Uranium - Sulfilimine chemistry: Synthesis and characterization of Cp*2UCl(NSPh2) and Cp*2U(NSPh2)2

Article abstract of DOI:10.1021/om020678i

Two imido derivatives of U(IV), Cp*₂UCl(NSPh₂) (1; Cp* = pentamethylcyclopentadienyl) and Cp*₂U(NSPh₂)₂) (2), have been prepared in high yield from Cp*₂)UCl₂) and LiNSPh₂

Full text of DOI:10.1021/om020678i

Organometallics 2002, 21, 5799-5802
5799
Ur a n iu m -Su lfilim in e Ch em istr y: Syn th esis a n d
Ch a r a cter iza tion of Cp *2UCl(NSP h 2) a n d Cp *2U(NSP h 2)2
Kanahara A. N. S. Ariyaratne,*,† Roger E. Cramer,*,‡ and J ohn W. Gilje*,§
Chemistry Department, University of Hawaii at Manoa, 2545 The Mall,
Honolulu, Hawaii 96822, Chemistry Department, J ames Madison University,
Harrisonburg, Virginia 22807, and Institute of Fundamental Sciences, Massey University,
Palmerston North, New Zealand
Received August 19, 2002
Two imido derivatives of U(IV), Cp*2UCl(NSPh2) (1; Cp* ) pentamethylcyclopentadienyl)
and Cp*2U(NSPh2)2 (2), have been prepared in high yield from Cp*2UCl2 and LiNSPh2.
Alternatively, 1 and 2 can be synthesized by treating Cp*2UCl[(CH2)2PPh2] with anhydrous
HNSPh2. Cp*2U(NSPh2)2 is the first structurally characterized uranium bis(sulfilimide)
complex. Its short U-N distance suggests significant uranium-imido multiple-bond
character.
In tr od u ction
The sulfilimide ion [NSPh2]- is electronically very
similar to the [CHPR3]- and [NPPh3]- ligands whose
organo-actinide chemistry we have reported.22-38 Al-
though several transition-metal-sulfilimide complexes
are known,39,40 only a single structurally characterized
uranium sulfilimide complex has been reported.41 The
synthesis of stable sulfilimide complexes using the
Early-transition-metal-imido complexes have been of
great interest.1-3 Many of these complexes belong to the
bent-metallocene family.4-11 Although a broad range of
transition-metal imido complexes are known, only a few
f-element imido complexes have been reported.12-18
While the set of compounds is limited, the Cp*2An (An
) actinide) bent-metallocene framework is able to
support imido complexes.12-18 The ability of the Cp*2-
An fragment to form stable complexes has been at-
tributed to factors such as the high polarity of the
actinide-element bonds that it forms, the enhanced
coordinative flexibility of the 5f ions, and the tendency
of the f orbitals to take part in bonding.19-21
(19) Arney, D. S.; Burns, C. J . J . Am. Chem. Soc. 1995, 117, 9448.
(20) Brennan, J . G.; Anderson, R. A. J . Am. Chem. Soc. 1985, 107,
514.
(21) Warner, B. P.; Scott, B. L.; Burns, C. J . Angew. Chem., Int. Ed.
1998, 37, 959.
(22) Marks, T. J .; Ernest, R. D. In Comprehensive Organometallic
Chemistry; Wilkinson, D., Stone, F. G. A., Abel, E. W., Eds.; Perga-
mon: Oxford, U.K., 1982; Vol. 3.
(23) Marks, T. J .; Day, V. W. Fundamental and Technological
Aspects of Organo-f-Element Chemistry; Marks, T. J ., Fragala, I. L.,
Eds.; Reidel: Dordecht, The Netherlands, 1985.
(24) Cramer, R. E.; Maynard, R. B.; Gilje, J . W. J . Am. Chem. Soc.
1978, 100, 5562.
† Massey University.
‡ University of Hawaii at Manoa.
§ J ames Madison University.
(1) Wigley, D. E. Prog. Inorg. Chem. 1994, 42, 439.
(2) Nugent, W. A.; Mayer, J . M. Metal-Ligand Multiple Bonds;
Wiley: New York, 1988.
(3) Nugent, W. A.; Haymore, B. L. Coord. Chem. Rev. 1980, 31, 123.
(4) Walsh, P. J .; Hollander, F. J .; Bergman, R. G. J . Am. Chem. Soc.
1992, 110, 8729.
(25) Cramer, R. E.; Maynard, R. B.; Gilje, J . W. Inorg. Chem. 1980,
19, 2564.
(26) Cramer, R. E.; Maynard, R. B.; Gilje, J . W. Inorg. Chem. 1981,
20, 2466.
(27) Cramer, R. E.; Maynard, R. B.; Paw, J . C.; Gilje, J . W.
Organometallics 1983, 2, 1336.
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Soc. 1992, 114, 1708.
(6) Baranger, A. M.; Walsh, P. J .; Bergman, R. G. J . Am. Chem.
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1993, 12, 3705.
(28) Cramer, R. E.; Maynard, R. B.; Paw, J . C.; Gilje, J . W. J . Am.
Chem. Soc. 1981, 103, 3589.
(29) Cramer, R. E.; Mori, A. L.; Maynard, R. B.; Gilje, J . W.; Tatsumi,
K.; Nakamura, A. J . Am. Chem. Soc. 1984, 106, 5920.
(30) Cramer, R. E.; Engelhardt, U.; Maynard, R. B.; Higa, K. T.;
Gilje, J . W. Organometallics 1987, 6, 41.
(8) Weiberg, N.; Haring, H. W.; Schubert, U. Z. Naturforsch., B 1980,
35B, 599.
(9) Gambarotta, S.; Chiesi-Villa, A.; Guastini, C. J . Organomet.
Chem. 1984, 270, C49.
(31) Cramer, R. E.; Maynard, R. B.; Paw, J . C.; Gilje, J . W.
Organometallics 1982, 1, 869.
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Chem. Soc. 1984, 106, 1853.
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Soc. 1985, 107, 7945.
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Maunder, G. H.; Mountford, P. J . Chem. Soc., Chem. Commun. 1992,
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1992, 114, 10068.
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Chem., Int. Ed. Engl. 1984, 23, 912.
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6, 2010.
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106, 7245.
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(17) Brennan, J . G.; Anderson, R. A. J . Am. Chem. Soc. 1985, 107,
514.
(37) Cramer, R. E.; J eong, J . H.; Richmann, P. N.; Gilje, J . W.
Organometallics 1990, 9, 1141.
(38) Cramer, R. E.; Edelmann, F.; Mori, A. L.; Roth, S.; Gilje, J . W.;
Tatsumi, K.; Nakamuara, A. Organometallics 1988, 7, 841.
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Sheldrick, G. M. Chem. Ber. 1988, 121, 1377.
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Naturforsch., B 1988, 43B, 1490.
(18) Cramer, R. E.; Panchanatheswaran, K.; Gilje, J . W. J . Am.
Chem. Soc. 1984, 106, 1853.
(41) Williams, V. C.; Muller, M.; Leech, M.; Denning, R. G.; Green,
M. L. H. Inorg. Chem. 2000, 39, 2538.
10.1021/om020678i CCC: $22.00 © 2002 American Chemical Society
Publication on Web 11/27/2002

5800 Organometallics, Vol. 21, No. 26, 2002
Ariyaratne et al.
7 Hz, m-C6H5), 6.18 (t, 4H, J ) 7 Hz, p-C6H5). IR (cm-1): 3075
m, 3010 m, 2890 m, 2860 m, 2300 w, 1965 w, 1585 w, 1465 w,
1425 m, 1300 w, 1080 s, 1000 vs, 990 s. Anal. Calcd for
Cp*2U framework appeared to us as a sensible target.
In a previous paper we described the synthesis and
structural characterization of Cp*2UCl2(HNSPh2), where
the imino hydrogen of HNSPh2 is hydrogen-bonded to
a chloro ligand.42 Since our initial attempts to produce
the sulfilimide complex Cp*2UCl(NSPh2) by dehydro-
chlorination of Cp*2UCl2 were unsuccessful, we looked
into alternative routes for its synthesis.43 Although Me3-
Si derivatives are commonly used in transition-metal
chemistry for replacing coordinated halides with other
anions, in our hands no reaction occurred between Me3-
SiNSPh2 and Cp*2UCl2.43 However, the two organou-
ranium imido complexes Cp*2UCl(NSPh2) (1) and Cp*2U-
(NSPh2)2 (2) could be obtained by the treatment of
LiNSPh2 with Cp*2UCl2 and from reactions of HNSPh2
with Cp*2UCl(CH2)2PPh2. Compounds 1 and 2 are the
only Cp*2U-sulfilimide complexes currently known. In
this paper we present their synthesis and characteriza-
tion.
C
44H50N2S2U: C, 58.13; H, 5.54; N, 3.08. Found: C, 57.10; H,
5.40; N, 2.77.
A saturated solution of Cp*2U(NSPh2)2 in tetrahydrofuran
produced dark red prismatic crystals upon standing at room
temperature for several weeks. These were washed with 2 ×
0.5 mL of pentane and dried under vacuum.
Rea ction s of HNSP h 2 w ith Cp *2UCl(CH2)2P P h 2. A.
P r ep a r a tion of Cp *2UCl(NSP h 2) (1). To a solution of 304
mg (0.40 mmol) of Cp*2UCl(CH2)2PPh2 in 25 mL of toluene was
added 80 mg (0.40 mmol) of solid anhydrous HNSPh2 slowly
with stirring at room temperature. A yellow precipitate began
to form as soon as the addition of HNSPh2 was started. Stirring
was continued for a further 3 h, and the yellow precipitate
was removed from the dark red solution by filtering through
a medium-porosity frit. The solution was evaporated to dry-
ness, rinsed with 2 mL of pentane, and dried under vacuum
to yield 193 mg (64%) of Cp*2UCl(NSPh2). The Cp*2UCl-
(NSPh2) was always contaminated by a small amount of
Cp*2U(NSPh2)2. Proton NMR spectra indicated this to be <5%,
providing no evidence of equilibrium between the two species.
Due to this impurity and traces of solvent that remained after
drying under vacuum, elemental analysis of Cp*2UCl(NSPh2)
was not successful.
B. P r ep a r a tion of Cp *2U(NSP h 2)2 (2). The above proce-
dure was repeated by using 168 mg (0.80 mmol) of anhydrous
HNSPh2 and 304 mg (0.40 mmol) of Cp*2UCl(CH2)2PPh2 to
yield 254 mg (71%) of Cp*2U(NSPh2)2.
Rea ction s of Me3SiNSP h 2 w ith Cp *2UCl2. Two NMR
samples were prepared in toluene-d8 using 29 mg (0.05 mol)
of Cp*2UCl2/14 mg (0.05 mol) of Me3SiNSPh2 and 29 mg (0.05
mol) of Cp*2UCl2/28 mg (0.10 mol) of Me3SiNSPh2. The 1H
NMR spectra were recorded before and after heating the two
samples at 100 °C for 12 h. Finally, the samples were exposed
to UV light for 12 h and the 1H NMR spectra were re-recorded.
No evidence of any chemical reactions was observed under any
of the conditions employed.
Exp er im en ta l Section
All reactions were carried out under a dinitrogen atmo-
sphere using normal Schlenk, glovebox, and vacuum tech-
niques. Solvents were dried and deoxygenated over sodium-
benzophenone and were distilled prior to use. Cp*2UCl2 and
Cp*2UCl(CH2)2P(Ph)2 were prepared by using literature meth-
ods, and HNSPh2 was purchased from Aldrich Chemical Co.
as HNSPh2‚H2O, which was dehydrated under high vacuum
for 3 days at room temperature.44,45 LiNSPh2 was synthesized
by reacting HNSPh2 with n-BuLi in tetrahydrofuran at -78
°C and recrystallizing from tetrahydrofuran. NMR spectra
were obtained using a Nicolet QE 300 MHz spectrometer, and
samples were prepared in d6-benzene, d8-toluene, or d8-
tetrahydrofuran. IR spectra were recorded on a Perkin-Elmer
1430 spectrometer or a Nicolet-740 IR spectrometer operating
in the Fourier transform mode. Microanalyses were performed
by Oneida Research Services Inc., Whitesboro, NY.
Da ta Collection a n d Red u ction of X-r a y Da ta . Single
crystals of 1 and 2 were selected and mounted and sealed in
thin-walled glass capillaries under dinitrogen. A Nicolet R3
computer-controlled diffractometer with graphite-monochro-
mated Mo KR radiation (KR1 ) 0.709 30 Å, KR2 ) 0.713 59 Å)
and a scintillation detector with pulse height analyzer was
used for the measurement of diffraction intensities. During
data collection, the intensities of 3 standard reflections were
remeasured every 97 reflections in each data set. Data
manipulation, structure solution, and refinement were carried
out using the SHELXL 97-2 program system.46 Data were
corrected for Lorentz and polarization effects and for decay of
the intensities of check reflections during data collection, and
an empirical absorption correction was applied to each data
set. The structure of 1 belongs to the monoclinic space group
P21/n with unit cell parameters a ) 12.120(5) Å, b ) 13.249-
(6) Å, c ) 21.644(8) Å, â ) 95.57(3)°, V ) 3445(2) Å3, and Z )
4. While the structure could not be satisfactorily refined due
to disordered Cp* groups and detailed metrical data could not
be obtained, the molecular connectivity could be determined.
The structure of 2 belongs to the monoclinic space group
C2/c. The position of the uranium was determined by Patterson
methods, and the remaining atoms were located in subsequent
difference Fourier maps and least-squares refinements. All
non-hydrogen atoms were refined anisotropically. During the
first few least-squares refinements all non-hydrogen atoms
were revealed. After an empirical absorption correction, the
R and Rg values were found to be 6.52% and 7.67%, respec-
tively. H atoms were added at calculated positions to the Cp*
Rea ction s of LiNSP h 2 w ith Cp *2UCl2. A. P r ep a r a tion
of Cp *2UCl(NSP h 2) (1). A solution of 84 mg (0.40 mmol) of
LiNSPh2 in 25 mL of toluene was added slowly to 230 mg (0.40
mmol) of Cp*2UCl2 dissolved in 25 mL of toluene and stirred
at -78 °C for 3 h. The dark red solution was warmed slowly
to room temperature over 6 h, filtered through a medium-
porosity frit, and evaporated to dryness under vacuum to yield
127 mg (72%) of red-orange Cp*2UCl(NSPh2). 1H NMR (d8-
toluene; ppm): 2.27 (s, 30H, Cp*), 8.37 (t, 2H, J ) 7 Hz,
p-C6H5), 8.48 (t, 4H, J ) 7 Hz, m-C6H5), 14.12 (d, 4H, J ) 7
Hz, o-C6H5). In addition, weak NMR resonances arising from
trace amounts of Cp*2U(NSPh2)2 were observed at -0.2, 3.9,
5.9, and 6.2 ppm. IR (cm-1): 3010 m, 3000 m, 2975 m, 2820
m, 2690 w, 1555 w, 1475 w, 1450 w, 1360 m, 1270 w, 1025 s,
800 vs, 750 s, 695 s. Dark red prismatic crystallographic
quality crystals were obtained from a concentrated toluene
solution of 1 after the addition of pentane. These were washed
with 2 × 0.5 mL of pentane and dried under vacuum.
B. P r ep a r a tion of Cp *2U(NSP h 2)2 (2). The procedure
described above was repeated by using 168 mg (0.8 mmol) of
LiNSPh2 and 230 mg (0.40 mmol) of Cp*2UCl2 to yield 224
mg (62%) of Cp*2U(NSPh2)2. 1H NMR (d8-toluene; ppm): -0.24
(s, 30H, Cp*), 3.93 (d, 8H, J ) 7 Hz, o-C6H5), 5.93 (t, 4H, J )
(42) Cramer, R. E.; Ariyaratne, K. A. N. S.; Gilje, J . W. Z. Anorg.
Allg. Chem. 1995, 621, 1856.
(43) Ariyaratne, K. A. N. S. Ph.D. Thesis, University of Hawaii,
1992.
(44) Fagan, P. J .; Manriquez, J . M.; Maata, E. A.; Seyam, A. M.;
Marks, T. J . J . Am. Chem. Soc. 1981, 103, 6650.
(45) Cramer, R. E.; Roth, S.; Edelmanm, F.; Bruck, M. A.; Kim, C.
C.; Gilje, J . W. Organometallics 1989, 8, 119.
(46) SHELXTL Version 6.10, W95/98/NT/2000; Bruker-AXS, Madi-
son, WI, 2000.

Uranium-Sulfilimine Chemistry
Organometallics, Vol. 21, No. 26, 2002 5801
Ta ble 1. Cr ysta llogr a p h ic Da ta for 2
Sch em e 1. Su m m a r y of Rea ction s In volved in th e
Syn th esis of 1 a n d 2
empirical formula
C44H50N2S2U
fw
909.01
temp
wavelength
cryst syst
space group
293(2) K
0.710 73 Å
monoclinic
C2/c
unit cell dimens
a
b
c
15.699(12) Å
12.999(10) Å
19.126(12) Å
90°
R
â
92.98(6)°
γ
90°
V
3898(5) Å3
Z
4
density (calcd)
abs coeff
1.549 Mg/m3
4.304 mm-1
F(000)
cryst size
θ range for data collecn
index ranges
1808
0.5 × 0.5 × 0.5 mm3
2.04-32.61°.
0 e h e 23, 0 e k e 19,
-28 e l e 28
7482
no. of rflns collected
no. of indep rflns
completeness to θ ) 32.61°
refinement method
no. of data/restraints/params
goodness of fit on F2
7048 (R(int) ) 0.0123)
98.9%
full-matrix least squares on F2
7048/0/229
1.053
final R indices (I > 2σ(I))
R1 ) 0.0373, wR2 ) 0.0937
R1 ) 0.0459, wR2 ) 0.0988
1.509 and -2.030 e Å-3
salt [Me2Ph2P]+Cl- and the complex 2. Furthermore,
Cp*2UCl2(HNSPh2) was found to react with LiNSPh2
in the presence of HNSPh2 to produce 2.43 These
reactions are summarized in Scheme 1.
Both 1 and 2 dissolve in organic solvents such as
toluene, benzene, and tetrahydrofuran to form dark red
solutions and rapidly decompose upon exposure to
moisture and air. The 1H NMR spectra of 1 and 2 appear
in the same general region with paramagnetic effects
of uranium on the chemical shifts and considerable
variations in the positions of the Cp* and phenyl
protons.
R indices (all data)
largest diff peak and hole
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 2
U-N
2.143(3)
1.552(4)
1.814(5)
1.822(5)
2.808(4)
U-C(32)
U-C(33)
U-C(34)
U-C(35)
2.792(4)
2.785(4)
2.830(4)
2.806(4)
S-N
S-C(11)
S-C(21)
U-C(31)
U-N-S
N-S-C(11)
N-S-C(21)
152.2(2)
109.1(2)
107.6(2)
N-U-N(A)
C(11)-S-C(21)
96.0(2)
98.7(2).
The asymmetric unit in the crystal structure of 1
contains a molecule of 1 and half a pentane molecule
that lies at a center of inversion. Therefore, the unit
cell contains four molecules of 1 and two pentane
molecules. Due to disorder in the Cp* groups, the
structure of 1 could not be refined to satisfactory error
indices and the metrical parameters could not be
determined with certainty. Nonetheless, the overall
connectivity the molecule is clearly established as
methyl and phenyl groups, and final refinement yielded the
following R values: R1 ) 3.73%, wR2 ) 9.41% (I > 2σ(I)); R1
) 4.59%, wR2 ) 9.93% (all data). The crystal data and data
collection and refinement details for 2 are summarized in Table
1, and important bond lengths and bond angles in Table 2.
Resu lts a n d Discu ssion
Two methodologies have been developed for the
preparation of 1 and 2. They are summarized in Scheme
1. The failure of Me3SiNSPh2 to yield 1 and 2 from the
treatment with Cp*2UCl2 is in contrast with the suc-
cessful synthesis of [Ph4P]+[OUCl4NSPh2]- by the reac-
tion of [Ph4P]+[OUCl5]- with Me3SiNSPh2.41 The reac-
tions of Cp*2UCl2 with LiNSPh2 are analogous to those
of Cp*2UCl2 with LiNPPh3 that produce Cp*2UCl-
(NPPh3) and Cp*2U(NPPh3)2.47 In the reaction between
Cp*2UCl(CH2)2PPh2 and HNSPh2, the precooordinated
phosphoylide ligand abstracts the imino hydrogen of
sulfilimine and leaves as the free ylide, while the
[NSPh2]- moiety coordinates to uranium. This behavior
is similar to the reaction between Cp3UdCHPR3 and
HNSPh2, which yields Cp3UNSPh2.48 A second equiva-
lent of sulifilimine replaces the chloride of complex 1
with the [NSPh2]- ligand, producing the phosphonium
In contrast, the structure of complex 2 is well-
behaved. In the unit cell of 2, the molecule lies on a
2-fold axis of symmetry so that the asymmetric unit
contains one unique sulfilimido group and one unique
pentamethylcyclopentadienyl group. A perspective draw-
ing of 2 is given in Figure 1, and the bond lengths and
angles of 2 are summarized in Table 1.
Both complexes belong to the bent-metallocene family
with pseudotetrahedral coordination about uranium.
The ring centroid-U-ring centroid angle of 133.2° and
(47) Roth, S. Ph.D. Thesis, University of Hawaii, 1988.-
(48) Afzal, D.; Ariyaratne, K. A. N. S. Unpublished results, Univer-
sity of Hawaii, 1988.

5802 Organometallics, Vol. 21, No. 26, 2002
Ariyaratne et al.
Previously, we have argued that a similarly short U-N
distance in Cp3UNPPh3 implies U-N multiple bond-
ing,29 and the U-N bond in the recently reported
ketimido complex Cp*2U(NdCPh2)2, where the U-N
distances are 2.179(6) and 2.185(5) Å, has been de-
scribed as containing significant π-bonding.52 DFT
calculations on [Ph4P]+[OUCl4NPPh3]-, whose structure
and U-N separation are very similar to those in
[Ph4P]+[OUCl4NSPh2]-,41 indicate that the U-N bond
order is best described as 3.53 However, the difference
between the U-N distance in 2 and in [Ph4P]+[OUCl4-
NSPh2]- (1.920(3) Å)41 of 0.22 Å exceeds the ap-
proximate 0.14 Å expected between U(IV) and U(VI) on
the basis of ionic radii.54 Thus, consistent with the
realization that transition-metal-imide bond orders are
often variable and lie between 2 and 3,55 the U-N bond
in 2 is likely to be best described by a combination of
resonance structures containing both double- and triple-
bonded canonical forms.
F igu r e 1. Ortep diagram of the non-hydrogen atoms of 2
showing the atom-labeling scheme.
the average U-Cp* distance of 2.804(4) Å in 2 are in
the same ranges found for other Cp*2U complexes.49 The
U-N-S angle of 152.2(2)° in 2 is considerably larger
than that in Cp*2UCl2(HNSPh2), 134(1)°, and similar
to that in [Ph4P]+[OUCl4NSPh2]-, 157.5(2)°. This angle
is well within the range of corresponding M-N-S
angles seen among transition-metal sulfilimide com-
plexes.50 The N-U-N equatorial angle of 96.8(3)° in 2
is significantly narrower than the Cl-U-Cl angle in
Cp*2UCl2(HNSPh2), 145.9(3)° , and lies in the same
range found for the corresponding angles in the analo-
gous U(VI) complexes Cp*2U(NPh)2 and Cp*2U[N(1-
adamantyl)]2.13,21
Ack n ow led gm en t. We are grateful to the National
Science Foundation for support of this research. We
thank Prof. G. B. J ameson and Dr. J . J . Adams of
Massey University for their assistance provided in the
crystal structure refinement.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data and data collection and refinement parameters and
interatomic distances and angles for 2. This material is
available free of charge via the Internet at http://pubs.acs.org.
OM020678I
The most interesting structural feature is the U-N
bond distance in 2, 2.143(3) Å, which is much shorter
than that in Cp*2UCl2(HNSPh2), 2.44(3) Å, and on the
long end of the range observed in uranium imides.51
(51) Short U-N bond distances of uranium imido complexes: Cp*2U-
(N-2,4,6-t-Bu3C6H2), 1.952(12) Å;19 [Li(TMED)][Cp*2U(NC6H5)Cl], 2.051-
(14) Å;19 (MeC5H4)3UNPh, 2.019 Å;20 [(NSiMe3)2]3U(NSiMe3)F, 1.854-
(23) Å;14 [(NSiMe3)2]3U(NPh)F, 1.979(8) Å;14 Cp*2U(NPh)2, 1.952(7) Å;13
Cp*2U(N-2,6-i-Pr2C6H3)(O), 1.988(4) Å;12 Cp3UNPPh3, 2.07(2) Å;38
Cp*2U[N(1-adamantyl)2], 1.94(2), 1.96(2) Å;21 [Ph4P]+[OUCl4NSPh2],
1.920(3) Å.41
(52) Kiplinger, J . L.; Morris, D. E.; Scott, B. L.; Burns, C. J .
Organometallics 2002, 21, 3073.
(53) Kaltsoyannis, N. Inorg. Chem. 2000, 39, 6009.
(49) Cp*-U distances: Cp*2U(N-2,4,6-t-Bu3C6H2), 2.790(12) Å;19 [Li-
(TMED)][Cp*2U(NC6H5)Cl], 2.767(2) Å;19 Cp*2U(NPh)2, 2.718(10) Å;13
Cp*2U(N-2,6-i-Pr2C6H3)(O), 2.730(6) Å;12 Cp*2UCl2(HNSPh2), 2.77(2)
Å.42
(50) M-N-S angles of sulfilimide complexes: F4W(NSPh2)2, 171.7-
(3), 138.4(3)°;39 Cl2VO(NSPh2), 134.5(4), 141.9(4)°;40 [Cl2Fe(NSPh2)]2,
138.3(5), 129.6(3)°.40
(54) Shannon, R. D. Acta Crystallogr. 1976, A32, 751.
(55) Cudari, T. R. Chem. Rev. 2000, 100, 807. Cundari, T. R.; Gordon,
M. S. Coord. Chem. Rev. 1996, 147, 87.