Lutetium alkyls supported by a dearomatized and functionalized terpyridine ligand: Preparation of fluorinated anilide complexes

Article abstract of DOI:10.1021/om701076n

Lutetium alkyl complexes supported by a monoanionic, tridentate ligand system formed by the dearomatization and functionalization of a 2,2′:6′,2″-terpyridine have been reacted with 2,4,6-triphenylaniline or the fluorinated anilines 4-F-C₆H ₄NH₂ and C₆F₅NH₂ to give both terminal mono(amide) and bis(amide) lutetium(III) complexes, which have been fully characterized. Both [^tBu₃(2′-Me ₃SiCH₂)tpy]Lu[NH(2,4,6-Ph₃-C₆H ₂)]₂ (3) and [^tBu₃(2′-Me ₃SiCH₂)tpy](C₅Me₅)Lu(NHC ₆F₅) (7) have been structurally characterized. The fluorinated anilide complexes [^tBu₃(2′-Me ₃SiCH₂)tpy](C₅Me₅)Lu(NHAr _F) (Ar_F = 4-F-C₆H₄ (6), C ₆F₅ (7)) provide rare examples of lutetium organofluorine complexes, with 7 featuring an intramolecular F...H-C interaction that is present in both solid state and solution.

Full text of DOI:10.1021/om701076n

Organometallics 2008, 27, 803–806
803
Lutetium Alkyls Supported by a Dearomatized and Functionalized
Terpyridine Ligand: Preparation of Fluorinated Anilide Complexes
Jason D. Masuda, Kimberly C. Jantunen, Brian L. Scott, and Jaqueline L. Kiplinger*
Los Alamos National Laboratory, Mail Stop J514, Los Alamos, New Mexico 87545
ReceiVed October 25, 2007
Summary: Lutetium alkyl complexes supported by a mono-
anionic, tridentate ligand system formed by the dearomatization
and functionalization of a 2,2′:6′,2′′-terpyridine haVe been
reacted with 2,4,6-triphenylaniline or the fluorinated anilines
4-F-C6H4NH2 and C6F5NH2 to giVe both terminal mono(amide)
and bis(amide) lutetium(III) complexes, which haVe been fully
characterized. Both [tBu3(2′-Me3SiCH2)tpy]Lu[NH(2,4,6-Ph3-
C6H2)]2 (3) and [tBu3(2′-Me3SiCH2)tpy](C5Me5)Lu(NHC6F5) (7)
haVe been structurally characterized. The fluorinated anilide
complexes [tBu3(2′-Me3SiCH2)tpy](C5Me5)Lu(NHArF) (ArF )
4-F-C6H4 (6), C6F5 (7)) proVide rare examples of lutetium
organofluorine complexes, with 7 featuring an intramolecular
F · · · H-C interaction that is present in both solid state and
solution.
set (B)5 is less prone to adverse side reactions, and this stability
has been exploited to stabilize extremely reactive systems such
as Ti alkylidenes,5d,f,j alkylidynes,5b,c and phosphinidines,5f Ta5a
alkylidenes, and Nb5e dinitrogen complexes. Our recent dis-
covery of the dearomatization and functionalization of 2,2′:6′,2′′-
terpyridines by lutetium(III) alkyls to form the monoanionic,
tridentate NNN′ ligand systems (C)6 prompted us to investigate
the ability of this unusual ligand framework to support f-element
complexes containing multiply bonded functional groups.7
Toward this goal, we now report the reactivity of one of these
systems, [tBu3(2′-Me3SiCH2)tpy]Lu(CH2SiMe3)2 (1), with anilines.
Introduction
Since the discovery of ferrocene,1 cyclopentadienyl-based
ligand sets have dominated the landscape of organometallic
chemistry. However, in recent years there has been a shift toward
using non-Cp, monoanionic, multidentate ligand sets to stabilize
highly reactive metal centers, in particular for the group 3 and
lanthanide metals.2 For example, the flexible bidentate “NacNac”
ligand framework (A) has been used extensively over the past
decade, but it tends to be susceptible to unwanted reactivity at
the imine functional groups.3,4 The rigid tridentate PNP ligand
Results and Discussion
Reaction of [tBu3(2′-Me3SiCH2)tpy]Lu(CH2SiMe3)2 (1) with
1 or 2 equiv of 2,4,6-triphenylaniline at ambient temperature
resulted in the formation of the mono(amide) and bis(amide)
complexes 2 (43% isolated yield) and 3 (73% isolated yield),
respectively, along with elimination of tetramethylsilane. For
3, the diastereotopic doublets attributed to the terpyridyl-based
methylene protons at δ 0.94 and 2.04 ppm (2JH-H ) 14.0 Hz)
* To whom correspondence should be addressed. Phone: 505-665-9553.
Fax: 505-667-9905. E-mail: kiplinger@lanl.gov.
(1) Kealy, T. J.; Pauson, P. L. Nature 1951, 168, 1039–1040.
(2) (a) Piers, W. E.; Emslie, D. J. H. Coord. Chem. ReV. 2002, 233–
234, 131–155. (b) Edelmann, F. T.; Freckmann, D. M. M.; Schumann, H.
Chem. ReV. 2002, 102, 1851–1896. (c) Mountford, P.; Ward, B. D. Chem.
Comm. 2003, 1797–1803.
2
are shifted from those of 1 (1.18 and 2.31 ppm; JH-H ) 14.5
Hz),6 while the two anilide N-H signals appear at δ 4.82 and
5.62 ppm. For 2, the terpyridyl-based methylene protons appear
at approximately δ 1.1 and 2.25 ppm (upfield signal obscured
(3) Feldman, J.; McLain, S. J.; Parthasarathy, A.; Marshall, W. J.;
Calabrese, J. C.; Arthur, S. D. Organometallics 1997, 16, 1514–1516.
(4) (a) For examples, see: Basuli, F.; Huffman, J. C.; Mindiola, D. J.
Inorg. Chim. Acta 2007, 360, 246–254. (b) Basuli, F.; Adhikari, D.;
Huffman, J. C.; Mindiola, D. J. J. Organomet. Chem. 2007, 692, 3115–
3120. (c) Bai, G.; Wei, P.; Stephan, D. W. Organometallics 2006, 25, 2649–
2655. (d) Bailey, B. C.; Basuli, F.; Huffman, J. C.; Mindiola, D. J.
Organometallics 2006, 25, 3963–3968. (e) Basuli, F.; Bailey, B. C.; Watson,
L. A.; Tomaszewski, J.; Huffman, J. C.; Mindiola, D. J. Organometallics
2005, 24, 1886–1906. (f) Basuli, F.; Tomaszewski, J.; Huffman, J. C.;
Mindiola, D. J. J. Am. Chem. Soc. 2003, 125, 10170–10171.
t
2
by a Bu peak; JH-H ) 14.5 Hz), while the anilide N-H peak
is located at δ 5.68 ppm. The asymmetric nature of 2 is revealed
by the diastereotopic doublets for the methylene protons of the
sole -CH2SiMe3 ligand at δ -0.35 and -0.45 ppm (2JH-H
)
11.3 Hz). Alternatively, complex 2 can be prepared by the
conproportionation of 1 and 3 (78% isolated yield). Heating
either complex 2 (benzene-d6, 60 °C, 20 days) or 3 (toluene-
d8, 75 °C, 1 day) did not result in the formation of the lutetium-
(5) (a) Gerber, L. C. H.; Watson, L. A.; Parkin, S.; Weng, W.; Foxman,
B. M.; Ozerov, O. V. Organometallics 2007, 26, 4866–4868. (b) Bailey,
B. C.; Fan, H.; Huffman, J. C.; Baik, M.-H.; Mindiola, D. J. J. Am. Chem.
Soc. 2007, 129, 8781–8793. (c) Bailey, B. C.; Huffman, J. C.; Mindiola,
D. J. J. Am. Chem. Soc. 2007, 129, 5302–5303. (d) Bailey, B. C.; Basuli,
F.; Huffman, J. C.; Mindiola, D. J. Organometallics 2006, 25, 3963–3968.
(e) Kilgore, U. J.; Yang, X.; Tomaszewski, J.; Huffman, J. C.; Mindiola,
D. J. Inorg. Chem. 2006, 45, 10712–10721. (f) Bailey, B. C.; Huffman,
J. C.; Mindiola, D. J.; Weng, W.; Ozerov, O. V. Organometallics 2005,
24, 1390–1393. (g) Fan, L.; Foxman, B. M.; Ozerov, O. V. Organometallics
2004, 23, 326–328. (h) Liang, L.-C.; Lin, J.-M.; Hung, C.-H. Organome-
tallics 2003, 22, 3007–3009. (i) Winter, A. M.; Eichele, K.; Mack, H.-G.;
Potuznik, S.; Mayer, H. A.; Kaska, W. C. J. Organomet. Chem. 2003, 682,
149–154. (j) Bailey, B. C.; Fout, A. R.; Fan, H.; Tomaszewski, J.; Huffman,
J. C.; Mindiola, D. J. Angew. Chem., Int. Ed. 2007, 46, 8246–8249.
(6) Jantunen, K. C.; Scott, B. L.; Hay, P. J.; Gordon, J. C.; Kiplinger,
J. L. J. Am. Chem. Soc. 2006, 128, 6322–6323.
(7) (a) Clark, D. L.; Gordon, J. C.; Hay, P. J.; Poli, R. Organometallics
2005, 24, 5447–5787. (b) Cui, D.; Nishiura, M.; Hou, Z. Angew. Chem.,
Int. Ed. 2005, 44, 959–962. (c) Giesbrecht, G. R.; Gordon, J. C. Dalton
Trans. 2004, 2387–2393. (d) Chan, H.-S.; Li, H.-W.; Xie, Z. Chem.
Commun. 2002, 652–653. (e) Gordon, J. C.; Giesbrecht, G. R.; Clark, D. L.;
Hay, P. J.; Keogh, D. W.; Poli, R.; Scott, B. L.; Watkin, J. G. Organome-
tallics 2002, 21, 4726–4734. (f) Xie, Z.; Wang, S.; Yang, Q.; Mak, T. C. W.
Organometallics 1999, 18, 1578–1579. (g) Hou, Z.; Yamazaki, H.; Fujiwara,
Y.; Taniguchi, H. Organometallics 1992, 11, 2711–2714. (h) Schumann,
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10.1021/om701076n CCC: $40.75
2008 American Chemical Society
Publication on Web 01/19/2008

804 Organometallics, Vol. 27, No. 4, 2008
Notes
Scheme 1. Synthesis of the Lutetium Anilide Complexes 2
and 3
Scheme 2. Synthesis of the Fluorinated Anilide Complexes 6
and 7
Figure 1. Thermal ellipsoid plot of 3 with ellipsoids projected at
the 50% probability level. The 2,4,6-Ph substituents on the two
anilide ligands have been omitted for clarity. Selected bond
distances (Å) and angles (deg): Lu(1)-N(1) 2.317(7), Lu(1)-N(2)
2.226(7), Lu(1)-N(3) 2.338(7), Lu(1)-N(4) 2.207(6), Lu(1)-N(5)
2.177(7), Lu(1)-N(4)-C(46) 147.6(6), Lu(1)-N(5)-C(28) 141.2(6),
N(1)-Lu(1)-N(3) 134.8(2).
-CH2SiMe3 group on the terpyridyl ligand shift slightly in the 1H
NMR spectrum from δ 1.23 and 2.17 ppm (2JH-H ) 14.4 Hz) for
5 to δ 1.18 and 2.19 ppm (2JH-H ) 14.5 Hz) for the 4-fluoro
derivative 6. However, in the case of the pentafluorophenyl
derivative 7 there is a major shift in the signals to δ 1.58 and 1.77
ppm (2JH-H ) 14.3 Hz). This significant deviation is attributed to
the interaction between an ortho fluorine atom on the C6F5 group
interacting with the methylene protons on terpyridyl ligand (Vide
infra). The anilide N-H resonances are observed at δ 4.60 and
4.52 ppm for complexes 6 and 7, respectively. The 19F NMR
spectrum of 6 displays the expected multiplet centered at δ -133.82
ppmforthesinglearomaticfluorine.Evidenceforthefluorine-methylene
interaction is also present in the 19F NMR spectrum of 7 with the
ortho fluorines appearing as a multiplet (instead of a doublet of
doublets) shifted slightly downfield to δ -162.66 ppm, rather than
upfield as expected, relative to C6F5NH2 (δ -163.94 (dd), -166.55
(t), -175.26 (m) ppm in C6D6). The meta and para fluorine
resonances all shift upfield relative to C6F5NH2, showing up at δ
-167.88 ppm (triplet) and -184.53 ppm (multiplet), respectively.
Single-crystal X-ray diffraction confirmed the existence of
the F · · · H-Cmethylene interaction in complex 7 (Figure 2).
Specifically, the structure reveals a fluorine-hydrogen interac-
tion between the ortho fluorine F(1) and one of the hydrogen
atoms attached to C(28). The F(1) · · · C(28) separation of
3.316(8) Å with a F(1)-H(28a)-C(28) angle of approximately
151° is consistent with intramolecular hydrogen bonding.10 The
F(1) · · · H(28a)-C(28) interaction has a distance of 2.434 Å,
which is shorter than the H · · · F van der Waals contact
separation of 2.55 Å.11 Thus, this interaction is maintained in
imido species 4 as monitored by 1H NMR spectroscopy; higher
temperatures afforded intractable materials.
Single crystals of 3 suitable for X-ray diffraction analysis
were obtained from a concentrated hexanes solution at -35 °C.
In addition to the modified terpyridyl ligand, two anilide ligands
are coordinated to the lutetium(III) center in a distorted square-
pyramidal geometry with one of the anilide ligands residing in
the apical position and the remaining nitrogen atoms completing
the base of the pyramid. The two terminal Lu-Nanilide bonds
have distances of 2.177(7) and 2.207(6) Å and are slightly
shorter than those reported for other structurally characterized
lutetium anilide complexes. For example, (C5Me5)Lu[N(H)Dipp]-
(CH2SiMe3)(bpy) and (C5Me5)Lu[N(H)Dipp]2(bpy)] (Dipp )
2,6- iPr2C6H3, bpy ) 2,2′-bipyridine) have Lu-Nanilide distances
ranging between 2.208(7) and 2.22(1) Å,8 and a Lu-Nanilide bond
distance of 2.238(4) Å was observed in the derivatized bipy-
ridine complex (C5Me5)Lu[2,2′-bipy-6-CH(O)CH2SiMe3]-
[N(H)Dipp].9 Lastly, the anionic amide moiety within the
terpyridyl ligand binds to the lutetium metal with a distance of
2.226(7) Å and compares well to the structurally analogous
systems [tBu3(2′-Me3SiCH2)tpy]Lu(CH2SiMe3)2 (1) (Lu-Namide
) 2.217(7) Å) and [tBu3(2′-Me3SiCH2)tpy](C5Me5)Lu(CH2-
SiMe3) (5) (Lu-Namide ) 2.253(4) Å).6
Reaction of the pentamethylcyclopentadienyl lutetium alkyl 5
with equimolar amounts of 4-fluoroaniline or pentafluoroaniline
at ambient temperature resulted in the formation of the monoanilide
complexes 6 (72% isolated yield) and 7 (60% isolated yield),
respectively. The diastereotopic methylene protons of the
1
both the solid state and solution, as evidenced by the H and
19F NMR data obtained for complex 7.
The terpyridyl amide-lutetium linkage, Lu(1)-N(1) )
2.239(5) Å, compares well with the analogous bond distances
(10) Desiraju, G. R.; Steiner, T. The Weak Hydrogen Bond; Oxford
University Press Inc.: New York, 2001; p 202.
(11) (a) Pauling, L. The Nature of the Chemical Bond; Cornell University
Press: Ithaca, NY, 1960; p 260. (b) Bondi, A. J. Phys. Chem. 1964, 68,
441–451.
(8) Cameron, T. M.; Gordon, J. C.; Scott, B. L. Organometallics 2004,
23, 2995–3002.
(9) Cameron, T. M.; Gordon, J. C.; Scott, B. L.; Tumas, W. Chem.
Commun. 2004, 1398–1399.

Notes
Organometallics, Vol. 27, No. 4, 2008 805
in complexes 1, 3, and 5. The terminal Lu-Nanilide bond has a
distance of 2.244(5) Å, which is slightly longer than those
reported for other lutetium anilide complexes8,9 and is likely a
consequence of the electron-withdrawing pentafluorophenyl
group on the amide ligand. There are only a handful12–14 of
structurally characterized lanthanide complexes suppor-
ted by fluorinated amide ligands: (η-C6H5Me)Nd[N(C6F5)2]3,12
Sm[N(H)C6F5]3(THF)3,12 and Sm[N(SiMe3)(C6F5)]3.13 However,
unlike these Sm and Nd complexes, which all exhibit
metal-fluorine interactions, the closest Lu-F distance in 7 is
2.943(4) Å, which is longer than the sum of the ionic radii of
both lutetium (0.861 Å) and fluorine (1.285 Å).15 The lack of
any Lu · · · F interactions in 7 is most likely the manifestation
of steric saturation at the lutetium metal center provided by
both the pentamethylcyclopentadienyl and alkylated terpyridyl
ligands.
In summary, although the modified terpyridyl framework C
is not able to support lutetium complexes containing multiply
bonded functional groups, we have demonstrated that both alkyl
complexes 1 and 5 react with anilines to give new lutetium
anilide complexes. Importantly, 6 and 7 provide rare examples
of lutetium complexes supported by fluorinated amide ligands,
with 7 featuring an intramolecular F · · · H-C interaction that is
maintained in both solid state and solution.
Figure 2. Thermal ellipsoid plot of 7 with ellipsoids projected at
the 50% probability level. The methyl groups on the C5Me5 ligand
have been omitted for clarity. Dashed line highlights the interaction
between F(1) and the methylene proton H(28a) on the functionalized
terpyridine ligand. Selected bond distances (Å) and angles (deg):
Lu(1)-N(1) 2.239(5), Lu(1)-N(2) 2.367(5), Lu(1)-N(3) 2.382(5),
Lu(1)-N(4)2.244(5),Lu(1)-N(4)-C(37)131.7(4),N(2)-Lu(1)-N(3)
133.53(19).
Experimental Section
General Procedures. All reactions and manipulations were
carried out using either a MBraun 150 B-G or a Vacuum
Atmospheres (MO 40-2 Dri-train) recirculating nitrogen atmosphere
drybox, or using standard Schlenk and high-vacuum-line techniques.
Glassware was dried at 150 °C before use. 1H, 13C{1H}, 19F, DEPT-
135, and two-dimensional 13C{1H}-1H NMR spectra were col-
lected using a Bruker Avance 300 MHz spectrometer. Chemical
shifts were referenced to the protio solvent impurity in benzene-d6
at δ 7.16 ppm (1H) and δ 128.39 ppm (13C{1H}). For 19F NMR
spectra, CFCl3 was used as an external reference at δ 0.00 ppm.
1H and 13C{1H} NMR assignments were confirmed through the
use of DEPT-135 and HMQC NMR experiments.
Melting points were determined with a Mel-Temp II capillary
melting point apparatus equipped with a Fluke 51 II K/J thermo-
couple using capillary tubes flame-sealed under nitrogen; values
are uncorrected. Mass spectrometric (MS) analyses were obtained
at the University of California, Berkeley Mass Spectrometry
Facility, using a VG ProSpec mass spectrometer. Elemental analyses
were performed at the University of California, Berkeley Microana-
lytical Facility, on a Perkin-Elmer Series II 2400 CHNS analyzer.
Unless otherwise noted, reagents were purchased from com-
mercial suppliers and used without further purification. Celite
(Aldrich), 4 Å molecular sieves (Aldrich), and alumina (Brockman
I, Aldrich) were dried under dynamic vacuum at 250 °C for 48 h
prior to use. Anhydrous toluene (Aldrich) and hexanes (Aldrich)
were passed through a column of activated alumina under nitrogen
and stored over activated 4 Å molecular sieves prior to use.
Benzene-d6 (Aldrich) was dried over activated 4 Å molecular sieves
prior to use. 4-Fluoroaniline (Aldrich) was passed through a column
of activated alumina and stored over activated 4 Å molecular sieves
prior to use. 4,4′,4′′-Tri-tert-butyl-2,2′:6′,2′′-terpyridine (Aldrich),
2,4,6-triphenylaniline (Aldrich), and pentafluoroaniline (Aldrich)
were purified by recrystallization from toluene at -35 °C. [tBu3(2′-
Me3SiCH2)tpy]Lu(CH2SiMe3)2 (1) and [tBu3(2′-Me3SiCH2)tpy]-
(C5Me5)Lu(CH2SiMe3) (5) were prepared according to literature
procedures.6
Synthesis of [tBu3(2′-Me3SiCH2)tpy]Lu[NH(2,4,6-Ph3-C6H2)]-
(CH2SiMe3) (2). Method A. A 125-mL side-arm flask equipped
with a stir bar was charged with [tBu3(2′-Me3SiCH2)tpy]Lu-
(CH2SiMe3)2 (1) (0.109 g, 0.13 mmol) and toluene (30 mL). To
the resulting dark green solution was added dropwise a 10 mL
toluene solution of 2,4,6-triphenylaniline (0.042 g, 0.13 mmol) with
stirring. The reaction mixture immediately turned a dark red color,
and stirring was continued for 90 min. The volatiles were removed
under reduced pressure to give 2 as an analytically pure dark red
powder (0.060 g, 0.06 mmol, 43%). Method B. A 20-mL scintil-
lation vial equipped with a stir bar was charged with 3 (0.130 g,
0.10 mmol) and toluene (10 mL). To the resulting room-temperature
dark red solution was added portionwise a 10 mL toluene solution
of 1 (0.076 g, 0.091 mmol). The resultant reaction mixture was
stirred at room temperature for 20 min. The volatiles were removed
under reduced pressure to give 2 as an analytically pure dark red
1
powder (0.152 g, 0.071 mmol, 78%). H NMR (benzene-d6, 301
K): δ 8.31 (d, 1H, 5.8 Hz, Ar-H), 8.17 (d, 1H, 5.8 Hz, Ar-H), 7.87
(d, 1H, 1.4 Hz, Ar-H), 7.65 (d, 1H, 1.4 Hz, Ar-H), 7.56–7.53 (m,
10H, Ar-H), 7.12–7.00 (m, 7H, Ar-H), 6.58 (m, 2H, Ar-H), 5.92
(s, 1H, Ar-H), 5.68 (s, 1H, NH), 5.32 (s, 1H, Ar-H), 2.25 (d, 1H,
14.0 Hz, CH2SiMe3), 1.42 (s, 9H, CMe3), 1.06 (s, 9H, CMe3), 0.98
(s, 9H, CMe3), 0.07 (s, 9H, CH2SiMe3), 0.01 (s, 9H, CH2SiMe3),
-0.35 (d, 1H, 11.3 Hz, CH2SiMe3), -0.45 (d, 1H, 11.3 Hz,
CH2SiMe3). The remaining CH2SiMe3 resonance is obscured by
the resonance at δ 1.06. 13C{H} NMR (benzene-d6, 301 K): δ
174.45 (s, CAr), 164.49 (s, CAr), 162.76 (s, CAr), 162.50 (s, CAr),
155.70 (s, CAr), 150.04 (s, CAr), 148 20 (s, CAr), 146.39 (s, CAr),
146.06 (s, CAr), 144.59 (s, CAr), 142.66 (s, CAr), 130.73 (s, CAr),
130.08 (s, CAr), 129.51 (s, CAr), 129.30 (s, CAr), 129.22 (s, CAr),
127.52 (s, CAr), 126.58 (s, CAr), 126.02 (s, CAr), 125.82 (s, CAr),
119.77 (s, CAr), 119.69 (s, CAr), 118.48 (s, CAr), 117.51 (s, CAr),
108.76 (s, CAr), 92.62 (s, CAr), 69.33 (s, CCH2SiMe3), 39.87 (s,
(12) Click, D. R.; Scott, B. L.; Watkin, J. G. Chem. Commun. 1999,
633–634.
(13) Click, D. R.; Scott, B. L.; Watkin, J. G. Acta Crystallogr., Sect. C:
Cryst. Struct. Commun. 2000, C56, 1095–1096.
(14) There is one example of a decamethyleuropocene complex with
an ArF-N-lanthanide architecture; however it is based on a reduced
diazabutadiene fragment, [C6F5NC(Me)C(Me)NC6F5]-: Moore, J. A.;
Cowley, A. H.; Gordon, J. C. Organometallics 2006, 25, 5207–5209.
(15) Shannon, R. D. Acta Crystallogr. 1976, A32, 751–767.

806 Organometallics, Vol. 27, No. 4, 2008
Notes
CH2SiMe3), 38.77 (s, CH2SiMe3), 35.70 (s CMe3), 35.36 (s CMe3),
34.51 (s CMe3), 30.50 (s, CMe3), 30.47 (s, CMe3), 30.39 (s, CMe3),
4.62 (s, CH2SiMe3), 1.35 (s, CH2SiMe3). Anal. Calcd for
C89H75N4LuSi2 (1071.39 g/mol): C, 66.14; H, 7.06; N, 5.23. Found:
C, 65.86; H, 6.95; N, 5.15. Mp ) 183–184 °C (dec).
173.79 (s, CAr), 163.97 (s, CAr), 163.10 (s, CAr), 162.86 (s, CAr),
155.87 (s, CAr), 155.86 (s, CAr), 149.83 (s, CAr), 148.38 (s, aryl
CAr), 147.87 (s, aryl CAr), 146.39 (s, CAr), 119.96 (s, CAr), 119.61
(s, CAr), 119.53 (s, CAr), 117.34 (d, 6.9 Hz, o-C6H4F), 116.68 (s,
CAr), 116.34 (s, C5Me5), 115.82 (d, 21.5 Hz, m-C6H4F), 111.79 (s,
CAr), 96.97 (s, CAr), 68.73 (s, CCH2SiMe3), 35.40 (s, CMe3), 35.31
(s, CMe3), 35.19 (s, CMe3), 32.28 (s, CH2SiMe3), 30.72 (s, CMe3),
30.48 (s, CMe3), 30.43 (s, CMe3), 11.47 (s, C5Me5), 0.37
(CH2SiMe3). 19F NMR (benzene-d6, 298 K): δ -133.82 (m, 1F).
Anal. Calcd for C47H66N4FLuSi (909.10 g/mol): C, 62.09; H, 7.32;
N, 6.16. Found: C, 61.85; H, 7.53; N, 5.90. MS(EI, 70 eV): m/z
909 (M+), 820 (M+ - SiMe4), 798 (M+ - NH(C6H4F)). Mp )
147–148 °C.
Synthesis of [tBu3(2′-Me3SiCH2)tpy]Lu[NH(2,4,6-Ph3-C6H2)]2
(3). A 125-mL side-arm flask equipped with a stir bar was charged
with [tBu3(2′-Me3SiCH2)tpy]Lu(CH2SiMe3)2 (1) (0.239 g, 0.29
mmol) and toluene (40 mL). To the dark green solution was added
portionwise a 10 mL toluene solution of 2,4,6-triphenylaniline
(0.147 g, 0.46 mmol) with stirring. The reaction mixture im-
mediately turned a dark red color, and stirring was continued for
30 min. The volatiles were removed under reduced pressure to give
3 as an analytically pure dark red powder (0.270 g, 0.21 mmol,
Synthesis of [tBu3(2′-Me3SiCH2)tpy](C5Me5)Lu(NHC6F5) (7). A
125-mL side-arm flask equipped with a stir bar was charged with
[tBu3(2′-Me3SiCH2)tpy](C5Me5)Lu(CH2SiMe3) (5) (0.370 g, 0.42
mmol) and hexanes (40 mL). To the dark green solution was added
a 10 mL hexanes solution of pentafluoroaniline (0.076 g, 0.42
mmol) with stirring. The resultant reaction mixture was stirred at
room temperature for 1 h. The volatiles were removed under
reduced pressure to give 7 as an analytically pure dark green powder
(0.247 g, 0.25 mmol, 60%). 1H NMR (benzene-d6, 298 K): δ 8.27
(d, 1H, 5.8 Hz, Ar-H), 8.12 (d, 1H, 5.8 Hz, Ar-H), 7.89 (s, 1H, 1.4
Hz, Ar-H), 7.65 (s, 1H, 1.4 Hz, Ar-H), 6.79 (dd, 1H, 5.8 Hz, 1.6
Hz, Ar-H), 6.69 (dd, 1H, 5.8 Hz, 1.6 Hz, Ar-H), 6.32 (s, 1H, 1.4
Hz, Ar-H), 5.33 (s, 1H, 1.4 Hz, Ar-H), 4.52 (s, 1H, NH), 1.83 (s,
15H, C5Me5), 1.77 (d, 1H, 14.3 Hz, CH2SiMe3), 1.58 (d, 1H, 14.3
Hz, CH2SiMe3), 1.39 (s, 9H, CMe3), 1.03 (s, 9H, CMe3), 0.97 (s,
9H, CMe3), -0.26 (s, 9H, CH2SiMe3). 13C{H} NMR (benzene-d6,
298 K): δ 173.70 (s, CAr), 164.15 (s, CAr), 162.94 (s, CAr), 162.86
(s, CAr), 149.76 (s, CAr), 147.70 (s, CAr), 147.52 (s, CAr), 146.47 (s,
CAr), 119.95 (s, CAr), 119.80 (s, CAr), 119.58 (s, CAr), 117.55 (s,
CAr), 117.37 (s, CAr), 117.01 (s, CAr), 116.97 (s, C5Me5), 115.70
(s, CAr), 115.24 (s, CAr), 110.98 (s, CAr), 97.27 (s, CAr), 68.89 (s,
CCH2SiMe3), 35.50 (s, CMe3), 35.29 (s, CMe3), 34.39 (s, CMe3),
31.43 (s, CH2SiMe3), 30.72 (s, CMe3), 30.46 (s, CMe3), 30.36 (s,
CMe3), 11.41 (s, C5Me5), 0.48 (s, CH2SiMe3). 19F NMR (benzene-
d6, 298 K): δ -162.66 (m, 2F, ortho), -167.88 (t, 2F, meta),
-184.53 (m, 1F, para). Anal. Calcd for C47H62N4F5LuSi (981.08
g/mol): C, 57.54; H, 6.37; N, 5.71. Found: C, 57.88; H, 6.73; N,
5.48. MS (EI, 70 eV): m/z 981 (M+), 893 (M+ - SiMe4), 799
(M+ - NH(C6F5)). Mp ) 195–196 °C.
1
73%). H NMR (benzene-d6, 298 K): δ 7.76 (d, 1H, 1.6 Hz, Ar-
H), 7.70 (d, 1H, 5.8 Hz, Ar-H), 7.57–7.55 (m, 6H, Ar-H), 7.51 (d,
1H, 1.6 Hz, Ar-H), 7.49–7.46 (m, 5H, Ar-H), 7.40–7.37 (m, 6H,
Ar-H), 7.26–7.16 (m, 2H, Ar-H), 7.13–6.81 (m, 16H, Ar-H), 6.59
(dd, 1H, 5.8 Hz, 1.9 Hz, Ar-H), 6.25 (dd, 1H, 5.8 Hz, 1.9 Hz, Ar-
H), 5.73 (s, 1H, Ar-H), 5.62 (s, 1H, NH), 5.24 (s, 1H, Ar-H), 4.82
(s, 1H, NH), 2.04 (d, 1H, 14.0 Hz, CH2SiMe3), 1.37 (s, 9H, CMe3),
1.08 (s, 9H, CMe3), 1.07 (s, 9H, CMe3), 0.94 (d, 1H, 14.0 Hz,
CH2SiMe3), -0.62 (s, 9H, CH2SiMe3). 13C{H} NMR (benzene-
d6, 298 K): δ 174.84 (s, CAr), 164.23 (s, CAr), 161.68 (s, CAr), 161.27
(s, CAr), 154.90 (s, CAr), 153.55 (s, CAr), 149.50 (s, CAr), 148.55 (s,
CAr), 147.01 (s, CAr), 145.93 (s, CAr), 144.32 (s, CAr), 144.10 (s,
CAr), 142.75 (s, CAr), 142.53 (s, CAr), 130.53 (s, CAr), 130.12 (s,
CAr), 129.85 (s, CAr), 129.66 (s, CAr), 129.61 (s, CAr), 129.22 (s,
CAr), 129.19 (s, CAr), 129.10 (s, CAr), 130.53 (s, CAr), 130.12 (s,
CAr), 129.93 (s, CAr), 129.85 (s, CAr), 129.66 (s, CAr), 129.61 (s,
CAr), 129.22 (s, CAr), 129.19 (s, CAr), 129.10 (s, CAr), 128.89 (s,
CAr), 128.48 (s, CAr), 128.24 (s, CAr), 128.17 (s, CAr), 127.76 (s,
CAr), 127.19 (s, CAr), 126.67 (s, CAr), 126.54 (s, CAr), 126.51 (s,
CAr), 126.03 (s, CAr), 125.83 (s, CAr), 119.75 (s, CAr), 119.28 (s,
CAr), 117.45 (s, CAr), 116.86 (s, CAr), 108.04 (s, CAr), 90.80 (s,
CAr), 68.52 (s, CCH2SiMe3), 39.00 (s, CH2SiMe3), 35.66 (s, CMe3),
35.27 (s, CMe3), 34.49 (s, CMe3), 30.54, (s, CMe3), 30.49 (s, CMe3),
30.36 (s, CMe3), 1.16 (s, CH2SiMe3). Anal. Calcd for C79H82N5LuSi
(1304.58 g/mol): C, 72.73; H, 6.34; N, 5.37. Found: C, 72.46; H,
6.63; N, 5.00. Mp ) 141–142 °C (dec).
Synthesis of [tBu3(2′-Me3SiCH2)tpy](C5Me5)Lu(NH-4-F-C6H4)
(6). A 125-mL side-arm flask equipped with a stir bar was charged
with [tBu3(2′-Me3SiCH2)tpy](C5Me5)Lu(CH2SiMe3) (5) (0.298 g,
0.34 mmol) and hexanes (30 mL). To the dark green solution was
added 4-fluoroaniline (0.032 mL, 0.34 mmol) with stirring. The
reaction mixture was stirred at room temperature for 1 h. The
volatiles were removed under reduced pressure to give 6 as an
analytically pure dark green powder (0.220 g, 0.24 mmol, 72%).
1H NMR (benzene-d6, 298 K): δ 8.25 (d, 1H, 5.8 Hz, Ar-H), 8.15
(d, 1H, 5.8 Hz, Ar-H), 7.87 (d, 1H, 1.4 Hz, Ar-H), 7.57 (d, 1H, 1.4
Hz, Ar-H), 6.85 (t, 2H, 8.8 Hz, Ar-H), 6.70 (dd, 1H, 5.8 Hz, 1.9
Hz, Ar-H), 6.60 (m, 3H, Ar-H), 6.28 (d, 1H, 1.4 Hz, Ar-H), 5.31
(d, 1H, 1.4 Hz, Ar-H), 4.60 (s, 1H, NH), 2.19 (d, 1H, 14.5 Hz,
CH2SiMe3), 1.88 (s, 15H, C5Me5), 1.38 (s, 9H, CMe3), 1.18 (d,
1H, 14.5 Hz, CH2SiMe3), 1.00 (s, 9H, CMe3), 0.97 (s, 9H, CMe3),
-0.36 (s, 9H, CH2SiMe3). 13C{H} NMR (benzene-d6, 298 K): δ
Acknowledgment. For financial support, we acknowledge
LANL (Director’s Postdoctoral Fellowship to J.D.M.), the
LANL G. T. Seaborg Institute for Transactinium Science
(Postdoctoral fellowship to J.D.M.; summer student fellow-
ship to K.C.J.), the Division of Chemical Sciences, Office
of Basic Energy Sciences, and the LANL Laboratory
Directed Research & Development Program.
Supporting Information Available: X-ray crystallographic data
for 3 and 7 (PDF, CIF). This material is available free of charge
via the Internet at http://pubs.acs.org.
OM701076N