Reactivity of pyridyl-1-azaallyl germanium(II) chloride: Synthesis of novel lithium germinate [{(PhC≡C)3Ge}3GeLi(Et 2O)3] and Ge(II)-M(I) (M = Cu and Au) adducts

Article abstract of DOI:10.1021/om060032g

The reaction of [Ge{N(SiMe₃)C(Ph)C(SiMe₃)(C ₅H₄N-2)}Cl] (1) with LiBu^t or LiC≡CPh in Et₂O afforded substituted products [Ge(R){N(SiMe₃)C(Ph) C(SiMe₃)(C₅H

Full text of DOI:10.1021/om060032g

Organometallics 2006, 25, 2851-2858
2851
Reactivity of Pyridyl-1-azaallyl Germanium(II) Chloride: Synthesis
of Novel Lithium Germinate [{(PhCtC)3Ge}3GeLi(Et2O)3] and
Ge(II)-M(I) (M ) Cu and Au) Adducts
Wing-Por Leung,* Cheuk-Wai So, Kim-Hung Chong, Kwok-Wai Kan, Hoi-Shan Chan, and
Thomas C. W. Mak
Department of Chemistry, The Chinese UniVersity of Hong Kong,
Shatin, New Territories, Hong Kong, China
ReceiVed January 11, 2006
The reaction of [Ge{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl] (1) with LiBut or LiCtCPh in Et2O
afforded substituted products [Ge(R){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}] [R ) But (2) or CtCPh (3)],
respectively. However, the one-pot reaction of 1 with PhCtCH and BunLi in Et2O afforded lithium
germinate [{(PhCtC)3Ge}3GeLi(Et2O)3] (4). Compound 1 can also undergo ligand transfer reaction with
LiAlH4 to give [AlH{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}2] (5). Treatment of 1 with excess NaBH4 in
THF afforded germanium(II) hydride-borane adduct [Ge(BH3){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}H]
(6). The reaction of 1 with MI (M ) Cu and Au) gave the first examples of Ge(II)-M(I) adducts [Ge-
(CuI){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl]4 (7) and [Ge(AuI){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}-
Cl] (8). Compounds 2-8 have been characterized by X-ray analysis.
cogen and transition metal complexes have also been investi-
gated.6 We have reported the synthesis of [Ge{N(SiMe3)C-
(Ph)C(SiMe3)(C5H4N-2)}Cl] and its reaction with chalcogens.7
Herein, we report the substitution and ligand transfer reaction
of [Ge{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl] and its reaction
with group 11 metal iodides.
Introduction
The chemistry of low-valent germanium complexes has
attracted much attention in the past decades.1 It has been realized
that this carbene analogue can be stabilized kinetically by using
bulky ligands and/or thermodynamically by using electron-
donating substituents at the germanium(II) center. Recently,
heteroleptic germanium chloride [RGeCl] complexes have been
synthesized by metathesis reaction. For example, [{HC-
(CMeNAr)2}GeX] (Ar ) 2,6-Pri2C6H3, X ) H, Me, Bun, OH;
Ar ) Ph, X ) I, Me, OMe, OTf),2 [MamxGeX] [Mamx )
methylamino-methyl-m-xylyl; X ) Me, Bun, But, CtCPh, OBut,
N3, N(SiMe3)2],3 [{Pri2ATI}GeX] (ATI ) aminotroponiminate;
X ) N3, OSO2CF3),4 and [(But)3Ge-Ge{C6H3-2,6-Mes}] (Mes
) 2,4,6-trimethylphenyl)5 have been reported. Recently, the
reactivities of heteroleptic germanium(II) chloride toward chal-
Results and Discussion
Substitution and Ligand Transfer Reaction. The reaction
of 1 with LiBut or LiCtCPh in Et2O afforded the substituted
products [Ge(R){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}] [R ) But
(2) or CtCPh (3)], respectively (Scheme 1). The products as
confirmed by X-ray structure analysis showed that compounds
2 and 3 are heteroleptic germanium(II) complexes with the
germanium bonded to a pyridyl-enamido ligand in N,N′-chelate
fashion and a But group or ethynyl substituent, respectively.
* To whom correspondence should be addressed. E-mail:
kevinleung@cuhk.edu.hk.
(1) (a) Davidson, P. J.; Harris, D. H.; Lappert, M. F. J. Chem. Soc.,
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Power, P. P.; Thorne A. J. J. Chem. Soc., Chem. Commun. 1983, 639. (c)
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2001, 20, 418. (r) Leung, W.-P.; Kwok, W.-H.; Weng, L.-H.; Law, L. T.
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(4) (a) Dias, H. V. R.; Wang, Z. J. Am. Chem. Soc. 1997, 119, 4650. (b)
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Y.-S.; So, C.-W.; Chan, H.-S.; Mak, T. C. W. Eur. J. Inorg. Chem. 2006,
808.
10.1021/om060032g CCC: $33.50 © 2006 American Chemical Society
Publication on Web 04/19/2006

2852 Organometallics, Vol. 25, No. 11, 2006
Leung et al.
Scheme 1
Scheme 2
Scheme 3
However, one-pot reaction of 1 with PhCtCH and BunLi in
Et2O gave [{(PhCtC)3Ge}3GeLi(Et2O)3] (4) instead of 3. The
mechanism for the formation of 4 is proposed in Scheme 2. It
is suggested that the intermediate 3 formed underwent a ligand
transfer reaction to give A. Subsequent addition reaction of A
with LiCtCPh formed [LiGe{CtCPh}3] (B) as the intermedi-
ate. The lithium germinate B then reacted as transfer reagent
with 1 to form C. Intermediate C underwent substitution and
addition reaction to afford 4. Similarly, germyllithium [(Me3-
Si)3GeLi(THF)3] has been prepared by Stalke and co-workers.8
Treatment of 1 with LiAlH4 in THF afforded [AlH-
{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}2] (5), as confirmed by
X-ray analysis. The result showed that 1 underwent a ligand
transfer reaction with LiAlH4. A similar result has been found
in the reaction of [{HC(CMeNAr)2}GeCl] with LiAlH4 to form
[{HC(CMeNAr)2}AlH2].2b In contrast, the reaction of 1 with
excess NaBH4 in THF afforded germanium(II) hydride-borane
adduct [Ge(BH3){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}H] (6).
Germylene acting as a Lewis base toward borane has been
demonstrated in [{Me2ATI}GePhfBPh3] (ATI ) aminotroponi-
minate)4a and [Ge{C6H3(NMe2)2-2,6}2BH3].9
(SiMe3)(C5H4N-2)}Cl] (8), respectively (Scheme 3). This result
demonstrated the Lewis base behavior of 1. To our knowledge,
compounds 7 and 8 are the first examples of a germanium-
(II)-copper(I) or -gold(I) adduct, although the Lewis base type
behavior of germylene toward transition metal complexes has
been investigated extensively.10 Recently, an example of a
germanium(II)-silver(I) adduct, [{Me2ATI}GeClfAg{(Pz-3,5-
(CF3)2)3BH}],11 has been reported.
Reaction with Group 11 Metal Iodides. The reaction of 1
with MI (M ) Cu and Au) afforded [Ge(CuI){N(SiMe3)C(Ph)C-
(SiMe3)(C5H4N-2)}Cl]4 (7) and [Ge(AuI){N(SiMe3)C(Ph)C-
(8) Freitag, S.; Herbst-Irmer, R.; Lameyer, L.; Stalke, D. Organometallics
1996, 15, 2839.
(9) Drost, C.; Hitchcock, P. B.; Lappert, M. F. Organometallics 1998,
17, 3838.
Spectroscopic Properties. Compound 2 is a red crystalline
solid, soluble in hydrocarbon solvents. Compounds 3-8 are
yellow crystalline solids, soluble in THF and sparingly soluble

Pyridyl-1-azaallyl Germanium(II) Chloride
Organometallics, Vol. 25, No. 11, 2006 2853
in Et2O and toluene. Compounds 2-8 are stable at room
temperature under inert atomosphere, but compound 8 is light-
sensitive in solution. These compounds have been characterized
by NMR spectroscopy and elemental analysis. Compound 6 has
also been characterized by IR spectroscopy.
1
The H NMR spectrum of 2 displayed one set of signals
assignable to the pyridyl-1-azaallyl ligand and But group,
respectively. The signals showed an upfield shift when compared
with 1. This is probably due to the electronic effect of the
substituents at the germanium.
In the 13C NMR spectrum of 3, the signals for the acetylenic
carbon atoms were observed at δ 112.1 and 115.8 ppm. These
signals are comparable to that of δ 109.6 and 111.2 ppm in
(Mamx)GeCtCPh.3
The 1H spectrum of 4 displayed one set of signals due to the
phenyl group and coordinated Et2O. In the 13C NMR spectrum,
the signals for the acetylenic carbon atoms were observed at δ
95.87 and 104.46 ppm, which showed a downfield shift
compared to free phenylacetylene (δ 78.6 and 84.6 ppm).12
1
The H NMR of 5 displayed three singlet signals and one
broad signal assigned to the two SiMe3 groups. It also showed
one set of signals due to the pyridyl and phenyl ring in the
normal range, consistent with the solid-state structure. The Al-H
chemical shift of δ 5.54 ppm in 5 is comparable to that of δ
5.61 ppm in [{2,4,6-Pri3C6H2}2AlH]213 and δ 4.72 ppm in [{N-
(SiMe3)C(Ph)C(SiMe3)2}AlH(µ-H)]2.14
Figure 1. Molecular structure of 2 (ellipsoids are drawn at the
30% probability level).
In the 1H NMR spectrum of 6, the Ge-H chemical shift of δ
6.07 ppm (broad singlet) at 298 K is similar to that of δ 6.70
ppm in [{HC(CMeNAr)2}GeH(BH3)]. However, a broad unre-
solved doublet of Ge-H at 5.95 and 5.96 ppm is observed at
223 K. A broad signal displayed at δ 0.3-1.5 ppm was assigned
to the protons of BH3. The 11B{1H} NMR signal of δ -38.88
ppm for 6 is similar to that of [{HC(CMeNAr)2}GeH(BH3)]
(-42 ppm)2b and [Ge{C6H3(NMe2)2-2,6}2BH3] (-35 ppm).9
1
The H and 13C NMR spectra of 7 and 8 are normal. The IR
absorptions at 1897 and 2149 cm-1 are indicative of the
existence of GeH and BH, respectively.
X-ray Structure. Compound 4 was crystallized as an ether
solvate in a stoichiometric ratio of 2:1. Compound 7 cocrys-
tallized with eight independent THF molecules. The molecular
structures with the atom-numbering schemes for compounds
2-8 are shown in Figures 1-7, respectively. Selected bond
distances (Å) and angles (deg) of 2-7 are listed in Tables 3-9,
respectively.
Figure 2. Molecular structure of 3 (ellipsoids are drawn at the
30% probability level).
Compound 2 is a monomeric heteroleptic germylene. The
pyridyl-1-azaallyl ligand is bonded in a N,N′-chelate fashion to
the germanium(II) center. The pyridyl-enamido character of the
pyridyl-1-azaallyl ligand was shown by short M-Namide, long
Namide-C, and short CdC bonds as compared with the η3-1-
azaallyl ligand (long M-N, short C-N, and long CdC bonds).15
The Ge-N(2) bond distance of 1.954(3) Å in 2 is comparable
to that in [Ge{N(SiMe3)2}2] (2.096(1), 2.088(6) Å)1b and [Ge-
{NCMe2(CH2)3CMe2}2] (1.90(1), 1.87(1) Å)1l. The Ge-N
distances of 1.954(3) and 2.059(3) Å in 2 are slightly longer
than that of 1.920(2) and 2.021(2) Å in 1. This shows the
influence of the substituents at the germanium center (the
electron-withdrawing Cl substituent vs the alkyl group). The
Ge-C(20) distance of 2.010(3) Å is similar to that of 2.002(4)
Å in [{CH(CMeNAr)2}Ge-Me] and 2.014(3) Å in [{CH-
(CMeNAr)2}Ge-(Bun)].2a
(10) Selected recent reviews and examples: (a) Petz, W. Chem. ReV.
1986, 86, 1019. (b) Lappert, M. F.; Rowe, R. S. Coord. Chem. ReV. 1990,
100, 267. (c) Herrmann, W. A.; Denk, M.; Behm, J.; Scherer W.; Klingan
F.-R.; Bock, H.; Solouki, B.; Wagner M. Angew. Chem., Int. Ed. Engl.
1992, 31, 1485. (d) Lappert, M. F.; Power P. P. J. Chem. Soc., Dalton
Trans. 1985, 51. (e) Lappert, M. F.; Miles, S. J.; Power P. P. J. Chem.
Soc., Chem. Commun. 1977, 458. (f) Hitchcock, P. B.; Lappert, M. F.;
Pierssens L. J.-M. Organometallics 1998, 17, 2686. (g) Ayers, A. E.; Dias,
H. V. R. Inorg. Chem. 2002, 41, 3259. (h) Tokitoh, N.; Manmaru, K.;
Okazaki, R. Organometallics 1994, 13, 167. (i) Barrau, J.; Rima, G.;
Amraoui, T. E. J. Organomet. Chem. 1998, 570, 163. (j) Kuhl, O.; Lo¨nnecke,
P.; Heinicke, J. Inorg. Chem. 2003, 42, 2836. (k) Litz, K. E.; Bender, J. E.;
Kampf, J. W.; Banaszak Holl, M. M. Angew. Chem., Int. Ed. Engl. 1997,
36, 496. (l) Litz, K. E.; Henderson, K.; Gourley, R. W.; Banaszak Holl, M.
M. Organometallics 1995, 14, 5008.
(11) Dias, H. V. R.; Wang, Z. Inorg. Chem. 2000, 39, 3890.
(12) Hesse, M.; Meier, H.; Zeeh, B. Spectroscopic Methods in Organic
Chemistry; Thieme Verlag: Stuttgart, Germany, 1984.
(13) Wehmschulte, R. J.; Ellison, J. J.; Ruhlandt-Senge, K.; Power, P.
P. Inorg. Chem. 1994, 33, 6300.
The structural features of 3 are similar to those found in 2.
The Ge(1)-C(20) and C(21)-C(22) bond distances of 2.004-
(14) Cui, C.; Roesky, H. W.; Noltemeyer, M.; Schmidt, H.-G. Organo-
metallics 1999, 18, 5120.
(15) Caro, C. F.; Lappert, M. F.; Merle, P. G. Coord. Chem. ReV. 2001,
219, 605.

2854 Organometallics, Vol. 25, No. 11, 2006
Leung et al.
Figure 3. Molecular structure of 4 (ellipsoids are drawn at the
25% probability level).
Figure 5. Molecular structure of 6 (ellipsoids are drawn at the
30% probability level).
the MO ab initio calculation of [(THF)2LiGe{C6H4-2-NMe2}3].16a
The average Ge-Ge bond distance is 2.464 Å, which is
comparable to those compounds containing Ge-Ge single bond
(2.41-2.48 Å).17 The average Ge-Cethynyl distance of 1.925 Å
is similar to that in [(Mamx)GeCtCPh] (2.001(4) Å) and
[(Mamx)GeCtCH] (1.989(6) Å).3 The average CtC distance
of 1.167 Å is slightly shorter than the C-C bond length of 1.204
Å in free acetylene.18
Compound 5 is a monomeric bis(pyridyl-1-enamido)alane.
The pyridyl-1-azaallyl ligand is bonded in an N,N′-chelate
fashion to the aluminum center and displays a trigonal bipyra-
midal geometry. The Al(1)-H(1) distance of 1.560(3) Å in 5
is similar to that of 1.509 Å in [Al{N(SiMe3)C(Ph)C(SiMe3)2}-
(µ-H)H]2 and 1.501(12) Å in [(Me3N)HAl{N(H)Dipp}2].19
14
Figure 4. Molecular structure of 5 (ellipsoids are drawn at the
30% probability level).
The Ge(1)-B(1) bond distance of 2.064(6) Å in 6 is
comparable to that of 2.041(11) Å in [Ge{C6H3(NMe2)2-2,6}2-
BH3],9 but slightly longer than that of 2.015(7) Å in [{HC-
(CMeNAr)2}GeH(BH3)]2b.
(4) and 1.213(5) Å are comparable to those in (Mamx)GeCt
CPh [Ge-Cethynl 2.001(4) Å, CtC 1.209(6) Å].3
Compound 7 is a complex with pyridyl-1-azaallyl germanium-
(II) chloride coordinated to the copper atoms of a distorted Cu4I4
cubane framework. This type of structure can also be found in
a CuI complex with a two-electron ligand such as Cu4(µ3-I)4L
(L ) NMe3, C5H5N, PPh3, AsPh3).20 The Ge(1)-Cu(1) bond
distance of 2.359(2) Å is longer than the theoretical calculation
of the Ge(II)-Cu(I) bond distance (2.250 Å).21 This may due
to the steric repulsion between the pyridyl-1-azaallyl ligand in
the cubane structure lengthening the Ge(II)-Cu(I) bond. All
the Cu‚‚‚Cu nonbonding and Cu-I distances in 7 are in the
Compound 4 is a monomeric base-stabilized lithium germi-
nate complex that exhibits two different germanium environ-
ments. Ge(2), Ge(3), and Ge(4) are bonded to three phenylacet-
ylenic groups and Ge(1). The four-coordinate Ge(1) is bonded
to three germyl atoms and Li(1). Each germanium center
displays a distorted tetrahedral geometry. No interaction between
CtC and Li was found. The Ge(1)-Li(1) distance of 3.066-
(15) Å is the longest among those of the characterized
lithiumgermyl compounds such as [(THF)2LiGe{C6H4-2-
NMe2}3] and [(THF)LiGe(SiMe3)3] (2.598(9)-2.759(24) Å).16
This suggests the ionic character of the Ge-Li bond in 4 is
more pronounced than the other similar compounds. The angle
sum at Ge(II) is 280.6°. This shows that the Ge(1) atom is almost
nonhybridized. The lone pair occupies an orbital with high s
character, and the σ-bonds to the germyl substituents are formed
by using p orbitals at the Ge(1) center. This is consistent with
(17) Baines, K. M.; Stibbs, W. G. Coord. Chem. ReV. 1995, 145, 157.
(18) CRC Handbook of Chemistry and Physics, 60th ed.; CRC Press:
Boca Raton, FL, 1979.
(19) Bauer, T.; Schulz, S.; Hupfer, H.; Nieger, M. Organometallics 2002,
21, 2931.
(20) (a) Babich, O. A.; Kokozay, V. N. Polyhedron 1997, 16, 1487. (b)
Raston, C. L.; White, A. H. J. Chem. Soc., Dalton Trans. 1976, 2153. (c)
Dyason, J. C.; Healy, P. C.; Engelhardt, L. M.; Pakawarchai, C.; Patrick,
V. A.; Raston, C. L.; White, A. H. J. Chem. Soc., Dalton Trans. 1985,
831. (d) Churchill, M. R.; Youngs, W. J. Inorg. Chem. 1979, 18, 1133. (e)
Bowmaker, G. A.; Effendy, H.; Hart, R. D.; Kildea, J. D.; White, A. H.
Aust. J. Chem. 1997, 50, 653.
(16) (a) Kawachi, A.; Tanaka, Y.; Tamao, K. Eur. J. Inorg. Chem. 1999,
461. (b) Hong, J.-H.; Pan, Y.; Boudjouk, P. Angew. Chem., Int. Ed. Engl.
1996, 35, 186. (c) West, R.; Sohn, H.; Powell, D. R.; Mu¨ller, T.; Apeloig,
Y. Angew. Chem., Int. Ed. Engl. 1996, 35, 1002. (d) Heine, A.; Stalke, D.
Angew. Chem., Int. Ed. Engl. 1994, 33, 113.
(21) Boehme, C.; Frenking, G. Organometallics 1998, 17, 5801.

Pyridyl-1-azaallyl Germanium(II) Chloride
Organometallics, Vol. 25, No. 11, 2006 2855
Figure 6. Molecular structure of 7 (ellipsoids are drawn at the 30% probability level).
Figure 7. Molecular structure of 8 (ellipsoids are drawn at the 30% probability level).
range of values observed in other Cu(I) iodide cubane systems
with a phosphine ligand.22 In contrast, compound 8 is a
monomeric germanium(II)-gold (I) adduct. The Ge(1)-Au(1)
bond distance of 2.346(2) Å is similar to the theoretical
calculation of 2.349 Å.21
density around the germanium center is diminished as compared
to compound 1.
Experimental Section
The Ge-Namide bond distances of 1.912(3) Å in 6, 1.888(8)
Å in 7, and 1.884(2) Å in 8 are slighter shorter than that of 1.
It is suggested that the germanium(II) center in 6-8 forms a
donor-acceptor interaction with the Lewis acid and the electron
All manipulations were carried out under an inert atmosphere
of dinitrogen gas by standard Schlenk techniques. Solvents were
dried over and distilled from CaH2 (hexane) and/or Na (Et2O,
toluene, and THF). [Ge{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl]
was prepared by literature procedures.6 ButLi (1.48 M in hexane),
BunLi (1.6M in hexane), LiCtCPh (1.0 M THF), PhCtCH,
(22) Vegal, A.; Saillard, J.-Y. Inorg. Chem. 2004, 43, 4012.

2856 Organometallics, Vol. 25, No. 11, 2006
Table 1. Crystallographic Data for Compounds 2-5
Leung et al.
2
3
4
5
formula
fw
color
C
23H36GeN2Si2
C
27H32GeN2Si2
C
86H80Ge4LiO3.5
C38H55AlN4Si4
707.20
yellow
469.31
red
513.32
yellow
1466.80
yellow
cryst syst
space group
a (Å)
b (Å)
c (Å)
monoclinic
P21/n
9.886(4)
13.942(5)
19.366(7)
90
103.139(8)
90
2599.3(17)
4
triclinic
P1h
monoclinic
P21/n
15.4011(7)
24.5315(11)
21.9725(10)
90
90.8000(10)
90
8180.3(6)
4
triclinic
P1h
8.3622(17)
11.227(2)
16.899(3)
107.28(3)
90.39(3)
100.47(3)
1486.6(5)
2
11.66(1)
12.74(1)
14.135(6)
90.94(4)
98.80(3)
94.91(2)
2068(3)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
2
d
calcd (g cm-3
)
1.199
1.281
992
1.147
1.126
536
1.191
1.500
3020
1.136
0.195
760
µ (mm-1
F(000)
)
cryst size (mm)
2θ range (deg)
index range
0.68 × 0.47 × 0.44
1.82-28.09
-13 e h e 9,
-18 e k e 17,
-25 e l e 25
17 301
0.50 × 0.40 × 0.20
2.53-25.23
-9 e h e 8,
0 e h e 13,
-20 e h e 19
4499
1.01 × 0.86 × 0.64
1.76-25.00
-18 e h e 18,
-29 e k e 28,
-26 e l e 22
43 596
0.25 × 0.22 × 0.20
1.60-24.99
-13 e h e 13,
0 e k e 15,
-16 e l e 16
4926
no. of reflns collected
no. of indep reflns
6274
4499
14 397
4926
R1, wR2 (I > 2(σ)I)
0.0453, 0.1003
0.0953, 0.1130
0.878
0.0524, 0.1413
0.0571, 0.1486
1.062
0.0658, 0.1795
0.1368, 0.2129
0.894
0.0663, 0.1564
0.0903, 0.1700
1.073
R1, wR2 (all data)
goodness of fit, F2
no. of data/restraints/params
6274/0/253
0.636 to -0.498
4499/0/289
0.384 to -0.607
14397/583/849
0.862 to -0.365
4926/0/429
0.295 to -0.361
largest diff peaks (e Å-3
)
Table 2. Crystallographic Data for Compounds 6-8
6
7
8
formula
fw
color
cryst syst
space group
a (Å)
C
19H31BGeN2Si2
C
108H172Cl4Cu4Ge4I4N8O8Si8
C
19H27AuClGeIN2Si2
427.04
3129.18
yellow
771.51
yellow
triclinic
P1h
8.4991(9)
11.1497(12)
14.3709(15)
80.216(2)
73.291(2)
85.197(2)
1284.5(2)
2
colorless
monoclinic
P21/n
18.195(4)
11.688(2)
11.192(2)
90
99.29(3)
90
2348.9(8)
4
tetragonal
P4h21c
22.2933(8)
22.2933(8)
14.1706(7)
90
90
90
7042.7(5)
2
1.476
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
d
calcd (g cm-3
)
1.208
1.411
896
1.995
8.281
728
µ (mm-1
F(000)
)
2.502
3152
cryst size (mm)
2θ range (deg)
index range
0.50 × 0.40 × 0.30
2.08-25.00
-21 e h e 21
-13 e k e 13
0 e l e 12
6089
0.40 × 0.30 × 0.20
1.29-25.00
-26 e h e 26
-24 e k e 26
-16 e l e 16
37 635
0.50 × 0.40 × 0.20
1.85-25.00
-9 e h e 10
-13 e k e 13
-17 e l e 17
6860
no. of reflns collected
no. of indep reflns
3568
6217
4472
R1, wR2 (I > 2(σ)I)
0.0542, 0.1490
0.0585, 0.1591
1.165
0.0429, 0.0901
0.1110, 0.1223
0.915
0.0951, 0.2724
0.1076, 0.2814
1.038
R1, wR2 (all data)
goodness of fit, F2
no. of data/restraints/params
3568/0/242
0.480 to -0.726
6217/0/334
0.515 to -0.936
4472/6/244
4.235 to -3.750
largest diff peaks (e Å-3
)
Table 3. Selected Bond Distances (Å) and Angles (deg) for
Compound 2
Table 4. Selected Bond Distances (Å) and Angles (deg) for
Compound 3
[Ge(But){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}] (2)
[Ge(CCPh){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}] (3)
Ge(1)-N(1)
Ge(1)-N(2)
Ge(1)-C(20)
2.059(3)
1.954(3)
2.040(3)
N(2)-C(10)
C(6)-C(10)
C(5)-C(6)
N(1)-C(5)
1.398(4)
1.372(4)
1.471(4)
1.363(4)
Ge(1)-C(20)
Ge(1)-N(2)
N(1)-C(5)
C(6)-C(10)
C(21)-C(22)
2.004(4)
1.966(3)
1.393(5)
1.394(5)
1.455(6)
Ge(1)-N(1)
C(20)-C(21)
C(5)-C(6)
2.052(3)
1.213(5)
1.494(5)
1.408(5)
C(10)-N(2)
C(20)-Ge(1)-N(1)
C(20)-Ge(1)-N(2)
N(1)-Ge(1)-N(2)
98.3(1)
106.0(1)
87.9(1)
Ge(1)-N(1)-C(5)
C(5)-C(6)-C(10)
C(6)-C(10)-N(2)
C(10)-N(2)-Ge(1)
123.5(2)
120.9(3)
123.7(3)
120.0(2)
N(1)-Ge(1)-N(2)
C(20)-Ge(1)-N(1)
N(1)-C(5)-C(6)
C(6)-C(10)-N(2)
Ge(1)-C(20)-C(21)
87.7(1)
N(2)-Ge(1)-C(20)
Ge(1)-N(1)-C(5)
C(5)-C(6)-C(10)
C(10)-N(2)-Ge(1)
C(20)-C(21)-C(22)
97.7(1)
93.8(1)
120.6(3)
124.7(3)
165.0(4)
121.5(2)
120.1(3)
117.2(2)
179.1(5)
LiAlH4, NaBH4, CuI, and AuI were purchased from Aldrich
Chemical Co. and used without purification. The 1H, 13C, and 11
B
were recorded on Bruker WM-300 or Varian 400 instruments. All
of [Ge{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl] (1) (0.45 g, 1.00
mmol) in Et2O (50 mL) at 0 °C. The resulting red suspension was
raised to ambient temperature and stirred for 17 h. It was filtered
and hexane was added to the filtrate and concentrated to yield red
crystals of 2. Yield: 0.33 g (70%). Mp: 125-126 °C. Anal.
Found: C, 58.77; H, 7.70; N, 6.12. Calcd for C23H36GeN2Si2: C,
spectra were recorded in C6D6 or THF-d8, and the chemical shifts
1
δ are relative to SiMe4 and BF3‚Et2O for H, 13C, and 11B NMR,
respectively.
[Ge(But){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}] (2). ButLi (0.68
mL, 1.00 mmol, 1.48 M in hexane) was added slowly to a solution

Pyridyl-1-azaallyl Germanium(II) Chloride
Organometallics, Vol. 25, No. 11, 2006 2857
Table 5. Selected Bond Distances (Å) and Angles (deg) for
Compound 4
Table 8. Selected Bond Distances (Å) and Angles (deg) for
Compound 7a
[{(PhCtC)3Ge}3GeLi(Et2O)3]‚0.5Et2O (4)
[Ge(CuI){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl]4.8THF (7)
Li(1)-O(1)
1.908(15)
1.915(15)
1.945(14)
3.066(15)
2.463(9)
2.462(9)
2.468(9)
1.909(7)
1.920(8)
1.920(7)
1.926(7)
1.935(6)
1.931(7)
Ge(4)-C(61)
Ge(4)-C(71)
Ge(4)-C(81)
C(1)-C(2)
C(11)-C(12)
C(21)-C(22)
C(31)-C(32)
C(41)-C(42)
C(51)-C(52)
C(61)-C(62)
C(71)-C(72)
C(81)-C(82)
1.907(7)
1.954(7)
1.926(8)
1.180(8)
1.159(9)
1.180(8)
1.147(8)
1.150(7)
1.175(8)
1.186(8)
1.171(8)
1.156(9)
Ge(1)-N(1)
Ge(1)-Cl(1)
Cu(1)-I(1)
Cu(1)-I(1B)
C(5)-C(6)
1.984(8)
2.252(3)
2.682(2)
2.756(2)
1.428(1)
1.443(1)
Ge(1)-N(2)
Ge(1)-Cu(1)
Cu(1)-I(1A)
N(1)-C(5)
C(6)-C(10)
I(1)-Cu(1C)
1.888(8)
2.359(2)
2.629(2)
1.366(1)
1.370(1)
2.756(2)
Li(1)-O(2)
Li(1)-O(3)
Ge(1)-Li(1)
Ge(1)-Ge(2)
Ge(1)-Ge(3)
Ge(1)-Ge(4)
Ge(2)-C(1)
Ge(2)-C(11)
Ge(2)-C(21)
Ge(3)-C(31)
Ge(3)-C(41)
Ge(3)-C(51)
C(10)-N(2)
N(2)-Ge(1)-N(1)
N(1)-Ge(1)-Cl(1)
Cu(1)-Ge(1)-N(2)
Ge(1)-N(1)-C(5)
C(5)-C(6)-C(10)
C(10)-N(2)-Ge(1)
Ge(1)-Cu(1)-I(1A)
Cu(1A)-I(1)-Cu(1)
Cu(1A)-I(1)-Cu(1C)
90.6(3)
N(2)-Ge(1)-Cl(1)
Cu(1)-Ge(1)-N(1)
Cu(1)-Ge(1)-Cl(1)
N(1)-C(5)-C(6)
C(6)-C(10)-N(2)
Ge(1)-Cu(1)-I(1)
Ge(1)-Cu(1)-I(1B)
Cu(1)-I(1)-Cu(1C)
99.5(3)
113.2(2)
113.6(9)
123.0(9)
123.5(9)
114.0(6)
99.4 (5)
67.5(4)
96.2(2)
135.6(3)
120.5(7)
121.1(9)
115.5(6)
118.0(6)
68.0(5)
Ge(2)-Ge(1)-Ge(3)
Ge(3)-Ge(1)-Ge(4)
Ge(2)-Ge(1)-Ge(4)
Li(1)-Ge(1)-Ge(2)
Li(1)-Ge(1)-Ge(3)
Li(1)-Ge(1)-Ge(4)
C(1)-Ge(2)-C(11)
C(1)-Ge(2)-C(21)
C(11)-Ge(2)-C(21)
Ge(1)-Ge(2)-C(1)
Ge(1)-Ge(2)-C(11)
Ge(1)-Ge(2)-C(21)
C(31)-Ge(3)-C(41)
C(31)-Ge(3)-C(51)
C(41)-Ge(3)-C(51)
Ge(1)-Ge(3)-C(31)
Ge(1)-Ge(3)-C(41)
93.1(3)
94.0(3)
93.5(4)
Ge(1)-Ge(3)-Ge(51)
Ge(1)-Ge(3)-C(31)
Ge(1)-Ge(3)-C(41)
Ge(1)-Ge(3)-C(51)
C(61)-Ge(4)-C(71)
C(71)-Ge(4)-C(81)
C(61)-Ge(4)-C(81)
Ge(1)-Ge(4)-C(61)
Ge(1)-Ge(4)-C(71)
Ge(1)-Ge(4)-C(81)
O(1)-Li(1)-O(2)
109.5(2)
113.4(2)
117.3(2)
109.5(2)
103.0(3)
103.8(3)
108.0(3)
117.2(2)
113.5(2)
110.3(2)
116.2(8)
113.6(8)
116.9(7)
108.1(6)
94.5(6)
68.2(5)
a Symmetry transformations used to generate equivalent atoms: A -x+2,
-y+2, z; B y, -x+2, -z+1; C -y+2, x, -z+1
123.7(3)
115.1(3)
128.8(3)
103.8(3)
102.2(3)
107.9(3)
110.7(2)
119.4(2)
111.4(2)
103.8(3)
103.1(3)
108.7(3)
113.4(2)
117.3(2)
Table 9. Selected Bond Distances (Å) and Angles (deg) for
Compound 8
[Ge(AuI){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl] (8)
Ge(1)-Au(1)
Ge(1)-N(1)
Ge(1)-Cl(1)
C(6)-C(10)
N(1)-C(5)
2.346(2)
1.942(1)
2.422(4)
1.400(2)
1.350(2)
Au(1)-I(1)
Ge(1)-N(2)
C(10)-N(2)
C(5)-C(6)
2.561(1)
1.844(2)
1.440(2)
1.410(3)
O(1)-Li(1)-O(3)
O(2)-Li(1)-O(3)
Ge(1)-Li(1)-O(1)
Ge(1)-Li(1)-O(2)
Ge(1)-Li(1)-O(3)
N(2)-Ge(1)-N(1)
N(1)-Ge(1)-Cl(1)
N(1)-Ge(1)-Au(1)
Ge(1)-Au(1)-I(1)
C(6)-C(10)-N(2)
N(1)-C(5)-C(6)
93.6(6)
96.7(5)
113.0(5)
172.8(6)
122.2(2)
121.7(2)
N(2)-Ge(1)-Cl(1)
Au(1)-Ge(1)-Cl(1)
N(2)-Ge(1)-Au(1)
C(10)-N(2)-Ge(1)
C(5)-C(6)-C(10)
102.2(5)
113.9(1)
130.9(4)
113.9(1)
122.3(2)
104.5(6)
Table 6. Selected Bond Distances (Å) and Angles (deg) for
Compound 5
[Al{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}2(H)] (5)
Al(1)-H(1)
Al(1)-N(1)
Al(1)-N(2)
N(1)-C(5)
C(5)-C(6)
C(6)-C(7)
C(7)-N(2)
1.560(3)
2.060(4)
1.914(4)
1.360(6)
1.480(7)
1.365(6)
1.389(5)
Al(1)-N(1′)
Al(1)-N(2′)
N(1′)-C(5′)
C(5′)-C(6′)
C(6′)-C(7′)
C(7′)-N(2′)
2.070(4)
1.897(4)
1.376(5)
1.456(6)
1.368(7)
1.397(6)
[Ge(CtCPh){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}] (3). LiCt
CPh (1.00 mL, 1.00 mmol, 1 M in THF) was added slowly to a
solution of 1 (0.44 g, 0.98 mmol) in Et2O (40 mL) at -90 °C. The
resulting yellow suspension was raised to ambient temperature and
stirred for 20 h. It was filtered and the filtrate concentrated to give
yellow crystals of 3. Yield: 0.20 g (40%). Mp: 140-142 °C. Anal.
Found: C, 63.33; H, 6.19; N, 5.36. Calcd for C27H32GeN2Si2: C,
63.17; H, 6.28; N, 5.46. 1H NMR (THF-d8): δ -0.21 (s, 9H,
SiMe3), -0.19 (s, 9H, SiMe3), 7.10-7.13 (m, 3H, Ph), 7.20-7.22
(m, 2H, Ph), 7.29 (m, 1H, 5-py), 7.31 (m, 3H, CethynylPh), 7.38 (d,
1H, CethynylPh), 7.39 (d, 1H, 3-py), 7.61 (m, 1H, CethynylPh), 7.88
(t, 1H, 4-py), 8.65-8.66 (d, 1H, 6-py). 13C{1H} NMR (C6D6): δ
2.28, 3.20 (SiMe3), 103.09 (CSiMe3), 112.06 (GeCCPh), 115.80
(GeCCPh), 127.13, 127.32, 129.49, 130.11 (GeCCPh), 118.94,
124.65, 125.89, 131.86, 132.73, 137.97, 144.68, 145.66, 156.56 (Ph
& Py), 170.98 (NCPh).
[{(PhCtC)3Ge}3GeLi(OEt2)3] (4). BunLi (0.46 mL, 0.73 mmol,
1.6 M in hexane) was added to a solution of PhCtCH (0.08 mL,
0.73 mmol) in Et2O (30 mL) at 0 °C. The solution was raised to
ambient temperature and stirred for 2 h. A solution of 1 (0.31 g,
0.69 mmol) in Et2O (30 mL) was then added slowly to the solution
at -90 °C. The resulting yellow suspension was raised to ambient
temperature and stirred for 17 h. The reaction mixture was filtered
and the filtrate concentrated under reduced pressure to yield yellow
crystals of the title compound 4. Yield: 0.73 g (70%). Mp: 95-
96 °C. Anal. Found: C, 70.21; H, 5.07. Calcd for C84H75Ge4LiO3:
C, 70.56; H, 5.29. 1H NMR (THF-d8): δ 1.09-1.14 (t, 3H, Et2O),
3.35-3.42 (q, 2H, Et2O), 7.01-7.78 (m, 15H, Ph). 13C{1H} NMR
(THF-d8): δ 15.68 (Et2O), 66.32 (Et2O), 95.87 (Ge-CtCPh),
104.46 (Ge-CtCPh), 127.39, 128.21, 128.54, 132.93 (Ph). IR:
2149 cm-1 (BH3), 1897 cm-1 (GeH).
N(2)-Al(1)-N(2′)
N(2)-Al(1)-H(1)
N(2′)-Al(1)-H(1)
N(1)-Al(1)-N(1′)
N(1)-Al(1)-N(2)
N(1)-Al(1)-N(2′)
N(1)-Al(1)-H(1)
N(1′)-Al(1)-N(2′)
N(1′)-Al(1)-N(2)
N(1′)-Al(1)-H(1)
118.3(2)
120.0(12)
121.5(12)
175.8(2)
85.8(2)
96.7(2)
91.9(13)
85.8(2)
Al(1)-N(1)-C(5)
N(1)-C(5)-C(6)
C(6)-C(7)-N(2)
C(7)-N(2)-Al(1)
Al(1)-N(1′)-C(5′)
N(1′)-C(5′)-C(6′)
C(6′)-C(7′)-N(2′)
C(7′)-N(2′)-Al(1)
122.2(3)
120.8(4)
127.4(5)
117.1(3)
122.0(3)
120.4(4)
126.9(4)
117.1(3)
96.1(2)
83.9(13)
Table 7. Selected Bond Distances (Å) and Angles (deg) for
Compound 6
[Ge(BH3){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}H] (6)
Ge(1)-jB(1)
Ge(1)-N(2)
C(5)-C(6)
2.064(6)
1.912(3)
1.488(5)
1.402(5)
Ge(1)-N(1)
N(1)-C(5)
C(6)-C(10)
1.994(3)
1.369(5)
1.400(5)
C(10)-N(2)
N(1)-Ge(1)-N(2)
B(1)-Ge(1)-N(1)
N(1)-C(5)-C(6)
C(6)-C(10)-N(2)
90.8(1)
110.3(2)
121.4(3)
124.5(3)
N(2)-Ge(1)-B(1)
Ge(1)-N(1)-C(5)
C(5)-C(6)-C(10)
C(10)-N(2)-Ge(1)
127.1(2)
117.8(2)
118.8(3)
112.1(2)
58.86; H, 7.73; N, 5.97. 1H NMR (THF-d8): δ -0.22 (s, 9H,
SiMe3), -0.05 (s, 9H, SiMe3), 0.95 (s, 9H, t-Bu), 6.97-7.03 (m,
1H, 5-py), 7.23-7.28 (d, 1H, 3-py), 7.36-7.40 (m, 3H, Ph), 7.45-
7.56 (m, 2H, Ph), 7.56-7.66 (m, 1H, 4-py), 8.43-8.48 (d, 1H,
6-py). 13C{1H} NMR (THF-d8): δ 2.30, 2.44 (SiMe3), 27.49 (t-
Bu), 105.76 (CSiMe3), 119.37, 125.34, 128.30, 129.93, 130.23,
131.44, 136.01, 142.83, 147.70, 161.64 (Ph and Py), 164.37 (NCPh).
[Al{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}2(H)] (5). LiAlH4 (0.39
mL, 0.39 mmol, 1 M in THF) was added slowly to a solution of 1
(0.35 g, 0.78 mmol) in THF (50 mL) at -90 °C. The yellow

2858 Organometallics, Vol. 25, No. 11, 2006
Leung et al.
suspension was raised to ambient temperature and stirred for 18 h.
A gray, shiny solid was found in the resulting solution. Volatiles
were removed under reduced pressure, and the residue was extracted
with Et2O. The mixture was filtered, concentrated, and stored at
-30 °C to yield yellow crystals of 5. Yield: 0.14 g (51%). Mp:
210-211 °C. Anal. Found: C, 64.15; H, 7.33; N, 8.02. Calcd for
[Ge(AuI){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl] (8). A solu-
tion of 1 (0.45 g, 1.01 mmol) in THF (30 mL) was added slowly
to a stirring suspension of gold(I) iodide (0.35 g, 1.08 mmol) in
THF (30 mL) at 0 °C in the absence of light. The resulting yellow
mixture was raised to ambient temperature and stirred for 20 h.
The solution was filtered, and the volatiles were removed under
reduced pressure. The residue was extracted with Et2O and filtered.
The yellow precipitates were separated and dissolved in THF. After
filtration, addition of 3 mL of CH2Cl2, and concentration of the
filtrate, a yellow crystalline solid of 8 was obtained. Yield: 0.25 g
(32%). Mp: 95-96 °C. Anal. Found: C, 29.24; H, 3.55; N, 3.51.
1
C38H55AlN4Si4: C, 64.54; H, 7.84; N, 7.92. H NMR (C6D6): δ
-0.24 (s, 9H, SiMe3), -0.16 (s, 2H, SiMe3), -0.02 (s, 2H, SiMe3),
0.44-1.41 (br, 5H, SiMe3), 5.54 (s, 1H, AlH), 6.39 (t, 1H, 3-py),
7.03-7.10 (m, 3H, Ph), 7.43-7.47 (m, 2H, Ph), 7.78 (dd, 2H, 4-py
and 5-py), 9.39-9.41 (d, 1H, 6-py). 13C{1H} NMR (C6D6): δ 1.36,
1.67, 2.14, 3.28 (SiMe3), 120.73 (CSiMe3), 124.82, 125.42, 129.20,
129.34, 130.64, 137.61, 138.78, 144.48, 145.72, 148.55, 158.74 (Ph
and Py), 158.74 (NCPh).
1
Calcd for C19H27AuClGeIN2Si2: C, 29.58; H, 3.53; N, 3.63. H
NMR (THF-d8): δ -0.15 (s, 9H, SiMe3), 0.02 (s, 9H, SiMe3),
7.47-7.53 (m, 5H, Ph), 7.57-7.60 (t, 1H, 5-py), 7.81-84 (d, 1H,
3-py), 8.21-8.23 (t, 1H, 4-py), 9.09 (d, 1H, 6-py). 13C{1H} NMR
(THF-d8): δ 1.70, 3.56 (SiMe3), 117.12 (CSiMe3), 122.70, 127.87,
128.70, 129.48, 131.51, 131.78, 132.52, 143.29, 144.26, 144.53,
156.86 (Ph and Py), 163.88 (NCPh).
X-ray Crystallography. Single crystals were sealed in Linde-
mann glass capillaries under nitrogen. X-ray data of 2-8 were
collected on a Rigaku R-AXIS II imaging plate using graphite-
monochromatized Mo KR radiation (I ) 0.71073 Å) from a
rotating-anode generator operating at 50 kV and 90 mA. Crystal
data for 2-8 are summarized in Tables 1 and 2. The structures
were solved by direct phase determination using the computer
program SHELXTL-PC23 on a PC 486 and refined by full-matrix
least squares with anisotropic thermal parameters for the non-
hydrogen atoms. Hydrogen atoms were introduced in their idealized
positions and included in structure factor calculations with assigned
isotropic temperature factor calculations. Full details of the crystal-
lographic analysis of 2-8 are given in the Supporting Information.
[Ge(BH3){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}H] (6). A solu-
tion of 1 (0.45 g, 1.01 mmol) in THF (30 mL) was added slowly
to a stirring suspension of sodium borohydride (0.010 g, 3.70 mmol)
in THF (30 mL) at room temperature. The resulting yellow mixture
was stirred for 3 days. The solution was filtered and concentrated
to yield pale yellow crystals of 6. Yield: 0.18 g (42%). Mp: 112-
115 °C. Anal. Found: C, 53.37; H, 7.28; N, 6.34. Calcd for C19H31-
BGeN2Si2: C, 53.43; H, 7.32; N, 6.56. 1H NMR (THF-d8): δ -0.20
(s, 9H, SiMe3), -0.18 (s, 9H, SiMe3), 6.07 (br s, 1H, GeH), 7.45-
7.51 (m, 5H, Ph), 7.53 (m, 1H, 5-py), 7.68-7.71 (d, 1H, 3-py),
1
8.08 (t, 1H, 4-py), 8.69 (d, 1H, 6-py). H NMR (THF-d8, 223 K):
δ 5.95, 5.96 (br.d, 1H, GeH). 13C{1H} NMR (THF-d8): δ 2.30,
2.67 (SiMe3), 116.16 (CSiMe3), 122.14, 125.78, 128.54, 129.16,
131.19, 131.53, 132.45, 141.42, 144.17, 144.74, 158.39, (Ph & Py),
172.27 (NCPh). 11B{1H} NMR (THF-d8): δ -38.88.
[Ge(CuI){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl(THF)2]4 (7).
A solution of 1 (0.45 g, 1.01 mmol) in THF (30 mL) was added
slowly to a stirring suspension of copper(I) iodide (0.20 g, 1.05
mmol) in THF (30 mL) at 0 °C. The resulting yellow mixture was
raised to ambient temperature and stirred for 18 h. The solution
was filtered, and the volatiles were removed under reduced pressure.
The residue was extracted with Et2O, followed by filtration and
concentration, to give 35 as yellow crystals. Yield: 0.98 g (38%).
Mp: 102-104 °C. Anal. Found: C, 35.41; H, 4.29; N, 4.18. Calcd
for C76H108Cl4Cu4Ge4I4N8Si8: C, 35.76; H, 4.26; N, 4.39. 1H NMR
(THF-d8): δ -0.21 (s, 9H, SiMe3), -0.02 (s, 9H, SiMe3), 1.69-
1.74 (t, 2H, THF), 3.54-3.56 (d, 2H, THF), 7.34-7.41 (m, 2H,
Ph), 7.50 (m, 1H, 5-py), 7.54 (m, 1H, 3-py), 7.63-7.67 (m, 3H,
Ph), 7.97-7.99 (t, 1H, 4-py), 9.50 (d, 1H, 6-py). 13C{1H} NMR
(THF-d8): δ 1.95, 4.16 (SiMe3), 26.39, 68.23 (THF), 116.09
(CSiMe3), 121.50, 126.66, 128.12, 128.99, 130.47, 131.58, 133.12,
141.26, 145.35, 146.55, 156.02 (Ph and Py), 164.74 (NCPh).
Acknowledgment. This work was supported by the
Hong Kong Research Grants Council (Project No. CUHK 4265-
00P).
Supporting Information Available: Details about the X-
ray crystal structures, including ORTEP diagrams and tables of
crystal data and structure refinement, atomic coordinates, bond
lengths and angles, and anisotropic displacement parameters for
2-8. This material is available free of charge via the Internet at
http://pubs.acs.org.
OM060032G
(23) Sheldrick G. M. In Crystallographic Computing 3: Data Collection,
Structure Determination, Proteins, and Databases; Sheldrick, G. M., Kruger,
C., Goddard, R., Eds.; Oxford University Press: New York, 1985; p 175.