of DOI:10.1134/S107032840811002X

ISSN 1070-3284, Russian Journal of Coordination Chemistry, 2008, Vol. 34, No. 11, pp. 799–804. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © Yu.V. Torubaev, A.A. Pasynskii, P. Mathur, 2008, published in Koordinatsionnaya Khimiya, 2008, Vol. 34, No. 11, pp. 807–811.
Synthesis and Molecular Structure of Tricarbonyl(diphenyl
ditelluride)diiodoiron (CO)3FeI2(Te2Ph2)
and Tricarbonyldiiodo[iodo(phenyl)tellurido]iron
(CO)3FeI2(PhTeI): First Example of the Coordination
of Unstable PhTeI to the Transition Metal Atom
Yu. V. Torubaeva, A. A. Pasynskiia, and P. Mathurb
a Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia
b Indian Institute of Technology, Bombay, India
E-mail: hansmail@rambler.ru
Received May 21, 2008
Abstract—A reaction of the tetramer [PhTeI]4 with Fe(CO)5 gave the monomeric complex (CO)3FeI2(Ph2Te2)
(I) containing a diphenyl ditelluride molecule linked with cis-tricarbonyldiiodoiron. According to X-ray dif-
fraction data, the Fe–Te distance in complex I (2.5724(6) Å) is appreciably shorter than the sum of the covalent
Fe and Te radii and the Te–Te bond (2.7705(5) Å) is only slightly longer than that in free Ph2Te2 (2.705(1) Å).
In the reaction of Fe(CO)5 with PhTeI3, a complex with PhTeI as a ligand to the transition metal atom was
obtained for the first time. Unlike free PhTeI, the resulting complex (CO)3FeI2(PhTeI) (II) is stable in air at
room temperature for several days. According to X-ray diffraction data, the ligand PhTeI (Te–C 2.126(4) Å,
Te–I(3) 2.7548(5) Å) is stabilized by the coordination of tellurium to both the iron (Te–Fe 2.5451(6) Å)
and iodine atoms (Te(1)–I(1) 3.1634(5) Å). The latter coordination probably involves the vacant d orbital of
tellurium and the lone electron pair on the iodide ligand.
DOI: 10.1134/S107032840811002X
Organotellurium halides RTeX (X = Cl, Br, or I), in
contrast to their sulfur and selenium analogs, are very
unstable in the solid state and in solutions [1]. The dis-
covery of PhTeI was first reported in 1947 [2]. How-
ever, free PhTeI is unstable and tetramerizes from an
ether solution to give a Te4 square framework; the Te–
Te distances are 3.125(2)–3.175(2) Å (X-ray diffraction
data [3, 4]):
Note that when recrystallized from toluene even at
room temperature, PhTeI disproportionates into ele-
mental tellurium, Ph2TeI2, and PhTeI3 [8].
Monomeric compounds were stable enough only if
they contained bulky organic substituents R in steri-
cally hindered RTeI molecules: (1,3,5)-tert-
Bu3ë6H2TeI, (1,3,5)-tert-Bu3ë6H2TeBr, 1,5-[(1,3,5)-
iso-Pr3ë6H2))2C6H3TeI, and (Me2PhSi)3CTeI [9, 10]. In
addition, aryltellurium halides ArTeX react with
nucleophiles (such as phosphines, nitrogen bases,
halide anions, and thiourea derivatives) to give various
monomeric adducts in which the tellurium–halide
bonding is implemented as in charge-transfer com-
plexes [1, 11]:
Ph
Te
I
Te
I
Ph
Ph
Te
Te
Ph
I
I
Ar
Te
Ar
Te
Ar
The Te–Te bonds are substantially longer than those
in free diphenyl ditelluride Ph2Te2 (2.705(1) Å) [5],
shorter by ~1 Å than the double van der Waals radius of
tellurium (4.12 Å [6]), and appreciably shorter than the
Te–Te distances in a similar but largely ionized Te4
square framework of triphenyltelluronium para-tolyl-
telluride [(Ph3Te)(ArTe)]2 (3.323–3.596 Å) [7].
Teꢀ
X
X
X
L
Y
L
X = Cl, Br, I
L = thiourea,
Òselenourea
X, Y = Cl, Br, I X = Cl, Br, I
L = formyl,
azomethine, amine
azophenyl
phosphine, benzothiazole
799

800
TORUBAEV et al.
On the other hand, the presence of lone electron
IR (hexane, cm–1): 2080 s (CO), 2040 s (CO), 2025
pairs on the Te atom makes ArTeX promising nucleo- s (CO).
philic reagents. That is why it was interesting to study
X-ray diffraction analysis. Selected crystallo-
the behavior of PhTeI in reactions with electron-defi-
cient carbonyl complexes of transition metals (e.g.,
iron).
graphic parameters and a summary of data collection
and refinement for structures I and II are given in
Table 1. Both structures were solved by the direct
method and refined by the least-squares method on F2
in the anisotropic (for H atoms, isotropic) approxima-
tion with the SHELXTL program package [12]. The
hydrogen atoms were located geometrically. Selected
bond lengths and angles in structures I and II are given
in Table 2. Atomic coordinates and other structural
parameters of complexes I and II have been deposited
with the Cambridge Crystallographic Data Center
(CCDC nos. 687773 (I) and 687774 (II); see
http://www.ccdc.cam.ac.uk/data_request/cif).
EXPERIMENTAL
All manipulations dealing with the synthesis and
isolation of the complexes were carried out under pure
argon in dehydrated solvents. IR spectra were recorded
on a Specord 75IR spectrophotometer for pellets with
KBr and solutions in hexane.
Synthesis of (CO)3FeI2(Ph2Te2) (I). Iodine (0.12 g,
0.5 mmol) was added at 0°C (ice bath) to a magnetically
stirred orange solution of Ph2Te2 (0.20 g, 0.5 mmol) in
diethyl ether (30 ml). The resulting black red mixture
was stirred at 0°C for 10 min and then Fe(CO)5 (0.14 ml,
1 mmol) was added in one portion. The reaction mix-
ture promptly turned dark red. Stirring was continued
for an additional 30 min, while slowly warming the
mixture to ambient temperature. Then the solution was
concentrated in a water aspirator vacuum until it
became turbid and kept at –10°ë for 12 h. A dark red
crystalline precipitate formed. The yield was 0.25 g
(30%).
RESULTS AND DISCUSSION
A direct reaction of the tetramer [PhTeI]4 with
Fe(CO)5 gave dark red crystalline monomeric complex
I. In the complex, the diphenyl ditelluride molecule is
bound to cis-tricarbonyldiiodoiron:
Te
Te
For C15H10FeI2O3Te2 (M = 803.10)
Fe(CO)5 + PhTel
0°C, Et2O
anal. calcd (%):
Found (%):
C, 22.43;
C, 21.49;
H, 1.26.
H, 1.27.
OC
OC
I
I
Fe
IR (KBr, cm–1): 2080 s, 2040 s, 2025 s, 710 s, 670 m,
580 m.
CO
(I)
Synthesis of (CO)3FeI2(PhTeI) (II). Iodine (0.19 g,
~0.75 mmol) was added at 0°C (ice bath) to a magneti-
cally stirred orange solution of Ph2Te2 (0.1 g,
0.25 mmol) in diethyl ether (30 ml). The mixture was
stirred for 30 min, while warming it to ambient temper-
ature. A solution of Fe(CO)5 (0.07 ml, ~0.5 mmol) in
ether (10 ml) was added dropwise to the dark red mix-
ture containing a red precipitate of PhTeI3. The color of
the reaction mixture deepened and the precipitate dis-
solved almost completely within an hour. Then the
reaction mixture was evaporated to dryness in a water
aspirator vacuum and the residue was dissolved in ether
(20 ml). The solution was filtered and concentrated
with hexane (10 ml) in a water aspirator vacuum to
slight turbidity. The concentrate was kept at –10°ë for
12 h. The black crystalline precipitate that formed was
filtered off, washed with hexane, and dried in vacuo.
The yield of solvate II · C6H14 was 0.15 g (36%).
According to X-ray diffraction data (Fig. 1), the
Fe−Te distance in complex I (2.5724(6) Å) is apprecia-
bly shorter than the sum of the covalent Fe and Te radii
(1.34 + 1.37 = 2.71 Å) and the Te–Te bond
(2.7705(5) Å) is only slightly longer than that in free
Ph2Te2 (2.705(1) Å). Similar bond characteristics have
been reported in [13] for a mononuclear complex of
diphenyl ditelluride with Cr(CO)5 (Cr–Te 2.679(3) Å,
Te–Te 2.737 Å). However, the torsion angle CTeTeC in
complex I is 60.26° (in Cr(CO)5(Ph2Te2), this angle is
97.19°). The intermolecular contacts Te···I and í···íÂ
in structure I (3.668 and 3.800 Å, respectively) do not
affect the geometry of the diphenyl ditelluride ligand,
although they are responsible for the crystal packing in
which the molecules of complex I are united into chains
composed of dimeric units (Fig. 2). Since the Te–Te
contact is already substantial in the starting tetramer
(PhTeI)4, the complexation involves only its decompo-
sition into two fragments (PhTeI)2 and transfer of two
iodine atoms to the Fe atom.
For C15H19FeI3O3Te (M = 811.47)
anal. calcd (%):
Found (%):
C, 22.12;
C, 22.46;
H, 2.35.
H, 0.93.
Nevertheless, complex II with PhTeI as a ligand was
obtained in a reaction of Fe(CO)5 with PhTeI3:
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 11 2008

SYNTHESIS AND MOLECULAR STRUCTURE
801
Table 1. Selected crystallographic parameters and a summa- Table 2. Selected bond lengths and angles in structures I and II
ry of data collection and refinement for structures I and II
Bond
d, Å
Bond
d, Å
Value
Parameter
I
II
I
II
Diffractometer
Bruker APEX II CCD
M
803.10
725.28
Fe(1)–Te(1)
Fe(1)–I(1)
2.5724(6) Te(1)–Fe(1)
2.6482(7) Fe(1)–I(1)
2.6541(6) Fe(1)–I(2)
2.5451(6)
2.6478(7)
2.6541(7)
2.126(4)
Radiation (λ, Å)
MoKα
(0.71073)
MoKα
(0.71073)
Temperature, K
Space group
a, Å
100(2)
P1
296(2)
C2/c
Fe(1)–I(2)
6.2512(13)
11.1091(19)
15.536(3)
107.134(8)
99.294(8)
95.614(6)
1005.3(3)
2
17.0941(12)
10.4824(7)
18.0252(13)
90
b, Å
Te(1)–C(4)
Te(2)–C(10)
Te(1)–Te(2)
2.127(3)
2.119(4)
Te(1)–C(4)
Te(1)–I(1)
c, Å
α, deg
3.1634(5)
2.7548(5)
β, deg
90.3440(10)
90
2.7705(5) Te(1)–I(3)
γ, deg
V, Å3
3229.8(4)
8
Angle
ω, deg
Angle
ω, deg
Z
ρ(calcd), g/cm3
µ, mm–1
F(000)
2.653
2.983
I
II
6.674
8.432
720
2560
Te(1)Fe(1)I(1)
Te(1)Fe(1)I(2)
84.11(2)
84.37(2)
Te(1)Fe(1)I(1) 75.031(18)
Te(1)Fe(1)I(2) 84.74(2)
θ scan range, deg
Scan mode
1.94–29.00
ω
2.26–29.00
ω
Number of measured re-
flections
10864
17322
Fe(1)Te(1)Te(2) 105.030(17) Fe(1)Te(1)I(3) 108.293(19)
Fe(1)Te(1)I(1) 53.959(16)
Number of independent re-
5288
4306
flections (N1)
(Rint = 0.0220) (Rint = 0.0228)
Number of reflections with
I > 2σ(I) (N2)
4569
3694
Number of parameters re-
fined
208
154
I(3)Te(1)I(1) 162.197(15)
GOOF (F2)
R1 for N2
0.976
0.0230
0.0565
1.065
0.0288
0.1026
C(4)Te(1)I(1) 92.15(11)
wR2 for N1
C(4)Te(1)I(3) 92.70(12)
∆ρmax/∆ρmin, e Å–3
1.110/–0.615 1.270/–1.451
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 11 2008

802
TORUBAEV et al.
C(13)
C(15)
C(12)
C(14)
C(11)
C(8)
C(7)
C(10)
C(6)
C(9)
C(5)
C(4)
Te(2)
Te(1)
O(3)
O(2)
C(3)
C(2)
Fe(1)
C(1)
I(1)
I(2)
O(1)
Fig. 1. Molecular structure I.
metry of the coordination environment of the Fe atom
(the angle Te(1)Fe(1)I(1) is 75.031(18)8). However, the
Fe–I distances remain nearly equal (Fe(1)–I(1)
2.6478(7) Å, Fe(1)–I(2) 2.6541(7) Å). The ligands to
the Te atom make a typical T-shaped environment (the
angle I(1)Te(1)I(3) is 162.197(15)°).
I
Te
Fe(CO)5 + PhTeI3
0°C, Et2O
OC
OC
I
I
Fe
Note that in complex II, which is the first complex
with halo(phenyl)tellurium as a ligand to the transition
metal atom, the Te–Fe bond is strongly shortened and
differs only slightly from that in structure I and
(CO)3FeI2(Ph2Te) (III) (2.585(2) Å [14]). Apparently,
tellurium and iron in all the above complexes are linked
by not only donor–acceptor bonding but also a dative
interaction of the lone electron pair on the Fe atom with
the vacant d orbital of the Te atom.
CO
(II)
Black crystals of complex II (Fig. 3) are stable in
air at room temperature for several days. According to
X-ray diffraction data, the ligand PhTeI (Te–C 2.126(4) Å,
Te–I(3) 2.7548(5) Å) is stabilized by the coordination
of tellurium to both the iron (Te–Fe 2.5451(6) Å) and
iodine atoms (Te(1)–I(1) 3.1634(5) Å). Apparently, the
Because complexes I and II are structurally similar,
latter coordination involves the vacant dorbital of tellu- their IR spectra are virtually identical in the carbonyl
rium and the lone electron pair on the iodine atom absorption range (2080, 2040, and 2025 cm–1). For
bound to the Fe atom. This distorts the octahedral sym- complex III, analogous bands appear at 2087, 2042,
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 11 2008

SYNTHESIS AND MOLECULAR STRUCTURE
803
x
0
z
y
Te
I
Fe
C
O
Fig. 2. Molecular packing of complex I in the crystal.
C(7)
C(6)
C(8)
C(5)
C(9)
C(4)
I(3)
Te(1)
O(3)
C(3)
O(2)
I(1)
Fe(1)
C(2)
I(2)
C(1)
O(1)
Fig. 3. Molecular structure II.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 11 2008

804
TORUBAEV et al.
and 2025 cm–1, respectively. The splitting of the lower-
frequency band is explained by the unsymmetrical
ligand environment of the Fe atom.
5. Liabres, G., Dideberg, O., and Dupont, L., Acta Crystal-
logr., Sect. B: Struct. Crystallogr. Cryst. Chem., 1972,
vol. 28, p. 2438.
6. Bondi, A., J. Phys. Chem., 1964, vol. 68, p. 441.
7. Jeske, J., du Mont,W.W., and Jones P.G, Angew. Chem.,
Int. Ed. Engl., 1996, vol. 35, p. 2653.
8. Alcock, N.W. and Harisson, W.D., J. Chem. Soc., Dalton
Trans., 1984, p. 869.
9. Klapotke, T.M., Krumm, B., Noth, H., et al., Inorg.
Chem., 2005, vol. 44, p. 5254.
ACKNOWLEDGMENTS
This work was supported by the Russian Foundation
for Basic Research (project no. 06-03-32891), the Divi-
sion of the Chemistry and Materials Sciences of the
Russian Academy of Sciences (grant no. OKh 1.5), and
the RAS Prisidium (project no. 8P15).
10. Beckmann, J. and Hesse, M., Acta Crystallogr., Sect. E,
2007, vol. 63, p. 1674.
REFERENCES
11. Foss, O. and Husebye, S., Acta Chem. Scand., 1966,
vol. 20, p. 132.
1. Sadekov, I.D. and Minkin, V.I., Zh. Org. Khim., 1999,
12. Sheldrick, G., M, SHELXTL-97. Version 5.50, Madison
vol. 35, no. 7, p. 981.
(WI, USA): Bruker AXS Inc., 1997.
2. Schulz, P. and Klar, G., Z. Naturforsch., A, 1975,
vol. 30b, p. 40.
13. Pasynskii, A.A., Torubaev, Yu.V., Drukovskii, A.V.,
et al., Zh. Neorg. Khim., 1997, vol. 42, no. 1, p. 42 [Russ.
J. Inorg. Chem. (Engl. Transl.), vol. 42, no. 1, p. 36].
3. Lang, E.S., Fernandes, R.M., Silveira, E.T., et al., Z.
Anorg. Allg. Chem., 1999, vol. 625, p. 1401.
4. Boyle, P.D., Cross, W.I., Godfrey, S.M., et al., Angew. 14. Liaw, W-F., Chiang, M-H., Lai, C-H., et al., Inorg.
Chem., Int. Ed. Engl., 2000, vol. 39, p. 1796. Chem., 1994, vol. 33, p. 2493.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 11 2008