The stable divalent homoleptic species (ArO)2M (Ar = 2,4,6-Tris((dimethylamino)methyl)phenyl; M = Ge, Sn, Pb)

Article abstract of DOI:10.1021/om9705665

The synthesis and characterization of new stable divalent germanium, tin, and lead homoleptic species (ArO)₂M: (Ar = 2,4,6-[(CH₃)₂NCH₂]₃C ₆H₂; M = Ge (2), Sn (3), Pb (4)) are des

Full text of DOI:10.1021/om9705665

Organometallics 1998, 17, 607-614
607
Th e Sta ble Diva len t Hom olep tic Sp ecies (Ar O)2M (Ar )
2,4,6-Tr is((d im eth yla m in o)m eth yl)p h en yl; M ) Ge,
Sn , P b)
J acques Barrau,* Ghassoub Rima, and Tajani El Amraoui
He´te´rochimie Fondamentale et Applique´e, UPRES-A 5069 du CNRS, Universite´ Paul-Sabatier,
118 route de Narbonne, 31062 Toulouse Cedex, France
Received J uly 3, 1997
The synthesis and characterization of new stable divalent germanium, tin, and lead
homoleptic species (ArO)2M: (Ar ) 2,4,6-[(CH3)2NCH2]3C6H2; M ) Ge (2), Sn (3), Pb (4)) are
described. 2-4 were obtained in good yields by alcoholysis of the M-N bonds of the divalent
precursors [(Me3Si)2N]2M by ArOH. However, the direct reaction of 2 equiv of [2,4,6-tris-
((dimethylamino)methyl)phenoxy]lithium trimer (1) with the divalent species MCl2 resulted
in the formation of 2-4 in lower yields along with the cluster Li5(ArO)2Cl3. The coordination
behavior of the (dimethylamino)methyl side chains toward the metal atom was studied by
variable-temperature NMR spectroscopy; on the NMR time scale 2 in solution exhibits a
temperature-dependent N‚‚‚M‚‚‚N coordination mode. The chemistry of 2-4 is illustrated
through their reactions with diphenylethanedione, 1,2- and 1,4-benzoquinones, and triazo-
linedione.
In tr od u ction
[(CH3)2NCH2]C6H2). Some preliminary aspects of this
work have been communicated earlier.20
The chemistry of the divalent species R2MII (M ) Ge,
Sn, Pb) has made important advances in the recent
years,1-11 and a large number of these species have been
isolated in a monomeric state.12 In particular, various
aryloxygermylenes and -stannylenes (Ar′O)2M (Ar′ )
2,6-t-Bu2C6H3, 2,6-t-Bu2-4-Me-C6H2, 2,4,6-t-Bu3C6H2)
stabilized by electronic and steric effects have been
isolated.13 However, few germylenes stabilized by in-
tramolecular complexation of the germanium atom by
a Lewis basic group have been described.12j,k,14-16 This
method of stabilization has been more widely used in
the chemistry of tin and silicon; it has been found to be
very effective in the case of stannylenes.17 It has failed
so far in all attempts at the stabilization of silylenes,
although several precursors with intramolecular coor-
dination of a amino aryl group to silicon have been
studied.18,19 In the present study we have focused on
new divalent species of germanium, tin, and lead
(ArO)2M (M ) Ge, Sn, Pb) with phenoxy ligands bearing
in the 2,4,6 position (dimethylamino)methyl groups
suitable for intramolecular coordination (Ar ) 2,4,6-
(12) For structurally characterized compounds see the following
examples. Ge: (a) Snow, J . T.; Murakami, S.; Masamune, S.; Williams,
D. J . Tetrahedron Lett. 1984, 25, 4191. (b) Lange, L.; Meyer, B.; du
Mont, W. W. J . Organomet. Chem. 1987, 329, C17. (c) Batcheller, S.
A.; Tsumuraya, T.; Tempkin, O.; Davis, W. M.; Masamune, S. J . Am.
Chem. Soc. 1990, 112, 9394. (d) J utzi, P.; Becker, A.; Stammler, H.
G.; Neumann, B. Organometallics 1991, 10, 1647. (e) Tokitoh, N.;
Manmaru, K.; Okazaki, R. Organometallics 1994, 13, 167. (f) Tokitoh,
N.; Manmaru, K.; Okazaki, R. Chem. Lett. 1995, 9, 827. (g) Kira, M.;
Iwamoto, T.; Maruyama, T.; Kabuto, C.; Sakurai, H. Organometallics
1996, 15, 3767. (h) J utzi, P.; Schmidt, H.; Neumann, B.; Stammler,
H. G. Organometallics 1996, 15, 741. (i) Simons, R. S.; Pu, L.;
Olmstead, M. M.; Power, P. P. Organometallics, 1997, 16, 1920. (j)
Ossig, G.; Meller, A.; Bro¨nneke, C.; Mu¨ller, O.; Scha¨fer, M.; Herbst-
Irmer, R. Organometallics 1997, 16, 2116. (k) Dias H. V. R.; Wang. Z.
J . Am. Chem. Soc. 1997, 119, 4650. Sn: ref 12i and (l) Bigwood, M. P.;
Corvan, P. J .; Zuckerman, J . J . J . Am. Chem. Soc. 1981, 103, 7643.
(m) Gru¨tzmacher, H.; Pritzkow, H.; Edelmann, F. T. Organometallics
1991, 10, 23. Lay, U.; Pritzkow, H.; Gru¨tzmacher, H. J . Chem. Soc.,
Chem. Commun. 1992, 260. (n) Kira, M.; Yauchibara, R.; Hirano, R.;
Kabuto, C.; Sakurai, H. J . Am. Chem. Soc. 1991, 113, 7785. (o) Saito,
M.; Tokitoh, N.; Okazaki, R. J . Am. Chem. Soc. 1993, 115, 2065. (p)
Weidenbruch, M.; Schlaefke, J .; Scha¨fer, A.; Peters, K.; von Schnering,
H. G.; Marsmann, H. Angew. Chem., Int. Ed. Engl. 1994, 33, 1846. (q)
Klinkhammer, K. W.; Schwartz, W. Angew. Chem., Int. Ed. Engl. 1995,
34, 1334. (r) Dias, H. V. R.; J in, W. Inorg. Chem. 1996, 35, 6546. Pb:
refs 12i,q and (s) Brooker, S.; Buijink, J . K.; Edelmann, F. T.
Organometallics 1991, 10, 25. (t) Tokitoh, N.; Kano, N.; Shibata, K.;
Okazaki, R. Organometallics 1995, 14, 3121.
(1) Satge´, J .; Massol, M.; Rivie´re, P. J . Organomet. Chem. 1973,
56, 1.
(2) Neumann, W. P. The Stannylenes R2Sn. In The Organometallic
and Coordination Chemistry of Ge, Sn, and Pb; Gielen, M., Harrison,
P., Eds.; Freund: Tel Aviv, 1978; p 51.
(13) C¸ etinkaya, B.; Gu¨mru¨kc¸u¨, I.; Lappert, M. F.; Atwood, J . L.;
Rogers, R. D.; Zacorotko, M. J . J . Am. Chem. Soc. 1980, 102, 2088.
(14) Veith, M.; Lisowsky, R. Angew. Chem. 1988, 100, 1124; Angew.
Chem., Int. Ed. Engl. 1988, 27, 1087.
(3) Petz, W. Chem. Rev. 1986, 86, 1099.
(4) Gaspar, P. P. Silylenes. In Reactive Intermediates III; Moss, R.
A., J ones, M., Eds.; Wiley: New York, 1985; p 333.
(5) (a) Satge´, J . Pure Appl. Chem. 1984, 56, 137. (b) Satge´, J . Rev.
Silicon, Germanium, Tin, Lead Compd. 1985, 8, 291.
(6) Rivie´re, P.; Rivie´re-Baudet, M.; Satge´, J . Compr. Organomet.
Chem. 1982, 2, 478.
(7) Nefedov, O. M.; Kolesnikov, S. P.; Ioffe, A. I. J . Organomet.
Chem. Libr. 1977, 5, 181.
(8) Satge´, J . J . Organomet. Chem. 1990, 400, 121.
(9) Lappert, M. F.; Rowe, R. S. Coord. Chem. Rev. 1990, 100, 267.
(10) Neumann, W. P. Chem. Rev. (Washington, D.C.) 1991, 91, 311.
(11) J utzi, P. Adv. Organomet. Chem. 1986, 26, 217.
(15) Kuchta, M. C.; Parkin, G. J . Chem. Soc., Chem. Commun. 1994,
1351.
(16) Atwood, D. A.; Atwood, V. O.; Cowley, A. H.; Atwood, J . L.;
Roman, E. Inorg. Chem. 1992, 31, 3871.
(17) Angermand, K.; J onas, K.; Kru¨ger, C.; Latten, J . L.; Tsay, Y.
H. J . Organomet. Chem. 1988, 353, 17.
(18) Belzner, J . J . Organomet. Chem. 1992, 430, C51.
(19) Corriu, R.; Lanneau, G.; Priou, C.; Solairol, F.; Auner, N.;
Probst, R.; Conlin, R.; Tan, C. J . Organomet. Chem. 1994, 466 (1-2),
55.
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S0276-7333(97)00566-9 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 01/27/1998

608 Organometallics, Vol. 17, No. 4, 1998
Barrau et al.
38
Sch em e 1
pert’s germylene Ge[N(SiMe3)2]2 with the phenol in
benzene. The rapid reaction is exothermic and proceeds
nearly quantitatively. At -30 °C in pentane a white,
analytically pure, air-sensitive solid, (ArO)2Ge (2),
precipitated. This product was fully characterized by
NMR, IR, UV, and mass spectroscopy.
I.2. Bis[2,4,6-tr is((d im eth yla m in o)m eth yl)p h e-
n oxy]sta n n ylen e a n d -p lu m bylen e, (Ar O)2M (M )
Sn , P b). Following the same approach, we prepared
the divalent tin and lead species (ArO)2M (3 and 4,
respectively) by reaction of the corresponding divalent
compounds M[N(SiMe3)2]2 with the phenol. These reac-
tions, as in the germanium case, gave high yields of the
expected products as white solids.
Resu lts a n d Discu ssion
I. Syn t h esis a n d St r u ct u r a l Ch a r a ct er iza t ion
of th e Diva len t Sp ecies (Ar O)2M (M ) Ge, Sn , P b).
I.1. Bis[2,4,6-tr is((dim eth ylam in o)m eth yl)ph en oxy]-
ger m ylen e, (Ar O)2Ge (Ar ) 2,4,6-[(CH 3)2NCH 2]3-
C6H2). We first tried to prepare bis[2,4,6-tris((dimethy-
lamino)methyl)phenoxy]germylene employing the clas-
sical method of synthesis of germylated ether, the
alkoxylation of germanium-halogen bonds, by carrying
out the reaction of [2,4,6-tris((dimethylamino)methyl)-
phenoxy]lithium with GeCl2‚C4H8O2 .
[2,4,6-Tris((dimethylamino)methyl)phenoxy]lithium
was prepared by the action of n-BuLi with the corre-
sponding alcohol in diethyl ether; it is soluble in diethyl
ether but can be isolated in the pure state as crystals
by precipitation at -20 °C from an ether/pentane (50/
50) solution. Cryoscopic molecular weight measure-
ments in benzene indicated the presence of a trimer,
(ArO)3Li3, in solution. Its mass spectrum displays the
same cluster structure (ArO)3Li3 also in the gas phase.
The electron impact results in the formation of the
radical cation (ArO)2Li3•+OAr, which loses NMe2; the
mass spectrum shows six fragment ions corresponding
to [(ArO)2Li3]+, [(ArO)Li2]+, Li+ and [ArO3Li3 - NMe2]+,
[(ArO)2Li2 - NMe2]+, [ArOLi - NMe2]+; the most
abundant species is [(ArO)Li2]+. Thus the fragmenta-
tions lead to the related species Lix(ArO)x, which lose a
NMe2 group.
A suspension of GeCl2‚C4H8O2 was treated with
(ArOLi)3 at room temperature. The yield of (ArO)2Ge
was high (52%), but along with germylene 2, which is
insoluble in diethyl ether, we extracted a solid phase
which mass spectrometric analysis showed to be a
mixture of the germylene ClGeOAr and the cluster
Li5(ArO)2Cl3. The action of (ArOLi)3 on GeCl2‚C4H8O2
thus can be summarized by Scheme 1.
Chloro[2,4,6-tris((dimethylamino)methyl)phenoxy]-
germylene (1a ) was identified by comparing its proper-
ties with those of an authentic sample prepared by a
ligand redistribution reaction between GeCl2‚C4H8O2
and (ArO)2Ge.21 The cluster Li5(ArO)2Cl3 (1b) was
identified by comparison with an authentic sample
obtained by mixing lithium chloride and the lithium
phenolate in diethyl ether.
The low yield of (ArO)2Ge and the difficulties arising
from the formation of byproducts which cannot be
isolated very easily led us to explore an alternate
method of preparing (ArO)2Ge. The known extreme
sensitivity of the germanium-nitrogen bond to alco-
holysis prompted us to carry out the reaction of Lap-
We have also investigated the organolithium route,
in the tin case, in the reaction of SnCl2 with ArOLi
species 1. As in the germanium case, this reaction
resulted in a mixture of homoleptic and heteroleptic
species (ArO)2Sn (3) and (ArO)SnCl (3a ),21 along with
the cluster Li5(ArO)2Cl3 and insoluble unidentified
products.
The divalent species (ArO)2M (2-4) are stable under
an argon atmosphere but are very sensitive to atmo-
spheric oxygen and moisture. Thus, bis[2,4,6-tris-
((dimethylamino)methyl)phenoxy]germanium, -tin, and
-lead oxides are formed when dry oxygen is bubbled in
solutions of 2, 3, and 4. Hydrolysis results in formation
of oxides via intermediates that are difficult to isolate
and identify. These divalent species are very soluble
in common organic solvents. The nature of solvent
(hexane, tetrahydrofuran, dioxane) does not influence
the chemical behavior of these divalent species in
solution, which points to a loss of Lewis acidity of the
M(II) centers.
I.3. P h ysicoch em ica l a n d Str u ctu r a l Stu d y of
t h e Diva len t Sp ecies (Ar O)2M (M ) Ge, Sn , P b ).
Cryoscopic mass determination showed that 2-4 are
monomeric in benzene solution. Compounds 2-4 have
1
been characterized by H and 13C NMR, IR, UV, and
mass spectroscopy and, for stannylene 3, also by 119Sn
NMR and Mo¨ssbauer spectroscopy. Spectroscopic data
are reported in Table 1. 1H NMR spectra of 2-4 at
(21) Improved detailed procedures for the syntheses of 1a and 3a
will be reported in a publication currently underway. 1a : mp 123-
125 °C. 1H NMR (C6D6): 2.22 (s, 6H), 2.39 (s, 12H), 3.27 (s, 2H), 3.66
(s, 4H), 7.06 (s, 2H). 13C NMR (C6D6): 44.61 (+), 45.73 (+), 60.14 (-),
65.01 (-), 126.1 (Cquat), 127.9 (+), 130.6 (Cquat), 158.2 (Cquat). MS: m/z
373 [M]•+. Anal. Calcd for C15H26N3OGeCl: C, 48.43; H, 6.99; N, 11.30.
Found: C, 48.26; H, 6.72; N, 10.94. 3a : mp 120-122 °C. 119Sn{1H} NMR
(C6D6): -435.2. 1H NMR (C6D6): 2.24 (s, 6H), 2.43 (s, 12H), 3.48 (s,
2H), 3.79 (s, 4H), 7.08 (s, 2H). 13C NMR (C6D6): 44.53 (+), 45.21 (+),
59.92 (-), 64.67 (-), 125.97 (Cquat), 127.2 (+), 130.3 (Cquat), 157.86
(Cquat). MS: m/z 419 [M]•+. Anal. Calcd for C15H26N3OSnCl: C, 43.08;
H, 6.22; N, 10.05. Found: C, 42.68; H, 6.06; N, 9.87.

A Stable Divalent Homoleptic Species
Organometallics, Vol. 17, No. 4, 1998 609
Ta ble 1. Sp ectr oscop ic Da ta for Com p ou n d s 2-4
NMR (C6D6; δ ppm)
1H
13C
Ge (2)
Sn (3)
Pb (4)
Ge (2)
Sn (3)
Pb (4)
Sn (3)
p-NMe2
o-NMe2
p-CH2N
o-CH2N
C6H2
2.18 (s)
2.16 (s)
3.35 (s)
3.57 (s)
7.28 (s)
2.16 (s)
2.13 (s)
3.32 (s)
3.54 (s)
7.28 (s)
2.18 (s)
2.00 (s)
3.40 (s)
3.37 (s)
7.20 (s)
44.88
44.45
60.25
44.70
45.37
60.57
44.69
45.44
60.54
-529.8
64.08
64.49
64.48
125.86
129.33
131.04
151.48
126.46
129.24
131.46
159.58
125.77
129.61
131.59
159.61
UV (C6H12; λmax, nm (ꢀ, L mol-1 cm-1
)
2
3
4
385 (360)a
372 (390)a
360 (420)a
a
Erroneous values due to the particular sensitivity of 2-4 to hydrolysis.
ambient temperature exhibit in all cases the equivalence
of the four o-NMe2 groups (broad singlet); a singlet also
is observed as the signal for the corresponding CH2N
groups.
Three explanations are possible for the magnetic
equivalence of the o-NMe2 groups of compounds 2-4.
(1) The structure is monomeric, without intramolecu-
lar interaction between the o-NMe2 groups and the
Group 14 atom and no intermolecular interactions, thus
allowing inversion of the nitrogen atom.
Molecular modeling (Insight II, Discover 95, esff force
field) allowed us to obtain the four equivalent limiting
forms resulting from this dynamic coordination process
corresponding to a molecular minimum total energy
estimated to be 31.5 kcal mol-1
.
The idea of such a coordination is lent support by the
unusual thermal stability of these divalent entities (no
polymerization even at 200 °C) and also by their
chemical properties, which clearly differentiate them
from the noncomplexed divalent species.
We were not able to define the nature of the interac-
tion between the NMe2 groups and the group 14 atom
since crystals suitable for X-ray structural analysis
could not be obtained.
(2) The structure, in which the monomeric species
(also without intramolecular interactions between the
o-NMe2 groups and the group 14 atom) are linked by
coordination of the oxygen lone pair of ArO groups to a
vacant p orbital of the group 14 metal.
To obtain information concerning the nature and
strength of coordination of the nitrogen atoms to the
metal atom, we conducted a variable-temperature 1H
NMR study with the germylene 2.
1
The H NMR spectrum of 2 at -60 °C exhibits three
resonances of equal intensity for the N-methyl protons
(1H NMR (CD2Cl2): δ 2.11 (s, 12H), 2.12 (s, 12H), 2.21
(s, 12H)). The observed nonequivalence of these protons
at low temperature indicates that the flip-flop coordina-
tion process is slow enough so that we can observe two
types of o-dimethylamino groups, along with the p-
dimethylamino group. One type probably corresponds
to two free o-dimethylamino groups far from the ger-
manium atom and the other to the two groups in
dynamic coordination, consistent with the two limiting
forms represented in Scheme 2. The two coordinated
nitrogens probably originate from two different ArO
ligands as shown, not from the same ArO ligand. The
structure corresponding to the latter possibility should
give four distinct NMe2 signals in the NMR spectrum,
and this is not what was observed.
(3) There is a dynamic N‚‚‚M‚‚‚N coordination-
decoordination process involving the four donor func-
tions in 2,6-positions of the phenoxy groups. Such “flip-
flop” coordination modes have already been reported for
tetravalent tin and silicon derivatives.22-24
(23) Handwerker, H.; Leis, C.; Probst, R.; Bissinger, P.; Grohmann,
A.; Kiprof, P.; Herdtweck, E.; Blu¨mel, J .; Auner, N.; Zybill, C.
Organometallics 1993, 12, 2162.
(22) van Koten, G.; J astrzebski, J . T. B. H.; Noltes, J . G.; Speck, A.
L.; Schoone, J . C. J . Organomet. Chem. 1978, 184, 233.
(24) Carre´, F.; Chuit, C.; Corriu, R. J . P.; Mehdi, A.; Reye´, C. Angew.
Chem., Int. Ed. Engl. 1994, 33, 1097.

610 Organometallics, Vol. 17, No. 4, 1998
Barrau et al.
Sch em e 2
Sch em e 3
intermolecular) N‚‚‚M14 coordination changes (reduc-
tion) in the solid phase. After the samples are heated
for 1 h at 120 °C, their spectroscopic analyses still
119
correspond to the structure of divalent species. The
-
Sn NMR analysis of the stannic compound, for instance,
notably exhibits three signals at δ -529.5, -532.1, and
-534.5 ppm. These only slightly different chemical
shifts can be attributed to identical or very similar
fundamental structures (divalent species), probably with
different coordinations at the central metal atom.
II. Ch em ica l Rea ctivity of th e Diva len t Sp ecies
(Ar O)2M (M ) Ge, Sn , P b). Due to their “carbene-
like” character, the free divalent species R2M have a
high potential for applications in organometallic chem-
istry. Insertion into various σ-bonds, addition or cy-
cloaddition to nonconjugated alkenes, alkynes or con-
jugated dienes, heterodienes, trienes and complexation
(by donors or acceptors) reactions are characteristic1-11
of these divalent species.
II.1. Beh a vior tow a r d σ-bon d s. We did not ob-
serve any insertion reactions of the divalent species
(ArO)2M into σ-bonds, in contrast to the behavior of the
free divalent species. Addition of methyliodide to
(ArO)2Ge results in the quaternization of the nitrogen
atoms and the formation of various insoluble solids
whose nature is still obscure (Scheme 3). An attempt
to obtain insertion products of (ArO)2Ge with methanol
failed; the action of water leads, via hydrolysis of the
Ge-O bonds of (ArO)2Ge, to Ge(OH)2. The latter, which
is yellow-orange and precipitates while cold, was char-
acterized by reaction with hydroiodic acid.27
On further lowering the temperature (-75 °C), we did
not observe demixing of signals of the o-NMe2 and
o-NCH2 atoms which whould be characteristic of their
static arrangement with all the o-NMe2 groups coordi-
nated to the metal atom.
We cannot exclude the possibility that the nonequiva-
lence of the two types of o-NMe2 groups observed at -60
°C may also result from hindrance to O-Ge-O rotation
or from formation of stereoisomers resulting from static
six-membered chelating geometries at this low temper-
ature.
In UV-vis spectroscopy, absorption maxima due to
2-4 were observed at 385, 372, and 360 nm, respec-
tively. As previously observed for germylene donor
complexes,25 these bands are shifted to shorter wave-
lengths compared to those of nonelectronically stabilized
divalent species of group 14 metals (M14). It is also
noteworthy that the λmax values decrease on going from
germylene to plumbylene, in contrast with what is
usually observed for free divalent M14 species, except
for some sterically overcrowed diaryl species.12i These
results probably indicate that the monomeric divalent
units are coordinated with lone-pair electrons of the
(dimethylamino)methyl side chains. The position of the
absorption maxima probably provides an indication of
the strength of the M‚‚‚N interaction. However, cor-
relation between λmax and the nature of the M‚‚‚N
coordination does not provide a full explanation, since
additional effects such as the bond angle at the metal
and the presence of an aryloxy group may play a role.
The tin-119 Mo¨ssbauer spectroscopy data are as
follows: isomer shift IS, 2.88; quadrupole splitting QS,
1.82.
II.2. Beh a vior t ow a r d Un sa t u r a t ed Syst em s.
II.2.1. 1,3-Dien es. (ArO)2M compounds react neither
with electron-poor or -rich 1,3-dienes nor with oxa-
dienes, again in contrast to the case for the free divalent
species. The germylene (PhO)2Ge reacts readily in a
classical way by 1,4 cycloaddition with 2,3-dimeth-
ylbuta-1,3-diene (DMB):
The isomer shift confirms the tin oxidation state +II,
since it is known that all the tin compounds with an
isomer shift greater than 2.03 mm/s are Sn(II)
compounds12l,26 and the quadrupole splitting reflects the
asymmetrical electron density at the tin nucleus.
Compounds 2-4 change color on heating; they turn
into yellow-orange solids after being heated to 120 °C
and become more sensitive to hydrolysis and oxidation.
This change of color probably reflects intramolecular (or
The presence of the dimethylamino groups on the
phenyl group, thus seems to be responsible for the loss
of this characteristic chemistry of free germylenes (with
both electrophilic Lewis-acid and nucleophilic Lewis-
base character) (Scheme 4).
II.2.2. Dik eton es a n d Qu in on es. Various hetero-
cyclization reactions have been observed for 2 and 3
with nonenolizable ketones and also with 1,2-quinones.
II.2.2.1. Dip h en yleth a n ed ion e a n d 1,2-Ben zo-
qu in on e. Germylenes and stannylenes (ArO)2M for
example react immediately at ambient temperature
(25) Ando, W.; Itoh, H.; Tsumuraya, T. Organometallics 1989, 8,
2759.
(26) Corvan, J . P.; Zuckerman, J . J . Inorg. Chim. Acta Lett. 1979,
L256.
(27) J olley, W. L.; Latimer, W. M. J . Am. Chem. Soc. 1952, 74, 5752.

A Stable Divalent Homoleptic Species
Organometallics, Vol. 17, No. 4, 1998 611
Sch em e 4
Sch em e 6
Sch em e 5
can also be involved in a single electron-transfer process
in accord with recent electrochemical and theoretical
studies of germylenes, stannylenes, and their complexes
with Lewis bases.36,37 The reactions leading to adducts
5 and 6 are summarized in Scheme 6.
II.2.2.2. 1,4-Ben zoqu in on es. With 1,4-benzoquino-
ne, the (ArO)2M species initiate and participate in
copolymerization reactions. These reactions are initi-
ated by simply mixing (ArO)2M and 1,4-benzoquinone
solutions in the absence of a catalyst. The copolymer
structures 9 and 10 were determined by 1H and 13C
NMR and IR spectroscopy and elemental analysis.
These copolymers are thermally stable and melt without
decomposition.
with 3,5-di-tert-butyl-1,2-benzoquinone and only at 80
°C with diphenylethanedione, leading to the new het-
erocycles 5-8, respectively, in good yields (Scheme 5).
Galvinoxyl, which is a very efficient inhibitor of
radical chain processes, has no effect on the rate of the
reactions between quinones and divalent species 2 and
3. (It is noteworthy that galvinoxyl is inert toward
quinones but reactive toward 2 and 3.) Additionally,
these reactions cannot be induced photochemically; at
high dilution and at -40 °C the thermal process is
strongly slowed but the reaction cannot be accelerated
at this temperature by UV irradiation. Therefore, it is
reasonable to assume that these reactions proceed by
single electron transfer with the formation of a pair of
radical ions in the first step. The ESR study of the
reaction mixture (in the case of germanium) clearly
shows the transient formation of a paramagnetic species
with a semi-quinonic structure. The ESR spectrum (g
) 2.0018, aH ) 3.5 G) of the green solution at -40 °C,
resulting from the mixture of the 3,5-di-tert-butyl-1,2-
benzoquinone and the divalent species in toluene, is
quite comparable to the o-semiquinone spectrum ob-
tained in other ways.28-30 Thus, divalent species 2 and
3, which are singlets in the ground state, behave like
electron donors, allowing immediate electron transfer
to the quinone. These results agree with previous
studies31-35 and demonstrate that germylenes, known
so far for their electrophilic and nucleophilic properties,
With 2,6-di-tert-butyl-1,4-benzoquinone, 1/1 copolym-
erization does not occur, probably because of the steric
hindrance due to the two tert-butyl groups. The reaction
of 1 equiv of (ArO)2Ge with 1 equiv of 2,6-di-tert-butyl-
1,4-benzoquinone mainly results in germadioxolane 11,
with substitued cyclohexadienone groups (Scheme 7).
In this reaction, various oligomers with paracyclophane
bridges have been detected by mass spectrometry.
These results are in agreement with those of
Kobayashi.33-35
II.2.2.3. Tr ia zolin ed ion e. The (ArO)2M species (2,
3) react at room temperature with the NdN double bond
of N-methyltriazolinedione to yield the corresponding
[2 + 1] addition products 13 and 14 (Scheme 8). To our
knowledge, these metalladiaziridines are the first three-
membered rings with M-N-N catenation.
These divalent group 14 compounds 2-4 are also
potential precursors of various stable doubly bonded
derivatives (ArO)2MdY (Y ) NSiMe3, S, Se, Te) and of
(28) Rivie´re-Baudet, M.; Rivie´re, P.; Khallaayoun, A.; Satge´, J .;
Rauzy, K. J . Organomet. Chem. 1988, 358, 77.
(29) Ryba, O.; Pilar, J .; Petraˆnek, J . Collect. Czech. Chem. Commun.
1968, 33, 26.
(30) Razuvaev, G. A.; Abakumov, G. A.; Klimov, E. S. Dokl. Akad.
Nauk SSSR 1971, 201, 624 (Russ.); Dokl. Chem. (Transl. of Dokl. Akad.
Nauk) 1971, 201 (3), 968.
(31) Rivie´re, P.; Castel, A.; Guyot, D.; Satge´, J . J . Organomet. Chem.
1986, 315, 157.
(32) Rivie´re, P.; Rivie´re-Baudet, M.; Castel, A. Main Group Met.
Chem. 1994, 17, 679.
(33) Kobayashi, S.; Iwata, S.; Abe, M.; Shoda, S. J . Am. Chem. Soc.
1990, 112, 1625.
(34) Kobayashi, S.; Iwata, S.; Abe, M.; Shoda, S. J . Am. Chem. Soc.
1995, 117, 2187.
(35) Kobayashi, S.; Shoda, S.; Iwata, S.; Abe, M.; Yajima, K.; Yagi,
K.; Hiraishi, M. Pure Appl. Chem. 1994, A31 (11), 1835.
(36) Egorov, M. P.; Galminas, A. M.; Basova, A. A.; Nefedov, O. M.
Dokl. Akad. Nauk 1993, 329, 594.
(37) Lee, V. Ya.; Basova, A. A.; Matchkarovskaya, I. A.; Faustov,
V. I.; Egorov, M. P.; Nefedov, O. M.; Rakhimov, R. D.; Butin, K. P. J .
Organomet. Chem. 1995, 499, 27.

612 Organometallics, Vol. 17, No. 4, 1998
Barrau et al.
EPR spectra were obtained on a Bruker ER 200 equipped with
a Gauss probe and an EiP frequency probe. Melting points
were taken uncorrected on a Leitz Biomed hot-plate microscope
apparatus. Elemental analyses (C,H,N) were performed at the
“Microanalysis Laboratory of the Ecole Nationale Supe´rieure
de Chimie de Toulouse”.
Sch em e 7
[2 ,4 ,6 -T r i s ((d i m e t h y l a m i n o )m e t h y l )p h e n o x y ]-
lith iu m , Tr im er , (Ar OLi)3 (1). n-BuLi (0.04 mmol, 25 mL
of a 1.6 M solution in hexane) was added to 2,4,6-tris-
((dimethylamino)methyl)phenol (10.6 g, 0.04 mmol) in dry
diethyl ether (100 mL). The solution was cooled to 0 °C for
30 min. The mixture was stirred for a further 2 h at room
temperature and the solvent was removed in vacuo. The
residue was extracted with an 1/1 ether/pentane solution (80
mL); after cooling to -20 °C for 12 h 1 was filtered off as white
crystals and dried in vacuo (9.8 g, 90%).
1: mp 168-170 °C. 7Li NMR (C6D6): 0.78. 1H NMR
(C6D6): 1.92 (s, 36H, NMe), 2.23 (s, 18H, NMe), 3.33 (s, 12H,
CH2), 3.42 (s, 6H, CH2), 7.14 (s, 6H, CH2). 13C (C6D6): 45.38
(+), 45.92 (+), 63.90 (-), 65.03 (-), 121.38 (Cquat), 126.42 (+),
131.53 (Cquat), 167.12 (Cquat). MS: m/z 813 [M]•+. Anal. Calcd
for C45H78N9O3Li3: C, 66.42; H, 9.59; N, 15.49. Found: C,
66.22; H, 9.54; N, 15.44.
Sch em e 8
B is [2,4,6-t r is ((d im e t h y la m in o )m e t h y l)p h e n o x y ]-
ger m a n iu m (II), (Ar O)2Ge (2). 1. A solution of 2,4,6-tris-
((dimethylamino)methyl)phenol (2.54 g, 9.58 mmol) in 30 mL
of pentane was added dropwise to a stirred solution of bis-
[bis(trimethylsilyl)amino]germanium(II)38 (1.88 g, 4.79 mmol)
in 20 mL of pentane. The mixture was stirred at room
temperature for 2 h. The solvent was removed in vacuo and
the residue was extracted with pentane (ca. 30 mL). On
cooling (-30 °C, 48 h) 2 separated as a white precipitate which
was filtered off and dried in vacuo (2.76 g, 96%).
2: mp 158-160 °C. 1H NMR (C6D6): 2.16 (s, 24H, NMe),
2.18 (s, 12H, NMe), 3.35 (s, 4H, CH2), 3.57 (s, 8H, CH2), 7.20
(s, 4H, C6H2). 13C (C6D6): 44.88 (+), 45.46 (+), 60.25 (-), 64.48
(-), 125.86 (Cquat), 129.33 (+), 131.04 (Cquat), 151.48 (Cquat).
MS: m/z 602 [M]•+. UV(C6H12): λmax 385 nm. IR (C6H6, cm-1):
νGe-O 1040. Anal. Calcd for C30H52N6O2Ge: C, 59.94; H, 8.65;
N, 13.98. Found: C, 59.96; H, 8.68; N, 14.02.
2. To a suspension of GeCl2-dioxane (0.17 g, 0.7 mmol) in
diethyl ether (20 mL) was added a solution of [2,4,6-tris-
((dimethylamino)methyl)phenoxy]lithium (0.4 g, 1.46 mmol)
in diethyl ether (40 mL). The mixture was stirred at room
temperature for 10 h. Filtration yielded a white precipitate;
the filtrate was concentrated in vacuo, and the residue was
redissolved in pentane (ca. 30 mL) and cooled (-30 °C) to afford
white crystals of 2 (0.23 g, 52%). The white precipitate
obtained above was analyzed by mass spectroscopy; analysis
showed that it was a mixture of (ArO)ClGe (1a ) and Li5(ArO)2-
Cl3 (1b). 1a : m/z 373 [M]•+. 1b: m/z 668 [M]•+. 1a and 1b
were respectively identified by comparison of the spectral data
with those of authentic samples. (See ref 21 for 1a . 1b: To a
suspension of ArOLi (0.54 g, 2 mmol) in 50 mL of diethyl ether
was added LiCl (0.13 g, 3 mmol). After stirring for 18 h at
room temperature, filtration gave 1b as a white powder. MS:
m/z 668 [M]•+. Anal. Calcd for C30H52N6O2Li5Cl3: C, 53.82;
H, 7.77; N, 12.55. Found: C, 53.45; H, 7.82; N, 12.36.
B is [2,4,6-t r is ((d im e t h y la m in o )m e t h y l)p h e n o x y ]-
tin (II) (Ar O)2Sn (3). 1. A solution of 2,4,6-tris((dimethy-
lamino)methyl)phenol (1.88 g, 7.1 mmol) in 30 mL of pentane
was added dropwise to a stirred solution of bis[bis(trimethyl-
silyl)amino]tin(II)38 (1.56 g, 3.55 mmol) in 20 mL of pentane.
After stirring was continued at room temperature for 2 h, the
solution was concentrated in vacuo (ca. 20 mL) and cooled to
-30 °C. Filtration, followed by drying in vacuo, afforded 3
(2.2 g, 96%).
organometallic complexes (ArO)2MdM′Ln (M′Ln ) Fe-
(CO)4, W(CO)5, Cr(CO)5, Pt(PPh3)2); these chemical
properties and the syntheses of the heteroleptic species
ArO(X)M: (X ) NSiMe3, Cl), in which the metal has a
prochiral structure, will be reported in future publica-
tions.
Exp er im en ta l Section
All the compounds described are sensitive to oxygen and
moisture. All manipulations were performed under an inert
atmosphere of nitrogen or argon using standard Schlenk and
high-vacuum-line techniques. Dry, oxygen-free solvents were
employed throughout. All solvents were distilled from sodium
benzophenone before use. 1H NMR spectra were recorded on
a Bruker AC 80 spectrometer operating at 80 MHz (chemical
shifts are reported in parts per million relative to internal Me4-
Si as reference) and 13C spectra on a AC 200 MHz spectrom-
eter; the multiplicity of the 13C NMR signals was determined
by the APT technique and quoted as: (+) for CH3 or CH, (-)
for CH2, and (Cquat) for quaternary carbon atoms. 1H-decoupled
119Sn NMR spectra were recorded on a Bruker AC 200 or 400
MHz (chemical shifts are reported in parts per million relative
to external Me4Sn as reference). Mass spectra under electron
impact (EI) or chemical ionization (CH4) conditions at 70 and
30 eV were obtained on Hewlett-Packard 5989 and Nermag
R10-10H spectrometers. IR and UV spectra were recorded on
Perkin-Elmer 1600 FT-IR and Lambda-17 spectrophotometers.
(38) Gynane, M. J . S.; Harris, D. H.; Lappert, M. F.; Power, P. P.;
Rivie´re, P.; Rivie´re-Baudet, M. J . Chem. Soc., Dalton Trans. 1977,
2004.

A Stable Divalent Homoleptic Species
Organometallics, Vol. 17, No. 4, 1998 613
3: mp 139-140 °C. 119Sn{1H} NMR (C6D6): -529.80. 1H
NMR (C6D6): 2.13 (s, 24H, NMe), 2.16 (s, 12H, NMe), 3.32 (s,
4H, CH2), 3.54 (s, 8H, CH2), 7.14 (s, 4H, C6H2). 13C NMR
(C6D6): 44.70 (+), 45.37 (+), 60.57 (-), 64.49 (-), 126.46 (Cquat),
(d, 1H, 4J HH ) 2.4 Hz). 13C NMR (C6D6): 30.15 (+), 32.15 (+),
34.62 (Cquat), 35.22 (Cquat), 44.01 (+), 47.10 (+), 59.05 (-), 64.09
(-), 109.69 (+), 112 (+), 132.1 (+), 132.5 (Cquat), 133.92 (Cquat),
139.06 (Cquat), 146.96 (Cquat), 151.23 (Cquat), 159.05 (Cquat),
129.24 (+), 131.46 (Cquat), 159.51 (Cquat). MS: m/z 648 [M]•+
.
159.13 (Cquat). MS: m/z 868 [M]•+
.
Anal. Calcd for
44H72N6O4Sn: C, 60.92; H, 8.30; N, 9.69. Found: C, 60.87;
H, 8.22; N, 9.57.
UV(C6H12): λmax 372 nm. Anal. Calcd for C30H52N6O2Sn: C,
55.66; H, 8.04; N, 12.98. Found: C, 55.73; H, 8.07; N, 13.03.
2. A suspension of anhydrous tin(II) chloride (0.095 g, 0.5
mmol) and [2,4,6-tris((dimethylamino)methyl)phenoxy]lithium
(0.27 g, 1 mmol) in diethyl ether (50 mL) was stirred at room
temperature for 10 h. Filtration yielded a white solid, which
was analyzed by 1H and 119Sn NMR and mass spectroscopy; it
is a mixture of (ArO)SnCl (3a ), (ArO)2SnLiCl (3b), and
Li5(ArO)2Cl3 (1b). 1b and 3a 21 were identified by comparison
of the spectral data with those of authentic samples; 3b was
chemically characterized (see next reaction). The filtrate was
concentrated in vacuo, and the residue was extracted with
pentane (ca. 30 mL) and cooled (-30 °C) to give compound 3
(0.1 g, 31%). 3a : m/z 419 [M]•+. 1b: m/z 668 [M]•+. 3b: m/z
C
Rea ction of 2 w ith Dip h en yleth a n ed ion e. To a solution
of diphenylethanedione (0.15 g, 0.7 mmol) in 10 mL of benzene
was added dropwise a solution of 2 (0.42 g, 0.7 mmol) in 15
mL of benzene. The mixture was refluxed with stirring for 2
h. Concentration in vacuo afforded the crude product which
was recrystallized from pentane/toluene (1/1, 30 mL) (-20 °C).
Filtration gave 7 as yellow crystals (0.46 g, 81%).
7: mp 105-106 °C. 1H NMR (C6D6): 2.11 (s, 24H, NMe),
2.20 (s, 12H, NMe), 3.37 (s, 8H, CH2), 3.58 (s, 4H, CH2), 6.80-
7.80 (m, 14H, C6H2,C6H5), 13C NMR (C6D6): 44.54 (+), 45.18
(+), 60.20 (-), 64.20 (-), 123.78 (Cquat) 127.80 (+), 128.34 (+),
130.14 (Cquat), 132.14 (+), 133.74 (Cquat), 134.5 (+), 151.20
690 [M]•+
.
.
(Cquat), 154.20 (Cquat). MS: m/z 812 [M]•+ IR (C6H6, cm-1):
B is [2,4,6-t r is ((d im e t h y la m in o )m e t h y l)p h e n o x y ]-
lea d (II), (Ar O)2P b (4). 2,4,6-Tris((dimethylamino)methyl)-
phenol (1.21 g, 4.56 mmol) in pentane (30 mL) was added
dropwise to a stirred solution of bis[bis(trimethylsilyl)amino]-
lead(II)38 in 20 mL of pentane. The mixture was stirred at
room temperature for 2 h and the solvent removed by evapora-
tion under reduced pressure. The resulting yellow solid
product, 4, was recrystallized from pentane at -30 °C. Yield:
1.6 g, 96%.
4: mp 110-111 °C. 1H NMR (C6D6): 2.00 (s, 24H, NMe),
2.18 (s, 12H, NMe), 3.37 (s, 8H, CH2), 3.40 (s, 4H, CH2), 7.20
(s, 4H, C6H2). 13C NMR (C6D6): 44.69 (+), 45.44 (+), 60.54
(-), 64.48 (-), 125.77 (Cquat), 129.61 (+), 131.59 (Cquat), 159.61
(Cquat). MS: m/z 736 [M]•+. UV (C6H12): λmax 360 nm. Anal.
Calcd for C30H52N6O2Pb: C, 48.96; H, 7.07; N, 11.42. Found:
C, 48.88; H, 7.16; N, 11.36.
νGe-O ) 680. Anal. Calcd for C44H62N6O4Ge: C, 65.14; H, 7.65;
N, 10.36. Found: C, 65.25; H, 7.68; N, 10.45.
Rea ction of 3 w ith Dip h en yleth a n ed ion e. Using the
same operating conditions as in the previous preparation, 8
was obtained from 3 (0.55 g, 0.85 mmol) and diphenyle-
thanedione (0.18 g, 0.85 mmol). Yield: 0.6 g, 82%.
8: mp 110-112 °C. 119Sn{1H} NMR (C6D6): -129. 1H NMR
(C6D6): 2.04 (s, 24H, NMe), 2.17 (s, 12H, NMe), 3.34 (s, 8H,
CH2), 3.51 (s, 4H, CH2), 6.8-8.02 (m, 14H, C6H2, C6H5). 13C
NMR (C6D6): 44.80 (+), 45.50 (+), 60.76 (-), 64.82 (-), 123.81
(Cquat), 129.10 (+), 129.33 (+), 130.04 (Cquat), 130.24 (+), 133.74
(Cquat), 134.49 (+), 152.06 (Cquat), 154.44 (Cquat). MS: m/z 858
[M]•+. IR (C6H6, cm-1): νSn-O 670. Anal. Calcd for C44H62N6O4-
Sn: C, 61.63; H, 7.23; N, 9.80. Found: C, 61.71; H, 7.28; N,
9.88.
Rea ction of 2 w ith 1,4-Ben zoqu in on e. 2 (0.22 g, 0.36
mmol) in 20 mL of benzene was added dropwise to a stirred
solution of 1,4-benzoquinone (0.04 g, 0.36 mmol) in 10 mL of
benzene. The mixture was stirred at room temperature for 2
h. Addition of 20 mL of pentane, filtration and drying in vacuo
afforded 9. Yield 0.23 g, 90%.
9: mp >300 °C. 1H NMR (C6D6): 2.05 (s, 12 H, NMe), 2.17
(s, 24H, NMe), 3.34 (s, 8H, CH2), 3.51 (s, 4H, CH2), 6.00 (s,
4H, C6H4), 7.23 (s, 4H, C6H2). 13C NMR (C6D6): 44.64 (+),
45.50 (+), 60.51 (-), 64.60 (-), 123.20 (+), 129.40 (Cquat), 129.60
(+), 134.90 (Cquat), 150.10 (Cquat), 156.20 (Cquat). IR (C6H6,
cm-1): ν 1462.3, 1220.2, 840. Anal. Calcd for (C36H56N6O4-
Ge)n: C, 60.96; H, 7.90; N, 11.85. Found: C, 60.88; H, 7.86;
N, 11.73.
Rea ction of 3 w ith 1,4-Ben zoqu in on e. In a similar way
the reaction of 3 (0.28 g, 0.43 mmol) with 1,4-benzoquinone
(0.046 g, 0.43 mmol) afforded 10 as a red solid product (0.29
g, 89%).
10: mp >300 °C. 119Sn{1H} NMR (C6D6): -693.44. 1H
NMR (C6D6): 2.05 (s, 12H, NMe), 2.16 (s, 24H, NMe), 3.32 (s,
8H, CH2), 3.49 (s, 4H, CH2), 6.04 (s, 4H, C6H4), 7.22 (s, 4H,
C6H2). 13C NMR (C6D6): 44.80 (+), 45.40 (+), 60.22 (-), 64.30
(-), 123.74 (+), 129.22 (Cquat), 129.65 (+), 135.89 (Cquat), 149.47
(Cquat), 155.90 (Cquat). IR (C6H6, cm-1): ν 1459, 1214.9, 780.
Anal. Calcd for (C36H56O4 N6Sn)n: C, 57.24; H, 7.42; N, 11.13.
Found: C, 57.16; H, 7.38; N, 11.06.
Rea ction of 2 w ith 2,6-Di-ter t-bu tyl-1,4-ben zoqu in on e.
A benzene solution (20 mL) of 2,6-di-tert-butyl-1,4-benzo-
quinone (0.56 g, 2.56 mmol) was added to 2 (1.54 g, 2.56 mmol)
in 10 mL of benzene. The solution turned red. The resulting
reaction mixture was stirred at room temperature for 4 h. The
1H NMR analysis indicates the formation of 11 in amounts
corresponding to the coupling of 42% of 2 with 84% of quinone.
Addition of 30 mL of pentane, filtration, and drying in vacuo
afforded pure 11 (0.22 g, 8.4%).
Rea ction of 2 w ith 3,5-Di-ter t-bu tyl-1,2-ben zoqu in on e.
To a solution of 2 (0.25 g, 0.41 mmol) in 80 mL of benzene
was added a solution of 3,5-di-tert-butyl-1,2-benzoquinone (0.09
g, 0.41 mmol) in benzene (10 mL). The mixture was stirred
at room temperature for 4 h. To this solution was added 20
mL of pentane; a yellow precipitate immediately appeared.
Filtration afforded 5 (0.3 g, 90%).
5: mp 133-135 °C. 1H NMR (C6D6): 1.34 (s, 9H, t-Bu), 1.54
(s, 9H, t-Bu), 1.90 (s, 3H, NMe), 2.07 (s, 3H, NMe), 2.18 (s,
12H, NMe), 2.76 (s, 6H, NMe), 2.23 (s, 6H, NMe), 2.60 (s, 3H,
2
NMe), 2.71 (s, 3H, NMe), 3.13 and 3.61 (AB system, 2H, J HH
) 12 Hz, CH2), 3.94 (s, 4H, CH2), 3.51 (s, 2H, CH2), 3.54 (s,
2
2H, CH2), 4.03 and 4.65 (AB system, 2H, J HH ) 12 Hz, CH2),
4
6.81 and 7.58 (dd, 4H, C6H2), 6.9 (d, 1H, J HH ) 2.4 Hz), 7.23
(d, 1H, 4J HH ) 2.4 Hz). 13C NMR (C6D6): 30.10 (+), 32.32 (+),
34.59 (Cquat), 35.18 (Cquat), 44.01 (+), 47.09 (+), 59.06 (-), 64.05
(-), 109.6 (+), 111.9 (+), 127.73 (Cquat), 132.1 (+), 132.5 (Cquat),
139.0 (Cquat), 146.9 (Cquat), 151.2 (Cquat), 159.01 (Cquat), 159.1
(Cquat). MS: m/z 822 [M]•+. Anal. Calcd for C44H72N6O4Ge:
C, 64.34; H, 8.77; N, 10.23. Found: C, 64.22; H, 8.71; N, 10.12.
Rea ction of 3 w ith 3,5-Di-ter t-bu tyl-1,2-ben zoqu in on e.
3,5-Di-tert-butyl-1,2-benzoquinone (0.2 g, 0.92 mmol) in 15 mL
of benzene was added dropwise to a stirred solution of 3 (0.6
g, 0.92 mmol) in 5 mL of benzene. The mixture was stirred
at room temperature for 4 h. Addition of 20 mL of pentane,
filtration, and drying in vacuo gave 6 as yellow crystals (0.75
g, 94%).
6: mp 124-125 °C. 119Sn{1H} NMR (C6D6): - 566.08. 1H
NMR (C6D6): 1.39 (s, 9H, t-Bu), 1.55 (s, 9H, t-Bu), 1.80 (s, 3H,
NMe), 2.01 (s, 3H, NMe), 2.16 (s, 6H, NMe), 2.18 (s, 12H,
NMe), 2.23 (s, 6H, NMe), 2.58 (s, 3H, NMe), 2.69 (s, 3H, NMe),
2
3.05 and 3.06 (AB system, 2H, J HH ) 12 Hz, CH2), 3.34 (s,
4H, CH2), 3.51 (s, 2H, CH2), 3.55 (s, 2H, CH2), 3.9 and 4.6 (AB
2
system, 2H, J HH ) 12 Hz, CH2), 6.8 and 7.67 (dd, 4 H, C6H2),
4
4
6.9 (d, 1 H, J HH ) 2.4 Hz), 7.26 (d, 1H, J HH ) 2.4 Hz), 7.26

614 Organometallics, Vol. 17, No. 4, 1998
Barrau et al.
11: 1H NMR (C6D6): 1.18 (s, 36H, t-Bu), 2.10 (s, 24H, NMe),
(s, 4H, CH2), 7.18 (s, 4H, C6H2). 13C NMR (C6D6): 21.13 (+),
45.34 (+), 45.75 (+), 61.01 (-), 64.57 (-), 128.69 (+), 130.16
(+), 156.46 (Cquat), 160.01 (Cquat). MS: m/z 715 [M]•+. IR (C6H6,
cm-1): νCO 1676, 1728. Anal. Calcd for C33H55N9O4Ge: C,
55.49; H, 7.70; N, 17.65. Found: C, 55.31; H, 7.62; N, 17.56.
2.18 (s, 12H, NMe), 3.36 (s, 8H, CH2), 3.56 (s, 4H, CH2), 6.46
4
(d, 4H, J HH ) 2.9 Hz, C6H2), 7.25 (s, 4H, C6H2). 13C NMR
(C6D6): 29.60 (+), 35.35 (Cquat), 44.52 (+), 45.16 (+), 60.17 (-),
64.19 (-), 80.90 (+), 127.80 (+), 128.34 (+), 132.14 (Cquat),
140.11 (Cquat), 151.20 (Cquat), 185.90 (Cquat). IR (C6H6, cm-1):
Rea ction of 3 w ith 4-Meth yl-1,2,4-tr ia zolid in e-3,5-d i-
on e. In a similar fashion the reaction of 4-methyl-1,2,4-
triazolinedione (0.02 g, 0.17 mmol) with 3 (0.11 g, 0.17 mmol)
afforded 14 (0.11 g, 85%).
ν 1659, 1636. MS: m/z 1042 [M]•+
.
12 was detected as impurities by mass spectroscopy: m/z
1642 [M]•+
.
Rea ction of 2 w ith 4-Meth yl-1,2,4-tr ia zolin e-3,5-d ion e.
A benzene solution (2 mL) of 4-methyl-1,2,4-triazolidione (0.02
g, 0.17 mmol) was added dropwise to a stirred solution of 2
(0.1 g, 0.17 mmol) in 5 mL of benzene. The reaction mixture
was then stirred at room temperature for 2 h, and the volatiles
were removed in vacuo. After addition of pentane (15 mL) to
the crude material, filtration and drying in vacuo gave 13 as
a pale yellow powder (0.11 g, 91%).
14: mp 124-126 °C. 119Sn{1H} NMR (C6D6): -448.03. 1H
NMR (C6D6): 2.20 (s, 24H, NMe), 2.27 (s, 12H, NMe), 2.69 (s,
3H, NMe), 3.45 (s, 8H, CH2), 3.66 (s, 4H, CH2), 7.20 (s, 4H,
CH2). 13C NMR (C6D6): 21.10 (+), 44.95 (+), 45.50 (+), 60.46
(-), 64.52 (-), 128.49 (+), 130.19 (+), 158.10 (Cquat), 160.30
(Cquat). MS: m/z 761 [M]•+. IR (C6H6, cm-1): νCO 1651, 1717.
Anal. Calcd for C33H55O4N9Sn: C, 52.12; H, 7.24; N, 16.58.
Found: C, 51.88; H, 6.94; N, 16.42.
13: mp 136-138 °C. 1H NMR (C6D6): 2.14 (s, 24H, NMe),
2.18 (s, 12H, NMe), 2.88 (s, 3H, NMe), 3.35 (s, 8H, CH2), 3.52
OM9705665